PURPOSE: To prevent a deformation of a drum and the like by receiving a piston thrust accurately in a simple structure, in a still type hydraulic cylinder system of clutch.

CONSTITUTION: A sleeve member 65 is formed to the second intermidiate shaft 24 of a transfer member in a thick wall form, and the side of the sleeve member 65 is held by a thrust bearing 66, so as to install the sleeve member to give a large rigidity to the piston thrust. And the drum 67 of a direct clutch 70 is connected integrally to the sleeve 65 to provide a clutch plate 74, a still type cylinder 72 is provided to a fixing side case 6 at the opposite side of the sleeve member 65 of the clutch plate 71, and the piston 73 of the hydraulic cylinder 71 is connected to operate the thrust to the sleeve member 65 through a ball bearing 76, a presser 77, and the clutch plate 74.