Multi-speed transmission for a front wheel drive vehicle
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 housing.
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;
a first, second, third and fourth planetary gear sets disposed within the housing, wherein the fourth 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 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 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 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 fourth planetary gear set, a second 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 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 first and second 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 first, third, fourth and sixth areas;
a second clutch disposed in at least one of the first, third and fourth areas;
a third clutch disposed in at least one of the second, fifth and sixth areas;
a fourth clutch disposed in at least one of the second, fourth, fifth and sixth areas;
a brake disposed in at least one of the first, second 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 and 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 and is disposed in the first area, the second clutch is disposed in the fourth area, the third clutch is disposed in the fifth area, the fourth clutch is disposed in the fifth area and the brake is disposed in the first area.
3. The transaxle of claim 1 wherein the first clutch is disposed within the first area.
4. The transaxle of claim 1 wherein the first clutch is disposed within the third area.
5. The transaxle of claim 1 wherein the first clutch is disposed within the fourth area.
6. The transaxle of claim 1 wherein the first clutch is disposed within the sixth area.
7. The transaxle of claim 1 wherein 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 and wherein the second clutch is disposed within the first area.
8. The transaxle of claim 1 wherein the second clutch is disposed within the third area.
9. The transaxle of claim 1 wherein the second clutch is disposed within the fourth area.
10. The transaxle of claim 1 wherein the third clutch is selectively engageable to interconnect the planet carrier member of the first planetary gear set with the sun gear members of the third and fourth planetary gear sets and wherein the third clutch is disposed within the second area.
11. The transaxle of claim 1 wherein the third clutch is disposed within the fifth area.
12. The transaxle of claim 1 wherein the third clutch is disposed within the sixth area.
13. The transaxle of claim 1 wherein the fourth clutch is selectively engageable to interconnect the ring gear member of the first planetary gear set with the sun gear members of the third and fourth planetary gear sets and wherein the fourth clutch is disposed within the second area.
14. The transaxle of claim 1 wherein the fourth clutch is disposed within the fourth area.
15. The transaxle of claim 1 wherein the fourth clutch is disposed within the fifth area.
16. The transaxle of claim 1 wherein the fourth clutch is disposed within the sixth area.
17. The transaxle of claim 1 wherein the brake is selectively engageable to interconnect the ring gear member of the fourth planetary gear set to the housing and wherein the brake is disposed within the first area.
18. The transaxle of claim 1 wherein the brake is disposed within the second area.
19. The transaxle of claim 1 wherein the brake is disposed within the sixth area.
20. 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;
a first, second, third and fourth planetary gear set disposed within the housing, wherein the fourth 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 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 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 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 fourth planetary gear set, a second 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 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 first and second 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 first, third, fourth and sixth areas;
a second clutch disposed in at least one of the first, third and fourth areas;
a third clutch disposed in at least one of the second, fifth and sixth areas;
a fourth clutch disposed in at least one of the second, fourth, fifth and sixth areas;
a brake disposed in at least one of the first, second 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 power transfer assembly having a first and second transfer gear, wherein the first transfer gear is rotatably fixed to the output member and the second transfer gear is rotatably fixed to a drive shaft;
a power transfer member rotatably coupling the first and second transfer gears for transferring rotational energy from the first transfer gear to the second transfer gear;
a final drive planetary gear set coupling the drive shaft for receiving a driving torque from the second transfer gear; and
a differential gear set coupled to the final drive planetary gear set and to a pair of road wheels for receiving a final drive rotational torque and transferring the final drive torque to the pair of road wheels.
21. The transaxle of claim 20 , wherein the power transfer member is a chain or a belt.