ELECTROMAGNETIC SPRING CLUTCH

摘要

PROBLEM TO BE SOLVED: To improve the reliability and durability of an electromagnetic spring clutch by increasing the hardness of a coil spring winding surface without degrading the magnetic characteristic of an input member. SOLUTION: The electromagnetic spring clutch is so designed that energization of an electromagnetic coil 5a attracts an armature 11 to an input pulley 1 to windingly constrict a coil spring 4 with one end coupled to the armature 11 and the other to an output hub 7 onto the peripheries of a cylindrical portion 1a of the input pulley 1 and of a flange portion 7b of the output hub 7, with the result that the torque of the input pulley 1 is transmitted to a pump shaft 8 of a water pump heater via the output hub 7. The input pulley 1 is formed from an S10C material, and a ring 2 of an S45C material is pressed in onto the periphery of the cylindrical portion 1a.