Patent ID: 7234577

Claim:
A torque converter having an impeller shell provided with a pump impeller and driven by an engine-output shaft, and a turbine runner opposing to said pump impeller and connected to a main shaft, the torque converter comprising: a front cover with an inside circular-plate portion attached to said engine-output shaft, a tubular drum portion extending axially from said inside circular-plate portion toward said pump impeller, and an outside circular-plate portion extending radially from said drum portion and forming a converter chamber with said impeller shell; a lock-up clutch constituted by a drive plate attached to said drum portion and a driven plate attached to a clutch hub connected to said main shaft; a lock-up piston attached to said front cover so as to be movable axially, and partitioning a clutch chamber accommodating said lock-up clutch and said converter chamber; a generator motor provided at an outer periphery of said lock-up clutch; and pressure regulation means for supplying operating oil to said clutch chamber having approximately the same pressure as that to said converter chamber at a time of releasing engagement of said lock-up clutch, and for making a pressure in said clutch chamber lower than that in said converter chamber at a time of engaging said lock-up clutch.