GE Drill GE752 User Manual

GEK–91584D  
VERTICAL DRILLING MOTOR  
TYPE GE752  
CONTENTS  
CONTENTS (CONT’D)  
Page  
Page  
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2  
GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . 2  
DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4  
SPECIAL TOOLS AND EQUIPMENT . . . . . . . . . . . 8  
GROUNDING INSTRUCTIONS . . . . . . . . . . . . . . . . 8  
GROUNDING PROCEDURES . . . . . . . . . . . . . . . 9  
OVERHAUL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9  
LUBRICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9  
GREASE TUBES AND PIPE PLUGS . . . . . . . . . 9  
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10  
MONTHLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10  
SEMI–ANNUALLY . . . . . . . . . . . . . . . . . . . . . . . . . 13  
BASIC REPAIRS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13  
BRUSH REPLACEMENT . . . . . . . . . . . . . . . . . . . 13  
BRUSHHOLDER REPLACEMENT . . . . . . . . . . 13  
BRUSHHOLDER CLEARANCE  
ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
COMMUTATOR RESURFACING . . . . . . . . . . . . 14  
BASIC OVERHAUL . . . . . . . . . . . . . . . . . . . . . . . . . 19  
TESTING BEFORE DISASSEMBLY . . . . . . . . . 19  
TABLE 2. DRAWING REFERENCE . . . . . . . . . . 20  
DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . 20  
CLEANING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30  
INSPECTION AND TEST OF  
BRUSHHOLDER SLEEVE REPLACEMENT . . 36  
ARMATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37  
TABLE 3. STANDARD BOLT TORQUE  
VALUES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37  
TEST AFTER REPAIR (Armature) . . . . . . . . . . . 44  
MOTOR FRAME FIELD COIL  
REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . . . 45  
TEST AFTER REPAIR  
(Coiled Frame Without Armature) . . . . . . . . . . 55  
TABLE 4. VARNISH VISCOSITY CHART  
FOR DIPPING COILED FRAME . . . . . . . . . . . . . 55  
VARNISH TREATMENT (ARMATURE) . . . . . . . 56  
BALANCING ARMATURE . . . . . . . . . . . . . . . . . . 56  
REASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56  
BRUSHHOLDER CLEARANCE  
ADJUSTMENT . . . . . . . . . . . . . . . . . . . . . . . . . . 65  
BRUSH INSTALLATION . . . . . . . . . . . . . . . . . . . . 65  
HUB MOUNTING . . . . . . . . . . . . . . . . . . . . . . . . . 66  
TESTING AFTER OVERHAUL . . . . . . . . . . . . . . . 67  
TESTING SERIES MACHINES  
(Models 5GE752AUP, AUT) . . . . . . . . . . . . . . . 67  
TESTING SHUNT MACHINES  
(Models 5GE752UP and US) . . . . . . . . . . . . . . 68  
REMOVING ARMATURE  
DISASSEMBLED MOTOR . . . . . . . . . . . . . . . . . . . 31  
BEARING INSPECTION . . . . . . . . . . . . . . . . . . . 31  
ARMATURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31  
COMMUTATOR . . . . . . . . . . . . . . . . . . . . . . . . . . . 32  
ARMATURE SHAFT INSPECTION . . . . . . . . . . 32  
MOTOR FRAME . . . . . . . . . . . . . . . . . . . . . . . . . . 32  
BRUSHHOLDERS . . . . . . . . . . . . . . . . . . . . . . . . . 35  
REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35  
LUBRICATION OF BOLTS . . . . . . . . . . . . . . . . . 35  
LOCKING ARRANGEMENT . . . . . . . . . . . . . . . . . . 69  
LOCKING THE ARMATURE FOR SHIPMENT . . 69  
SHIPPING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69  
HANDLING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69  
CLEANING AND SLUSHING . . . . . . . . . . . . . . . 69  
SKIDDING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70  
PROTECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70  
ARMATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70  
PREPARATION OF BOX . . . . . . . . . . . . . . . . . . . 70  
BOXING THE ARMATURE . . . . . . . . . . . . . . . . . 71  
STORAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71  
PLACING INTO STORAGE . . . . . . . . . . . . . . . . . 71  
REMOVING FROM STORAGE . . . . . . . . . . . . . 72  
Revisions are indicated by margin bars.  
ECopyright 1992, 1993, 2005 General Electric Company. All rights reserved. This copyrighted document may be reproduced free of charge by  
General Electric Company customers (OEM’s) and their customers, if such reproduction is used exclusively in connection with equipment used in  
those customers’ internal operations.  
These instructions do not purport to cover all details or variations in equipment nor to provide for every possible contingency to be met in connection with installation, operation, or mainte-  
nance. Should further information be desired or should particular problems arise which are not covered sufficiently for the user’s purposes, the matter should be referred to the General  
Electric Company. Any applicable Federal, State or local regulations or company safety or operating rules must take precedence over any instructions given in this material. GE has no  
obligation to keep the material up to date after the original publication.  
THERE ARE NO WARRANTIES OF ACCURACY, MERCHANTABILITY OR FITNESS FOR PARTICULAR PURPOSE.  
Verify numbers for parts, tools, or material by using the Renewal Parts or Tool Catalogs, or contact your General Electric repre-  
sentative for assistance.  
Do not order from this publication.  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
TABLE 1. MODEL DIFFERENCES  
Motor  
Model Differences  
Superseded By  
752UP1  
This is a shunt motor with the following distinctions:  
– Has internal greasing tubes for both drive end (pinion end)  
and commutator–end bearings  
– Has a double–ended shaft.  
752UP2  
Same as UP1 except:  
– Has armored cable  
– Has no grease tubes at commutator end  
Motor  
Model Differences  
Superseded By  
752UP3  
Same as UP2 except:  
– Has a single grease tube at drive end which is part of the  
framehead/bearing assembly for ease of armature  
disassembly.  
752UP3A  
752UP4  
752UP5  
Same as UP3 except:  
– Has class H Kapton wrapped exciting coils  
Same as UP3A except:  
– Has an ABS certified shaft.  
Same as UP3A except:  
– Has a thermal sensor embedded in each of its exciting and  
commutating coils.  
752UP6  
752US1  
Same as UP3A except:  
– Has an improved commutator–end bearing assembly and an  
ABS–certified armature shaft.  
This is a shunt motor with the following distinctions:  
– Same as UP3 except:  
– Has an AG type armature with an AF commutator and  
a standard AUP flash ring.  
– Has AG type commutating coils and poles with brazed  
instead of bolted connections.  
– Has air vents in the drive–end framehead  
– Has a frame specially machined for mounting the  
customer gearbox at the drive end.  
– Has a different drive–end grease arrangement.  
– Has rubber hardtop brushes instead of regular duplex  
brushes.  
752US2  
Same as US1 except:  
– Has an improved commutator–end bearing assembly and an  
ABS–certified armature shaft.  
752AUP1  
This is a series motor with the following distinctions:  
– Has internal greasing tubes for both drive end and  
commutator–end bearings  
– Has a double–ended shaft.  
752AUP2  
Same as AUP1 except:  
– Has armored cable  
– Has no grease tubes at commutator end  
– Mounting feet have dowel holes for vertical mounting.  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
TABLE 1 (Cont’d) MODEL DIFFERENCES  
Motor  
Model Differences  
Superseded By  
752AUP3  
Same as AUP2 except:  
– Has a single grease tube at drive end which is  
part of framehead/bearing assembly for ease of  
armature disassembly.  
752AUP4  
752AUP5  
Same as AUP3 except:  
– Has improved insulation for higher temperatures.  
Same as AUP4 except:  
– Has an improved commutator–end bearing assembly and an  
ABS–certified armature shaft.  
752AUT1  
This is a series motor with the following distinctions:  
– Same as 752AUP3 except:  
– Has an AG type armature with an AF commutator and  
a standard AUP flash ring.  
– Has AG type commutator coils and poles with brazed  
instead of bolted connections.  
– Has air vents in the drive–end framehead  
– Has a frame specially machined for mounting the  
customer gearbox at the drive end.  
– Has a different drive–end grease arrangement.  
– Has rubber hardtop brushes instead of regular duplex  
brushes.  
752AUT2  
Same as AUT1 except:  
– Has an improved commutator–end bearing assembly and an  
ABS–certified armature shaft.  
DATA  
Max. Permissible Speed (rpm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1800  
Max. Permissible Vibration (Commutator End) (in.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.002  
“Resistance at 25_ C (Ohms):  
Min.  
Max.  
Armature  
Model 752UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00912  
Model 752AUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00912  
Model 752US . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00749  
Model 752AUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00749  
Exciting Field (With Cables)  
0.00949  
0.00949  
0.00800  
0.00800  
Model 752UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.25  
Model 752UP (After 3/88) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.13  
Model 752AUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00512  
Model 752US . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.13  
Model 752AUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00486  
Commutating Field (With Cables)  
1.33  
1.22  
0.00558  
1.22  
0.00535  
Model 752UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00508  
Model 752UP (After 3/88) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00439  
Model 752AUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00439  
Model 752US . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00432  
Model 752AUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.00432  
0.00540  
0.00534  
0.00477  
0.00480  
0.00480  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
DATA (Cont’d)  
Carbon Brushes  
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T900  
Size (in.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3/4 x 2–1/4 x 2  
Minimum Brush Length (length at which brush becomes inoperative) (in.) . . . . . . . . . . . . . . . . . . . . . . . . . 1–3/32  
(brush is measured on the longest side)  
Spring Pressure on Brush, Preset (lb.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10–12  
Brushholder  
Clearance to Commutator (in.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1/16–3/32  
Clamp Bolt Torque (lb.–ft.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225–250  
Commutator  
Side Mica Thickness (in.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.060  
Slot Depth (in.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.047  
Undercutting Saw:  
Width (in.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.063  
Diameter (in.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.000  
Diameter: (in.)  
New . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.625  
Worn (minimum permissible) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15.375  
Riser Width (minimum permissible) (in.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.625  
Dust Groove: (in.)  
Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.250  
Depth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.125  
Commutator (Cont’d)  
Concentricity – New Commutator (in.)  
Total Indicated Runout, TIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.001  
Variation of Indicator Runout within (in.)  
any Group of 20 Bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0004  
Variation of Indicator Reading between (in.)  
any Two Adjacent Bars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0001  
Concentricity – Used Commutator (in.)  
(Resurface if runout exceeds 0.010 TIR  
or 0.003 within any group of 6 bars):  
After Resurfacing, TIR (in.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.001  
Bar–To–Bar Test (500 v) Voltage  
Variation Bar–To–Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +/– 5%  
Armature Balance  
Commutator End . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 grams (0.42 oz.)  
Drive End . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 grams (0.35 oz.)  
Armature Bearings  
Min.  
Max.  
Diametral Clearance, Assembled (In.)  
Drive End . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.005  
Commutator End . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0005  
Runout Measured from Shaft to Outer Race (in.):  
0.009  
0.0035  
Drive End . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.004  
Commutator End . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.003  
5
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GEK–91584D, Vertical Drilling Motor, Type GE752  
DATA (Cont’d)  
Pole Bore Diameter (measured at center of pole) (in.)  
Motors:  
Min.  
Max.  
19.640  
19.640  
19.998  
Exciting Poles (Shunt models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19.606  
Exciting Poles (Series models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19.613  
Commutating Poles (Both Shunt and Series models) . . . . . . . . . . . . . . . . . . . . 19.956  
Impedance Test  
(Coiled Frame Without Armature):  
Exciting Field (With Cables)  
Voltage Drop  
Min.  
Max.  
Model 752UP (0.5 Amps @ 60 Hz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59.0  
Model 752AUP (24 Amps @ 60 Hz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.1  
Model 752US (0.5 Amps @ 60 Hz)* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59.0  
Model 752AUT (24 Amps @ 60 Hz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.1  
Commutating Field (With Cables)  
66.6  
15.6  
66.6  
15.6  
Model 752UP (24 Amps @ 60 Hz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3  
Model 752AUP (24 Amps @ 60 Hz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2  
Model 752US (24 Amps @ 60 Hz)** . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3  
Model 752AUT (24 Amps @ 60 Hz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7  
Lubrication* – Armature Bearings  
8.5  
8.5  
8.1  
8.5”  
Grease Capacities (oz.):  
Drive End . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39.1  
Commutator End . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.8  
Lubricant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GE–D6A2C10*  
**See Grease Specification at the end of the DATA table.  
Weights (lb.) (approx.)  
Complete . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6720  
Armature Only . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2100  
High–Potential Test  
60 Hz, a–c, to ground for one minute (All Windings) (volts):  
New or Rewound Armature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3500  
Reconditioned . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000  
Megger Test  
Reading (megohms)  
Shunt Models  
Minimum Megohmmeter  
A1–A2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4  
F1–F2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3  
Series Models  
A1–A2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4  
F1–F2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4  
* With Commutating Poles (CP) out.  
**Excitation Field in.  
6
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Vertical Drilling Motor, Type GE752, GEK–91584D  
DATA (Cont’d)  
Motor Ratings*  
Shunt (UP)  
Continuous  
Max. HP  
Volts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750  
Armature Amps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1050  
Field Amps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57  
RPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1050  
Horsepower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000  
Series (AUP)  
Volts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750  
Armature Amps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1050  
Field Amps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100%  
RPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 975  
Horsepower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000  
*NOTE: With 2800 SCFM air flow.  
Motor Ratings**  
Continuous  
Max. HP  
Continuous  
Max. Torque  
Intermittent  
Duty Cycle  
Shunt (US)  
Volts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750  
650  
1250  
60  
900  
5995  
1030  
750  
1435  
60  
1065  
6745  
1365  
Armature Amps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1185  
Field Amps* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60  
RPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1040  
Torque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5705  
Horsepower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1130  
Series (AUT)  
Volts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 750  
Armature Amps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1150  
Field Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100%  
RPM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 965  
Torque . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5900  
Horsepower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1085  
570  
1250  
100%  
700  
6620  
880  
750  
1400  
100%  
920  
7530  
1320  
**NOTE: With 2800 SCFM air flow and ABS temperature rise standards, 155_C over 40_C ambient.  
Grease Specification  
D6A2C10 grease is a lithium soap base grease with added antioxidant. It contains an oil of heavy viscosity and is  
especially suitable for high speed, high temperature open or shielded bearings in drilling motors.  
Specifications:  
Worked Consistency, 77_ F, MM/10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220–240  
Dropping Point, Degrees F (Min) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380  
Mineral Oil Viscosity At 100_ F, SSU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475–525  
Free Alkali, Percent (Max) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.50  
Free Acid, Percent (Max) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nil  
Color . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Amber  
Base (With Antioxidant) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lithium  
Oxidation Resistance Time To Reach 20 psi Drop At 210_ F, Hr. (Min) . . . . . . . . . . . . . . . . . . . . . . . . . . 1000  
Corrosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Must Pass  
Approved Vendor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shell Oil  
Brand Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cyprina RA  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
SPECIAL TOOLS  
AND EQUIPMENT  
GROUNDING INSTRUCTIONS  
Grounding motor frames is required to safeguard  
personnel from electric shock in event of an insulation  
failure in the machine.  
CAUTION: This machine is of open splash–proof  
construction. It is force–ventilated and requires  
an ample supply of cooling air. The cooling air  
should not contain combustible gases. If it is  
applied in an environment which may contain  
combustible gases, an adequate supply of non–  
contaminated cooling air must be provided.  
WARNING: Failure to properly ground electrical  
equipment may expose personnel to a potentially  
hazardous condition in which serious or fatal in-  
jury from electrical shock is possible.  
Grounding conductors must be provided between  
the machine frame and the supporting structure to avoid  
hazardous potential difference between the machine  
frame and the adjacent surface on which a person may  
be standing while touching the machine.  
The following items are required to maintain, repair  
and overhaul the motors:  
Part  
Megohmmeter (or “Megger”*)  
600 volts . . . . . . . . . . . . . . . . 111X910 or equivalent  
NOTE: This type of ground connection is re-  
ferred to in electrical standards as “equipment  
grounding” or “enclosure grounding” which is  
not to be confused with “system” or “circuit”  
grounding. Drilling drive systems normally do  
not have intentional circuit ground connec-  
tions, except through high impedance detec-  
tors.  
Voltmeter . . . . . . . . . . Simpson Multimeter, Model 260  
or equivalent  
Puller Tools . . . . . . . . . . . . . . . . . . . . . . . 41E903423G1  
Commutator Grinder . . . . . . . . . . . . . . . . . 427C592G1  
Resurfacing Stones:  
Medium Grade . . . . . . . . . . . . . . . . . . . 8828492P11  
Finish Grade . . . . . . . . . . . . . . . . . . . . . . 8828492P8  
Brush–Seater Stone (White) . . . . . . . . . . . 106X98  
Grounding conductors must be provided on drilling  
units on which the construction of the unit and/or the in-  
stallation of the machines do not inherently insure posi-  
tive grounding of the equipment. Examples are those  
portable (modular) platform rigs and land rigs which do  
not already have ground cables to all machinery struc-  
tures. Offshore rigs with equipment fastened to the  
Lifting Eye . . . . . . . . . . . . . . . . . . . . . . . . . . P9945894P8  
Crows–Foot Pressing Tool . . . . . . . . . . 41C685430G1  
Ball and Socket Tool . . . . . . . . . . . . . . . 41C685080G1  
Guide Pins, Three (3) Recommended  
for Armature Asm. In Frame . . . . . . . . 6717114P1  
Spanner Wrench . . . . . . . . . . . . . . . . . . . . . 8843522G1  
Spring Scale (for brush–spring  
pressure check) . . . . . . . . . . . . . . 0–20 lb. capacity  
Hub Assembly Gauge . . . . . . . . . . . . . . 41D790941G1  
Hub Puller (Less Pump) . . . . . . . . . . . . 41B535703G1  
Pump (For Above) . . . . . . . . . . . . . . . . . . . . 8843947G1  
FIG. 2. DRILLING MOTOR – FRAME GROUNDING  
CABLE CONNECTIONS. E–28717.  
*Tradename of James G. Biddle Co.  
8
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Vertical Drilling Motor, Type GE752, GEK–91584D  
decks by bolting or welding should not require additional  
grounding. (References: ABS Rules for Building and  
Classing Steel Vessels, Section 35.9.6, and IEEE Stan-  
dard 45–1977, Recommended Practice for Electrical In-  
stallations on Shipboard, Section 21.4.)  
5. Use a digital ohmmeter to check that the bolted  
connections are solid, low resistance connec-  
tions from the cable conductor to the ground  
point and to the motor frame. The meter reading  
should be 0.2 ohms or less.  
OVERHAUL  
GROUNDING PROCEDURES (Fig. 2)  
Overhaul intervals will depend on the severity of serĆ  
vice seen by the machine. However, General Electric  
Co. recommends that an overhaul be performed every  
18,000 hours (approximately every two years) on all  
machines subjected to normal operation.  
Most GE drilling machines have extra tap blocks on  
the frame for mounting of the connection boxes. One of  
these may be used for attaching the grounding cable. If  
one is not available, use the lower chain case mounting  
boss on the end opposite the drive end in accordance  
with Step 2.  
The motor should be removed, disassembled,  
cleaned, inspected and reconditioned as necessary (in-  
cluding varnish treatment of armature and fields). Motor  
bearings should be repacked with grease. See the  
DATA section for grease type and quantity.  
1. To attach the ground cable to a tap block, obtain  
a 0.75–10 bolt with length of 1.0 to 1.5 in. and a  
lockwasher. Also obtain a cable lug to fit the  
ground cable and large enough for the 0.75 di-  
ameter bolt.  
LUBRICATION  
Periodic lubrication is required on all GE752 drilling  
machines designed for vertical operation between  
scheduled overhaul periods. Every six months or 2500  
hours, whichever comes first, apply approximately 2 oz.  
of grease at each end.  
2. To attach the cable to the chain case boss, obtain  
a 1.25–7 bolt with length of 1.0 to 1.75 in. and a  
lockwasher. Prepare a copper plate at least 1/8  
in. thick with a 1.25 in. diameter hole for bolting to  
the chain case boss, and with enough extra area  
for holes to attach a cable lug. Drill hole(s) in  
plate for cable lug. Clean all paint, rust and oil  
from the chain case boss and bolt the copper  
plate to the chain case boss.  
GREASE TUBES AND PIPE PLUGS  
The following lists grease tube and pipe plug configu-  
rations for all models covered in this publication:  
3. Prepare a ground conductor* long enough to run  
from the motor frame to an existing ground con-  
ductor system or to a suitable equipment ground  
point as defined by the National Electrical Code  
Article 250 or other applicable regulation. Check  
that the system ground detector is also con-  
nected to the Common ground point for the rig  
and make connection if necessary.  
1. UP1 and AUP1 — Four grease tubes with pipe  
plugs, two at each end.  
2. UP2 and AUP2 — Two grease tubes with pipe  
plugs, one at each end.  
3. UP3, UP3A, UP4, UP5, UP6, AUP3, AUP4,  
AUP5 – One grease tube with a pipe plug at the  
drive end, one pipe plug only at the commutator  
end.  
4. US1, US2, AUT1, AUT2 – One pipe plug only at  
each end.  
4. Install terminal lugs on cable. Remove paint, rust  
and oil from the surfaces to which the cables are  
to be attached and bolt the lugs securely to these  
surfaces.  
Pipe plugs are provided on bearing caps and on the  
ends of all grease tubes to prevent the ingress of dirt or  
other contamination.  
Remove the pipe plugs and install grease fittings to  
facilitate lubrication. Replace the pipe plugs after adding  
lubricant. See the DATA section for recommended  
grease type.  
*Use 4/0 size or larger copper cable for GE752 ma-  
chines. (Reference: National Electrical Code, 1978  
Edition, Table 250–95.)  
9
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GEK–91584D, Vertical Drilling Motor, Type GE752  
INSPECTION  
MONTHLY  
Inspect the exterior of the machine, including cables,  
for damage.  
Covers, Seals, Latches  
Clean the outside of the machine and remove the in-  
spection covers. Use clean, dry compressed air and  
blow the dirt and carbon dust from the interior of the ma-  
chine.  
WARNING: When using compressed air for clean-  
ing purposes, flying debris and particles may  
present a hazard to personnel in the immediate  
area. Personnel should be provided with, and  
trained in the use of, personal protective equip-  
ment as specified by applicable federal or state  
safety regulations.  
