MOTOR BRAKE

摘要

The present invention is a fail safe motor brake (10) for use with relatively large industrial motors and particularly electric hoist motors as used with large overhead industrial cranes. The present brake includes an actuation linkage (64, 68, 76, 78) which results in relatively little change in the initial height or air gap of the solenoid plunger (78) or armature, as the brake linings (30A, 30B) wear. The limited change in the air gap is due to a mechanical stop (54, 56) which is built into the adjustment and actuation linkage (64, 68, 76, 78), as well as the clamping pressure provided by the spring arrangement which serves to actuate the breaks. The solenoid (78) of the present brake is offset from the plane of the break shoes (30A, 30B), thus allowing removal and replacement of one or both shoes without the need to remove the solenoid (78). This allows the brake shoes (30A, 30B) to be removed without the need to readjust the actuation linkage (64, 68, 76, 78). The present motor brake provides excellent performance throughout the life of the brake linings, without the need to adjust the actuation linkage during this period. The present motor brake may also include other features which provide for long life and ease of maintenance, such as sealed bearings (52, 128), additional lubrication points, and an attached air gap gauge (92) and brake drum locking pin (106), to prevent 'block drop', or falling of the hoist block due to the motor being allowed to turn, when the brake is released for service.