(4) Remove four motor assembly bolts (11) an d nuts (2 I;
6-10. Drive Motor Disassembly
separate end frame (3) and end frame (101 from stator
a. Removal. Refer to paragraph 4-44. b.
assembly -6).
b. Disassembly.
(5) Remove two screws (16) and lockwashers (17 I, securing
(1) Drive out tapered pin (12, fig. 6-4), securing motor shaft
wire support bracket (4) to end frame (3). Remove bracket.
gear (13) (to rotor (7) and remove gear.
(2) Remove two screws (1), securing wire cover plate (18) to
(6) Slide out rotor assembly and, using a gear puller, remove
end frame (3). Lift off plate.
gear-end bearing (9, fig. 6-4) from rotor (7). In similar manner,
(3) Disconnect motor cable (15) from the leads of stator
remove bearing (5).
assembly (6) by removing three contact insulators (14).
Remove cable from end frame (3).
(7) Do not remove motor fan (8) from rotor (-1) unless it must
be replaced, for it will be damaged in removal. Press off fan (8)
if necessary.
Figure 6-4. Drive motor, exploded view.
replaced. Inspect the bearings for loose inner and outer races
6-11. Drive Motor Cleaning and Inspection
and for overall wear. Replace defective bearings. Check the
motor shaft gear for worn and broken teeth and replace if
Wipe all parts of the motor except the bearings with a cloth
necessary. Use a test probe for grounded coils of stator
dampened with cleaning solvent. The bearings are life-sealed;
assembly. To test, place one probe on frame of stator and
to clean wipe exterior surfaces with an oil-damp cloth. Check
touch the other probe to the coil terminals. If lamp lights, the
all metal parts such as end frames, cover plate, and stator
coil is grounded. Check the rotor for broken or worn insulation
assembly casing for cracks and breaks. Examine the motor fan
covering and for damaged shaft. Inspect for loose rotor bars,
for distortion and for bent or broken blades. Bent fan blades
using a growler and a hacksaw blade. Vibration of hacksaw
may be straightened by the fingers, as fan is made of thin
blade should be felt at
metal. Do not remove fan from rotor shaft uless it is to be
6-5
