Patent ID: 8241167
Filing Date: 2012-08-14
Classification: F16H

Abstract:
1. A transaxle comprising: a transmission input member; a transmission output member; a housing having a first wall, a second wall, and a third wall extending between the first and second walls; a first, second, third and fourth planetary gear sets disposed within the housing, wherein the second planetary gear set is adjacent the first wall, the first planetary gear set is adjacent second wall, the third planetary gear set is adjacent the second planetary gear set and the fourth 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 ring gear member of the first planetary gear set is permanently coupled to the sun gear member of the fourth planetary gear set, the sun gear member of the first planetary gear set is permanently coupled to the sun gear member of the second planetary gear set, the planet carrier member of the second planetary gear set is permanently coupled to the ring gear member of the third planetary gear set, the planet carrier member of the third planetary gear set is permanently coupled to the planet carrier member of the fourth planetary gear set, the transmission output member is permanently coupled with the carrier members of the third and fourth planetary gear sets, and the transmission input member is permanently coupled with the carrier member of the first 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 second planetary gear set, a second 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 third area defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the third and fourth planetary gear sets, a fourth area defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the first and fourth planetary gear set, a fifth area defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the first 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 disposed in at least one of the second, third, fourth and sixth areas; a second clutch disposed in at least one of the third, fourth, fifth and sixth areas; a third clutch disposed in at least one of the second, third, fourth and sixth areas; a first brake disposed in at least one of the first, second, third and sixth areas; a second brake disposed in at least one of the first, second, third 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 transmission input member and the transmission output member; a transfer gear train having a first and second transfer gear, wherein the first transfer gear is rotatably fixed to the transmission 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.