FIG. 3. RESIZING BRUSHHOLDER  
CARBONWAYS. E–11281.  
Start at one end and work along the ridge to the  
other end.  
Check exterior covers to be sure felt seals are intact.  
If seals are missing or covers are damaged, replace  
seals or covers as necessary. Make sure covers fit prop-  
erly and cover latches work properly.  
2. Check progress frequently by means of a “Go/  
No–Go” gage made to the dimensions shown in  
Fig. 4.  
Brushholders (Fig. 5)  
Satisfactory operation of the drilling motor requires  
the brushholders to be in good condition. Of particular  
importance is the inside dimension of the carbonways.  
Operation may also be impaired by brushholders which  
have been mechanically damaged or sustained dam-  
age as the result of motor flashovers.  
Inspect the brushholders for damage. If they require  
replacement, refer to BASIC REPAIRS, Brushholder  
Replacement section for instructions.  
When new, brushholder carbonways should mea-  
sure 0.753 +/–0.002 in x 2.2575 +/–0.0025 in. If or when  
the 0.753 in. dimension exceeds 0.765 in., the brushhol-  
der should be scrapped. If it falls between 0.758 and  
0.765 in., the carbonway can be restored to its proper  
dimension according to the following instructions:  
FIG. 4. BRUSHHOLDER CARBONWAY  
GAGE. E–11283A.  
1. Remove the brushholder. Position it as shown in  
Fig. 3 and tap the metal ridge with a hammer.  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
3. Continue tapping as described in Step 1 until the  
0.753 dimension falls between 0.751 and 0.755.  
spots caused by flashovers. Replace any damaged  
brushholder or one having a damaged sleeve.  
WARNING: MEK is a volatile solvent. The fumes  
should not be inhaled. Use only in a well–venti-  
lated area and take adequate precautions to pro-  
tect eyes, skin and hands.  
4. If, due to excessive pounding, the inside dimen-  
sion becomes less than 0.751 in., file back to size  
with a fine mill file.  
Additional repairs can be made to restore damaged  
brushholder bodies. Brushholder damage is fairly typi-  
cal when flashovers have occured, resulting in some  
burning or melting of metal at the corners of the brush-  
holder. Metal thus removed can be restored according  
to the following instruction, unless more than 1/4 in.  
buildup of metal is required in the affected area, in which  
case the brushholder should be scrapped. Proceed as  
follows:  
NOTE: Never paint these sleeves. Periodically  
wipe them clean with a dry cloth or a cloth  
dipped in an approved non–oily cleaning sol-  
vent.  
Inspect the brushholder cables and make sure all  
terminal bolts and all brushholder clamp bolts are tight.  
Brush Spring Pressure  
Lift the brush pressure fingers to the “toggled–up”  
position, Fig. 5, and check for free movement of the  
spring assembly.  
1. Thoroughly clean the affected area by wire  
brushing, and grind off any metal flow resulting  
from a flashover.  
Inspect the brush springs for obvious failure or dam-  
age. Check brush–spring pressure by comparing spring  
pressure with a spring known to be good. Refer to the  
DATA section for brush spring–pressure value.  
2. Apply  
a
suitable brazing flux such as  
GE–A10B15 to the area to be built up.  
3. Insert a carbon brush into the brushholder to pre-  
vent the brazing material from flowing into the  
carbonway.  
BRUSH PRESSURE FINGER  
(IN TOGGLED–UP POSITION)  
TEFLON  
PRESSURE  
SLEEVES  
SPRING  
4. Using a brazing torch and a 1/16 in. diameter  
brass brazing rod, puddle in sufficient metal to  
restore the metal that had been removed.  
CARBONWAY  
5. Check the carbonway for size with the “Go/No–  
Go” gage after the brushholder has cooled to  
room temperature.  
6. Resize as required using the preceding method.  
BRUSH–SHUNT  
TERMINAL  
SCREWS  
Brushholder Sleeves  
FIG. 5. BRUSH SPRING ARRANGEMENT.  
E–18963.  
Use a clean, lintless cloth and wipe dirt and grease  
from the Teflon* brushholder sleeves, Fig. 5. If neces-  
sary, use a cleaner such as MEK (methyl ethyl ketone)  
to clean the sleeves. Inspect sleeves for cracks and thin  
*Product of E.I. duPont de Nemours Company.  
11  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
brush–shunt terminal connections and all brush-  
holder cable connections are tight.  
Brushes  
Brush wear is determined by measuring actual brush  
length from the top of the carbon. Lift the brush spring,  
remove the brush and measure brush length on the  
longest side.  
Commutator  
Inspect the commutator for possible flashover dam-  
age. The commutator should be clean, smooth, glossy  
and free of high mica, high bars, flat spots or rough sur-  
faces.  
NOTE: If brush replacement is not required, be  
sure that brushes are of sufficient length to last  
until the next inspection.  
If there are indications that the commutator is out–  
of–round (as evidenced by variations in width of the  
ridge between brush paths), check the concentricity of  
the commutator with a dial indicator. Condemning limits  
for concentricity are listed in the DATA section.  
If one or more brushes are worn to or near the mini-  
mum length listed in the DATA section it is generally rec-  
ommended that all twelve brushes be replaced at the  
same time.  
If the commutator requires grinding, refer to Com-  
mutator Resurfacing in the BASIC REPAIRS section of  
this manual for instructions.  
WARNING: To avoid possible electrical shock or  
injury from rotating equipment, do not remove or  
replace brushes while equipment is energized or  
rotating.  
Creepage Band  
Clean the creepage band (located on the commuta-  
tor cap) with a clean cloth dipped in an approved sol-  
vent. Inspect the band for possible flashover damage.  
If brushes are to be replaced, see the BASIC RE-  
PAIRS, Brush Replacement section for brush installa-  
tion instructions.  
Make sure the creepage band is tight on the commu-  
tator cap.  
If brushes are not to be replaced, the following brush  
inspection should be made:  
Flash Ring  
CAUTION: When replacing brushes, use only the  
GE recommended grade. Mixing of brush grades  
in the same motor or changing brushes to anoth-  
er grade may seriously affect commutation, sur-  
face film, commutator and brush life. See the  
DATA section for brush grade.  
Examine the flash ring for possible flashover dam-  
age. Wipe the flash ring clean. Keep ring free of dirt and  
varnish.  
1. Inspect all brushes to be sure they are not  
chipped or broken. Make sure brush shunts are  
not frayed or broken. Replace any brush which  
shows damage of any kind.  
KEEP SHUNTS CLEAR  
OF LEVER ARMS  
BRUSH  
SHUNTS  
NOTE: Chipped, burned or rough–faced  
brushes may indicate the commutator needs  
resurfacing.  
2. Move the brushes up and down in their carbon-  
ways to be sure brushes slide freely.  
3. Check brush shunts to be sure they are not  
twisted or out of position, Fig. 6. Make sure all  
FIG. 6. CORRECT POSITION OF BRUSH  
SHUNTS. E–22568.  
12  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
ger over the center of each brush. See the DATA  
section for limits.  
Insulation  
Measure the insulation resistance with a meg– ohm-  
1. Remove the commutator inspection covers.  
meter (Megger) to determine the condition of the insula-  
tion. If reading is low, make a further inspection to deter-  
mine if insulation failure or excessive moisture is caus-  
ing the low megohmmeter reading. Correct the cause of  
low readings before returning the motor to service.  
2. Disconnect the brush shunt from the terminal  
screw, Fig. 5, located on the brushholder body.  
3. Lift the pressure finger away from the brush to  
the toggled–up position. Remove the brush.  
Inspect all accessible parts of the field coil insulation  
for cracking and evidence of overheating.  
4. Use dry, compressed air and blow the carbon  
dust from the carbonway.  
WARNING: When using compressed air for clean-  
ing purposes, flying debris and particles may  
present a hazard to personnel in the immediate  
area. Personnel should be provided with, and  
trained in the use of, personal protective equip-  
ment as specified by applicable federal or state  
safety regulations.  
Power Cables  
Inspect the power cables for signs of excessive heat-  
ing, poor insulation or mechanical damage. Assure all  
terminals are tight. Replace any cables which show low  
insulation resistance or will not stand 75% above rated  
voltage.  
5. Insert a new brush and make sure it slides freely  
in the carbonway.  
Mounting Bolts  
6. Carefully lower the pressure finger on the brush.  
Do not allow the finger to snap down on the  
brush; this could damage the brush.  
Check all mounting bolts to assure tightness.  
SEMI–ANNUALLY  
7. Bolt the brush shunt terminals to the brushhol-  
der(s). Arrange the brush shunt strands so they  
clear the pressure fingers, Fig. 6, and tighten the  
terminal screw(s). Make sure brush shunts are  
not positioned under the pressure fingers. Check  
and tighten all brushholder cable connections.  
1. Perform inspection operations listed under  
Monthly section.  
2. Refer to the DATA section for the Brushholder  
Clearance dimension, and check the clearance  
between the brushholders and the commutator  
surface.  
8. Seat the new brushes with a white seater stone.  
CAUTION: When replacing brushes, use the GE  
recommended grade. Mixing of brush grades in  
the same motor or changing brushes to another  
grade will seriously affect commutation, surface  
film, commutator and brush life. See the DATA  
section for brush grade.  
If clearance adjustment is required, refer to the BA-  
SIC REPAIRS, Brushholder Clearance Adjustment sec-  
tion for instructions.  
BASIC REPAIRS  
BRUSH REPLACEMENT  
BRUSHHOLDER REPLACEMENT  
Removal  
NOTE: Brush spring pressure is pre–set and  
non–adjustable for the brushholders used on  
these machines. Any brushholder that is dam-  
aged or has a low spring pressure should be re-  
placed before installing new brushes. Spring  
pressure can be measured with a 20–lb. spring  
scale pulling radially on the brush pressure fin-  
1. Remove brushes from the brushholders and  
cover the commutator with heavy paper.  
2. Disconnect the cable from the brushholder(s) in-  
volved.  
13  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
3. Remove bolt, washer and brushholder clamp.  
Lift the brushholder out of the frame.  
COMMUTATOR RESURFACING  
Prior to resurfacing, consider the following:  
Installation  
1. The brush surface diameter of the commutator  
must not be less than the minimum permissible  
diameter, listed in the DATA section, after resur-  
facing operations are completed.  
1. Position the brushholder in the frame with the  
brushholder studs resting in the clamp surfaces  
of the brushholder support.  
2. The commutator can be resurfaced by sanding,  
stoning or grinding. Choose the method to be  
used based on the condition of the commutator.  
2. Install bolt and washer. Tighten bolt but do not  
torque until the brushholder–to–commutator  
clearance has been established. Refer to Brush-  
holder Clearance Adjustment section for instruc-  
tions to adjust brushholder clearance.  
NOTE: Outside power will be required to oper-  
ate the motor for the following commutator–re-  
surfacing procedure.  
3. After brushholder clearance has been set, con-  
nect the brushholder cable and remove protec-  
tive paper from commutator surface.  
WARNING: For the safety of personnel during  
resurfacing operations, the following safety  
precautions must be adhered to:  
4. Check brushes to insure they exceed the mini-  
mum brush length dimension and are free of any  
damage. If they are long enough and are not  
damaged, they can be re–used. If not, replace  
with new brushes.  
1. A second person must be at the auxiliary  
power (welder) control station, ready to  
shut off power in case of an emergency  
during the grinding operation.  
2. The grinding operator should wear  
goggles and a dust mask when resurfac-  
ing or blowing out the commutator.  
BRUSHHOLDER CLEARANCE  
ADJUSTMENT  
Refer to the DATA section for the brushholder–to–  
commutator clearance dimension and adjust brushhol-  
der as follows:  
3. To avoid electrical shock, do not touch  
any part of the machine interior during  
grinding operations.  
1. Remove the brushes.  
Preparation For Operating Series Model  
Machines For Commutator Resurfacing  
CAUTION: Do not allow the brushholder to  
touch, bump or rest on the commutator.  
1. Break the coupling (if applicable) so the machine  
can be operated from a d–c welding set or other  
outside d–c power source.  
2. Insert a fiber gauge (equal in thickness to the  
clearance dimension) between the commutator  
and the brushholder. (Loosen brushholder first if  
below minimum allowable clearance.)  
2. Lift all the brushes except two of opposite polarity  
(adjacent brushholders) which are necessary to  
operate the motor.  
Do NOT use a metallic gauge.  
3. Loosen the brushholder support bolt and move  
the brushholder against the fiber gauge so clea-  
rance–to–commutator is the same as the gauge  
thickness.  
3. Connect the machine to an outside source of  
controlled d–c power; such as a 3–5 kw, 100 vdc  
welding set which is capable of driving it at a  
speed of 900–1000 rpm.  
4. Torque bolt to 225–250 ft.–lb. and recheck the  
brushholder clearance gap.  
4. Refer to Fig. 7 for diagram of connections to run  
a series machine from a welding set. Connect  
14  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
NOTE: When shutting down, increase the field  
supply to maximum, and then turn off the arma-  
ture supply. After the armature supply has been  
shut off, shut down the field supply.  
Sanding Procedure  
If the commutator is dirty, blackened or slightly  
rough, resurface it by sanding with 00 sandpaper, or fin-  
er, as follows:  
FIG. 7. DIAGRAM OF CONNECTIONS TO RUN  
A SERIES MACHINE FROM A WELDING SET.  
E–28718.  
1. Attach the fine sandpaper to a wooden block  
shaped to fit the commutator, Fig. 9.  
leads so machine will operate as a series motor,  
and the armature will rotate counterclockwise  
(viewed from the commutator end).  
2. Run the machine at approximately 1000 rpm and  
hold the block against the commutator with a  
light, even pressure. Move the block back and  
forth longitudinally to clean the commutator.  
Preparation For Operating Shunt Model  
Machines For Commutator Resurfacing  
3. Use clean, dry compressed air, to remove dust  
and sand.  
1. Break the coupling (if applicable) so the machine  
can be run from a d–c power source.  
Hand Stoning Procedure  
2. Lift all brushes except two of opposite polarity  
(adjacent brushholders) which are necessary to  
operate the motor.  
If the commutator surface is mildly grooved,  
threaded or burned, and only a small amount of copper  
has to be removed to correct the trouble, use a hand  
stone. Hand stoning will not correct an out–of–round  
commutator. See “Fixture Grinding” section.  
3. Connect the machine to an outside source of  
controlled d–c power, Fig. 8.  
4. Apply power as follows:  
1. Use a fine–grade stone ground to fit the commu-  
tator curvature, Fig. 10. It should also be of suffi-  
cient width to bridge any flat spots; otherwise,  
the stone will ride in and out of the flat and will not  
correct it.  
a. Increase the field supply (0–50 v) to 32.0 volts  
at 25 amps.  
b. Increase the armature supply (0–150 v) to  
150 volts.  
2. Remove one brushholder for access to the com-  
mutator.  
c. Slowly decrease the field supply to bring the  
speed up to 1000 rpm.  
WOOD BLOCK  
SHAPED TO  
WOOD SCREW  
AND WASHER  
COMMUTATOR  
FINE  
SANDPAPER  
FIG. 8. CONNECTIONS TO RUN A SHUNT  
MACHINE FROM A D–C POWER SOURCE.  
E–23930A.  
FIG. 9. METHOD OF SANDING COMMUTATOR.  
E–18149.  
15  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
CAUTION: Never use an emery cloth on this or  
any commutator. The abrasive particles on  
emery cloth scratch the commutator surface  
and lodge in the groves between commutator  
segments. The condition creates the possibil-  
ity of an eventual flashover which could seri-  
ously damage the machine.  
WARNING: Do not come into close proximity  
of an energized motor during the cleaning pro-  
cess. The armature commutator and brush rig-  
ging have a high electrical charge which could  
cause serious injury or death. Always use a  
hose tip that is an electrical non–conductor  
when cleaning with air.  
WARNING: When using compressed air for  
cleaning purposes, flying debris and particles  
may present a hazard to personnel in the im-  
mediate area. Personnel should be provided  
with, and trained in the use of, personal pro-  
tective equipment as specified by applicable  
federal or state safety regulations.  
WARNING: Do not come into close proximity  
of an energized motor during the cleaning pro-  
cess. The armature commutator and brush rig-  
ging have a high electrical charge which could  
cause serious injury or death. Always use a  
hose tip that is an electrical non–conductor  
when cleaning with air.  
Fixture Grinding  
WARNING: When using compressed air for  
cleaning purposes, flying debris and particles  
may present a hazard to personnel in the im-  
mediate area. Personnel should be provided  
with, and trained in the use of, personal pro-  
tective equipment as specified by applicable  
federal or state safety regulations.  
Perform fixture–grinding operations to correct a  
commutator that is grooved, threaded or out–of–round.  
CAUTION: Be sure there is enough material on  
the commutator so grinding will not decrease  
the commutator diameter below the minimum  
permissible diameter listed in the DATA sec-  
tion.  
3. Run the motor at approximately 1000 rpm.  
Refer to SPECIAL TOOLS AND EQUIPMENT sec-  
tion for commutator grinder part number. See Fig. 11 for  
grinder nomenclature.  
4. Hold the stone firmly against the commutator  
surface, and with even pressure, move the stone  
back and forth longitudinally across the commu-  
tator surface.  
Grinder Installation  
5. Blow away dust and sand with clean, dry, com-  
pressed air.  
NOTE: Inspect the grinder before installing it to  
be sure it is reasonably clean. Make sure the tra-  
verse slides are free of accumulated dirt and  
copper chips; otherwise, the carriage may bind  
during the grinding operation.  
1. Remove the inspection covers from the ma-  
chine.  
2. Remove the most accessible brushholder, and  
clamp the grinder mounting bracket to the frame.  
3. Remove the brushes from one brushholder adja-  
cent to grinder in a CCW direction.  
4. Install old brushes in remaining brushholders.  
5. Bolt the grinder to the mounting bracket.  
FIG. 10. PROPER SHAPE OF  
HANDSTONE. E–8779A.  
16  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
FIG. 11. COMMUTATOR GRINDER. E–18249.  
NOTE: For most applications, finish–grade  
resurfacing stones are recommended. Medium  
grade stones can be used for rough grinding a  
deeply grooved or threaded commutator, or a  
commutator with deep flat spots, followed by fi-  
nish–grade stones for the final grinding. If new  
stones will be used, they should be contoured  
on a Carborundum wheel to approximate the  
curvature of the commutator.  
Install the resurfacing stones in the grinder and pro-  
ceed as follows:  
1. Traverse the carriage to one end of the commu-  
tator and check the clearance between the com-  
mutator surface and one stone with a feeler  
gauge or a fiber strip (approximately 0.030 in.  
thick). Traverse the carriage to the other end of  
the commutator and check the clearance under  
the same stone. The clearance should be the  
same at both ends. If clearance is not equal at  
both ends, adjust the mounting bracket by  
means of the set screws to obtain equal clear-  
ance at both ends.  
Install the stones in the grinder so the entire surface  
of the commutator will be resurfaced when the carriage  
is traversed from side–to–side. Proceed with alignment  
of the grinder as follows:  
17  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
2. Turn the feed control to back the stones away  
from the commutator before starting the ma-  
chine.  
NOTE: If possible, use some method of collect-  
ing the copper chips and abrasive dust pro-  
duced by the grinding operation. For example,  
use a vacuum cleaning device with the suction  
wand set just behind the trailing edge of the  
stones.  
FIG. 12. COMMUTATOR SLOT RAKING TOOL.  
E–19771A.  
Grinding  
7. If necessary, continue grinding to meet concen-  
tricity values listed in the DATA section.  
1. Apply power to the machine and gradually in-  
crease speed to 900–1000 rpm.  
8. Remove the grinder.  
NOTE: Do not grind the commutator to a depth  
where no mica undercut remains, or to a diame-  
ter which is smaller than the minimum permis-  
sible diameter listed in the DATA section.  
9. See Fig. 12 for slot raking tool. Rake the commu-  
tator slots to remove projecting mica fins or cop-  
per whiskers.  
10. Run the machine again at 1000 rpm and polish  
the commutator with 00 sandpaper, crocus cloth  
or 400A Triemite* paper. The abrasive sheet  
should be mounted on a wooden block curved to  
fit the surface of the commutator.  
2. Begin grinding by radially feeding the stones  
lightly against the commutator. Then, slowly  
move the carriage back and forth longitudinally  
across the surface. When the cutting action of  
the stone ceases, again feed the stone lightly  
against the commutator and continue grinding.  
Use care to make a light cut and to avoid chatter.  
Cutting action should take place at the trailing  
edge of the stones. Heavy cuts will cause exces-  
sive copper drag.  
CAUTION: Never use an emery cloth on this or  
any commutator. The abrasive particles on  
emery cloth scratch the commutator surface  
and lodge in the grooves between commuta-  
tor segments. This condition creates the pos-  
sibility of an eventual flashover which could  
seriously damage the machine.  
3. Grind the commutator to obtain a uniformly  
smooth surface, but do not remove any more  
copper than necessary.  
11. Blow the dust from the commutator and the inte-  
rior of the motor with dry, compressed air. Hold  
the air nozzle one to two inches from the surface  
of the commutator and sweep nozzle longitudi-  
nally to dislodge copper chips and mica dust.  
4. Lighten the cutting pressure on the stones near  
the end of the grinding operation. If medium–  
grade stones were used, stop the motor, change  
to finish–grade stones and repeat Steps 1, 2, 3  
and 4. After the final cut, traverse the stones  
back and forth without changing the feed until  
cutting action ceases.  
12. Air cure the commutator. See the following sec-  
tion for air curing instructions.  
5. Remove power from the machine.  
*Product of Minnesota Mining and Manufacturing  
Co.  
6. Check commutator runout with a dial indicator.  
Refer to the DATA section for concentricity limits.  
18  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
3. Increase the machine speed to approximately  
900 rpm and blow air on the commutator until the  
sparking stops.  
WARNING: When using compressed air for  
cleaning purposes, flying debris and particles  
may present a hazard to personnel in the im-  
mediate area. Personnel should be provided  
with, and trained in the use of, personal pro-  
tective equipment as specified by applicable  
federal or state safety regulations.  
4. Increase the speed until full speed is reached (do  
not exceed 1000 rpm) and continue to blow air on  
the commutator until all sparking stops.  
5. Stop the machine.  
6. Disconnect external power supply to machine.  
Make all necessary mechanical and electrical  
changes to restore the machine to service.  
