Electricdrivemotor–1760

Service/Repairs

•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.

8.2.2Assemblingofmotor

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.

8.2.3Cleaning

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.

9.2Leakagefromtopcover

Dismantling

•Lift up the truck, and block up to ensure that it is stable.

•Unscrew the drive wheel.

•Unscrew the M8 nuts (28), that hold the gear and motor, with a box wrench. Support the gear so that it does not drop.

•Release the M8 bolts (12), that hold the cover (3), with a 6 mm hex socket wrench.

•Change the gasket (6).

Assembling

Assemble in reverse order.

•Tighten the four M8 bolts and the four M8 nuts to a torque of 26.6 Nm Lock with Loctite 242.

•Tighten the drive gear’s 5 bolts to a torque of 65 Nm.

9.3Changingofthedriveshaft’ssealing ring

The drive shaft’s sealing ring can be changed with the gear mounted in the truck.

Follow the instructions below if oil is leaking from the drive shaft.

Dismantling

•Unscrew the drive wheel 1).

•Remove the lower cover and drain off the oil (22).

•Release the drive shaft nut. Remove the nut and washer (16,17).

•Carefully tap out the drive shaft with a brass drift and hammer (32).

•Pull off the bearing from the drive shaft with tool 08-13022 (29).

•Check that the bearing washers are not damaged. If they have been damaged by the puller tool, measure the total thickness of the shim washers and change them before assembling (30).

•Remove the sealing ring from the drive shaft (31).