Patent ID: 8550954
Filing Date: 2013-10-08
Classification: F16H

Abstract:
1. A transaxle comprising: an input member; an output member; a housing having a first wall, a second wall, and a third wall extending between the first and second walls, wherein the input member and the output member both extend through the second wall; first, second, third and fourth planetary gear sets disposed within the housing, wherein the fourth planetary gear set is adjacent the first wall, the third planetary gear set is adjacent second wall, the first planetary gear set is adjacent the fourth planetary gear set and the second planetary gear set is between the first and third planetary gear sets, each planetary gear set having a sun gear member, a ring gear member, and a planet carrier member supporting a plurality of planet gears each configured to intermesh with both the sun gear member and the ring gear member, and wherein the sun gear member of the first planetary gear set is permanently coupled to the sun gear member of the fourth planetary gear set, the ring gear member of the first planetary gear set is permanently coupled to the sun gear member of the second planetary gear set, the ring gear member of the second planetary gear set is permanently coupled to the sun gear member of the third planetary gear set, the ring gear member of the third planetary gear set is permanently coupled to the planet carrier member of the fourth planetary gear set, the input member is permanently coupled to the planet carrier member of the first planetary gear set, and the output member is permanently coupled to the planet carrier member of the third planetary gear set, and wherein the housing has a first area defined radially inward from an outer periphery of the planetary gear sets and axially bounded by the first wall and the fourth planetary gear set, a second area defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the fourth and first planetary gear sets, a third area defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the first and second planetary gear sets, a fourth area defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the second and third planetary gear sets, a fifth area defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the third planetary gear set and the second wall, and a sixth area defined radially inward from the third wall and radially outward from the outer periphery of the planetary gear sets and axially bounded by the first wall and the second wall, a first clutch only disposed in one of the third, fourth, and sixth areas; a second clutch only disposed in one of the third, fourth, and fifth areas; a third clutch only disposed in one of the third, fourth, fifth and sixth areas; a first brake only disposed in one of the first, second, and sixth areas; a second brake only disposed in one of the first, second, third, fifth, and sixth areas, and wherein the clutches and the brakes are selectively engageable to establish at least eight forward speed ratios and at least one reverse speed ratio between the input member and the output member and wherein the first clutch is selectively engageable to interconnect the planet carrier member of the second planetary gear set with at least one of the planet carrier member of the third planetary gear set and the output member, the second clutch is selectively engageable to interconnect at least one of the sun gear member of the second planetary gear set and the ring gear member of the first planetary gear set with at least one of the sun gear member of the third planetary gear set and the ring gear member of the second planetary gear set, the third clutch is selectively engageable to interconnect at least one of the sun gear member of the third planetary gear set and the ring gear member of the second planetary gear set with at least one of the planet carrier member of the first planetary gear set and the input member, the first brake is selectively engageable to interconnect at least one of the sun gear member of the first planetary gear set and the sun gear member of the fourth planetary gear set with the housing, and the second brake is selectively engageable to interconnect the ring gear member of the fourth planetary gear set with the housing, a transfer gear train having a first transfer gear intermeshed with a second transfer gear, wherein the first transfer gear is rotatably fixed to the output member and the second transfer gear is rotatably fixed to an intermediate shaft; a differential gear set for driving a pair of road wheels; a pinion gear rotatably fixed to the intermediate shaft; and an input differential gear in mesh with the pinion gear and configured to rotatably drive the differential gear set.