Abstract: In a spring type clutch disc, torque is transmitted from a disc plate (2) to a hub (3) through coil springs (12, 13). A slide member (11b, 14) making sliding contact with the hub (3) is interposed between the disc plate (2) and the hub (3). An electroless plate Ni coating is provided on one of the slide member (11b, 14) and the hub (3), while an electroless plate Ni-P-BN coating is provided on the other, so as to stabilize the coefficient of friction of and improve the wear resistance of the slidingly frictional engaging portion therebetween, whereby the first-stage hysteresis torque in the torsional characteristic of the clutch disc is stably maintained at a minimum.

Abstract: A clutch disc for an automobile transmits torque from engine to a transmission through a disc plate, a torsion spring and a hub connected to an output shaft. A bush is press-fitted between the sliding surfaces of the disc plate and the hub to reduce the surface pressure at the sliding surfaces and also to prevent intrusion of dust into the sliding surfaces. The torsion spring and a sub-torsion spring disposed between a hub plate and a friction plate holding the hub plate therein are retained at their both ends in position by means of spring-retaining lugs formed integrally with spring holding portions of the hub plate. Thus, generation of noise from the individual members is prevented.