Patent ID: 7506740
Filing Date: 2009-03-24
Classification: F16D

Abstract:
1. A power transmission device, comprising: a first rotary member; a second rotary member; a friction clutch operably disposed between said first and second rotary members; a hydraulic clutch actuation system for generating and applying a clutch engagement force to said friction clutch, said hydraulic clutch actuation system including a hydraulic actuator in fluid communication with a clutch actuator, an accumulator operable to store pressurized fluid supplied by said hydraulic actuator and a control valve for controlling delivery of pressurized fluid from said accumulator to said clutch actuator, said hydraulic actuator including a first piston disposed in a first chamber and an electromagnetic operator energizable to control movement of said first piston in said first chamber, and said clutch actuator includes a second piston disposed in a second chamber to apply said clutch engagement force to said friction clutch, said hydraulic clutch actuation system further including a second control valve operable for selectively controlling the delivery of fluid from said second chamber to said first chamber; and a control system for controlling energization of said electromagnetic operator and said control valve.