Air Curing Commutator  
After the commutator has been sanded, stoned or  
ground and blown clean, it should be air cured as fol-  
lows:  
7. Use a clean cloth and wipe off the brushholders,  
creepage band and accessible surfaces in the  
commutator chamber.  
8. Brushholder Clearance – Install the brushholder  
previously removed and check and adjust as re-  
quired the brushholder–to–commutator clear-  
ance on all brushholders. See previous Brush-  
holder Replacement and Brushholder Clearance  
Adjustment sections for instructions to install the  
brushholder, and to adjust brushholder clear-  
ance.  
1. Rotate the armature slowly with the same source  
of power used for sanding, stoning or grinding.  
2. Use a rubber air–hose with the nozzle removed  
and sweep the commutator surface with 70 psi  
air pressure.  
WARNING: Observe all the following safety  
precautions to avoid injury.  
9. Installing Brushes – Refer to BASIC REPAIRS,  
Brush Replacement section, and install  
serviceable or new brushes per instructions  
listed.  
1. Remove all metal fittings from the air hose  
or, if impossible to remove, insulate the  
fitting.  
10. Vacuum interior of commutator chamber.  
BASIC OVERHAUL  
2. Be certain an operator is stationed at the  
power–supply control to quickly remove  
power from the machine should an emer-  
gency arise.  
NOTE: Be sure to use the correct drawings for  
the machine being overhauled. Refer to Table 2  
on page 20 to determine the correct drawing.  
3. Wear rubber–insulated gloves and  
goggles while air curing. Stand on an in-  
sulated platform.  
It is recommended that a basic overhaul be per-  
formed every two years, or 18,000 hours. The time inter-  
val between overhauls may vary, depending on the con-  
dition of the machine and the severity of service.  
4. Avoid contact with the cable terminals.  
The following basic overhaul procedures include in-  
structions to disassemble, clean, inspect, repair, reas-  
semble and test the machine.  
WARNING: Do not come into close proximity  
of an energized motor during the cleaning pro-  
cess. The armature commutator and brush rig-  
ging have a high electrical charge which could  
cause serious injury or death. Always use a  
hose tip that is an electrical non–conductor  
when cleaning with air.  
TESTING BEFORE DISASSEMBLY  
Perform the following tests prior to disassembly of  
the machine:  
19  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
TABLE 2. DRAWING REFERENCE  
Inst.  
Book  
Longi–  
tudinal  
Bearing Grease  
Distribution  
Arm.  
Locking  
Connection  
Diagram  
Coiled  
Frame As-  
sembly  
Puller Tools  
Comm. Pinion  
Arm.  
Shaft  
GE752  
Model  
Drive  
End  
Comm. Arrange-  
End  
End  
End  
ment  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Fig. 43  
Outline  
Fig. 48  
Fig. 48  
Fig. 48  
Fig. 48  
Fig. 48  
Fig. 49  
Fig. 49  
Fig. 48  
Fig. 48  
Fig. 48  
Fig. 48  
Fig. 48  
Fig. 48  
Fig. 48  
Fig. 49  
Fig. 49  
AUP1  
AUP2  
AUP3  
AUP4  
AUP5  
AUT1  
AUT2  
UP1  
Fig. 15  
Fig. 15  
Fig. 15  
Fig. 15  
Fig. 15  
Fig. 18  
Fig. 18  
Fig. 15  
Fig. 15  
Fig. 15  
Fig. 15  
Fig. 15  
Fig. 15  
Fig. 15  
Fig. 18  
Fig. 18  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 16 Fig. 17  
Fig. 20  
–––  
Fig. 22  
Fig. 22  
Fig. 22  
Fig. 22  
Fig. 22  
Fig. 24  
Fig. 24  
Fig. 21  
Fig. 21  
Fig. 21  
Fig. 21  
Fig. 21  
Fig. 21  
Fig. 21  
Fig. 23  
Fig. 23  
Fig. 29  
Fig. 29  
Fig. 29  
Fig. 29  
Fig. 29  
Fig. 32  
Fig. 32  
Fig. 30  
Fig. 30  
Fig. 30  
Fig. 30  
Fig. 30  
Fig. 30  
Fig. 30  
Fig. 31  
Fig. 31  
Fig. 34  
Fig. 34  
Fig. 35  
Fig. 35  
Fig. 35  
Fig. 36  
Fig. 36  
Fig. 34  
Fig. 34  
Fig. 35  
Fig. 35  
Fig. 35  
Fig. 35  
Fig. 35  
Fig. 36  
Fig. 36  
Fig. 38  
Fig. 38  
Fig. 38  
Fig. 38  
Fig. 39  
Fig. 38  
Fig. 39  
Fig. 38  
Fig. 38  
Fig. 38  
Fig. 38  
Fig. 38  
Fig. 38  
Fig. 39  
Fig. 38  
Fig. 39  
–––  
–––  
–––  
–––  
–––  
Fig. 20  
–––  
UP2  
UP3  
–––  
UP3A  
UP4  
–––  
–––  
UP5  
–––  
UP6  
–––  
US1  
–––  
US2  
–––  
Megohmmeter Test  
DISASSEMBLY  
Armature Removal From Frame  
Lift the brushes and perform a megohmmeter test on  
the armature windings and field coils to determine the  
condition of the insulation. A reading of less than 2  
megohms indicates poor insulation, dirt accumulation or  
excessive moisture.  
Models UP, AUP  
Before turning the machine from horizontal to verti-  
cal (or vice–versa), attach the armature locking ar-  
rangement to prevent the armature from moving axially.  
Remove the armature locking arrangement before op-  
erating the machine.  
Bar–To–Bar Resistance Test  
See Table 2 to determine the correct armature lock-  
ing arrangement drawing.  
Test for open or short–circuited armature coils.  
Refer to the longitudinal drawing, Fig. 15, and puller  
tool drawings, Figs. 16 and 17.  
1. Pass a regulated d–c current through the arma-  
ture coils.  
1. Clean the outside of the frame.  
2. Remove the hubs from the shaft if not already re-  
moved.  
2. Read the voltage drop between the commutator  
bars with a millivoltmeter. if the reading varies  
more than +/– 5% from the average value, a de-  
fective or short–circuited coil is indicated.  
3. Remove the commutator covers. Disconnect  
and remove all brushes and brushholders. Wrap  
20  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
heavy paper around the commutator for protec-  
tion during handling.  
4. Remove grease tubes from the commutator–  
end bearing cap:  
a. On UP1 and AUP1 models, there are two  
grease tubes (19, 20).  
b. On UP2 and AUP2 models, there is one  
grease tube (19).  
c. On all other models, only a pipe plug is pro-  
vided in the bearing cap.  
5. Install puller (Part 6751547G4) and pull sleeve  
(42) from the shaft at the commutator end. The  
sleeve has four tapped holes for applying the  
puller. Apply heat to the sleeve with a torch while  
pulling to facilitate removal.  
3
6. Remove bolts and washers (52) and remove  
bearing cap (4) and gasket (57) from the frame  
head.  
7. Make sure the armature locking arrangement is  
securely installed. Turn the machine on end on a  
stand (commutator–end down) and level it so the  
armature can be lifted vertically out of the frame  
without damaging the bearings, commutator or  
brushholders. Remove the armature locking ar-  
rangement.  
FIG. 13. COMMUTATOR–END BEARING PILOT.  
E–18150.  
FIG. 14. ARMATURE LIFTING BAIL. E–23932.  
21  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
VIEW OF COMMUTATOR END FOR  
ALL MODELS EXCEPT UP1, UP2, AUP1 AND AUP2  
VIEW OF PINION END FOR ALL  
MODELS EXCEPT UP1, UP2, AUP1  
AND AUP2  
THIS GREASE TUBE CONFIGURATION  
IS APPLICABLE TO MODELS UP1, UP2  
AUP1 AND AUP2 ONLY. SEE VIEW ABOVE FOR  
ALL OTHER MODELS  
56  
57  
52  
42  
43  
46  
44  
45  
FIG. 15. LONGITUDINAL SECTION (41D732922 CHG. N). E–28621D.  
22  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
VIEW OF COMMUTATOR END  
FOR UP6 AND AUP5  
NOTE: UP1 AND AUP1  
MODELS HAVE 2 TUBE ASSEMBLIES,  
UP2 AND AUP2 HAVE ONE.  
55  
54  
53  
51  
47  
49  
50  
48  
MODELS  
SEE TABLE 2, PAGE 20  
FIG. 15. LONGITUDINAL SECTION (41D732922 CHG. N). E–28621D.  
23  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
REF. DESCRIPTION  
1
COILED FRAME  
2
COILED FRAME  
3
4
5
6
ARMATURE AND BEARING ASSEMBLY  
OUTER BEARING CAP  
OUTER BEARING CAP  
CARBON BRUSH  
7
8
9
COVER (TOP INSPECTION)  
COVER (BOTTOM INSPECTION)  
COVER (HAND HOLE)  
BOLT (FRAMEHEAD), N22P39032, 1.00–8 X 2.00  
BOLT (FRAMEHEAD), N22P39036, 1.00–8 X 2.25  
LOCKWASHER, N405P50P, 1.00 MEDIUM  
BOLT (COVER) N22P29014B13, 0.50–13 X 0.88  
LOCKWASHER, N405P45P, 0.50 MEDIUM  
NAMEPLATE  
ESCUTCHEON PIN, N532P1106, NO. 12 X 0.38  
MONOGRAM  
ESCUTCHEON PIN, N532P1108, NO. 12 X 0.50  
TUBING  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
57  
TUBING  
TUBING (SEE NOTE)  
TUBING (SEE NOTE)  
PIPE PLUG, N5700P31, 1/4  
SPACER, 1/4 EXST. PIPE 3/4 LG.  
CLAMP  
BOLT, N22P21020B13, 0.25–20 X 1.25  
LOCKWASHER, N405P41P, 0.25 MEDIUM  
SEALER, RTV 108  
1ST TAPING, 12.00 (IT–1/2L), 41A239176P112  
2ND TAPING, 24.00 (IT–1/2L), 41A239176P18  
COILED FRAME  
COILED FRAME  
TUBING (SEE NOTE)  
GREASE (SEE NOTE)  
CAP  
ARMATURE AND BEARING ASSEMBLY  
BEARING ASSEMBLY (PE) (SEE NOTE)  
PLUG  
COVER (TOP INSPECTION)  
COVER (BOTTOM INSPECTION)  
COVER (HAND HOLE)  
SLEEVE  
SPACER  
BALL BEARING  
SLEEVE  
BEARING HOUSING  
SLEEVE  
ROLLER BEARING  
FLINGER  
SLEEVE  
BEARING HOUSING  
BOLTS AND WASHERS  
BOLTS AND WASHERS  
GASKET  
FRAMEHEAD  
FRAMEHEAD  
GASKET  
FIG. 15. LONGITUDINAL SECTION (41D732922 CHG. N). E–28621D.  
24  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
REF  
DESCRIPTION  
CLAMP PLATE  
BOLT  
REF  
12  
18  
DESCRIPTION  
NUT, 5/8–11  
RING  
REF  
21  
22  
DESCRIPTION  
STUD  
STUD  
4
5
6
PRESSURE CAP  
20  
STUD  
23  
NUT, 7/16–14  
FIG. 16. PULLER TOOLS (41D731569 CHG. 0). E–14383C.  
8. Reach into the drive–end of the motor and dis-  
connect grease tubes.  
9. Place three 0.125 in. spacers (wedge shaped)  
around the armature in the air gap between the  
armature and the fields to maintain a vertical atti-  
tude of the armature and to prevent the armature  
from contacting the fields.  
a. On UP1 and AUP1 models, disconnect two  
grease tubes (21 and 22) from the inner bear-  
ing cap (51). Pull these tubes out through  
their hole in the frame. The sealing RTV in the  
hole will separate with sufficient force.  
10. Remove bolts (10) and lockwashers (12) from  
the framehead (55). Insert bolts into the jackout  
holes in the framehead.  
b. On UP2 and AUP2 models, disconnect one  
grease tube (21) from the inner bearing cap  
(51). Pull this tube out through its hole in the  
frame. The sealing RTV in the hole will sepa-  
rate with sufficient force.  
11. Install a lifting bail, Fig. 14, onto the end of the  
shaft.  
12. Line up the hoist cable with the centerline of the  
armature before engaging the hook in the lifting  
bail on the end of the shaft. Engage the hook and  
lift slightly. With sufficient strain on the hoist  
cable to take the weight of the armature off the  
c. On all other models, only one grease tube is  
used, connected between the inner bearing  
cap and the framehead. Remove this tube.  
25  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
REF  
4
5
DESCRIPTION  
CLAMP PLATE  
BOLT  
REF  
17  
18  
DESCRIPTION  
CLAMP  
RING  
REF  
21  
22  
DESCRIPTION  
STUD  
STUD  
6
12  
PRESSURE CAP  
NUT, 5/8–11  
19  
20  
CLAMP  
STUD  
23  
NUT, 7/16–14  
FIG. 17. PULLER TOOLS. E–18155A.  
framehead, jack the drive–end framehead loose,  
and lift the complete armature assembly out of  
the frame. DO NOT DAMAGE THE COMMUTA-  
TOR.  
14. Install puller (Part 6751547G4) and pull sleeve  
(47) from the shaft at the drive end. Heat may be  
applied.  
15. Remove bolts and lockwashers (53) from bear-  
ing cap (5). Remove the bearing cap and gasket  
(54).  
13. Move the armature to a suitable fixture for further  
bearing disassembly or repair.  
26  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
16. Remove the framehead. It will come with the  
bearing outer race and bearing rollers.  
end up and remove bolts (11) and lockwashers  
(12). Use bolts in the framehead jackout holes  
to break the fit and remove the framehead.  
17. Pull the inner bearing race off the drive end of the  
shaft with puller (Part 6751547G5).  
Armature Removal From Frame  
18. Remove flinger (49) and inner bearing cap (51)  
with puller (Part 6751547G6) by inserting the  
four puller bolts into tapped holes in the inner  
bearing cap.  
CAUTION: When lifting the armature out of the  
frame, proceed slowly so that no damage will  
occur to the armature end–windings, bear-  
ings, bearing fits or the commutator.  
Models US1, AUT  
19. If necessary, remove inner sleeve (50) with puller  
(Part 6751547G7).  
Before turning the machine from horizontal to verti-  
cal (or vice–versa), attach the armature locking ar-  
rangement to prevent the armature from moving axially.  
Remove the armature locking arrangement before op-  
erating the machine.  
20. Press the outer bearing race and rollers from the  
framehead with an arbor press.  
NOTE: Before pressing the drive–end outer  
bearing race out of the framehead, observe and  
record the number on the face of the race which  
is opposite the arrow on framehead. After re-  
moval, mark the date (with electric pencil) un-  
der this number to indicate that this position  
has been used. Reassemble the bearing with  
another number opposite the arrow. If the bear-  
ing has not been previously marked, etch Nos.  
1, 2, 3 and 4 (spaced 90 degrees apart) on the  
face of race with an electric pencil. Locate No. 1  
opposite the arrow on the framehead and mark  
it with the date.  
See Table 2 to determine the correct armature lock-  
ing arrangement drawing.  
Refer to the longitudinal drawing, Fig. 18, and puller  
tool drawings, Figs. 16 and 17.  
1. Clean the outside of the frame, using com-  
pressed air, a steam–jenny or cleaning solvents,  
to remove accumulated dirt.  
2. Remove the coupling hub from the shaft, if not al-  
ready removed.  
3. Remove the commutator covers. Disconnect  
and remove all brushes, and wrap heavy paper  
around the commutator for protection during  
handling.  
21. Install puller (Part 6751547G10) and pull spacer  
(43) from the commutator end of shaft.  
22. Install puller (Part 6751547G6) and pull bearing  
housing (46) with bearing (44) from the shaft.  
4. Install puller tool (Part 6751547G4) and pull the  
sleeve (6) from the commutator end of the shaft.  
23. Press ball bearing (44) from bearing housing  
(46) using an arbor press.  
5. Remove bolts (10) which hold the bearing cap  
and the bearing housing to the commutator–end  
framehead. Remove the bearing cap (8) and  
gasket (11).  
24. If applied, remove the nilos ring (4), Fig. 39, from  
the bearing and discard.  
6. Turn the machine on end on a stand, commuta-  
tor end down, and level it so that the armature  
can be lifted vertically out of the frame without  
damaging the bearings, commutator or brush-  
holders.  
25. If applied, remove the seal ring (5), Fig. 39, from  
the sleeve and discard.  
26. Install puller (Part 6751547G11) and pull sleeve  
(45) from the shaft.  
7. Screw three guide pins into the commutator–end  
bearing housing (3) to help guide the armature  
out of the frame.  
27. If it is necessary to remove the commutator end  
framehead (56), place the frame commutator  
27  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
9
VIEW OF COMMUTATOR END  
FIG. 18. LONGITUDINAL SECTION (41D735357, CHG. A). E–37949B  
28  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
REF.  
1
DESCRIPTION  
SHAFT  
REF.  
22  
DESCRIPTION  
ARMATURE  
2
3
4
5
6
7
8
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
SLEEVE  
23  
24  
MAGNET FRAME  
EXCITING POLE BOLT AND  
HARDENED WASHER  
EXCITING FIELD COIL  
WASHER  
BEARING HOUSING  
BALL BEARING  
SPACER  
SLEEVE  
CAP  
BEARING CAP (OUTER)  
PIPE PLUG  
BOLT AND LOCKWASHER  
GASKET  
25  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
FITTING  
FRAME HEAD  
BOLT AND LOCKWASHER  
GASKET  
FITTING  
FITTING  
BOLT AND LOCKWASHER  
GASKET  
BEARING CAP (OUTER)  
SLEEVE  
ROLLER BEARING  
FLINGER  
BEARING CAP (INNER)  
SLEEVE  
BOLT  
BOLT AND LOCKWASHER  
FRAME HEAD  
FLASH RING  
BRUSH HOLDER CLAMP  
BOLT AND LOCKWASHER  
BRUSH HOLDER  
CARBON BRUSH  
COMMUTATING FIELD COIL  
COMMUTATING POLE BOLT AND  
HARDENED WASHER  
T.  
0  
0  
5  
5  
3  
MODELS  
SEE TABLE 2  
FIG. 18. LONGITUDINAL SECTION (41D735357, CHG. A). E–37949B.  
29  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
8. Screw a lifting bail, Fig. 14, on the drive end of the  
shaft.  
NOTE: Before pressing the drive–end outer  
bearing race out of the framehead, observe and  
record the number on the face of the race which  
is opposite the arrow on the framehead. After  
removal, mark the date (with electric pencil) un-  
der this number to indicate that this position  
has been used. Reassemble the bearing with  
another number opposite the arrow. If the bear-  
ing has not been previously marked, etch Nos.  
1, 2, 3 and 4 (spaced 90 degrees apart) on the  
face of race with an electric pencil. Locate No. 1  
opposite the arrow on the framehead and mark  
it with the date.  
9. Remove drive–end framehead bolts (30) and in-  
sert three jack screws in the threaded holes pro-  
vided in the framehead.  
10. Line up the hoist cable with the centerline of the  
armature before engaging the hook in the lifting  
bail on the end of the shaft. Engage the hook and  
lift slightly. With sufficient strain on the hoist  
cable to take the weight of the armature off the  
framehead, jack the drive–end framehead loose,  
and lift the complete armature assembly out of  
the frame. DO NOT DAMAGE THE COMMUTA-  
TOR.  
19. Install puller tool (Part 6751547G10) and pull  
spacer (5) from the commutator end of the shaft.  
20. Install puller tool (Part 6751547G6) and pull  
bearing (4) and bearing housing (3) from the  
commutator end of the shaft.  
CAUTION: Special precautions should be taken to  
avoid damage to the armature end–windings,  
bearings or bearing fits, and the commutator  
when lifting the armature in the vertical position  
or turning the armature to a horizontal position.  
21. Press the bearing from the framehead with an  
arbor press.  
22. If applied, remove the nilos ring (4), Fig. 39, from  
the bearing and discard.  
11. Place the armature horizontally in an armature  
saddle for bearing disassembly.  
23. If applied, remove the seal ring (5) Fig. 39, from  
the sleeve and discard.  
12. At the drive end, remove the lubricating tube as-  
sembly (9, 33, 32 and 28) from the framehead.  
24. Install puller tool (Part 6751547G11) and pull  
sleeve (2) from the commutator end of the shaft.  
13. Using puller tool (Part 6751547G4), pull the out-  
er sleeve (37) from the drive end of the shaft. The  
sleeve has tapped holes for applying the puller.  
Heat may be applied.  
25. If necessary to remove the commutator  
framehead (14), turn the frame commutator end  
up and remove bolts and lockwashers (13). Use  
bolts in the framehead jack–out holes to break  
the fit and remove.  
14. Remove bolts (34), and then remove outer bear-  
ing cap (36) and gasket (35).  
15. Slide framehead (29) off the shaft together with  
the outer race and rollers of bearing (38). The in-  
ner race will remain on the shaft.  
CLEANING  
The two recommended methods for cleaning are  
steam cleaning and vapor degreasing.  
16. Pull the inner bearing race off the shaft with puller  
(Part 6751547G5).  
CAUTION: Do not use caustic soda solution  
on the armature or coiled frame.  
17. Remove flinger (39) and inner bearing cap (40)  
with puller (Part 6751547G6) by inserting the  
four puller bolts into the tapped holes in inner  
bearing cap (40).  
Steam Cleaning  
(Recommended for both insulated and metal parts)  
18. Press the outer bearing race and rollers from the  
framehead with an arbor press.  
1. Use steam in combination with a commercial  
non–caustic cleaner.  
30  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
2. Suspend the part in a position accessible from all  
directions to a direct flow of steam from the hose.  
wear on rollers and balls. Replace the bearing if  
any of these conditions is found.  
3. Look for evidence of smearing caused by inade-  
quate lubrication, and corrosion pitting (usually  
at roller spacing) caused by moisture or other  
corrosive agent. Replace the bearing if any of  
these conditions are found.  
3. Rinse all residue from parts with a mixture of  
clean steam and water.  
4. Bake insulated parts for at least 8 hours at 150_  
C (302_ F) to remove all moisture.  
