Patent attributes
An electromagnetic clutch comprises: a drive shaft of a compressor in an air conditioner for a vehicle in which a combustible refrigerant or a CO2 refrigerant circulates; a rotor which is rotated about the drive shaft by receiving a motive power from an engine or a motor of the vehicle; and a torque limiter connected to an armature disposed so as to face the rotor through an elastic member, the torque limiter being rotated integrally with the drive shaft, in which the torque limiter includes a transmission cutting-off portion for, when the state of a lock is caused in the drive shaft, perfectly separating the armature side from the drive shaft side, and for, unless the lock state is released, prohibiting the connection between the armature side and the drive shaft side from being recovered.