Clutch and gear arrangement for a front wheel drive vehicle
View Patent ↗A front wheel drive transmission is provided having an input member, an output member, four planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes a sun gear member, a planet carrier member, and a ring gear member. The torque transmitting devices include clutches and a brake arranged within a transmission housing. Each of the clutches and the brake are located within specific areas defined by the planetary gear sets and the housing walls.
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;
first, second, third and fourth planetary gear sets disposed within the housing, wherein the first planetary gear set is adjacent the first wall, the fourth planetary gear set is adjacent second wall, the second planetary gear set is adjacent the first planetary gear set and the third planetary gear set is between the second and fourth 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 second planetary gear set, the ring gear member of the second planetary gear set is permanently coupled to the planet carrier 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 sun gear member of the third planetary gear set is permanently coupled to the sun gear member of the fourth planetary gear set, the output member is permanently coupled with the carrier member of the fourth planetary gear set, the input member is permanently coupled with the carrier member of the first planetary gear set, and the sun gear member of the first planetary gear set is permanently coupled to the first wall of the housing, 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 first planetary gear set, a second 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 third 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 fourth 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 fifth area defined radially inward from the outer periphery of the planetary gear sets and axially bounded by the fourth 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 first, second, third, fourth, fifth, and sixth areas;
a second clutch disposed in at least one of the first, second, third, fourth, and sixth areas;
a third clutch disposed in at least one of the second, third, fourth, fifth and sixth areas;
a fourth clutch disposed in at least one of the second, third, fourth, and sixth areas;
a brake disposed in at least one of the first, second, third, fourth, fifth, and sixth areas, and
wherein the clutches and the brake 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;
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.
2. The transaxle of claim 1 wherein the first clutch is selectively engageable to interconnect the planet carrier member of the second planetary gear set with the ring gear member of the fourth planetary gear set, the second clutch is selectively engageable to interconnect the planet carrier member of the second planetary gear set with the planet carrier member of the first planetary gear set and the input member, the third clutch is selectively engageable to interconnect the planet carrier member of the first planetary gear set and the input member with the sun gear members of the third and fourth planetary gear sets, the fourth clutch is selectively engageable to interconnect the ring gear member of the first planetary gear set and the sun gear member of the second planetary gear set with the sun gear members of the third and fourth planetary gear sets, and the brake is selectively engageable to interconnect the ring gear member of the fourth planetary gear set to the housing.
3. The transaxle of claim 2 wherein the first clutch is disposed in the sixth area, the second clutch is disposed in the first area, the third clutch is disposed in the fifth area, the fourth clutch is disposed in the third area, and the brake is disposed in the fifth area.