Drive unit assembly

Abstract

A two speed differential axle is disclosed having a lubricant containing housing which encloses engageable differential and planetary gear assemblies. An input shaft extends into the housing and has a pinion gear rigidly affixed to an inner portion thereof. The pinion gear is adapted to drive the differential and planetary gear assemblies. Two pinion bearing assemblies are positioned within a bore in the housing through which the input shaft extends. The pinion bearings operatively support the rotatable input shaft. A generally flat and annular baffle is rigidly affixed to the inner portion of the input shaft between the pinion bearings and the pinion gear. The baffle, the innermost pinion bearing, and a portion of the housing define a lubricant pump chamber for pressurizing and pumping lubricant. The housing further comprises a lubricant passageway having an inlet in communication with the lubricant pump chamber and positioned between the pinion bearings and the baffle, and an outlet adjacent the differential gear assembly. Means are provided for circulating lubricant from the differential gears to an area adjacent the pinion bearings, which are adapted for pumping the lubricant into the lubricant pump chamber and against the rotatable baffle. In operation the rotating baffle creates a lubricant pressure head within the lubricant pump chamber and at the inlet of the lubricant passageway which induces rapid circulation of lubricant through the housing.