DISASSEMBLY. -The careless disassembly of a motor can cause serious damage to the delicate components within the motor. Remove and handle all parts with care and always use the proper tools. It is just as important to tag all parts, take down accurate data, and store the parts in an orderly arrangement in a safe 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.

Remove sleeve bearings with arbor plates and an arbor press. When an arbor press isn't available, sleeve bearings may be removed with a well-fitted arbor and hammer.

Sometimes you may be required to remove sleeve bearings by drilling them out with a drill press.

Handle bearings with clean, dry hands or clean canvas gloves. Handling a bearing with hands that are perspiring can cause corrosion. Fingerprint patterns are sometimes found rusted into bearing surfaces.

Keep bearings in their packages or in oil-proof paper until they are installed

Brush Removal.- Brush removal is necessary when you are replacing brushes or you need access to parts of the unit otherwise inaccessible. If the brushes are not to be removed, place them in the raised position. Use the following procedure for removing brushes and brush rigging:

1.      Record the placement and angle of brush rigging and brushes.

2.      Check the brush spring pressure.

3.      Remove the screws holding the brush pigtails and rigging.

4.      Clean, inspect, and store the brushes and brush rigging.

Centrifugal Switch Removal.- Internal switches of the centrifugal type are usually attached to the inside of end bells. When you are removing the end bells, be careful not to break the switch springs. For removing a centrifugal switch, follow these steps:

1. Note and record the lead connections to the switch.

2. Disconnect the leads.

3. Remove the mounting screws of the stationary part of the switch which is secured to the end bell.

4. Clean and inspect the switch and replace the damaged parts.

5. Tag and store the unit.