Toyota Jidosha Kabushiki Kaisha

Hiroshi Hori

Kiyoshi Taniyama

Yasuyoshi Yasui

Katumi Huruhata

A final drive and differential unit for a motor vehicle comprises a differential carrier integrally formed with a cylindrical support structure, a differential gear unit rotatably mounted within the carrier and provided thereon with a ring gear, and a drive pinion shaft supported by a pair of axially spaced outside and inside bearings within the support structure, the pinion shaft extending outwardly through an annular oil seal member mounted within the outer end portion of the support structure and being provided at its inner end with a pinion in mesh with the ring gear. The support structure is formed in one side wall thereof with an oil supply passage for permitting the flow of lubricating oil passing therethrough from the interior of the carrier into an annular space 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 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 located above the annular space around the pinion shaft, and an impeller member 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.

Lubrication mechanism in final drive and differential unit

Outside of the oil seal attached to the side gear shaft position in the final reduction gear apparatus, a guide member is installed which has an inner diameter slightly larger than that of the main lip of the oil seal and has a guide surface concentric to the main lip; the side gear shaft is pushed along the guide surface of said guide member, whereby the interference between the side gear shaft and the main lip of the oil seal can be minimized, thus preventing damage to the main lip and assuring the normal function of the oil seal to prevent oil leakage; and the assembling of the side gear shaft is facilitated through exact and easy centering of the side gear shaft.

Final reduction gear apparatus

In a final drive and differential unit comprising a ring gear integral with a differential gear unit rotatably mounted within a carrier, and a drive pinion shaft supported by a pair of axially spaced bearings within a cylindrical support structure of the carrier, the shaft extends outwardly through an oil seal member mounted within an outer end portion of the support structure and is provided at its inner end with a drive pinion in mesh with the ring gear. The support structure is formed at one side thereof with an enlarged portion formed therein with an oil supply passage opening at its one end into the carrier at the same side as the ring gear and is formed at the other side thereof with another enlarged portion formed therein with an oil return passage opening at its opposite ends into the carrier and into a first annular space between the oil seal member and the bearing. The support structure is formed in its side wall with first and second lateral holes respectively for communication between the oil supply passage and a second annular space between the bearings and for communication between the oil supply passage and the first annular space. The lowermost edge of the second lateral hole is positioned below the lowermost edge of the first lateral hole to ensure the flow of lubricating oil into the first annular space passing across the second lateral hole.

Lubrication mechanism in final drive and differential units

A lubricating structure of a differential carrier includes a drive pinion shaft attaching portion, an oil supply hole and an oil return hole extended respectively along and provided on both sides of the attaching portion and a ring gear attaching portion formed to extend the axis of a ring gear in the direction crossing these holes. A gap between a portion located on the lower side of the oil supply hole in a member surrounding the ring gear attaching portion and the ring gear disposed in the attaching portion is formed so as to be larger than that between a portion located on the upper side of the oil supply hole in the member and the ring gear. The oil supply hole is formed to give an inclination downward in front when the differential carrier is mounted on a car body.

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Toyota, Japan

Hiroshi Hori