Patent ID: 6953411

Claim:
A drive axle assembly for use in a motor vehicle to transfer drive torque from a powertrain to a pair of wheels, comprising: a hydromechanical coupling having an input shaft driven by the powertrain, a pinion shaft, a transfer clutch disposed in a clutch chamber between said input shaft and said pinion shaft, a piston disposed in a piston chamber and actuatable to engage said transfer clutch for transferring drive torque from said input shaft to said pinion shaft, a fluid pump for pumping hydraulic fluid from a sump to said piston chamber in response to relative rotation between said input shaft and said pinion shaft, and a first control valve mounted to said piston, said control valve operable to vent fluid from said 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; a fluid control system including a first flow path communicating with said piston chamber, a second flow path communicating with said clutch chamber, and a second control valve operable in a first mode to prevent fluid flow from said first flow path to said second flow path and in a second mode to permit fluid flow from said first flow path to said second flow path; and a traction control system including sensors for detecting operating characteristics of the motor vehicle and a control module for receiving sensor signals from said sensors and controlling actuation of said second control valve in response thereto.