PURPOSE: To arrange an aligning mechanism on the inside diameter side, and make a device compact by supporting a pair of aligning members interposed in an annular space between a sleeve and a bearing so as to move slidingly freely in the radial directions different from each other to respective sleeves.

CONSTITUTION: A sleeve 15 arranged slidably on a front cover 31 of a transmission mechanism and either one of an inner ring 10 or an outer ring 9 of a bearing 8 arranged on the outer periphery of the sleeve 15, come into contact with a diaphragm spring 30, and release a clutch. In this mechanism, when a stationary side orbit ring is the inner ring 10, a pair of ring shape aligning springs 23 and 25 installed between the inner ring 10 and the sleeve 15 move slidingly on an outside diameter of the sleeve 15 by eccentricity of the inner ring 10, and generate prescribed frictional force. The inner ring 10 does not destroy the position due to this frictional force when it is aligned once. Thereby, dislocation between the rotational center of the diaphragm spring 30 and the shaft center line of the clutch release bearing 8 is corrected when the springs 23 and 25 are rotating in a contact condition, and the clutch release bearing 8 can be held in an aligning position.