Patent ID: 10408321

Abstract:
A lock-up device includes a clutch portion, a piston, a sleeve and an oil chamber plate. The clutch portion is disposed between the front cover and a turbine. The piston is movable in an axial direction. The piston turns the clutch portion into a torque transmission state. The sleeve is fixed to a front cover and includes an outer peripheral surface and a protrusion. The outer peripheral surface supports an inner peripheral surface of the piston such that the piston is movable in the axial direction. The protrusion has an annular shape and protrudes radially outward from the outer peripheral surface. The oil chamber plate has a disc shape and is joined to a piston-side lateral surface of the protrusion of the sleeve. The oil chamber plate defines an oil chamber together with the piston therebetween. The oil chamber is supplied a hydraulic oil for activating the piston.