Hydraulic differential lock

Abstract

A drive axle assembly includes a differential case that is operably coupled to a pair of axle shafts that drive vehicle wheels. A locking mechanism includes a clutch housing that is externally mounted to the differential case. The clutch housing defines a fluid chamber in which first and second sets of discs are mounted. The first set of discs is fixed for movement with the clutch housing and the second set of discs is fixed for movement with one of the axle shafts. An actuating mechanism is used to selectively compress the discs together to lock the clutch housing and associated differential case to the axle shaft under predetermined conditions. A fitting is fixed to the axle housing that defines a fluid path to connect an external fluid supply to the actuating mechanism. The fitting is resistant to torsional and axial movement resulting from the lock mechanism moving to a locked position by the actuating mechanism. The actuating mechanism includes a piston housing held fixed to the axle housing by the fitting as an actuation plate compresses the discs together. A piston is mounted within a piston chamber formed within the piston housing. Actuation thrust force is transferred from the stationary piston to the actuation plate through a pair of thrust bearings.

Dependencies are inferred from the claim text.