Patent ID: 6688446
Filing Date: 2004-02-10
Classification: F16D,F16H,Y10T

Abstract:
A drive axle assembly for transferring drive torque from a vehicle drivetrain to an axleshaft, comprising:a drive case driven by the drivetrain; an output shaft rotatably supported by said drive case and adapted for connection to the axleshaft; and a hydraulic coupling operably installed between said drive case and said output shaft and including a friction clutch, a fluid pump operable to pump fluid from a sump to a pressure chamber in response to speed differentiation between said drive case and said output shaft, a piston operable to exert a clutch engagement force on said friction clutch proportional to the fluid pressure in said pressure chamber, and a control valve having a valve member moveable from a closed position to an open position when the fluid pressure in said pressure chamber exceeds a predetermined maximum pressure value for venting fluid from said pressure chamber to said sump, and a thermal actuator operable for moving said valve member from its closed position to its open position when the temperature of the fluid exceeds a predetermined maximum temperature level.