ABB BUL2 Maintenance Manual - Page 14

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3.6 Toothed belt

Check that the toothed belt is sufficiently tight. If tightening

is required, adjust the motor support. The tightness of the

belt can be checked by a spring balance attached to the belt

halfway between the pulleys (see Fig. 5). At a 10 N load the

belt should yield about 5 mm on BUE, and at a 6 N load the

belt should yield about 2 mm on BUL2.

3.7 Motor cable connections

Check that all cable connections within reach are secure.

Apply load

Fig. 5. Check of toothed belt.

Brake disc

Red mark ±25°

from mark on

brake pad

Red mark

Brake pads

Fig. 6. Brake adjustment, type BUE.

14 Maintenance guide BUE/BUL2 | 1ZSC000498-ABH en, Rev. 1

3.8 Overhaul type BUE

3.8.1 Disc brake

Wipe the brake disc free from grease.

See Fig. 6. The kinetic energy in the motor and the toothed

wheels should be absorbed by the brake, and the motor-

drive mechanism should stop with a tolerance of ± 25° as

measured on the brake disc (± 125° measured on the hand

crank).

This can be adjusted by tightening both of the spring bolts

on the brake. Using the hand crank, operate the motor-drive

mechanism until the brake is fully open. At this point the

length of the springs must not be less than 35 mm. If the

brake still does not function with that spring length, oil or

grease has entered the brake linings, which will then need

cleaning.

Yield

Clean as follows: Using a pair of tongs, remove the roll pins

that hold the supporting shafts on the brake blocks; see

Fig. 2. Then remove the shaft and the brake blocks. Clean the

brake linings on the two brake blocks with degreasing agent.

When refitting the brake, check that the brake disc is

completely free from grease. Adjust the spring force of the

brake until the motor-drive mechanism stops within the

tolerances given above.

Adjusting nuts