Patent ID: 6948604
Filing Date: 2005-09-27
Classification: B60K,F16D

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 transfer clutch operably disposed between said input member and said output member and a clutch actuator for controlling engagement of said transfer clutch, said transfer clutch including a first friction clutch and a second friction clutch, said clutch actuator including a fluid pump, a rotary operator and a thrust mechanism, said rotary operator including first and second components defining an actuation chamber therebetween that is adapted to receive pressurized fluid from said pump, 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 in response to the fluid pressure in said actuation chamber, and said thrust mechanism is operable for applying a clutch actuation force on said second friction clutch in response to rotation of said second component relative to said first component for causing a corresponding clutch engagement force to be applied to said first friction clutch; and a control system including a motor driving said pump, a control valve disposed in a hydraulic circuit between said pump and said actuation chamber, and a control unit for controlling actuation of said motor and said control valve for regulating the fluid pressure supplied to said actuation chamber.