Vapor Degreasing  
4. Inspect bearing outer races for indentations  
caused by dirt or foreign material having gone  
through the bearing. If the indentations are small  
and few in quantity, the bearing can be used. If  
the indentations are large and numerous, this  
may be an indication the rollers or cone are start-  
ing to spall out. Examine the rollers and cone  
carefully for spalled areas. Replace the bearings  
if spalled areas are found.  
(Recommended for metal parts)  
1. Bring the cleaning solution to a boil, and allow the  
vapor line in the tank to rise to the condenser  
coils at the top of the tank.  
2. Keep the vaporized cleaning solution at about  
120_ C (248_ F).  
3. Lower the part to be cleaned into the vapor–la-  
den atmosphere, so the vapor will condense on  
the part.  
5. Dip good bearing parts in a light mineral oil  
(SAE–10) heated to 90_ C (194_ F) to avoid cor-  
rosion before reassembly.  
6. If a bearing will not be mounted immediately,  
wrap it in an oil–proof paper.  
4. To speed the removal of heavy dirt accumula-  
tions, spray hot solution directly from the tank  
onto the part being cleaned. The temperature of  
the solution must be kept below its boiling point.  
CAUTION: Do not interchange bearing parts of  
different manufacture or mix new and used  
bearing parts.  
5. Remove the cleaned part from the degreaser.  
Drain and cool the part.  
Perform the following inspection and tests to deter-  
mine the condition of the armature, coiled motor frame  
and brushholders.  
Anti–Friction Bearings/Shaft  
Tapers/Bearing Fits  
After the inspection and test procedures have been  
completed and all defects or damage noted, refer to the  
REPAIR section for the correct repair procedure.  
Use a cleaning solution that leaves an oil film to pro-  
tect finished surfaces from rust. Kerosene, petroleum  
spirits or other petroleum–base cleaners provide limited  
protection for these surfaces.  
ARMATURE  
Handle the armature carefully during overhaul oper-  
ations to avoid damage to the core, banding, end turns,  
shaft fits and commutator. Support the armature in a  
saddle to protect the commutator and to coil the ends.  
Keep the commutator covered with heavy paper.  
INSPECTION AND TEST OF  
DISASSEMBLED MOTOR  
BEARING INSPECTION  
1. Clean the bearings. See Cleaning section.  
Armature Test  
2. Inspect for broken or cracked races, broken or  
cracked rollers and balls, broken, cracked or dis-  
torted retainers, scored, pitted, scratched or  
chipped races, and for indication of excessive  
1. With the armature at room temperature, 25_ C  
(77_ F), use a 500 or 1000 vdc megohmmeter  
and make a dielectric test of the armature insula-  
31  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
tion. A reading of one megohm or higher should  
be obtained. If necessary, perform additional  
cleaning and baking operations to obtain this val-  
ue before proceeding.  
check for movement of the band to determine if loose. If  
the band is loose or has deep burns, replace it. See RE-  
PAIR section for instructions.  
COMMUTATOR  
NOTE: If additional cleaning and baking opera-  
tions do not increase the resistance value of the  
insulation, it may be necessary to replace the  
creepage band and rewind the armature.  
Check the commutator for threading, pitting, groov-  
ing, burns, flat spots, high bars and copper drag.  
Check the commutator to make sure that it is not  
out–of–round. See the DATA section for concentricity  
limits.  
2. Measure and record armature resistance. See  
the DATA section for values.  
Resurfacing  
3. If there are no armature coils grounded, perform  
a bar–to–bar comparison test to check for open  
or short–circuited armature coils.  
For the resurfacing procedure for a commutator, see  
REPAIR, Armature section.  
a. Pass a regulated d–c current through the ar-  
mature coils.  
Refer to the DATA section for the minimum permissi-  
ble commutator diameter dimension and check the di-  
ameter of the commutator.  
b. Read the voltage drop between the commu-  
tator segments with a millivoltmeter. If the  
reading varies more than plus or minus 5%, a  
defective or short–circuited coil is indicated. If  
the armature fails the bar–to–bar test, the ar-  
mature must be rewound.  
NOTE: If the brush surface diameter will be less  
than the minimum permissible diameter after  
resurfacing operations are performed, the com-  
mutator must be replaced.  
Tightening  
If the armature will not be rewound, proceed  
to inspect the following items.  
If the commutator is loose (has high bars), see the  
“REPAIR, Commutator Tightening” section for instruc-  
tions to tighten the commutator.  
Insulation  
Inspect the insulation of armature coils for cracks,  
physical damage, burns and deterioration. If minor re-  
pairs are required, refer to Fig. 19 for insulation details.  
ARMATURE SHAFT INSPECTION  
Armature shaft bearing fit dimensions can be  
checked and compared to armature shaft drawings pro-  
vided in Fig. 20. If the bearing fit dimensions are not  
within stated tolerances the shaft must be replaced or  
repaired. Refer to Table 2 to determine the correct shaft  
drawing for the machine being repaired.  
Glass Band, Commutator End  
Inspect the glass bands for split, frayed or loose con-  
dition.  
Wire Band, Drive End  
MOTOR FRAME  
1. Check the connection strap insulation for dam-  
age, signs or burning, cracks or discoloration.  
Inspect the wire band for physical damage, loose tie  
clips or broken wire.  
2. Check the insulation on the coils for damage,  
signs of burning, cracks or discoloration.  
Creepage Band  
Inspect the surface of the Teflon creepage band for  
possible flashover damage. Tap the band lightly and  
3. Check the lead cables for damage, overheating  
and signs of deterioration.  
32  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
3/4 REF.  
ASSEMBLE AROUND  
ASSEMBLE AROUND  
4–1/4  
BUTTED JOINT OF PT48  
BUTTED JOINT OF PT48  
49  
49  
61  
1/4  
37  
60,78  
1/4  
48,77  
ASSEMBLE IN LINE  
WITH NO. 1 SLOT  
1
17,  
71  
11  
5,  
7,  
29  
33  
13  
16  
68 69  
32  
3
32  
52,  
76  
EXTEND A THIN COATING  
OF PT32 OVER TOP OF  
EQUALIZERS BOTH DECKS  
9,65  
3/4 LAPPED  
28 ACTIVE TURNS AT  
8
70  
67  
6,  
66  
P70 TO BE APPLIED  
OVER P68 TO LEVEL  
THE SURFACE  
+
400 50 LB. TENSION  
OVER TOP OF EQUALIZERS  
53  
5/8  
3/8  
REF.  
3
29  
11–1/4 R.  
54  
NOTE FOR P54:  
MATL: 41B537080P1  
ALT. MATL: 41A230144P3  
57  
NOTE FOR P57:  
MATL: 41A230144P40  
TOP COILS  
BOTTOM COILS  
TO #94  
TO #185  
TO #96  
TO #183  
TO #92  
TO #1  
EQUALIZER CONNECTIONS  
COMM. SEGMENTS  
NUMBERED SEGMENTS ARE FOR  
PURPOSE OF INDICATING SPAN OF  
EQUALIZER CONNECTIONS AND DO  
NOT NECESSARILY CORRESPOND  
TO NUMBERED SEGMENTS IN  
MAIN CONNECTION DIAGRAM.  
SLOT #1  
ORPHAN  
COIL  
30  
MAIN WINDING  
CONNECTIONS  
NOTE FOR P62:  
SLOT #15  
C SLOT #1  
ON CMICA  
L
SLOT #16  
L
APPLY TO SIDES OF CORE SLOT  
ON PINION END ONLY.  
INSTALL P11.  
NOTE FOR P47:  
TOP COILS  
ENCLOSE ONE IDENTIFICATION C–SIZE  
PRINT OF 41D730423 IN EACH  
CARTON OF SUPPLY INSUL.  
BOTTOM COILS  
NOTE FOR P32:  
TAPE OVER RISERS WITH 3/4 WIDE A2L14B GLASS TAPE  
LEAVING 1/4 IN. OF RISERS EXPOSED ON THE CORE END. FILL  
BETWEEN ARMATURE LEADS BEHIND RISERS AND OVER  
BACK 1/4 IN. OF RISER. WRAP OVER PUTTY WITH A16B39B  
MYLAR TAPE AND BAKE AS PART OF THE PREHEAT PERIOD  
FOR INSTALLING P37.  
NOTE FOR P37 (C.E. BINDING):  
APPLY THE P37 PERMANET CE BINDING (COLD TAPE TO HOT  
125–135 C ARMATURE)  
+
APPLY 77 ACTIVE TURNS OF P37 AT 500 25 LB. TENSION.  
FIG. 19 ARMATURE INSULATION (41D731545 CHG. F). E–18156A.  
33  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
5 REQ’D.  
+
38 SEE NOTE  
1–1/16  
1/16  
+1/8  
–0  
2–5/8  
39  
27  
39  
18,19,20,75  
4–7/8 MAX.  
12  
25  
4
11  
62  
14  
1
15  
3
55  
1
2
SATURATE P2 THOROUGHLY  
WITH P56  
NOTE FOR TEMPORARY BINDING:  
26 PT26 TO BE APPLIED  
OVER COILS TO LEVEL  
THE SURFACE  
APPLY TEMPORARY BINDING. 6 TOTAL PASSES WITH 0.102  
DIAM. B4Y19B AT 800 LB. TENSION. BAKE IN A 150 C OVEN  
FOR 4 HOURS.  
FIRST TURN  
2ND DECK  
REF.  
1
2
3
4
5
6
7
8
DESCRIPTION  
REF.  
40  
41  
DESCRIPTION  
BINDING CLIP  
TIE CLIP  
HEAD INSUL. P.E.  
HEAD INSUL. P.E.  
FILLER  
ARMATURE COIL  
INSUL. OVER EQUALIZERS  
INSUL. IN EQUALIZER LOOP  
INSUL. OVER EQUALIZER  
EQUALIZER  
HEAD INSUL. C E  
SLOT STRIP BOT  
U PIECE AT SLOT ENDS  
SLOT WEDGE  
WINDING INSUL. C E  
INSUL. IN LOOP P.E.  
INSUL. IN LOOP  
FILLER STRIP  
FILLER  
A
A
42  
METHOD OF FASTENING  
BINDING WIRE (P.E.)  
METHOD OF SWAGING  
COMM. RISERS  
CORE INSUL.  
WINDING INSUL.  
BINDING AND BINDING INSUL.  
IDENTIFICATION PRINT  
BINDING BASE  
JOINT INSUL.  
PAD  
SLOT WEDGE  
SLOT STRIP BOTTOM  
TAPE  
TEFLON BAND  
43  
LAST TURN  
3RD DECK  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
57  
58  
59  
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
TOP BAND  
B
B
FIRST TURN  
(LOWER DECK)  
LAST TURN  
(LOWER DECK)  
SLOT STRIP (UNDER WEDGE)  
FILLER STRIP  
FILLER STRIP  
SLOT STRIP CENTER  
RADIUS SPACER C.E. TOP  
AND BOTTOM  
TEFLON GLASS TAPE  
VARNISH  
TEFLON BAND  
EQUALIZER  
FILLER FOR COMM.  
STRING BAND  
28  
SECTION A–A  
SECTION B–B  
LAST TURN  
3RD DECK  
23  
24  
BINDER OVER COMM. MICA  
SEAL OVER COMM.  
MICA AND STRING BAND  
BINDING INSUL. P.E.  
FILLER P.E.  
BINDING BASE  
TIE CLIP  
RADIUS SPACER (C.E. BOTT.)  
DIAGRAM  
SHIM (IN RISER SLOT)  
FILLER PUTTY  
WINDING INSUL. C.E.  
FILLER FOR COMM.  
STRING BAND  
FILLER FOR COMM.  
STRING BAND  
BINDING BASE  
BANDING  
BINDING WIRE  
BINDING CLIP P.E.  
60  
61  
62  
63  
64  
65  
66  
67  
68  
69  
70  
71  
72  
73  
74  
75  
76  
77  
78  
BINDING BASE  
MYLAR TAPE  
CEMENT  
CEMENT  
CORE INSUL.  
41  
28  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
HEAD INSUL.  
INSUL. IN EQUALIZER LOOP  
BAND FOR EQUALIZERS  
INSUL. OVER EQUALIZERS  
INSUL. OVER EQUALIZERS  
FILLER  
27  
2ND AND 3RD DECK  
CONTINUOUS WIRE  
FILLER  
WINDING INSULATION  
ASBESTOS ROPE  
ARMATURE COIL  
FILLER STRIP  
SLOT STRIP BOTTOM  
BINDING BASE  
BINDING BASE  
35  
36  
37  
38  
39  
NOTE FOR P38 (P.E. BINDING):  
APPLY THE P38 PERMANET BINDING.  
+
APPLY 37 ACTIVE TURNS OF P38 AT 650 20 LB. TENSION  
+
APPLY 34 ACTIVE TURNS OF P38 AT 550 20 LB. TENSION  
AS THE 1ST DECK.  
AS THE 3RD DECK  
+
APPLY 35 ACTIVE TURNS OF P38 AT 600 20 LB. TENSION  
AS THE 2ND DECK.  
THE 2ND AND 3RD DECK MUST BE A CONTINUOUS BAND.  
FIG. 19. ARMATURE INSULATION (41D731545 CHG. F). E–18156A.  
34  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
MODELS  
SEE TABLE 2  
FIG. 20. ARMATURE SHAFT (334B336 CHG. D). E–39091A.  
4. Conduct a 500 volt megohmmeter test on the  
coils. A reading of 20 megohms or more is ac-  
ceptable.  
BRUSHHOLDERS  
1. Inspect the brushholder for flashover damage,  
cracks and burned or pitted areas.  
2. Check the brush springs to be sure they move  
freely and do not bind.  
5. See Figs. 21 thru 24 and measure and record  
commutating and exciting–coil resistance. Re-  
fer to Table 2 to determine the correct connection  
diagram for the machine being repaired.  
3. Insert a new brush in the carbonway and move it  
up and down in the carbonway to be sure it  
moves freely.  
REPAIR  
6. High–potential test the field coils to ground.  
LUBRICATION OF BOLTS  
WARNING: Electric shock can cause serious  
injury or death. Strict safety precautions must  
be taken and observed by personnel conduct-  
ing a high–potential test.  
The threads and washer faces of bolts and nuts  
should be lubricated to obtain maximum clamping force  
(at the nominal or at a recommended torque value)  
when bolts and nuts are installed at reassembly. Lubri-  
cate all bolts.  
Apply a high–potential test of 2000 volts, 60 Hz for  
one minute.  
Use a High Pressure Lubricant such as; graphite in  
oil (1 part graphite to 5 parts machine oil by volume), Lu-  
35  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
briplate* (Part 147X1614), Molykote** (Part 147X1143),  
Dag*** (Part 147X1613), or anti–seize compound (Part  
147X1640) to lubricate bolts.  
BRUSHHOLDER SLEEVE REPLACEMENT  
1. Remove the damaged Teflon sleeve from the  
brushholder stud. To remove sleeve, heat the  
brushholder in an oven to 150_ C (302_ F) then  
peel or cut sleeve from the stud.  
NOTE: Threads and washer–contact surfaces  
must be clean before lubricant is applied.  
Where specific torque values are not listed in these  
instructions, refer to Table 3 for standard bolt torque val-  
ues of lubricated bolts.  
2. Thoroughly clean the surface of the stud and re-  
move any carbon or dirt build–up.  
3. Heat a new Teflon sleeve in a 150_ C (302_ F)  
oven for 15 minutes.  
*Product of Fisk Bros. Refining Co., Newark, N.J.  
**Registered trademark of Dow Corning Corp.  
***Acheson Colloids Co., Port Huron, Mich.  
4. Using adequate hand protection, immediately  
assemble the hot sleeve on the stud.  
MODELS  
SEE TABLE 2  
TO CHANGE MOTOR DIRECTION:  
TO RUN CCW VIEWED FROM COMMUTATOR END,  
CONNECT:  
F1 TO POSITIVE  
F2 TO NEGATIVE  
A1 TO POSITIVE  
A2 TO NEGATIVE  
TO RUN CW VIEWED FROM COMMUTATOR END,  
CONNECT:  
F1 TO NEGATIVE  
F2 TO POSITIVE  
A1 TO POSITIVE  
A2 TO NEGATIVE  
FIG. 21. CONNECTION DIAGRAM (493A210 CHG. 4). E–39092B.  
36  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
ARMATURE  
TABLE 3  
STANDARD BOLT TORQUE VALUES  
(For Lubricated Bolts)  
Creepage Band Replacement  
USE THE TORQUE VALUES IN THIS TABLE AS A GUIDE TO IN-  
SURE SATISFACTORY TIGHTENING OF BOLTS AND NUTS  
WHERE A SPECIFIC VALUE IS NOT GIVEN IN THE INSTRUC-  
TIONS.  
Because of its superior adhesion qualities, the Teflon  
creepage band on the outer end of the commutator  
should be applied using the “hot bond” process. A copy  
of this process is included in each Teflon Band Kit, Part  
No. 76518, which can be ordered from the following ad-  
dress:  
*INCLUDES SOCKET HEAD SCREWS.  
TORQUE VALUES (LB./FT.)  
MEDIUM CARBON  
(SAE GRADE 5)  
ALLOY STEEL  
(SAE GRADE 8)*  
THREADS  
PER  
INCH  
BOLT  
DIAM.  
General Electric Company  
Insulating Materials Product Section  
One Campbell Road  
Schenectady, NY 12345  
Attn: Customer Service  
1/4  
20  
28  
5–8  
5–8  
10–12  
10–12  
5/16  
3/8  
18  
24  
12–15  
12–15  
18–21  
20–23  
16  
24  
20–25  
25–28  
30–36  
34–40  
NOTE: The Teflon band is not included in the  
kit, but can be ordered through normal Renewal  
Parts channels.  
7/16  
1/2  
14  
20  
35–40  
40–45  
50–56  
60–65  
13  
20  
55–60  
60–70  
80–90  
95–105  
Inspect the Band  
9/16  
5/8  
12  
18  
75–80  
110–123  
130–145  
90–100  
1. There should be no gaps at the joint or between  
the edge of the Teflon band and the copper bars.  
11  
18  
105–115  
125–140  
152–169  
185–205  
3/4  
10  
16  
185–205  
220–245  
285–315  
340–370  
2. The band surface must be smooth, free of var-  
nish and bonded to the underlay material. There  
must not be any bubbles under the Teflon or  
buckling of the band.  
7/8  
9
14  
300–330  
340–380  
440–490  
510–565  
1
8
12  
440–490  
530–570  
685–735  
790–8665  
3. The surface must be free of damage including  
scratches and cuts.  
1–1/8  
1–1/4  
1–3/8  
1–1/2  
7
620–690  
750–830  
935–1040  
1115–1240  
12  
7
12  
890–990  
1040–1160  
1250–1360  
1600–1750  
Rewinding Armature  
The armature must be rewound if any coils are  
shorted or grounded.  
6
12  
1160–1290  
1420–1580  
1745–1940  
2125–2360  
6
12  
1570–1740  
1800–2000  
2300–2600  
2600–3020  
Riser Width  
E–38274  
During the rewinding procedure, the TIG welds on  
the commutator risers are machined to break the arma-  
ture coil connections. Machining reduces the width of  
the risers 1/32 to 1/16 in. each time, which in turn de-  
creases the current–carrying capacity of the risers.  
Diameter  
Refer to the DATA section for the Minimum Permissi-  
ble Commutator Diameter dimension. If the commutator  
brush–surface diameter will be less than the minimum  
permissible diameter after resurfacing operations are  
performed, replace the commutator before the new ar-  
mature coils are assembled.  
If the calculated width of the risers (after machining)  
will be less than the Minimum Permissible Riser Width  
listed in the DATA section, a new commutator must be  
installed before new armature coils are assembled.  
37  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
NOTE: Before rewinding the armature, first  
check the shaft pinion and bearing fits to deter-  
mine whether or not shaft replacement is re-  
quired. See Table 2 to determine the correct  
shaft drawings.  
2. Torque the commutator bolts by one of the fol-  
lowing methods.  
Hydraulic Press (Preferred Method)  
1. Clean the front face of the cap and the segments,  
Fig. 25. Remove ONE bolt at a time, and lubri-  
cate the bolt threads and under the bolt head.  
See Lubrication of Bolts section. Follow the se-  
quence shown on Fig. 27 for bolt removal. Reas-  
semble bolt and tighten to the initial breakaway  
torque value.  
The armature can be rewound using a GE Co. Sup-  
ply Kit, Part 41D730545G8, and the information  
supplied in the kit.  
NOTE: After the armature is rewound, the arma-  
ture coil leads must be TIG welded to the com-  
mutator risers, the armature must be Vacuum  
Pressure Impregnated, and the commutator  
must be cleaned and polished.  
2. Using a depth micrometer, measure the distance  
(X in Fig. 25) between the face of the cap and the  
segments at four points, 90 degrees apart. The  
face of the cap and the segments should be par-  
allel within 0.020 in. If necessary, tighten the ap-  
propriate cap bolts to obtain this parallel relation-  
ship between the face of cap and the segments.  
Commutator Tightening  
If the commutator requires tightening, commutator  
assembly pressure can be restored at overhaul by per-  
forming a commutator tightening procedure; however, it  
is necessary that spin–seasoning and resurfacing oper-  
ations be performed after the commutator is tightened.  
3. Place the armature in a vertical press. Position  
ball and socket tool (Part 41C685080G1) and  
crow–foot pressing fixture (Part 41C685430G1)  
on the commutator, and apply 70 tons pressure  
at the diameter shown on Fig. 26.  
Before proceeding to tighten a loose commutator, it  
must first be determined whether or not the brush–sur-  
face diameter of the commutator will be larger than the  
minimum permissible diameter after the commutator is  
resurfaced.  
4. Tighten the commutator bolts to 145 lb.–ft.  
torque in a crisscross sequence, Fig. 27. Tighten  
the bolts twice in this sequence, then tighten  
bolts once–around at 145 lb.–ft. torque.  
If the brush–surface diameter is calculated to be  
smaller (after resurfacing) than the minimum  
permissible diameter, listed in the DATA section, the  
commutator must be replaced.  
NOTE: The specified torque values have no sig-  
nificance unless the bolts are lubricated.  
5. Check the dimension between cap face and seg-  
ments at four locations, 90 degrees apart, to as-  
sure surfaces are still parallel within 0.020 in.  
After a long period of service, the mica insulation  
may relax, due to temperature cycling, and relieve com-  
mutator assembly pressure. This could result in a loose  
commutator (with raised bars), or an out–of–round com-  
mutator.  
