Lubrication mechanism in final drive and differential unit.

摘要

A final drive and differential unit for a motor vehicle comprises a differential carrier (20) integrally formed with a cylindrical support structure (21), a a differential gear unit (10) rotatably mounted within the carrier and provided thereon with a ring gear (11), and a drive pinion shaft (30) supported by a pair of axially spaced outside and inside bearings (41,42) within the support structure, the pinion shaft extending outwardly through an annular oil seal member (50) mounted within the outer end portion of the support structure and being provided at its inner end with a pinion (30b) in mesh with the ring gear. The support structure is formed in one side wall thereof with an oil supply passage for (22) permitting the flow of lubricating oil passing therethrough from the interior of the carrier into an annular space (R2) around the pinion shaft between the oil seal member and the outside bearing and is formed in the other side wall thereof with a return passage (23) for permitting the flow of lubricating oil passing therethrough from the annular space into the carrier. The support structure is formed at the inner wall thereof with a recessed portion (24) located above the annular space (R2) around the pinion shaft, and an impeller member (32) is mounted on the pinion shaft for rotation therewith to pick up lubricating oil stored in the annular space toward the recessed portion of the support structure.