GE GE752 manual Brush Installation, Brushholder Clearance Adjustment

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).

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.

8.Install framehead bolts and lockwashers(30). Torque to 440±495 lb.±ft.

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.

NOTE: Be sure drive±end framehead bolt holes are aligned with holes in inner bearing cap be- fore assembling bolts and lockwashers (30).

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.

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.

11.Pack 4.8 oz. of grease in the outer circumference of outer bearing cap (36).

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).

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.

NOTE: Prior to heating sleeve (6), apply NALCO RC ªRail Conditionerº 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.

17.Heat sleeve (6) to 180￿ C (356￿ F) rise and shrink it onto the shaft tight against the spacer

(5).

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.

BRUSHHOLDER CLEARANCE

ADJUSTMENT

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.

2.Connect the cable leads to the brushholder ter- minals and tighten the terminal bolts.

BRUSH INSTALLATION

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.

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.

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