place. Before a motor is disassembled, consider the following:
The area for disassembly must be clean.
Tag all leads and the point of connection from where the leads have been removed.
Wipe all excess dirt, grease, and oil from the exterior surface with an clean cloth moistened with an approved solvent.
Inspect all leads for burned, cracked, or deteriorated insulation at the point of their entry into the motor.
Turn the motor shaft by hand to determine whether the armature turns freely. If not, inspect the motor for a bent shaft, misalignment of the end bells, loose or frozen bearings, a loose pole piece, or foreign objects inside the motor.
WARNING Use gloves or a cloth to protect your hands from the sharp edges of the keyway when turning the shaft.
End Bell Removal. - When you are removing the end bells, remember that on some motors the bearings must be removed before the end bells. To remove the end bells, use the following procedure:
1. Punch mark the frame and end bells for reassembly purposes (fig. 7-56).
2. Remove the end bell fastening screws or bolts.
3. Remove the bearing first, if necessary.
4. Part the end bells from the frame, as shown in figure 7-57.
5. Record and disconnect the leads from the internal mechanism and components.
6. Clean the end bells and frame.
7. Inspect the disassembled parts and replace as needed.
Bearing Removal. - Sometimes you can remove the bearings before removing the end bells. In other cases, the bearings slip off the shafts with the end bells. Frequently, the bearings are press fitted to the shafts and end bells, making their removal difficult. Since bearing removal varies with the different types of motors, only some of the most important procedures and precautions are listed.
Never remove bearings in good condition from the shafts or end bells unless it is absolutely necessary.
Remove all bearing attachment screws or bolts before attempting to remove the bearings.
Remove ball bearings which are to be reused by arbor plates and an arbor press to prevent distortion.
Remove ball bearings to be discarded with a hook-type puller.
Figure 7-56. - Punch marking motor frame and end belts.
Figure 7-57. - Separating motor frame from end bells.Continue Reading