Torque Wrench (Acceptable Method)  
In the absence of a suitable press, bolts may be tight-  
ened with a torque wrench adjusted to apply the indi-  
cated torque to each bolt.  
The assembly pressure can be restored by tighten-  
ing the commutator bolts. This must be done before un-  
dertaking any resurfacing operation on the commutator.  
1. Clean the front face of the cap and the segments.  
Using a depth micrometer, measure the distance  
(X in Fig. 25) between the face of the cap and the  
segments at four points, 90 degrees apart. The  
face of the cap and the segments should be par-  
allel within 0.020 in.  
Procedure  
1. Chip the weld from the commutator bolt heads to  
free bolts from the cap.  
38  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
If necessary, tighten the appropriate cap bolts to  
obtain this parallel relationship between the face  
of the cap and the segments.  
3. Heat the commutator to 155–165_ C (312–330_  
F) in 60 minutes at 2940 rpm. Spin at 155–165_  
C (312–330_ F) for 30 minutes at 2940 rpm. Cool  
to 50_ C (112_ F) maximum in 30 minutes at  
2940 rpm. Repeat for a total of 2 cycles.  
2. Remove ONE bolt. Clean and lubricate the bolt  
threads under the bolt head. Reassemble bolt,  
and torque to 97 lb.–ft.  
4. Heat the commutator to 140–150_ C (284–302_  
F) in 60 minutes at 2940 rpm, and check commu-  
tator smoothness at 2940 rpm.  
3. Repeat Step 2 for remaining bolts, following the  
crisscross tightening sequence shown on Fig.  
27.  
5. Allow the commutator to cool, and grind cold.  
See the “Commutator Resurfacing” section.  
Check commutator runout per the information in  
the DATA section. If the commutator is rough or  
has high bars, repeat the pressing, tightening,  
spin–seasoning and resurfacing procedures un-  
til the runout is within the limits specified in the  
DATA section.  
4. Repeat the tightening sequence increasing the  
torque by 10% each time until a FINAL value of  
145 lb.–ft. torque for all bolts is obtained.  
5. Check the dimension between face of cap and  
segments to assure these surfaces are parallel  
within 0.020 in.  
6. Tack–weld the bolts to the commutator cap with  
bronze welding rod, GE–B50E37.  
NOTE: Do not tack–weld the bolts to the com-  
mutator cap before spin seasoning or resurfac-  
ing operations are performed.  
7. Refer to the “Test After Repair (Armature)” sec-  
tion for the test voltage, and perform a High–Po-  
tential test on the armature windings.  
Refer to following sections for instructions to spin  
season and resurface the commutator.  
Commutator Resurfacing  
Spin Seasoning  
(Commutator Assembled On Armature)  
Prior to turning or grinding the commutator, be cer-  
tain there is sufficient stock so the commutator will not  
be turned or ground below the minimum permissible di-  
ameter.  
A commutator seasoning cycle is required after com-  
mutator tightening operations have been performed.  
Refer to the DATA section for the minimum permissi-  
ble commutator diameter dimension.  
Prior to spin–seasoning, dynamically balance the ar-  
mature to within 12 grams on the commutator end and  
10 grams on the drive end. Refer to longitudinal section  
for balance weight locations (see Table 2 to determine  
the correct drawing).  
If the brush surface diameter will be less than the  
minimum permissible diameter after the resurfacing op-  
erations are performed, the commutator must be re-  
placed.  
Grinding  
To spin season the commutator, place the armature  
in a spin–seasoning stand and proceed as follows:  
1. Prior to grinding, true the shaft centers with re-  
spect to the bearing fits by scraping.  
1. Heat the commutator to 155–165_ C (312–330_  
F) in 60 minutes at 2940 rpm. Spin at 155–165_  
C (312–330_ F) for 60 minutes at 2940 rpm. Cool  
to 50_ C (122_ F) maximum in 30 minutes at  
2940 rpm.  
2. Place the armature in a lathe equipped with a  
grinding attachment or in a grinding machine.  
Check the concentricity of the bearing fits. The  
TIR should not exceed 0.001 in.  
2. Allow the commutator to cool, and grind cold.  
See “Commutator Resurfacing” section.  
3. Cover the armature windings to prevent entry of  
grinding dust and chips.  
39  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
MODELS  
SEE TABLE 2  
TO CHANGE MOTOR DIRECTION:  
TO RUN CCW VIEWED FROM COMMUTATOR END,  
CONNECT:  
F1 TO POSITIVE  
F2 TO NEGATIVE  
A1 TO POSITIVE  
A2 TO NEGATIVE  
TO RUN CW VIEWED FROM COMMUTATOR END,  
CONNECT:  
F1 TO NEGATIVE  
F2 TO POSITIVE  
A1 TO POSITIVE  
A2 TO NEGATIVE  
FIG. 22. CONNECTION DIAGRAM (41A237276 CHG. 0). E–39093A.  
4. Grind the commutator and check commutator  
2. Cover the windings to keep out chips.  
runout with a dial indicator. The maximum com-  
mutator runout is 0.001 in.  
3. Set the cutting tool for turning copper, and set  
lathe speed to give a commutator surface speed  
of 300 feet per minute. Refer to the DATA section  
for dust groove dimensions.  
5. Perform the undercutting, raking and polishing  
operations.  
4. Make clean, smooth cuts to remove just enough  
copper to renew the commutator surface. Do not  
allow the cutting tool to chatter.  
Turning  
If the surface of the commutator is badly worn,  
burned or scarred, turn the commutator in a lathe as fol-  
lows:  
5. After turning operations have been completed,  
check commutator runout with a dial indicator.  
The maximum runout is 0.001 in.  
1. True the shaft centers with respect to the bearing  
fits by scraping. Place the armature in a lathe and  
check the concentricity of the bearing fits. The  
TIR should not exceed 0.001 in.  
6. Perform the undercutting, raking and polishing  
operations.  
40  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
TO CHANGE MOTOR DIRECTION:  
TO RUN CCW VIEWED FROM COMMUTATOR END,  
CONNECT:  
F1 TO POSITIVE  
F2 TO NEGATIVE  
A1 TO POSITIVE  
A2 TO NEGATIVE  
TO RUN CW VIEWED FROM COMMUTATOR END,  
MODELS  
SEE TABLE 2  
CONNECT:  
F1 TO NEGATIVE  
F2 TO POSITIVE  
A1 TO POSITIVE  
A2 TO NEGATIVE  
FIG. 23. CONNECTION DIAGRAM (41A330278, CHG. 0). E–38055B.  
small cracks in the mica into which dirt or moisture may  
Undercutting  
accumulate and cause a breakdown in the insulation be-  
tween the commutator segments.  
See Fig. 28 for a diagram of proper undercut.  
With practice, hand–held power undercutters can be  
used. Follow the tool manufacturer’s instructions and  
A sharp hacksaw blade may be used but caution  
must be observed since a dull blade or saw produces  
41  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
I
O
S
O
O
I
I
N
S
#1  
#184  
#2  
#22  
#23  
O
EVERY BAR  
EQUALIZED  
I
N
N
#12  
I
O
#92  
N
S
#93  
#94  
I
I
A1  
A2  
O
O
S
O
I
F2  
F1  
VIEW AT COMMUTATOR END  
TO CHANGE MOTOR DIRECTION:  
TO RUN CCW VIEWED FROM COMMUTATOR END,  
CONNECT:  
F1 TO POSITIVE  
F2 TO NEGATIVE  
A1 TO POSITIVE  
A2 TO NEGATIVE  
TO RUN CW VIEWED FROM COMMUTATOR END,  
MODEL  
SEE TABLE 2  
CONNECT:  
F1 TO NEGATIVE  
F2 TO POSITIVE  
A1 TO POSITIVE  
A2 TO NEGATIVE  
FIG. 24. CONNECTION DIAGRAM (41A330179, CHG. A). E–37950A  
42  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
WARNING: When using compressed air for  
cleaning purposes, flying debris and particles  
may present a hazard to personnel in the im-  
mediate area. Personnel should be provided  
with, and trained in the use of, personal pro-  
tective equipment as specified by applicable  
federal or state safety regulations.  
Raking  
FIG. 25. COMMUTATOR TIGHTENING.  
E–4270B.  
Resurfacing usually leaves particles and slivers of  
copper hanging on the bar edges or lodged in the under-  
cut slots. These must be removed before the motor is  
placed in service, or the particles may bridge the side  
mica and cause a flashover.  
WARNING: During resurfacing operations,  
eye protection and a respirator should be  
worn to protect personnel from dust and fly-  
ing particles.  
1. Brush out dirt and copper whiskers attached to  
the trailing edge of the bars with a stiff–bristle  
brush; preferably one with nylon bristles. A new  
paint brush or stencil brush with the bristles cut  
short for added stiffness may also be satisfacto-  
ry. If stoning and undercutting have produced  
considerable dragging of copper from the edges  
of the bars, use a raking tool to remove the cop-  
per fins and ragged edges. Use the tool to rake  
the bar edges with the point inserted in the slot so  
that sides of the V rake the trailing edge of the  
bar. If the tool is ground with flat sides and used  
with moderate pressure as a raking tool, it will re-  
move ragged copper fins and break the sharp  
use slot guides and depth gauges for accurate, uniform  
cuts. Make a few practice passes over a scrap commu-  
tator to get the “feel” of the tool. Care must be taken to  
prevent the power undercutter from jumping out of the  
slot and across the commutator surface. The high–  
speed operation of the blade will quickly gouge the com-  
mutator.  
1. After a commutator has been resurfaced, the  
mica between the bars should be undercut to a  
depth of 0.047 in. Undercutting should be done  
with a sharp–edged tool with a cutting width of  
0.063 in.  
1
12  
5
2. Blow loose material off the commutator with dry,  
compressed air.  
8
9
3
4
7
10  
11  
6
2
FIG. 27. COMMUTATOR BOLT TIGHTENING  
SEQUENCE. E–4502.  
FIG. 26. COMMUTATOR PRESSING  
DIAMETER. E–18140  
43  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
edges of the bars. See Fig. 12 for an illustration  
of the tool. Another method of removing copper  
fins is to rake the slots with a piece of fiberboard  
approximately 0.045 in. thick.  
Used Armature  
Apply a high–potential test voltage of 2000 volts, 60  
Hz for one minute.  
Rewound Armature  
2. After slots have been raked with fiberboard or a  
raking tool, sand the commutator with fine sand-  
paper to remove small pieces of copper sticking  
from edges of slots.  
Apply a high–potential test voltage of 3500 volts, 60  
Hz for one minute.  
NOTE: Measure leakage current to ground dur-  
ing test 3–85.0 milliamps.  
3. Thoroughly clean the armature core and com-  
mutator with dry, compressed air to remove cop-  
per and dust.  
WARNING: Electric shock can cause serious  
or fatal injury. To avoid such injury, personnel  
should take and observe proper precautions  
during the high–potential testing.  
1. If the commutator is discolored or smudged, pol-  
ishing with canvas, crocus cloth, fine (4/0) sand-  
paper or 400A Triemite paper is usually suffi-  
cient.  
Resistance Measurement  
Abrasive paper should be mounted on a wooden  
block curved to fit the surface of the commutator.  
Refer to the DATA section for armature the resis-  
tance value and measure armature resistance.  
2. Blow loose material off the commutator with dry,  
compressed air.  
NOTE: Insulation Processing (Armature VPI)  
After the armature has been cleaned and re-  
paired or rewound, it must be vacuum pressure  
impregnated. See the Varnish Treatment, “Vac-  
uum Pressure Impregnation” section for fur-  
ther required processing of the armature.  
3. Check commutator concentricity with a dial indi-  
cator. Refer to the DATA section for runout limits.  
4. Cover the commutator with heavy paper or felt to  
protect it from damage.  
WARNING: Personal injury may result if prop-  
er eye protection is not worn when cleaning  
with compressed air.  
CAUTION: Never use an emery cloth on this or  
any commutator. The abrasive particles on  
emery cloth scratch the commutator surface  
and lodge in the grooves between commuta-  
tor segments. This condition creates the pos-  
sibility of an eventual flashover which could  
seriously damage the machine.  
A. MICA PROPERLY UNDERCUT.  
B. UNDERCUTTING TOOL TOO NARROW, LEAVING FIN  
AT ONE SIDE OF SLOT.  
C.UNDERCUTTING TOOL VERY NARROW, LEAVING  
FINS AT BOTH SIDES OF SLOT.  
D.SLOT IMPROPERLY INDEXED, PART OF BAR CUT  
AWAY AND FIN OF MICA LEFT.  
E. TOOL TOO WIDE, PART OF BAR CUT AWAY.  
F. UNDERCUTTING TOO SHALLOW, SERVICE LIFE  
SHORTENS BEFORE NEXT UNDERCUTTING.  
TEST AFTER REPAIR (Armature)  
High Potential Test  
G.UNDERCUTTING TOO DEEP, POCKET COLLECTS  
CARBON AND COPPER DUST, SHORT CIRCUITING  
BARS.  
FIG. 28. COMMON MISTAKES IN  
UNDERCUTTING COMMUTATOR SLOTS.  
E–5024A.  
Apply test voltage between the commutator (with all  
segments shorted) and the shaft.  
44  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
Remove the pole bolts and the coil–pole assem-  
bly from the magnet frame.  
MOTOR FRAME FIELD COIL  
REPLACEMENT  
3. Mark any shims for reassembly with the corre-  
sponding pole when the coil(s) is installed in the  
frame.  
Refer to Table 2, Page 20, to determine the correct  
coiled frame assembly drawing for the machine being  
repaired.  
Coil Installation  
Coil Removal  
Procedure for New Coil–Pole Assembly  
1. Remove terminal insulation and disconnect coil  
leads. Use a gas torch or brazing tongs to sepa-  
rate brazed connections. When using brazing  
tongs use low voltage and high a–c current to  
heat coil connections.  
NOTE: Install any exciting coils and braze their  
connections before installing commutating  
coils.  
1. Before installing any coil and pole, clean the pole  
contact surface on the frame and the pole piece  
mounting surface.  
WARNING: Safety glasses and leather gloves  
must be worn at all times during brazing oper-  
ations to protect personnel from physical  
harm.  
2. Install the new pole and coil in the frame with any  
shims that were on the damaged coil. Use new  
washers under bolt heads. Lubricate the bolt  
heads, threads and washers and draw the pole  
bolts moderately tight.  
NOTE: If a gas torch is used, coil insulation  
must be protected from heat by a non–flam-  
mable heat absorbent.  
3. Refer to Table 2, Page 20, to determine the cor-  
rect coiled frame assembly drawings. All coil  
connections must be brazed with silver solder,  
GE–B20A6. Use two pieces of solder (0.010 x 1  
in. x 1 in.) between terminal surfaces and braze  
terminals as follows:  
1. Pack absorbent around the insulation near  
the connection and over adjacent coils.  
2. Make sure all exposed insulation is covered  
with a thick layer of absorbent, then heat and  
separate the coil connections.  
2. Heat the coiled frame in an oven at 150_ C (302_  
F) for four hours to soften the varnish so pole  
bolts can be removed.  
45  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
15,16  
17  
15,  
16,  
17  
29  
37  
18,  
19  
APPLY ONE COAT OF P23  
15,  
16,  
17  
AFTER ALL P18 & P19 TAPINGS.  
11,  
45  
7
26  
9
24 SEE NOTE  
26  
5
2
4
10  
18,19  
6
D
15,16  
29  
VIEW AT Z OF  
BRUSH HOLDER  
CONNECTION  
3
28  
1
15,16  
E
10  
11,45  
A1  
30  
Z
13,50  
F2  
3
27  
E
13,50  
F1  
12,46  
A2  
62  
62  
22,  
49  
16,  
22,  
49  
2
8
31  
17,  
54  
1
33,  
35  
32,35,74  
FILL C’BORES  
WITH P25  
(24 PLACES)  
VIEW OF PINION END  
VIEW OF COMM. END  
21  
20  
INSULATE EXCITING & COMMUTATING FIELD COIL  
TERMINALS BY FILLING ALL CAVATIES & COVERING  
ALL BOLT HEADS WITH P24 THEN INSULATE ENTIRE  
TERMINALASSEMBLY WITH P18 & P19 AND THOROUGHLY  
BRUSH WITH P23.  
BEFORE ASSEMBLING  
CONNECTIONS INSULATE  
9 O’CLOCK CABLE SUPPORT  
AS SHOWN WITH P20 TAPED  
WITH P21 (COMM. END)  
15,  
16,  
17  
15,  
16,  
17  
1
18,  
19  
18,19  
9
2
5
7
4
24 SEE NOTE  
26  
D
29  
3
6
28  
1
15,16  
18,19,24,30  
11,47  
A1  
E
E
Y
10  
27  
31  
3
13,50  
F1  
12,48  
A2  
62  
62  
13,50  
F2  
33,35  
22,  
49  
2
8
32,35,74  
22,  
49  
10  
VIEW OF COMM. END  
VIEW OF PINION END  
37  
17  
15,16,18,19,24  
VIEW AT Y OF  
BRUSH HOLDER  
CONNECTION  
11,47  
15,16  
30  
FIG. 29. COILED FRAME ASSEMBLY (41D732353 CHG. N). E–39094A.  
46  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
ASSEMBLE FLUSH TO TOP OF INSIDE  
9
2,  
3
15  
16  
62  
+
WALL WITHIN .25 & TIGHEN UNTIL  
PLUG IS EXPANDED & TIGHT IN HOLE  
2,3  
17  
VIEW AT B ENLARGED (TYPICAL)  
17  
1
VIEW AT A ENLARGED (TYPICAL)  
P44 FOR PRESSURE SWITCH USAGE  
ON CONNECTION BOX SIDE ONLY.  
IF NO PRESSURE SWITCH IS  
REQUIRED, PLUG HOLE WITH P42  
41  
CONN. BOX  
42  
GROUND ARMOR WITH P52  
(G3 & G4 ONLY)  
VIEW AT D  
42,44  
42,44  
STAPLE  
10  
MAG. FRAME  
WALL  
SECTION C–C  
SIDE VIEW OF COMM. CHAMBER  
SHOWING PLUGS ON SIDE  
OPPOSITE CONNECTION BOX.  
SECTION E–E  
ATTACH BRUSH HOLDER CABLES  
AGAINST INSIDE WALL OF MAG. FRAME  
34,  
36  
38  
NOTE FOR P61: ATTACH MARKING BAND (P61) TO  
EACH END OF CABLE PTS. 11,12,13,45,46,47,48,  
50,56,57,58,64,65,67 & STAMP WITH APPROPRIATE  
MARKINGS AT ASSEMBLY.  
CARBON  
BRUSH  
37  
VIEW SHOWING  
BRUSH HOLDER ASSEMBLY  
MODELS  
SEE TABLE 2, PAGE 20  
LUBRICATE BOLTS  
TORQUE TABLE  
PART  
32–74  
33  
SIZE  
TORQUE LB.–FT.  
900–1000  
1.25–7  
1.25–12  
.875–9  
435–483  
34  
115–125  
FIG. 29. COILED FRAME ASSEMBLY (41D732353 CHG. N). E–39094A.  
47  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
8,60  
11,13  
50  
VIEW AT Z OF  
BRUSH HOLDER  
CONNECTION  
18  
24 SEE NOTE  
7
6
11,13  
33  
2,  
26  
16,  
17  
7
3
1
5
25 SEE NOTE  
28  
6
2
4
11,  
13  
50  
58  
FILL C’BORES  
22  
36  
22  
WITH P25  
13,18,66  
37  
(24 PLACES)  
Z
57  
F
48  
9 A2,  
61  
6
12,14,15  
F
22  
59  
18  
75  
8 A1,  
60  
10 F1  
45 F2  
+
.19  
.06  
7
21,64  
39,  
41  
49  
46  
38,41,76  
B
FILL C’BORES  
WITH P25  
(24 PLACES)  
A
35  
75  
D
51  
VIEW OF COMM. END  
VIEW OF PINION END  
30  
ASSEMBLE FLUSH TO TOP OF  
INSIDE WALL WITHIN .25  
+
AND TIGHTEN UNTIL PLUG IS  
75  
ENLARGED VIEW AT B  
EXPANDED AND TIGHT IN HOLE  
75 ASSEMBLE FLUSH TO TOP OF  
+
.19  
.06  
INSIDE WALL WITHIN .25  
+
AND TIGHTEN UNTIL PLUG IS  
EXPANDED AND TIGHT IN HOLE  
29  
ENLARGED VIEW AT D  
31  
30  
32  
.12  
75  
ENLARGED VIEW AT A  
11,  
13  
2,  
26  
24 SEE NOTE  
7
16,  
17  
5
25 SEE NOTE  
28  
1
3
28  
7
50  
6
E
58  
22  
36  
57  
37  
59  
Y
F
4
6
22  
49  
F
11,  
13,  
18  
22  
16,17,24,48  
12,14,15  
75  
8 A1,  
62  
D
10 F1  
39,41  
9 A2,  
63  
B
45 F2  
38,41,76  
VIEW OF PINION END  
35  
46  
21,  
64  
A
7
VIEW OF COMM. END  
11,13  
6
18  
38  
NOTE FOR P74:  
VIEW AT Y OF  
BRUSH HOLDER  
CONNECTION  
11,13  
8,62  
ATTACH MARKING BAND (P74) TO EACH END  
OF CABLE PTS. 8,9,60,61,62,63,68,69,76,77,78,  
81,82,83. STAMP WITH APPROPRIATE MARKING  
AT ASSEMBLY.  
48  
11,13  
FIG. 30. COILED FRAME ASSEMBLY (41D732345 CHG. V). E–39095A.  
48  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
MAG. FRAME  
WALL  
12  
7,10,45  
STAPLE  
COIL TERM.  
OR  
CABLE TERM.  
19  
20  
22  
BEFORE ASSEMBLING  
CONNECTIONS, INSULATE  
6
CABLE SUPPORTS AS SHOWN  
WITH P19 TAPED WITH P20  
(COMM. END)  
15  
14  
SECTION F–F  
VIEW SHOWING METHOD  
OF CONNECTING SHUNT  
CABLES.  
VIEW SHOWING METHOD  
OF ASSEMBLING CABLES  
THRU STAPLES.  
ATTACH BRUSH HOLDER  
CABLES AGAINST INSIDE  
WALL OF MAG. FRAME.  
