Patent ID: 6626787
Filing Date: 2003-09-30
Classification: B60K,F16H

Abstract:
A drive axle assembly for use in a motor vehicle to transfer drive torque from a powertrain to a pair of wheels, comprising:a first hydromechanical coupling having an input shaft driven by the powertrain, a pinion shaft, a first transfer clutch operably disposed between said input shaft and said pinion shaft, a first piston disposed in a first piston chamber and actuatable to engage said first transfer clutch for transferring drive torque to said pinion shaft, a first fluid pump for pumping hydraulic fluid from a sump to said first piston chamber in response to relative rotation between said input shaft and said pinion shaft, and a control valve mounted to said first piston, said control valve operable to vent fluid from said first piston chamber to said sump in response to the occurrence of either of an over-pressure and an over-temperature condition; first and second output shafts adapted for connection to the pair of wheels; a differential assembly including a casing driven by said pinion shaft, and a gearset interconnecting said casing to said first and second output shafts; and a second hydromechanical coupling having a second transfer clutch operably disposed between said casing and said gearset of said differential assembly, a second piston disposed in a second piston chamber which is actuatable in response to fluid pressure in said second piston chamber to engage said second transfer clutch for biasing torque and limiting slip between said first and second output shafts, and a second pump for pumping fluid from said sump to said second piston chamber in response to relative rotation between said casing and one of said first and second output shafts.