Electromagnetic clutch

摘要

Disclosed is an electromagnetic clutch comprising a field member with an exciting coil member disposed therein; a shaft extending through the field member and the exciting coil member; a rotor member fixedly disposed on the shaft at a position opposing to the filed member; a drive mechanism rotatably provided on the shaft; a contact member provided on the drive mechanism on the side facing the rotor member; an elastic member disposed on the drive mechanism for biasing the contact member to the drive mechanism. The contact member is positioned to form a clearance of a first dimension G1 along the shaft between the surfaces of the contact member and the rotor member and the first dimension G1 is set to be smaller than a limit dimension G3. A deformation of the elastic member by the limit dimension along the axial direction results in the elastic limit. The electromagnetic clutch has a restricting member provided on the drive mechanism for restricting a displacement of the contact member along the axial direction of the shaft to be less than a second dimension G2. The dimension G2 is set within a range between the first dimension G1 and the limit dimension G3.