US Patent 7114604 Torque converter

A torque converter which can prevent an engagement pressure of a lockup clutch from becoming very high. A converter chamber is formed between an outer disc portion of a front cover and an impeller shell. A partition wall separating a clutch chamber and a converter chamber is provided in the outer disc portion. A clutch chamber has a drive plate serving as an input side of an engine output, a driven plate serving as an output side, and a lockup piston forming an engagement oil chamber along with an inner disc portion of the front cover. Since the partition wall is provided, the lockup clutch can be engaged without being affected by the hydraulic pressure within the converter chamber.