Removal and installation
Disassembly
WARNINGS:
- Removing the rear cover can be difficult due to the rear bearing circlip. To facilitate removal of the cover, heat only the bearing housing with a soldering iron. Do not use a blow dryer to avoid overheating the rectifier diodes.
- Do not reuse a removed rear bearing.
- Do not lubricate the rear bearing outer race.
Examination
Rotor. Check rotor winding resistance (see subsection «Specifications and control data»). If it is not within the specified limits, replace the rotor.
Measure the insulation resistance between the winding and the rotor shaft. If there is a short circuit, replace the rotor.
Check the degree of wear of slip rings (the minimum allowable diameter is given in subsection «Specifications and control data»).
brushes. Check the ease of movement of the brushes in the holder. Clean or replace the brush holder if necessary.
The brushes must be replaced if they are worn down to the line indicating the maximum allowable wear.
stator. Check the windings for open circuits and winding shorts to ground. Replace stator if necessary.
Rectifier Diodes. To test the diodes, touch the ohmmeter probes to one of the diode leads and the positive plate. Then swap the probes. Conductivity should only exist in one direction. Do the same for the rest of the pins, and then repeat the measurements for the negative plate.
Assembly
Insert the retaining ring into the groove of the rear bearing so that it is as close as possible to the adjacent parts.
When installing the back cover, insert the brush holder, diode block, voltage regulator and stator first. Then press the brushes into the holder with your fingers and install them on the rotor.
Be careful not to damage the rotor slip rings.