(PINION END)  
54  
P27 FOR PRESSURE SWITCH  
USAGE ON OPPOSITE SIDE  
ONLY, IF NO PRESSURE SWITCH  
REQUIRED PLUG HOLE WITH P51  
51  
C
C
SECTION C–C  
27,  
51  
SIDE VIEW OF COMM. CHAMBER  
SHOWING PLUGS OPPOSITE SIDE  
OF CONNECTION BOX.  
40,  
42  
34  
CARBON  
BRUSH  
33  
VIEW SHOWING BRUSH HOLDER ASSEMBLY  
NOTE FOR P10 AND P15:  
INSTALL P10 AND P45 WITH LARGER  
TERMINAL ON EXC. COIL CONNECTION.  
NOTE FOR P52 AND P53:  
INSTALL P52 AND P53 ON CONNECTION  
BOX END OF P10 AND P45.  
60,  
63  
CONNECTION  
61,64  
BOX  
A2  
A1  
VIEW AT E  
GROUND A1 AND A2  
CABLES WITH P65  
(G3 AND G4)  
MODELS  
SEE TABLE 2, PAGE 20  
FIG. 30. COILED FRAME ASSEMBLY (41D732345 CHG. V). E–39095A.  
49  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
TORQUE TABLE  
PART  
4
SIZE  
TORQUE LBS.–FT.  
1.25–12  
1.25–7  
.875–9  
.4375–14  
.25–20  
435–483  
900–995  
240–260  
25–35  
6
21  
23  
28  
6–8  
1  
MODELS  
SEE TABLE 2, PAGE 20  
NOTE FOR PARTS 37,38,39:  
INSULATE EXCITING AND COMMUTATING FIELD COIL TERMINALS BY FILLING ALL CAVITIES  
AND COVERING ALL BOLT HEADS WITH P37 THEN INSULATE ENTIRE TERMINAL ASSEMBLY  
WITH 1T–1/2 L. OF P38 AND 1T–1/2 L. OF P39.  
NOTE FOR P40:  
ASSEMBLE P40 FLUSH TO TOP OF INSIDE WALL OF MAGNET FRAME WITHIN .25 AND  
TIGHTEN UNTIL PLUG P40 IS EXPANDED AND TIGHT IN HOLE (1–PLACE SEE ENLARGED VIEW  
@ ”A”).  
V.P.I. COILED FRAME, ONE COAT STATIONARY BAKE, FOLLOWED BY ONE SPRAY COAT ON  
THE COMM. CHAMBER.  
FIG. 31. COILED FRAME ASSEMBLY (41D735440, CHG. A). E–38056B  
50  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
REF.  
1
4
5
6
7
8
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
DESCRIPTION  
MAGNET FRAME  
BOLT(NON–MAGNETIC), 1 1/4–12X4  
HARD WASHER, 1 1/4  
BOLT, 1 1/4–7X3 3/4  
EXCITING COIL AND POLE  
BUSHING  
CABLE  
CABLE  
CABLE  
CABLES  
CABLES  
CABLE  
CABLE  
MARKER  
MARKER  
TAG  
BRUSHHOLDER ASSEMBLY  
BRUSHHOLDER SUPPORT  
BOLT, 7/8–9X3 1/4  
LOCKWASHER, 7/8  
REF.  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
DESCRIPTION  
BOLT, 7/16–14X1  
LOCKWASHER, 7/16  
BRAZING STRIP, 1X1  
BRAZING ROD  
PIPE PLUG, 1/2 NPT  
BOLT/WASHER, 1/4–20X1/2  
BELL WASHER, 1/4  
NUT, 1/4–20  
REDUCER  
FITTING  
SEALER #1473, SILMATE  
PAD  
PAD  
TWINE  
PUTTY  
1ST TAPING  
2ND TAPING  
PLUG  
COMMUTATOR POLE AND COIL  
FIG. 31. COILED FRAME ASSEMBLY (41D735440, CHG. A). E–38056B.  
51  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
FILL C’BORES WITH P31  
(12–PLACES)  
38  
36,  
38  
38  
15  
13,  
14  
7,10  
17  
16  
22,  
23 FOR FILLETS  
8–PLACES  
1,39  
12  
CARBON  
BRUSH  
8,9  
TYPICAL  
8,9  
20,  
21  
11  
11  
20,21  
38  
11  
11  
20,  
21  
VIEW SHOWING BRUSH  
HOLDER ASSEMBLY  
(COMMUTATOR END)  
36,38  
37,38  
24  
11  
20,21  
18  
8,9  
32  
38  
A1  
24  
32  
19  
A2  
38  
15 8,  
9
36,  
38  
38  
1,  
39  
1,39  
COMMUTATOR END  
22,  
23 FOR FILLETS  
8–PLACES  
TYPICAL  
28  
25  
FILL C’BORES WITH P31  
(12–PLACES)  
6,  
7
28  
.09 MIN. TYP.  
26  
SIDE VIEW OF COMMUTATOR  
CHAMBER SHOWING PIPE PLUG  
LOCATIONS (BOTH SIDES)  
2,  
4,  
5
3,4,5  
3,4,5  
2,  
4,  
5
24  
29  
32  
28  
F2  
24  
F1  
29  
1,  
39  
32  
PINION END  
FIG. 32. COILED FRAME ASSEMBLY (41D735343, CHG. C). E–37951C  
52  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
REF.  
1
2
3
4
5
6
7
8
DESCRIPTION  
MAGNET FRAME  
EXCITING COIL  
EXCITING COIL  
EXCITING POLE  
SPRING COLLAR  
BOLT 1 1/4–7 X 3 3/4  
HARDENED WASHER 1 1/4  
COMMUTATING COIL  
COMMUTATING POLE  
BOLT 1 1/4–12 X 4  
BRUSH HOLDER ASSEMBLY  
BRUSH HOLDER SUPPORT  
BOLT 7/8–9 X 3 1/4 N22P37052  
LOCKWASHER 7/8 N405P49P  
CABLE  
REF.  
20  
21  
22  
23  
24  
25  
26  
28  
29  
31  
32  
33  
34  
35  
36  
37  
38  
39  
DESCRIPTION  
BOLT 7/16–14 X 1 N22P27016B13  
LOCKWASHER 7/16 N405P44P  
BRAZING STRIP 1 X 1  
ROD  
BUSHING  
PIPE PLUG 1/2 NPT N5700P51  
PIPE PLUG 3/4 NPT N5700P63  
CONNECTION STRAP  
CABLES  
SEALER NO. 1473 SILMATE 497A806P60  
TAG  
PUTTY 41A239176P443  
1 ST TAPING 41D735343P34  
2 ND TAPING 41D735343P35  
PAD  
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
CABLE  
CABLE  
CABLES  
CABLES  
PAD  
CORD 41D735343P38  
MAGNET FRAME  
TORQUE TABLE  
PART  
6
10  
13  
20  
SIZE  
TORQUE LBS. FT.  
900–995  
1.25–7  
1.25–12  
.875–9  
.4375–14  
435–483  
240–260  
+
5
30  
NOTE FOR PTS. 33, 34, AND 35  
INSULATE EXCITING AND COMMUTATING FIELD COIL TERMINALS BY  
FILLING ALL VAVITIES WITH P33 THEN INSULATE ENTIRE TERMINAL  
ASSEMBLY WITH 2T–1/2L. OF P34 AND 2T–1/2L. OF P35.  
V.P.I. COILED FRAME ONE COAT. STATIONARY BAKE, SPRAY PAINT  
THE COMMUTATOR CHAMBER INNER SURFACES AND THE FRAME  
EXTERIOR. DO NOT SPRAY THE EXCITING AND COMMUTATING COILS.  
MODELS  
SEE TABLE 2, PAGE 20  
FIG. 32. COILED FRAME ASSEMBLY (41D735343, CHG. C). E–37951C  
53  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
NOTE: If a gas torch is used, coil insulation  
must be protected from heat by a non–flam-  
mable heat absorbent.  
Machine Brazing  
1. The recommended brazing current is 10,800  
amperes at 1.6 volts. With silver–solder brazing  
strips inserted between connections, clamp the  
brazing tongs on the connection and braze the  
joint. If necessary, add additional solder to fill the  
joint and form a level surface.  
1. Pack absorbent around the insulation near  
the connection and over adjacent coils.  
2. Make sure all exposed insulation is covered  
with a thick layer of absorbent, then heat and  
separate the coil connections.  
2. Braze all exciting–coil connections before install-  
ing the commutating coils.  
2. Heat the coiled frame in an oven at 150_ C (302_  
F) for four hours to soften the varnish so pole  
bolts can be removed.  
Gas Torch Brazing  
1. Pack the coil insulation with non–flammable heat  
absorbent material; e.g., interwoven glass cloth.  
Remove the pole bolts and the coil–pole assem-  
bly from the magnet frame.  
2. Insert the brazing strips and use a C–clamp or vi-  
se–grip pliers to clamp the connection surfaces  
tightly together.  
3. Mark any shims for reassembly with the corre-  
sponding pole when the coil(s) is installed in the  
frame.  
3. Use a torch tip with a 0.1 in. orifice and adjust the  
torch to obtain a slightly reduced flame. As the  
brazing strips melt, add more solder to fill the  
joint and form a level surface.  
Coil Installation  
Procedure for New Coil–Pole Assembly  
4. Remove heat absorbent packing from insulation.  
Use dry, compressed air and blow out the inside  
of the frame.  
NOTE: Install any exciting coils and braze their  
connections before installing commutating  
coils.  
WARNING: Personal injury may result if prop-  
er eye protection is not worn when cleaning  
with compressed air.  
1. Before installing any coil and pole, clean the pole  
contact surface on the frame and the pole piece  
mounting surface.  
5. Torque the pole bolts to the values listed in Table  
3, Page 37, Standard Bolt Torque Values.  
2. Install the new pole and coil in the frame with any  
shims that were on the damaged coil. Use new  
washers under bolt heads. Lubricate the bolt  
heads, threads and washers and draw the pole  
bolts moderately tight.  
6. Check the polarity of the field poles:  
Energize the field circuit with a battery and check  
pole polarity with a compass, Fig. 33.  
3. Refer to Table 2, Page 20, to determine the cor-  
rect coiled frame assembly drawings. All coil  
connections must be brazed with silver solder,  
GE–B20A6. Use two pieces of solder (0.010 x 1  
in. x 1 in.) between terminal surfaces and braze  
terminals as follows:  
7. Insulate the connections with silicone putty and  
wrap connections with Mylar film (30). Apply  
glass tape and extend each taping 1/2 in. beyond  
the bare area of the connection. Brush the con-  
nections with air–drying alkyd varnish GE–8001.  
8. Install and connect any cables previously re-  
moved.  
Brazing Coil Terminals  
NOTE: Do not flood–dip the coiled frame before  
the cables are installed and the connections are  
insulated.  
Braze the coil terminals by one of the following meth-  
ods:  
54  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
TABLE 4  
Flood Dipping Coiled Frame  
VARNISH VISCOSITY CHART FOR  
DIPPING COILED FRAME  
After field coils have been repaired or replaced and  
electrical tests completed, insulate the coiled frame by  
flood dipping in GE–8001 varnish. See Table 4, Page  
55, for varnish viscosity limits.  
NOTE: When necessary, use Solvesso No. 100 to thin var-  
nish.  
GE NO. 8001 VARNISH  
NO. 3 ZAHN CUP  
Varnish may be thinned, as necessary, with Solves-  
so* No. 100 thinner. Agitate varnish for 15 minutes be-  
fore dipping frame.  
70  
60  
50  
40  
30  
20  
10  
0
1. Be sure all coil connections are made and insu-  
lated, and all cables and ties for cables and con-  
nection straps are in place. Tie cable ends above  
the varnish level.  
2. Coat all machine–fit surfaces with GE–271 black  
varnish or stripping compound and plug bolt  
holes with dummy bolts.  
3. Heat the coiled frame to 40–80_ C (104–176_ F)  
and dip the frame drive end down (with all coil  
connections covered) for at least 15 seconds.  
Drain and remove the frame from the varnish. Al-  
low the frame to drain for at least 5 minutes in a  
vertical position, drive end down.  
4. Bake the frame in a pre–heated oven at 150_ C  
(302_ F) for 30 minutes, minimum.  
5. Clean the varnish from machined surfaces and  
unplug the tapped holes.  
0
10  
20  
30  
40  
50  
60  
TEMP. DEGREES C  
TEST AFTER REPAIR  
(Coiled Frame Without Armature)  
1. Pass 24.0 amperes(60 Hz current) through the  
exciting (series) field and read the voltage drop.  
Minimum Volts . . . . . . . . . . . . . . . . . . . . . . 13.1  
Maximum Volts . . . . . . . . . . . . . . . . . . . . . . 15.6  
2. Pass 24.0 amperes (60 Hz current) through the  
commutating (CP) field and read the voltage  
drop.  
For Non–Magnetic retainers:  
FIG. 33. FIELD COIL POLARITY CHECK. E–888A.  
*Standard Oil Co. of Pa.  
55  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
Minimum Volts . . . . . . . . . . . . . . . . . . . . . . . 7.3  
Maximum Volts . . . . . . . . . . . . . . . . . . . . . . . 8.5  
For Magnetic retainers:  
Varnish Immersion Treatment After VPI  
(Armature)  
The following immersion process must be performed  
on the armature assembly after the VPI process.  
Minimum Volts . . . . . . . . . . . . . . . . . . . . . . . 0.7  
Maximum Volts . . . . . . . . . . . . . . . . . . . . . . 12.4  
1. Preheat the armature in an oven at 140_ C for at  
least five hours.  
High–Potential Test  
2. The temperature of the armature must not be  
less than 90_ C, or above 120_ C, before im-  
mersing. Immerse the armature in a vertical po-  
sition (commutator end up) in the varnish (GE  
Spec. No. A15B53A) for at least one minute.  
Frame With Used Coils  
Apply a high–potential test voltage of 2000 volts, 60  
Hz for one minute.  
NOTE: One minute is the minimum time to in-  
sure adequate varnish penetration.  
Frame With All New Coils  
Apply a high–potential test voltage of 3500 volts, 60  
Hz for one minute.  
3. Lift the armature out of the varnish and spin until  
the excess varnish is removed. Clean the shaft  
with Xylene (GE Spec. No. D5B9).  
Measure leakage current to ground during this test.  
5.0 milliamps is maximum.  
4. Bake at 140_ C in an oven for at least eight  
hours.  
WARNING: Electric shock can cause serious  
or fatal injury. To avoid such injury, personnel  
should take and observe proper precautions  
during the high–potential testing.  
BALANCING ARMATURE  
Refer to the appropriate longitudinal section (see  
Table 2, Page 20, to determine the correct drawing) for  
balance weight locations. Dynamically balance the ar-  
mature within 10 grams (0.35 oz.) on the drive end and  
12 grams (0.42 oz.) on the commutator end by adding  
weights on the commutator cap and the armature head.  
Resistance Measurement  
Refer to the DATA section for values and measure  
the resistance of the exciting and commutating fields.  
VARNISH TREATMENT (ARMATURE)  
Vacuum Pressure Impregnation (VPI)  
REASSEMBLY  
Brushholders  
After all repairs have been completed, the armature  
must be vacuum pressure impregnated in GE–702C  
polyester varnish.  
1. Using a bolt and washer, attach the brushholder  
clamp to the frame mount. Position the studs of  
the brushholder in the clamp, and move the  
brushholder radially outward as far as possible.  
Refer to GEK–101183 for VPI procedure.  
Following the VPI processing, the armature must be  
given a varnish immersion treatment.  
2. Tighten the brushholder clamp bolt but do not  
torque. Install all brushholders.  
NOTE: Do NOT clean previously protected ma-  
chined surfaces, threads and tapped holes be-  
fore varnish treating the armature.  
3. Connect the brushholder cables. Refer to Table  
2, Page 20, to determine the correct connection  
diagram.  
56  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
13. Assemble the grease tubes to the inner bearing  
cap:  
Armature Bearings  
NOTE: Parts that will be shrink–fitted should be  
heated in an oven and assembled hot. Make  
sure shrink–fitted parts are tight against adja-  
cent parts after they have cooled.  
a. On UP1 and AUP1 models, there are two  
grease tubes, assembled to the inner bearing  
cap and protrude through a hole in the frame.  
b. On UP2 and AUP2 models, there is one  
grease tube, assembled to the inner bearing  
cap and protrudes through a hole in the  
frame.  
Drive–End Bearing  
(Figs. 34, 35, 36 and 37)  
c. On all other models, there is one grease tube  
assembled to the inner bearing cap and pro-  
trudes through a hole in the framehead.  
1. Place the armature in a saddle.  
2. If the inner sleeve was removed, heat it to 110_ C  
(230_ F) and shrink it tight on the shaft against  
the shoulder.  
14. Pack 4.8 oz. of grease in the outer circumference  
of the outer bearing cap and install the bearing  
cap to the framehead. Secure the assembly with  
bolts and lockwashers. Torque to the appropriate  
value in Table 3, Page 37.  
3. Spread 0.5 oz. of grease onto the seals on the  
inner and outer bearing caps and the inner  
sleeve.  
Commutator–End Bearing  
4. Pack 4.8 oz. of grease in the outer circumference  
of the inner bearing cap as shown by the shaded  
area in the bearing cap.  
(All Models Except US2, UP6, AUT2 and AUP5)  
Refer to Fig. 38.  
5. Install the inner bearing cap on the sleeve.  
1. Clean and inspect the bearing and the shaft  
bearing fit. Remove nicks and burrs.  
6. Heat and install the flinger tight against the  
sleeve.  
2. If sleeve (16) was removed, heat it to 110_ C  
(230_ F) and shrink it tight onto the shaft against  
the shoulder.  
7. Heat and install the inner race of the roller bear-  
ing tight against the flinger.  
8. Install the outer race of the bearing in the  
framehead.  
3. Pack 5.25 oz. grease into the outer circumfer-  
ence of the cavity of bearing housing (8).  
9. Fill the roller bearing completely with 29.0 oz. of  
grease.  
4. Heat bearing housing (8) in an oven to 100_ C  
(212_ F). While hot, assemble ball bearing (3)  
into the housing firmly against the shoulder at the  
bottom of the bearing fit.  
10. Install the gasket onto the inner bearing cap.  
11. Install guide pins into the inner bearing cap to  
guide the framehead into position.  
5. Fill all voids in the ball bearing completely with  
approximately 20.8 oz. of grease, Fig. 38. Smear  
0.5 oz. of grease on the bearing housing and the  
bearing cap seals.  
12. Assemble the framehead/bearing assembly  
onto the shaft, over the guide pins until seated  
against the bearing cap. Remove the guide pins.  
6. Heat the bearing and housing assembly in an  
oven to 100_ C (212_ F). While hot, assemble it  
onto the shaft, with the inner race tight against  
sleeve (16).  
NOTE: Orient the inner bearing cap on UP, AUP,  
US and AUT models to facilitate grease tube as-  
sembly.  
57  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
SMEAR 0.50 OZ. OF  
GREASE  
ON GREASE SEALS.  
MODELS  
SEE TABLE 2, PAGE 20  
FIG. 34. DRIVE–END BEARING ASSEMBLY. E–18166E.  
NOTE: Do not heat the bearing and housing as-  
sembly above 100_ C (212_ F). Higher tempera-  
tures may cause the oil to “bleed” from the  
grease.  
7. Heat spacer (9) to 110_ C (230_ F) and shrink it  
onto the shaft tight against the inner race of ball  
bearing (3).  
58  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
MODELS  
SEE TABLE 2, PAGE 20  
FIG. 35. DRIVE–END BEARING ASSEMBLY. E–39301.  
The bearing assembly will be completed when the  
armature is assembled into the frame.  
2. If sleeve (13) was removed, heat it to 110_ C  
(230_ F) and shrink it tight onto the shaft against  
the shoulder.  
Commutator–End Bearing  
3. When sleeve (13) has cooled, assemble a new  
seal ring (5) onto the sleeve, oriented as shown  
in Fig. 40.  
(Models US2, UP6, AUT2 and AUP5)  
Refer to Fig. 39.  
1. Clean and inspect the bearing and the shaft  
bearing fit. Remove nicks and burrs.  
4. Pack 5.20 oz. grease into the outer circumfer-  
ence of the cavity of bearing housing (8).  
59  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
14 ASSEMBLED TO EITHER P13  
OR P17, DEPENDING ON MODEL.  
13 NOT INCLUDED ON ALL MODELS  
12 NOT INCLUDED ON ALL MODELS  
16,21  
APPLY P15 TO THREADS  
AT BOTH ENDS OF P12  
19  
18  
17  
2
2
20 USE IF NECESSARY TO  
ADJUST FOR PROPER  
NOT INCLUDED ON  
ALL MODELS  
4,5  
ASSEMBLY OF PARTS  
17, 18 AND 19  
24  
23  
TORQUE TO  
110–120 FT. LBS.  
3
22 FILL BEARING COMPLETELY  
WITH 29 OZ. OF P7  
6
USE 4.8 OZ. OF  
P7 IN EACH CAVITY  
SMEAR .5 OZ. OF  
P7 ON SEALS  
MODELS  
SEE TABLE 2, PAGE 20  
REF.  
1
2
3
4
5
6
7
DESCRIPTION  
FRAME HEAD  
GASKET  
REF.  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
DESCRIPTION  
LOCK–TITE 497A806P36  
FRAME HEAD  
FITTING 90 ELBOW  
FITTING 90 ELBOW  
FITTING BULKHEAD  
WASHER 9/16 N402P46B13  
FRAME HEAD  
BEARING CAP  
LOCKWASHER 5/8 N405P47P  
BOLT 5/8–11 X 3 1/2 N22P33056  
SLEEVE  
GREASE  
PIPE 1/4 X 6 IN.  
12  
13  
14  
ROLLER BEARING  
BEARING CAP  
FLINGER  
COUPLING 1/4 NPT  
PIPE PLUG 1/4 N5700P31  
FIG. 36. DRIVE–END BEARING ASSEMBLY (41B537821, CHG. B). E–37952B  
60  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
5. Heat bearing housing (2) in an oven to 100_ C  
(212_ F). While hot, assemble nilos ring (4) (ori-  
ented as shown in Fig. 40), and the ball bearing  
(3) into the housing firmly against the shoulder at  
the bottom of the bearing fit.  
