Lubrication device for differential gear unit

摘要

A power transmission unit comprises a trans-axle casing provided with an upright partition wall to subdivide the interior of the casing into front and rear chambers and having a cover plate for sealingly closing the forward open end of the front chamber, a differential gear unit arranged within the front chamber and having a pair of side-journals rotatably supported by a pair of spaced tapered roller bearings carried on a pair of carrier portions of the casing, and a crown wheel integral with the differential gear unit and in mesh with a drive pinion of a final drive gearing. The cover plate is provided at its inner wall integral with a pair of lateral protrusions or ribs extending oppositely downwardly from an upper portion of the cover plate toward each of the carrier portions to receive lubricating oil flowing around the crown wheel and convey it into a pair of side-spaces formed behind the roller bearings, and a pair of annular shim plates are further interposed between each of the carrier portions and each of the roller bearings, each of the shim plates being provided with an oil dam to remain a part of the lubricating oil within the side-spaces.