Patent ID: 6264018
Filing Date: 2001-07-24
Classification: F16H

Abstract:
A lockup device adapted to be used in a torque converter having a front cover with a friction surface on its inner side, an impeller and a turbine, said lockup device being adapted to be disposed in a space between the turbine and the front cover for mechanically engaging and disengaging the front cover to the turbine, said lockup device comprising:a plate disposed adjacent a friction surface of the front cover;a damper mechanism arranged to elastically couple said plate and the turbine in a rotating direction, said damper mechanism having a drive member for receiving a torque from said plate, a driven member for outputting the torque to said turbine, and at least one torsion spring for elastically coupling said drive member and said driven member together in the rotating direction;a piston adapted to move within the space in accordance with pressure changes in the space, said piston being an annular member disposed on a side of said plate away from the friction surface of the front cover, said piston being non-rotatably coupled to said front cover, but axially movable relative to said front cover, said piston having an inner diameter that is larger than an outer diameter of said driven member of said damper mechanism, said piston being arranged radially outside of said driven member of said damper mechanism.