Patent ID: 6814195
Filing Date: 2004-11-09
Classification: F16H

Abstract:
A lockup clutch for a torque converter, for connecting a pump impeller and a turbine impeller of the torque converter directly to each other, said lockup clutch comprising:a pump extension connected to the pump impeller and surrounding the turbine impeller, a receiving plate connected to said pump extension to define, within said pump extension, a hydraulic pressure chamber communicating with an oil chamber defined between the pump impeller and the turbine impeller, a pressing plate opposed to said receiving plate for movement toward and away from said receiving plate, an annular friction clutch plate which is interposed between said receiving plate and said pressing plate and connected to the turbine impeller, a return spring for biasing said pressing plate in a direction away from said receiving plate, and an escape bore extending through said receiving plate to permit an inside and outside of said receiving plate to communicate with each other on a side of an inner periphery of said friction clutch plate, wherein when a rotational speed of the pump impeller is increased to a value equal to or higher than a predetermined value, said pressing plate clamps said friction clutch plate in cooperation with said receiving plate under an action of a centrifugal hydraulic pressure which is raised within said hydraulic pressure chamber in response to the increase in the rotational speed.