Brake motor comprising an asynchronous motor with capacitor and zero current brake

摘要

The motor-brake unit has a brake (7,8) attached to the shaft of an asynchronous squirrel cage motor (2). The brake functions when the current falls to zero, and has a moving plate (7) sliding on the rotor shaft (6) to press against a fixed plate (8) under the action of a spring (9). When current is flowing a flux deflector (10) draws the moving plate clear. An electronic switch briefly short circuits the starting capacitor to pull the moving plate clear during starting.