Torsion damping device for an automotive clutch plate assembly with two friction washers, one of which is freely slidably mounted

摘要

A torsion damping device for an automotive clutch plate assembly comprising two rotary parts, i.e. a hub with a hub disc and a pair of guide washers fixed to a friction disc. First and second spring stages are operatively circumferentially interposed between the rotary parts, the first stage spring(s) having relative low stiffness and being operative during small relatively angular displacements of the rotary parts and the second stage spring(s) having relatively high stiffness and being operative during larger relative angular displacements of the rotary parts. A friction washer in frictional engagement between the rotary parts and producing most of the frictional torque is freely angularly mounted and has a position in the rest position of the torsion damping device independent of the springs. The angles subtended by the circumferential play J between second stage spring(s) and one of the rotary parts and the circumferential play L between a lug associated with the friction washer being such that the subtended angle corresponding to J-L is between a value greater than 0 DEG (preferably 1 DEG ) and 5 DEG .