8. Heat spacer (6) to 110_ C (230_ F) and shrink it  
onto the shaft tight against the inner race of ball  
bearing (3).  
The bearing assembly will be completed when the  
armature is assembled into the frame.  
6. Fill all voids in the ball bearing completely with  
approximately 20.8 oz. of grease. Smear 0.5 oz.  
of grease on the bearing housing and bearing  
cap seals, and on the seal ring wear surface on  
the nilos ring (4).  
Armature Assembly Into Frame  
Models UP and AUP  
Refer to Fig. 15.  
1. Assemble the brushholders into the frame. Move  
them well back from commutator to avoid inter-  
ference when installing the armature. Fasten  
and insulate the connections and install outgoing  
cables.  
7. Heat the bearing and housing assembly in an  
oven to 100_ C (212_ F). While hot, assemble it  
onto the shaft, with the inner race tight against  
sleeve (13).  
2. Block and level the frame in a vertical position,  
commutator–end down, on a heavy duty stand.  
Be sure there is clearance for the commutator–  
end shaft extension when the armature is low-  
ered into the frame.  
CAUTION: Be sure that the nilos ring is assembled  
over sleeve (13), not pinched between the sleeve  
and the bearing.  
3. Install three guide studs in the commutator–end  
bearing housing bolt circle to guide the housing  
into the framehead fit.  
NOTE: Do not heat the bearing and housing as-  
sembly above 100_ C (212_ F). Higher tempera-  
tures may cause the oil to “bleed” from the  
grease.  
4. Pack 5.25 oz. of grease in the outer circumfer-  
ence of bearing cap (4).  
5. Lift the armature with the hoist and lifting bail at  
the drive end. Line up the hoist directly over the  
center of the cavity in the frame.  
DIAL INDICATOR  
OUTER BEARING  
POINTER RESTS  
RACE WITH  
AGAINST OUTER  
BEARING RACE  
ROLLERS  
6. Lower the armature slowly into the frame, being  
careful not to damage the commutator. When  
the armature is almost fully inserted, use the  
guide studs to align bearing housing (46) and  
framehead bolt holes (56). (Position the bearing  
cap to accommodate the grease tubes in UP1  
and AUP1 models.)  
SUPPORT FOR  
INDICATOR ON  
ARMATURE SHAFT  
7. When the armature has reached its limit of travel,  
remove the guide studs and install bearing cap  
(4) with a new gasket (57) using bolts and wash-  
ers (52). Draw the bearing housing into  
framehead (56). Torque bolts to 105–115 ft.lbs.  
INNER BEARING  
FRAMEHEAD  
RACE  
FIG. 37. CHECK ALIGNMENT OF BEARING  
AFTER ASSEMBLY. A–120402.  
61  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
MODELS  
SEE TABLE 2, PAGE 20  
FIG. 38. COMMUTATOR–END BEARING ASSEMBLY (41B532745 CHG. F). E–39090A.  
8. Install framehead bolts (10) and lockwashers  
(12). Torque to 440–495 lb.–ft.  
ing cap so that they protrude through a hole in  
the frame. Seal around the grease tubes at  
their hole in the frame with RTV.  
CAUTION: Alternate tightening of commu-  
tator–end bearing housing and drive–end  
framehead bolts. Uneven tightening of bolts  
could damage bearings or related fitted sur-  
faces.  
b. On UP2 and AUP2 models, one grease tube  
is required. The procedure is the same as in-  
dicated in Step 9a.  
c. On all other models, one grease tube is re-  
quired. This tube connects the inner bearing  
cap with the framehead, and should have  
been assembled with the drive–end bearing  
assembly.  
NOTE: Be sure framehead bolt holes are  
aligned with bolt holes in inner bearing cap be-  
fore assembling bolts (10) and lockwashers  
(12).  
9. Install grease tubes at the drive end:  
NOTE: Insure that all grease tubes are packed  
full of grease.  
a. On UP1 and AUP1 models, two grease tubes  
are required. Clean all residual sealing RTV  
from the grease tube clearance hole in the  
frame. Then, reach into the cavity of the ma-  
chine, around the drive–end inner bearing  
cap (51), and install these tubes to the bear-  
10. Use a feeler gauge and check the radial clear-  
ance on the drive–end bearing between each  
bearing roller and the inner race, at the top of the  
bearing, Fig. 40. Place the feeler gauge between  
the top roller and the inner race.  
62  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
REF.  
1
2
3
4
DESCRIPTION  
FRAME HEAD  
BEARING HOUSING  
BALL BEARING  
NILOS RING  
2
5
6
7
SEAL RING  
SPACER  
SLEEVE  
8
9
10  
11  
12  
13  
BEARING CAP  
BOLT, 5/8-11 X 2 3/4 N22P33044  
LOCKWASHER, N405P47B13  
GREASE  
GASKET  
SLEEVE  
4
5
13  
1
MODELS  
US2, UP6, AUT2 AND AUP5  
APPLY NALCO RC TO BORE  
OF P7 AND SHAFT  
o
o
HEAT P7 TO 180 C. (356 F)  
RISE AND ASSEMBLE AS SHOWN  
12  
REFER TO ASSEMBLY INSTRUCTIONS  
FOR DETAILS  
9,10  
8
FILL BEARING COMPLETELY  
WITH 20.8 OZ. OF P11  
2
3
USE 5.2 OZ. OF P11  
IN THIS CAVITY  
USE 5.2 OZ. OF P11  
IN THIS CAVITY  
4
7
6
13  
5
SMEAR 0.80 OZ. OF P11 ON GREASE  
SEALS AND SEAL SURFACE  
FIG. 39. COMMUTATOR-END BEARING ASSEMBLY (41B538068 CHG. 0). E-39300.  
63  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
17. At the commutator end, smear the seals on bear-  
ing cap (4) and sleeve (42) with grease.  
OUTER BEARING  
RACE WITH  
ROLLERS  
NOTE: Prior to heating sleeve (42), apply NAL-  
CO RC* “Rail Conditioner” to the inside diame-  
ter of the sleeve and to the mating surface on  
the shaft. Apply the NALCO with a Scott–150  
white paper towel only and allow it to dry to a  
thin white film on both surfaces before pro-  
ceeding with Step 18.  
BEARING  
CAGE  
18. Heat sleeve (42) to 180_ C (356_ F) rise and  
shrink it onto the shaft tight against the spacer  
(43).  
FEELERS  
19. Assemble the grease tubes to the bearing cap  
(4) (UP1 and AUP1 models only). Install pipe  
plugs in tubes and tube fittings as indicated in  
Fig. 15.  
SHAFT  
NOTE: Insure that grease tubes are packed full  
of grease.  
INNER BEARING  
RACE  
Armature Assembly Into Frame  
FRAMEHEAD  
Models US1, AUT  
FIG. 40. CHECKING INTERNAL CLEARANCE OF  
BEARING. A-120403.  
Refer to Fig. 18.  
1. Assemble the brushholders into the frame. Move  
them well back from the commutator to avoid in-  
terference when installing the armature. Fasten  
and insulate the connections and install outgoing  
cables.  
11. The clearance between the rollers and the inner  
race should measure between 0.0012 and 0.004  
in. Try various gauge thicknesses until clearance  
can be determined by the feel of the gauge as the  
gauge is slowly pulled from between the roller  
and the inner race.  
2. Block and level the frame in a vertical position,  
commutator–end down, on a heavy duty stand.  
Be sure there is clearance for the commutator–  
end shaft extension when the armature is low-  
ered into the frame.  
12. Pack 4.8 oz. of grease in the outer circumference  
of outer bearing cap (5).  
13. Install a new gasket (54) and bearing cap (5) with  
bolts and lockwashers (53).  
3. Install three guide studs in the commutator–end  
bearing housing bolt circle to guide the housing  
into the framehead fit.  
14. Smear seals on bearing cap (5) and sleeve (47)  
with grease.  
4. Pack 5.25 oz. of grease in the outer circumfer-  
ence of bearing cap (8).  
15. Heat sleeve (47) to 110_ C (230_ F) rise and  
shrink it onto the shaft tight against the roller  
bearing inner race (48).  
5. Lift the armature with the hoist and lifting bail at  
the drive end. Line up the hoist directly over the  
center of the cavity in the frame.  
16. Seal the grease tubes which protrude through  
the hole in the frame with RTV–108.  
*Product of NALCO Chemical Co.  
64  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
6. Lower the armature slowly into the frame, being  
careful not to damage the commutator. When  
the armature is almost fully inserted, use the  
guide studs to align bearing housing (3) and  
framehead bolt holes (14).  
15. Finish the assembly of grease tube fittings and  
washer (27) where it passes through the  
framehead. Tighten all fittings and hardware.  
16. At the commutator end, smear the seals on bear-  
ing cap (8) and sleeve (6) with grease.  
7. When the armature has reached its limit of travel,  
remove the guide studs and install bearing cap  
(8) with a new gasket (11) using bolts and wash-  
ers (10). Draw the bearing housing into  
framehead (14). Torque bolts to 110–120 ft.lbs.  
NOTE: Prior to heating sleeve (6), apply NALCO  
RC “Rail Conditioner” to the inside diameter of  
the sleeve and to the mating surface on the  
shaft. Apply the NALCO with a Scott–150 white  
paper towel only and allow it to dry to a thin  
white film on both surfaces before proceeding  
with Step 18.  
8. Install framehead bolts and lockwashers(30).  
Torque to 440–495 lb.–ft.  
17. Heat sleeve (6) to 180_ C (356_ F) rise and  
shrink it onto the shaft tight against the spacer  
(5).  
CAUTION: Alternate tightening of commu-  
tator–end bearing housing and drive–end  
framehead bolts. Uneven tightening of bolts  
could damage bearings or related fitted sur-  
faces.  
18. Install pipe plugs in grease tubes and tube fit-  
tings as indicated in Fig. 18.  
NOTE: Insure that grease tubes are packed full  
of grease.  
NOTE: Be sure drive–end framehead bolt holes  
are aligned with holes in inner bearing cap be-  
fore assembling bolts and lockwashers (30).  
BRUSHHOLDER CLEARANCE  
ADJUSTMENT  
9. Use a feeler gauge and check the radial clear-  
ance on the drive–end bearing between each  
bearing roller and the inner race, at the top of the  
bearing, Fig. 40. Place the feeler gauge between  
the top roller and the inner race.  
1. Remove the protective covering from the com-  
mutator. Place a 1/16 in. fiber spacer between  
the bottom of the brushholder and commutator.  
Loosen the brushholder clamp bolts and move  
the brushholders so they touch the fiber spacer.  
Tighten the clamp bolts to 225–250 lb.–ft. torque  
and remove the spacer.  
10. The clearance between the rollers and the inner  
race should measure between 0.0012 and 0.004  
in. Try various gauge thicknesses until clearance  
can be determined by the feel of the gauge as the  
gauge is slowly pulled from between the roller  
and the inner race.  
2. Connect the cable leads to the brushholder ter-  
minals and tighten the terminal bolts.  
BRUSH INSTALLATION  
11. Pack 4.8 oz. of grease in the outer circumference  
of outer bearing cap (36).  
1. Install new brushes.  
CAUTION: When replacing brushes, use only  
the GE recommended grade. Mixing of brush  
grades in the same motor or changing  
brushes to another grade will seriously affect  
commutation, surface film, commutator and  
brush life. See the DATA section for brush  
grade.  
12. Install a new gasket (35) and bearing cap (36)  
with bolts and lockwashers (34). Torque bolts to  
110–120 ft.lbs.  
13. Smear seals on bearing cap (36) and sleeve (37)  
with grease.  
14. Heat sleeve (37) to 110_ C (230_ F) rise and  
shrink it onto the shaft tight against the roller  
bearing inner race (38).  
2. Carefully lower the spring–loaded brush lever on  
each brush. Do not allow the lever to snap  
against the brush, as the brush may chip.  
65  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
3. Attach the brush–shunt terminals to the brush-  
holder body under the screws provided.  
7. Blue the hub bore again (see Step 1) and repeat  
Steps 2, 4, 5 and 6. Be sure to place the hub onto  
the shaft in the same position as marked.  
4. Inspect the interior of the machine for foreign ob-  
jects. Install the commutator covers on the motor  
and check for proper fit and latch operation.  
Generally, the fit will be improved, but the forego-  
ing procedure may have to be repeated several  
times to obtain a 75 percent fit.  
5. Clean the terminals.  
Under no circumstances use a lapping com-  
pound since lapping will produce a shoulder at  
the large end of the tapered fit. A shoulder will  
prevent a perfect fit when the hub is mounted  
hot; i.e., when it is mounted in the advanced posi-  
tion.  
HUB MOUNTING  
Hub Fitting  
NOTE: GE does not supply the hub for vertical  
drill motors. This procedure is included for cus-  
tomer use as a reference when installing the  
hub.  
8. After a good fit has been obtained, thoroughly  
clean the shaft and the hub bore to remove all  
blueing, oil or grease. Then mount the hub.  
Hub Mounting  
To prevent a hub from slipping, it should have at least  
75 percent fit on the shaft; i.e., at least 75 percent of the  
tapered bore of the hub should be in contact with the ta-  
pered fit on the shaft. Before mounting a hub, check and  
correct the fit as follows:  
1. Thoroughly clean the hub fit on the shaft and  
bore of the hub (see the procedure in the Clean-  
ing section). Remove any scoring on the shaft or  
hub bore.  
2. Spot the cold hub on the shaft by hand and check  
for at least 75 percent fit. See the “Hub Fitting”  
section. If necessary, dress the shaft to obtain  
this fit.  
1. Lightly cover the bore of the hub with a blueing  
compound such as Prussian Blue.  
2. Snap the cold hub forcefully onto the shaft.  
3. Trial mount the cold hub onto the shaft. Measure  
and record the position of the hub with respect to  
the end of the shaft. Take measurements with a  
micrometer advance gauge similar to that shown  
in Fig. 41. Zero the gauge.  
3. Mark the relative angular position of hub with re-  
spect to the shaft.  
4. Remove the hub from the shaft. A convenient  
method of removal is by the use of two finely ta-  
pered steel wedges (hardened and ground)  
which are carefully driven between the hub and  
the bearing outer sleeve on the shaft.  
Mark points of measurement, and mark across  
the end of shaft and hub face so that the hub,  
when heated, can be mounted in exactly the  
same angular position, and so the advance mea-  
surement can be made from the same point.  
5. Inspect the taper fit of the shaft; blueing of the  
hub bore should now show on the shaft. If at least  
75 percent of shaft surface shows traces of blue-  
ing, the fit is satisfactory. If, however, only a few  
spots of blueing show on the shaft, the fit is not  
satisfactory.  
4. Mount the hub hot onto the shaft so as to secure  
an advance from the cold position to the hot posi-  
tion along the axis of the shaft as indicated in this  
section. The ESTIMATED difference between  
shaft temperature and hub temperature (temper-  
ature rise) which will provide this advance is also  
given. The temperature difference is only an esti-  
mate and should be adjusted (if necessary) to  
provide the advance within prescribed limits.  
6. Dress down the blue spots on the shaft very light-  
ly with a fine emery cloth such as No. 400A Trie-  
mite.  
66  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
hub is nearly in engagement with the taper fit (not  
in actual contact), snap it forcibly into place with a  
quick push. It is important that the hot hub be in-  
stantly snapped into position before it has  
cooled; otherwise, it will freeze to the shaft and  
cannot be adjusted further.  
CAUTION: Zero settings of advance gauge  
must not be disturbed until all readings on the  
hub are completed.  
Heat the hub in an oven until it has reached a uni-  
form temperature (the desired number of de-  
grees above shaft temperature). For example, if  
shaft temperature is 25_ C (77_ F), heat hub to  
25_ C (77_ F) +171_ C (339_ F) = 196_ C (385_  
F). This procedure should provide an advance of  
approximately 0.085 in.  
6. Check the hot or shrunk–on position of the hub  
on the shaft. The advance from cold to hot posi-  
tion along the axis of the shaft must be held with-  
in the limits indicated. Check the actual advance  
with an indicator gauge, located in the same rela-  
tive position as used to measure the cold position  
in Step 3, Fig. 41.  
An accurate method must be provided for mea-  
suring hub and shaft temperatures quickly be-  
fore mounting the hub. This can best be done  
with a hand pyrometer. In using the pyrometer,  
place points of the gauge inside the bore of the  
hub, Fig. 42.  
If the advance is not within specified limits, re-  
move the hub and repeat the assembly proce-  
dure.  
TESTING AFTER OVERHAUL  
NOTE: The part must be left in the oven long  
enough for the heat to penetrate throughout the  
part.  
TESTING SERIES MACHINES  
(Models 5GE752AUP, AUT)  
After the motor has been reconditioned and reas-  
sembled, make the following tests to assure it will oper-  
ate satisfactorily.  
Measure the temperature of the shaft and the  
hub with the same instrument.  
5. Insure that the hub bore and the shaft taper are  
clean. Then, using adequate hand protection,  
quickly mount the hot hub on the shaft in the  
same angular position as when cold. When the  
Connect the motor to a d–c arc–welding generator,  
Fig. 7. Refer to connection diagrams, Figs. 22 and 24,  
for connections. Run the machine series–connected  
without load at 900 rpm and measure bearing tempera-  
tures.  
1. Use Duxseal* putty to hold the thermometers on  
the drive end and commutator–end outer bear-  
PLACE PYROMETER  
POINTS IN BORE  
OF HUB  
FIG. 42. MEASURING TEMPERATURE OF  
COUPLING HUB WITH PYROMETER. E–5976.  
FIG. 41. METHOD OF USING ADVANCE  
GAUGE. E–5975A.  
67  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
ing caps. Thermometers should contact the  
bearing caps for best results.  
tions. Run the machine by separately exciting the shunt  
field from a 125 vdc source. From another source of  
power, apply voltage to the armature circuit until the de-  
sired speed is obtained.  
2. Seat the brushes and run for ten minutes at 900  
rpm.  
Motor Operation  
Frame temperature should not exceed 25 C rise.  
3. With machine running up to speed, measure vi-  
bration. Vibration should not exceed 0.002 on  
commutator end. If vibration exceeds this  
amount, rebalance the armature.  
Ventilated (2300 cfm at 7.6 in. H O  
at Commutator Chamber)  
2
Hold separate field excitation at 50.5 amperes. Vary  
the armature voltage to obtain the required rpm. At ap-  
proximately 700 terminal volts (no load), the speed will  
be 900 rpm.  
4. Check the commutator for roughness and make  
sure the brushes are riding properly.  
5. Use a listening rod to check for noisy bearings.  
Unventilated  
6. Stop the machine and mount an indicator on the  
frame. While turning the armature by hand, mea-  
sure commutator runout. It should not exceed  
0.001 in.  
Hold the separate field excitation at 10 to 15 am-  
peres. Vary the armature voltage to obtain the required  
rpm. At approximately 338 terminal volts (no load), the  
speed will be 900 rpm.  
7. Measure field impedance. With 60 Hz a–c and 24  
amperes through each field, measure the volt-  
age drop across total exciting and commutating  
fields. See the DATA section for voltage limits.  
1. Run the motor for five minutes at 450 rpm. In-  
crease the speed to 900 rpm and run for two  
hours. Bearing temperatures should not exceed  
70_ C (158_ F). Run until the bearing tempera-  
ture remains constant for 30 minutes. Increase  
the speed to 1300 rpm and hold it while perform-  
ing Steps 2, 3 and 4. Then shut down the motor.  
Do not exceed 1300 rpm.  
8. Apply a high–potential test to the windings of the  
assembled machine, as specified in the DATA  
section.  
WARNING: Electric shock can cause serious  
or fatal injury. Proper precautions should be  
taken and observed by personnel performing  
testing to avoid such injury.  
2. Measure vibration when running the motor up to  
speed. Vibration should not exceed 0.004 in. If  
excessive, rebalance the armature.  
3. Check the commutator for roughness. Be sure  
brushes are riding properly.  
TESTING SHUNT MACHINES  
(Models 5GE752UP and US)  
4. Listen for noisy bearings with a listening rod.  
After the motor has been reconditioned and reas-  
sembled for service, make the following tests to be sure  
it will operate satisfactorily.  
5. Stop the motor and mount an indicator on the  
frame. Turn the armature by hand and measure  
commutator runout. Runout should not exceed  
0.001 in.  
Connect the motor to a d–c welding generator. Refer  
to connection diagrams (Figs. 21 and 23) for connec-  
6. Measure the insulation resistance of the wind-  
ings with a megohmmeter. If the resistance mea-  
sures not less than one megohm, apply an a–c  
high–potential test to ground for one minute as  
outlined in the DATA section.  
*Product of Johns Manville Co.  
68  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
LOCKING THE ARMATURE  
FOR SHIPMENT  
WARNING: Electric shock can cause serious  
or fatal injury. To avoid such injury, personnel  
should take and observe proper precautions  
during the high–potential testing.  
(See Fig. 43)  
1. Remove two diametrically opposite bolts in the  
commutator end bearing cap.  
REMOVING ARMATURE  
LOCKING ARRANGEMENT  
2. Install shipping bolts (1) (painted yellow) with jam  
nuts (2) applied. Torque bolts to 30 lb.–ft. and  
tighten the jam nuts.  
(See Fig. 43)  
CAUTION: Do not rotate the armature when  
the locking bolts are in place. Bearing and  
commutator damage may result.  
1. Remove the two shipping bolts (1) from the bear-  
ing cap. These bolts are longer and can be identi-  
fied from the factory by their yellow heads.  
3. Attach the two regular bolts and bag–tag (5) to  
one of the locking bolts (1).  
2. Install the two regular bolts which are in a bag at-  
tached to one of the shipping bolts.  
SHIPPING  
Whenever drilling motors are to be shipped, they  
must be properly skidded and secured to prevent any  
damage in transit. The photographs and drawings which  
follow illustrate a proven method of skidding these ma-  
chines for handing and shipment.  
3. Torque the regular bolts to 115 lb.–ft.  
NOTE: The shipping bolts and bag should be  
saved for future armature locking require-  
ments.  
HANDLING  
To avoid damage to the machine during handling, re-  
view the following cautionary statements:  
1. Do not lift motors by the shaft extension of the ar-  
mature.  
2. Do not allow the armature to bump another ob-  
ject.  
3. Do not tighten coupling assembly bolts with an  
air wrench or by pounding.  
