Patent ID: 6945374
Filing Date: 2005-09-20
Classification: B60K

Abstract:
1. A power transmission device comprising: a rotary input member adapted to receive drive torque from a source of drive torque; a rotary output member adapted to transmit drive torque to an output device; a torque transmission mechanism operable for transferring drive torque from said input member to said output member, said torque transmission mechanism including a friction clutch operably disposed between said input member and said output member and a clutch actuator for controlling engagement of said friction clutch, said clutch actuator including a rotary operator and a thrust mechanism, said rotary operator having first and second components defining an actuation chamber and a return chamber therebetween, said first component being fixed for rotation with one of said input and output members and said second component adapted to rotate relative to said first component, and said thrust mechanism is operable for applying a clutch engagement force on said friction clutch in response to rotation of said second component relative to said first component; and an electrohydraulic control system including a fluid pump, an electric motor driving said fluid pump, a control valve disposed in a hydraulic circuit between said fluid pump and said actuation and return chambers, and a control unit for controlling actuation of said control valve for regulating the fluid pressure supplied to at least one of said actuation and return chambers for controlling rotation of said second component relative to said first component of said rotary operator.