Electric drive motor – 1000

Service/Repairs

7.2.3 Dismantling of motor

•Release the brake disc’s companion flange by first removing the locking ring together with the washer in the end of the rotor shaft. The companion flange can now be lifted off. It may be necessary to unclamp it with an appropriate tool.

•Remove the four plugs that cover the carbon brushes, move the springs on the carbon brushes to one side and pull out the carbon brushes.

•Dismantle the commutator end’s bearing shield (2) together with the carbon brush bridge (5) and carbon brushes (8) by unscrewing the eight screws (1). Now put down the motor with a firm resting point against the edge of the bearing shield, and carefully tap on the rotor shaft’s end with a rubber mallet.

•Dismantle the drive end’s bearing shield (15) together with the rotor (9). Make sure not to damage the motor windings when the rotor is removed from the motor housing.

•After dismantling the motor’s bearing shields and removing the rotor from the motor housing, the gear wheel in the rotor’s drive end is removed. This is done by unscrewing the nuts on the gear wheel and then pulling the gear wheel off with a puller. Note that the gear wheel is locked with Loctite to the rotor shaft.

•Now release the inner locking ring together with the underlying washer. Pull out the rotor shaft from the bearing (18).

•Release the outer locking ring together with its washer, and remove the bearing from the bearing shield.

•Remove the bearing shield’s seal (17) and carefully clean the bearing shield.

•Fit a new seal in the bearing shield.

7.2.4 Assembling of motor

Assemble the motor in the reverse order.

•Carefully check that the rotor can move freely in the direction of rotation and that the carbon brushes are flush with the commutator.

•Check the motor’s insulation resistance (between respective winding and the motor housing). For a new motor this should lie between 2 - 3 Mohm. When a used motor has been exposed to impurities an insulation resistance down to approx. 1 Mohm is acceptable.

•Fit a new O-ring in the drive shaft end’s bearing shield and a new seal on the collar of the bearing shield.

7.2.5 Cleaning

An extremely critical factor to ensure correct functioning of the motor is that it is kept as clean as possible. The motor and the motor compartment must be regularly checked for dust, oil, and other impurities.

A vacuum cleaner with an appropriate nozzle can be used to clean the motor if the motor windings and inner compartment are dry Compressed air can be used in combination with a vacuum cleaner. In which case the compressed air must be clean and dry.

A cloth of non-fluffing material should be used if the windings have a coating. The cloth can also be moistened with a grease-dissolving, organic and volatile detergent that does not damage the windings. Use detergent sparingly to avoid it penetrating into the parts of the motor. Residual detergent should be removed with an appropriate solvent, if it leaves a greasy surface.

If the parts of the motor are heavily fouled it may be necessary to use a solvent that is sprayed onto the parts. It is important that the detergent is applied in a way to prevent dirt from penetrating into the parts of the motor, especially for the rotor.

One method of cleaning the rotor is to dip it in solvent. If this is done then the rotor must always be dried with the application of heat. There must be adequate ventilation during the drying process, and the drying should continue until a number of measurements of the insulation resistance provide equivalent and approved results.