4. Do not remove armature end–play by any other  
means than axial blocking.  
5. Do not load the armature radially (strap down) for  
shipment.  
CLEANING AND SLUSHING  
Before skidding the machine for shipment, all ex-  
posed finished surfaces not already painted should be  
cleaned and slushed as follows:  
FIG. 43. ARMATURE LOCKING ARRANGEMENT  
(41B535748 CHG. 0). E–28735A.  
69  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
1. Remove all corrosion.  
curely support and enclose the armature in a totally en-  
closed wooden box of sufficient strength to protect the it  
from damage.  
2. Wipe off the surface with clean rags and wet with  
petroleum spirits GE–D5B8.  
1. Clean the armature by removing dirt, oil or  
grease from its surface.  
3. Follow with a clean rag wet with methanol, then  
wipe dry. DO NOT touch the cleaned surface  
with bare hands.  
2. Treat all unpainted, exposed finished surfaces  
as follows:  
4. Slush immediately after cleaning with  
GE–D6C6A1 slushing compound.  
a. Remove any corrosion.  
b. Wipe off the surface with a clean cloth dipped  
in petroleum spirits, GE–D5B8.  
SKIDDING  
Use yellow pine timbers large enough to support the  
weight of the machine. The recommended size is illus-  
trated in Fig. 44.  
c. Wipe off the surface with a clean rag, dipped  
in methanol, and wipe dry. DO NOT touch the  
cleaned surfaces with bare hands.  
PROTECTION  
d. Immediately after cleaning, slush the cleaned  
surface with GE–D6C6A1 shushing com-  
pound.  
When any apparatus is shipped in the open, it should  
be fully protected from rain, snow, dirt, etc., by covering  
with some suitable weatherproof material.  
3. Wrap heavy paper or cardboard around the com-  
mutator for protection.  
ARMATURES  
4. Wrap and secure waterproof paper around ar-  
mature punchings. This will prevent saddle tim-  
ber moisture from condensing on the core  
punchings.  
To prepare drilling motor armatures for shipment or  
storage, clean, slush and wrap the armature. Then, se-  
5. Wrap both ends of the shaft with Grade C, Type  
1, wax treated cloth and tape it securely into  
place.  
7–1/2”  
3/4” DIA. (4 HOLES)  
7–1/2”  
25–1/4”  
23–1/2”  
2” X 6”  
NOTE: Wherever metal parts come in contact  
with the wood, insert a good grade of water-  
proof paper between metal and wood. This will  
prevent rust formation from the condensation  
of moisture on the metal.  
PREPARATION OF BOX  
1. Make a suitable box from yellow–pine lumber us-  
ing timbers of proper size to support the weight of  
each armature. See Fig. 45.  
2” X 6”  
25–1/4”  
62–1/4”  
11–1/2”  
2. Make 4 saddle blocks of 3 by 6 in. timber cut out  
to fit circumference of armature core. Nail two to  
the bottom of the box in the proper position to  
FIG. 44. CONSTRUCTION DETAILS. E–7754.  
70  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
WRAP HEAVY  
2 X 6 X 20–1/2  
(8 PIECES)  
WRAP WATERPROOF  
PAPER AROUND  
PAPER AROUND  
COMMUTATOR  
PUNCHINGS  
50–1/2  
ALL DIMENSIONS IN INCHES  
1 X 6 X 22  
(NO HOLE)  
9–1/2  
3 X 6  
3 X 6  
1 X 6 X 57–1/2  
(18 PIECES)  
1 X 6 X 22  
(2 PIECES)  
WITH HOLES  
ADJUST THICKNESS  
OF END BOARD TO  
SUIT LENGTH OF  
SHAFT  
2 X 6 X 24  
(4 PIECES)  
1 X 6 X 22  
(18 PIECES)  
2 SKIDS –  
3 X 6 X 57–1/2  
FIG. 46. ARMATURE PLACED IN  
SHIPPING BOX. E–3783.  
FIG. 45. BOX FOR SHIPPING  
ARMATURES. E–3782A.  
3. Place two saddle blocks over the core punch-  
ings, as shown in Fig. 46, and nail them to the  
side boards. If the box is the correct size, the top  
of the saddles will be flush with the top of the side  
boards. See Fig. 47.  
support the armature on core punchings.  
CAUTION: Locate the saddle blocks so they  
do not project beyond the punchings; other-  
wise, scuffing of coil insulation could occur.  
4. Nail the top cover in place. Also nail through to  
the top saddle blocks to prevent them from mov-  
ing.  
3. Support the commutator–end of the shaft by two  
1 X 6 in. boards nailed to the end of the box. Drill a  
hole in the two boards just large enough for the  
end of the shaft. See Fig. 45. The end of the shaft  
will fit in this hole against the end of the box to  
prevent movement.  
STORAGE  
PLACING INTO STORAGE  
When placing GE drilling motors into storage, the fol-  
lowing preparations should be performed to prevent  
damage to the equipment as a result of the storage.  
4. After the armature has been placed in the box,  
insert a board of proper thickness between the  
end of the shaft and the end of the box. Securely  
nail it in place. This will prevent any lateral move-  
ment of the armature in the box.  
1. Machines should be placed on a pallet and  
stored indoors if possible. A clean, dry ambient of  
60 F is preferred. In a high humidity environ-  
ment, an ambient of 70 F is recommended. Ev-  
ery attempt should be made to avoid widely vary-  
ing temperatures and high humidity.  
BOXING THE ARMATURE  
2. If it is necessary to store outdoors, a protective  
cover should be used to prevent entrance of rain,  
dust, etc.  
1. Prepare the armature as specified in the forego-  
ing.  
2. Place it in the box. Support it on two saddle  
blocks under the punchings and secure it against  
lateral movement. See Fig. 46.  
3. All exposed machined steel parts and surfaces  
should be slushed. These areas are slushed  
prior to shipment from the factory, but should be  
71  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
examined for rust. Any rust found should be re-  
moved using fine abrasive paper, after the old  
slushing compound has been removed with min-  
eral spirits (GE–D5B8). Methanol should be  
used to remove all residue.  
slush compound, Kendell Grade 5, or the equiva-  
lent.  
4. Brushes should be removed from their holders  
and clamped under the spring clips to prevent  
corrosion of the commutator surface as a result  
of moisture absorption by the carbon.  
WARNING: Cleaning solvents may be toxic and/  
or inflammable. They can cause serious or fatal  
injury if used without proper precautions. For  
safety:  
5. Do not completely seal the motor, but cover ma-  
jor vent areas with a waterproof shipping tape.  
Leave enough opening so the machine can  
breathe – i.e., moist air is not trapped. The inten-  
tion is to prevent entrance of water, dust, small  
animals, etc., but not to seal airtight. GE does not  
recommend the use of a silica gel or dehydrating  
agent.  
1. Do not inhale solvent fumes.  
2. Use solvents only in adequately ventilated  
areas.  
3. Avoid contact of solvent with the skin.  
4. Do not expose solvent to flame or sparks.  
5. Observe caution statements issued by the  
manufacturer of the solvent.  
6. Since the lubricant drains from the top half of  
bearings during storage, this area is subject to  
corrosion. The shaft should be rotated periodi-  
cally to redistribute a protective film. If stored in-  
side, rotate every three months. If outside, every  
month. Before placing the machine back into  
service after prolonged storage (1 year or more)  
bearings should be inspected and repacked with  
new grease meeting the recommended GE lubri-  
cation specification.  
Extreme care should be exercised not to dam-  
age critical machined surfaces such as the ta-  
pered shaft surface while removing rust. The  
surfaces should be reslushed with GE–D6C6A1  
7. The machine should be meggered when placed  
into storage and periodically while in storage  
(3–month intervals). Keep a record of these  
megger readings as a rapid decrease in insula-  
tion resistance indicates the machine condition  
is deteriorating and the storage conditions inade-  
quate.  
Before placing a stored motor back into service, refer  
to the applicable instruction “Removing Motors From  
Storage”.  
REMOVING FROM STORAGE  
Before placing a stored motor in service, perform the  
following:  
1. Blow dust and dirt accumulation out of the wind-  
ings with clean, dry air.  
2. Visually inspect for spring corrosion, sticking  
brushes in brushholders and general defects.  
FIG. 47. SHIPPING BOX WITH ARMATURE,  
LESS COVER. E–3784.  
72  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
3. Check winding insulation continuity to ground  
with a 500 volt megger. If the megger reading is  
less than 2 megohms, the winding should be  
baked or dried until the moisture content is suffi-  
ciently reduced to raise the megger reading to 2  
megohms.  
a. Remove the armature from the frame and re-  
move bearings from the armature shaft.  
b. Heat the frame and armature until dried suffi-  
ciently to obtain the 2 megohm reading.  
c. Pack bearings with new grease. Refer to the  
DATA table for the proper grease. Refer to the  
appropriate bearing illustration for the proper  
amount of grease.  
4. An electrical source of heat is best for drying as it  
can be easily regulated and is clean. Proceed as  
follows:  
d. Reassemble the motor.  
NOTE: Before drying windings, consideration  
must be given to bearings and lubricants. Not  
only can bearing lubricants be damaged by  
heat, but they can also deteriorate with age. For  
this reason, it us usually best to remove bear-  
ings before drying and repack with new grease  
before reassembly.  
e. If facilities are available, give the reas-  
sembled machine a running test to check the  
bearings.  
Refer to Figs. 48 and 49 for outline drawings.  
73  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
ONE .25 PIPE PLUG–REPLACE  
WITH GREASE FITTING FOR  
REGREASING (ALL MODELS EXCEPT UP1, UP2, AUP1 AND AUP2)  
2.25 DIA. (3 HOLES)  
FOR LIFTING  
15.09  
15.09  
.50–13 TAP X 1.00 DEEP  
8 HOLES  
AIR OUT  
(4 CORNERS)  
+
.25  
+
.25  
16.82  
16.82  
15.53  
+.000  
–.010  
16.656  
F2  
F1  
.375–24 THD.  
1.72  
18.00  
14.78  
+.000  
–.010  
36.000  
VIEW SHOWING HYDRAULIC  
PUMP OFF FOR HUB  
BOTH ENDS  
MODEL  
UP1  
AUP1  
”E”  
.75–10  
THRU  
”F”  
22.12  
”G”  
16.50  
.04R  
.01R  
+ .002  
.000  
UP2, 3 & 4  
AUP2, & 3  
1.005  
DIA. THRU  
22.124  
22.116  
16.500  
–A– –B– –C– .004R  
F1  
F2  
.06 THICK TERMINALS FOR  
NO. 10 SCREW ON 37/24 CABLES  
EXTENDING 10 FEET FROM FRAME  
FIG. 1  
GE–752–UP  
SAME AS GE–752–AUP EXCEPT  
F1 AND F2 CABLES AS SHOWN  
FIG. 48. OUTLINE, UP AND AUP (41E903631 CHG. H). E–28755B.  
74  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
NOTE FOR ARMATURE LOCKING ARRANGEMENT  
LOCATED ON COMMUTATOR END  
TO BE IN PLACE DURING MOUNTING OF MOTOR  
BUT TO BE REMOVED BEFORE OPERATION OF  
MOTOR  
ONE .25 PIPE PLUG–REPLACE  
WITH GREASE FITTING FOR  
REGREASING (ALL MODELS EXCEPT  
UP1, UP2, AUP1 AND AUP2)  
G
58.50  
ARMATURE LOCK  
ARRANGEMENT  
SEE NOTE  
9.56  
7.88  
AIR OUT  
.50 NPT FOR  
AIR PRESSURE  
MEASUREMENT  
C ARMATURE  
L
+
.005  
11.375  
DIA.  
A1  
F2  
1.06  
1.06  
A2  
F1  
+
.562 DIA.  
2 HOLES  
.06  
13.43  
F
+
.06  
GE–752–AUPSHOWN IN MAIN VIEWS  
GE–752–UPSHOWN IN FIG. 1  
9.24  
E HOLE  
APPROXIMATE WEIGHTS  
GE–752–UP6750 POUNDS  
GE–752–AUP6850 POUNDS  
10.50  
1.56 DIA. THRU  
(4 HOLES)  
AIR FLOW REQUIREMENTS  
2300 CFM OF STANDARD AIR  
MINIMUM 900 HP  
2800 CFM OF STANDARD AIR  
MINIMUM 1000 HP  
G
C MOTOR  
IMPORTANT  
THE ELECTRICAL EQUIPMENT SHOULD BE  
LOCATED IN A SPACE WHICH  
L
(1) PROVIDES SUFFICIENT ACCESSIBILTY  
FOR BRUSH INSPECTION  
(2) ALLOWS REMOVAL OF ALL THE BRUSHES  
AND PIGTAIL FASTENERS  
(3) ALLOWS MAINTENANCE PERSONNEL TO  
COMPLY TO THE GE MAINTENANCE  
INSTRUCTION SPECIAL REQUIREMENTS  
G
+
E HOLE  
.75–10 TAP THRU  
(2 HOLES)  
FOR JACKING  
FOOT  
DIMENSIONS  
FIG. 48. OUTLINE, UP AND AUP (41E903631 CHG. H). E–28755B.  
75  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
GREASE TUBE  
FITTING ”C”  
SEE TABLE 1  
GREASE VENT TUBE  
FITTING ”A”  
SEE TABLE 1  
GREASE TUBE  
FITTING ”B”  
SEE TABLE 1  
.50 NPT THRU  
2 HOLES  
2.00 DIA.  
4 BOSSES  
FURNISHED ON MODELS  
SHOWN IN TABLE 1  
FURNISHED ON MODELS  
SHOWN IN TABLE 1  
.562 DIA. THRU  
2 HOLES  
H
H
1.25 TAPER IN DIA.  
PER FOOT IN LENGTH  
(BOTH ENDS)  
+
.005  
11.375  
DIA.  
3.125–8 NS–2A THREADS  
(BOTH ENDS)  
AIR INLET  
13.50  
FURNISHED ON MODELS  
SHOWN IN TABLE 1  
.50–13 TAP X 1.00 DEEP  
6 HOLES  
.390 DIA. DRILL THRU  
.578 DIA. DRILL X 1.50 DEEP  
1.25 DIA. C’BORE X .20 DEEP  
.4375–20 TAP THRU AND .375 NPT  
GREASE VENT TUBE  
FITTING ”D”  
SEE TABLE 1  
9.50  
.656 DIA. DRILL X 2.12 DEEP  
.75–10 TAP X 1.50 DEEP  
4 HOLES AS SHOWN  
REF.  
1.25  
.20  
VIEW AT G  
1.50  
SECTION H–H  
ENLARGED  
TABLE 1  
FITTING  
MODELS  
UP1, AUP1  
.25 PIPE  
PLUG  
.25 MALE  
NPT  
.25 MALE  
NPT  
.25 PIPE  
PLUG  
MODELS  
UP2, AUP2  
.NOT  
MODELS  
(SEE NOTE)  
NOT  
”A”  
”B”  
”C”  
”D”  
FURNISHED FURNISHED  
.25 PIPE  
PLUG  
NOT  
FURNISHED FURNISHED  
.25 PIPE  
PLUG  
NOT  
FURNISHED  
NOT  
NOT  
FURNISHED  
NOTE: ALL MODELS EXCEPT UP1, UP2, AUP1 AND AUP2)  
FIG. 48. OUTLINE, UP AND AUP (41E903631 CHG. H). E–28755B.  
76  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
MINIMUM REQUIRED  
TO REMOVE COVER  
AIR INLET FLANGE  
TOP INSPECTION  
COVER  
B
21.00  
.50 NPT  
2 HOLES REF.  
2.50  
A1  
1.00  
A2  
.56  
F
1.12  
1.00–8 UNC–2B THREAD X 1.50 DEEP  
8 HOLES EQ. SPACED ON 25.00 DIA. B.C.  
A
.812 DIA. X 1.94 DEEP  
8 HOLES EQ. SPACED  
ON 25.00 DIA. B.C.  
.562 DIA.  
2 HOLES REF.  
BOTTOM INSPECTION  
COVER  
COMMUTATOR END  
.687 DIA. IN 1325/24 CABLES  
EXTENDING 10 FEET FROM  
FRAME  
1.12  
8.00  
11.00  
3.25 10.25  
8.00  
1.12  
8.00  
8.00  
1.12  
1.12  
VIEW AT F  
SHOWING FLANGE  
WITH COVER REMOVED  
VIEW AT A  
VIEW AT B  
SHOWING FLANGE  
SHOWING FLANGE  
WITH COVER REMOVED  
WITH COVER REMOVED  
FIG. 48. OUTLINE, UP AND AUP (41E903631 CHG. H). E–28755B.  
77  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
.25 NPT FOR  
REGREASING  
2.25 DIA. (3 HOLES)  
FOR LIFTING  
AIR OUT  
(4 CORNERS)  
+
.25  
AIR OUT  
16.82  
15.53  
.50–13 TAP 1.00 DEEP  
(8HOLES)  
IMPORTANT:  
THE ELECTRICAL EQUIPMENT SHOULD  
BE LOCATED IN A SPACE WHICH–  
(1) PROVIDES SUFFICIENT ACCESSIBILITY  
FOR BRUSH INSPECTION.  
(2) ALLOWS REMOVAL OF ALL THE  
BRUSHES AND PIGTAIL FASTENERS.  
(3) ALLOWS MAINTENANCE PERSONNEL  
TO COMPLY TO THE GE MAINTENANCE  
INSTRUCTION SPECIAL REQUIREMENTS  
+ .000  
– .010  
16.656  
GE752AUT AND US1 SHOWN IN  
MAIN VIEWS.  
F2  
FI  
APPROX. WEIGHT:  
GE–752–AUT= 7035 LBS.  
1.72  
.000  
.010  
+
AIR FLOW REQUIREMENTS:  
2300 CFM OF STANDARD AIR  
MINIMUM, 900 HP.  
36.000  
THIS AREA OF FOOT FLUSH  
WITH FRAME FACE.  
BOTH SIDES  
2800 CFM OF STANDARD AIR  
MINIMUM, 1000 HP.  
1.12  
.50–13 TAP THRU  
(4 HOLES)  
1.12  
8.00  
.75  
FLAT  
.50–13 TAP THRU  
(4 HOLES)  
11.00  
8.00  
1.12  
.75  
FLAT  
8.00  
1.12  
VIEW AT ”B”  
.75  
FLAT  
SHOWING FLANGE  
WITH COVER  
REMOVED  
VIEW AT ”A”  
SHOWING FLANGE  
WITH COVER  
REMOVED  
.375–24 THREAD  
10.25  
.50–13 TAP THRU  
(4 HOLES)  
8.00  
.50  
FLAT  
1.12  
VIEW SHOWING HYDRAULIC  
PUMP OFF FOR HUB  
BOTH ENDS  
1.12  
VIEW AT ”C”  
SHOWING FLANGE  
WITH COVER  
REMOVED  
FIG. 49. OUTLINE, US1, AUT (41E903745, CHG. A). E–37954B  
78  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
58.50  
”D”  
AIR OUT  
7.88  
6.37  
.25 NPT  
2 INTERCONNECTED  
HOLES  
8.55  
+
.005  
11.375  
DIA.  
1.06  
A1  
A2  
1.06  
4.63  
5.69  
F2  
F1  
4.89 0.05  
13.44  
+
4.25  
ARMATURE LOCK  
ARRANGEMENT  
SEE NOTE  
.078  
.059  
5.25  
1/2 NPT (2 HOLES)  
FOR PRESSURE TAPS  
1.38  
1.74  
10.50  
23.12  
16.500  
NOTE FOR ARMATURE LOCKING  
ARRANGEMENT LOCATED ON  
COMMUTATOR END:  
6.50  
8.25  
TO BE IN PLACE DURING MOUNTING  
OF MOTOR BUT TO BE REMOVED  
BEFORE OPERATION OF MOTOR.  
22.120  
+
.12  
1.56 DIA. THRU  
(4 HOLES)  
2.38  
16.500  
3.19  
1.00 R.  
.002  
.000  
+
1.005 DIA. THRU  
(2 HOLES)  
3.62  
5.25  
.75–10 TAP  
THRU  
(2 HOLES)  
FIG. 49. OUTLINE, US1, AUT (41E903745, CHG. A). E–37954B  
79  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
.562 DIA.  
THRU  
(2 HOLES)  
D
D
1.25 TAPER IN DIA.  
PER FT. IN LENGTH  
(BOTH ENDS)  
+
.005  
11.375  
13.50  
3.125–8 NS–2A  
THREADS  
(BOTH ENDS)  
5.31  
AIR INLET  
0.656 DIA. DRILL X 2.12 DEEP  
0.750–10 TAP X 1.50 DEEP  
4 HOLES AS SHOWN  
.50–13 TAP 1.00 DEEP  
(6 HOLES)  
VIEW AT ”D”  
9.50  
.390 DIA. DRILL THRU  
.578 DIA. DRILL X 1.50 DEEP  
1.25 DIA. C’BORE X .20 DEEP  
.4375–20 TAP THRU AND .375 NPT  
AIR INLET FLANGE  
TOP INSPECTION COVER  
.20  
”C”  
1.50  
.25 NPT (2 HOLES)  
FOR REGREASING  
REF  
1.25  
SECTION D–D  
(ENLARGED)  
.50 NPT (2 HOLES) REF.  
A1  
1.00–8 UNC–2B THREAD  
1.50 DEEP (8 HOLES EQ.  
SP. ON 25.00 DIA. B.C.  
”A”  
A2  
.812 DIA. 1.94 DEEP  
(8 HOLES EQ. SP. ON  
25.00 DIA. B.C.  
2.00  
1325/24 ARMORED  
CABLES EXTENDING  
10 FEET FROM  
FRAME  
.562 DIA. (2 HOLES) REF.  
COMMUTATOR END  
BOTTOM INSPECTION  
COVER  
”B”  
FIG. 49. OUTLINE, US1, AUT (41E903745, CHG. A). E–37954B  
80  
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Vertical Drilling Motor, Type GE752, GEK–91584D  
81  
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GEK–91584D, Vertical Drilling Motor, Type GE752  
GE Transportation Systems  
NEW 5–90, WLF  
REVISED 10–90, WLF  
REVISED 8–92, WLF  
REVISED 11–93, WLF  
REVISED 02–05, NBS  
2901 East Lake Road  
Erie, Pennsylvania 16531  
PRINTED  
IN  
U.S.A.  
E
82  
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