Method for monitoring a chain hoist and chain hoist

摘要

Method for monitoring a chain hoist that has an electric motor (2) connected to a gearbox (7) via a friction coupling (14), wherein a sensor (18) is used to measure the rotation speed of the gearbox. The measured rotation speed is used, in a control unit, to calculate a corresponding operating speed of the motor. The calculated operating speed is compared with a value derived from operating data of the motor and, if the difference exceeds a threshold value taking into account the gearbox transmission ratio, the motor is switched off. The invention also relates to a corresponding chain hoist.