| 摘要 |
A rear 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 brakes arranged within a transmission housing. Each of the clutches and brakes are located within specific areas defined by the planetary gear sets and the housing walls. |
| 主权项 |
1. An automatic transmission comprising:
an input member; an output member; a transmission housing having a first wall, a second wall and a third wall extending between the first and the second walls; a first, a second, a third and a fourth planetary gear assembly disposed within the transmission housing, wherein the first planetary gear assembly is adjacent the first wall, the second planetary gear assembly is adjacent the first planetary gear assembly, the third planetary gear assembly is adjacent the second planetary gear assembly, and the fourth planetary gear assembly is between the third planetary gear assembly and the second wall, each of the planetary gear assemblies including a sun gear, a ring gear and a planet carrier member supporting a plurality of planet gears, wherein the input member is coupled to the sun gear of the second planetary gear assembly, the output member is coupled to the planet carrier of the fourth planetary gear assembly and the ring gear of the third planetary gear assembly, the ring gear of the first planetary gear assembly is coupled to the ring gear of the second planetary gear assembly, the planet carrier member of the first planetary gear assembly is coupled to the planet carrier member of the second planetary gear assembly, the planet carrier member of the second planetary gear assembly is coupled to the sun gear of the third planetary gear assembly, and the planet carrier member of the third planetary gear assembly is coupled to the ring gear of the fourth planetary gear assembly, wherein the transmission housing has a first area radially inward from an outer periphery of the planetary gear assemblies and axially bounded by the first wall and the first planetary gear assembly, a second area radially inward from the outer periphery of the planetary gear assemblies and axially bounded by the first and the second planetary gear assemblies, a third area radially inward from the outer periphery of the planetary gear assemblies and axially bounded by the second and the third planetary gear assemblies, a fourth area radially inward from the outer periphery of the planetary gear assemblies and axially bounded by the third and the fourth planetary gear assemblies, a fifth area radially inward from the outer periphery of the planetary gear assemblies and axially bounded by the fourth planetary gear assembly and the second wall, and a sixth area between the outer periphery of the planetary gear assemblies and the third wall and axially bounded by the first wall and the second wall; a first clutch selectively engageable between the input member and the ring gear of the fourth planetary gear assembly; a second clutch selectively engageable between the input member and the sun gear of the fourth planetary gear assembly; a first brake selectively engageable between the sun gear of the first planetary gear assembly and the transmission housing; a second brake selectively engageable between the ring gear of the first planetary gear assembly and the transmission housing; a third brake selectively engageable between the planet carrier member of the first planetary gear assembly and the transmission housing; and a fourth brake selectively engageable between the planet carrier member of the third planetary gear assembly and the transmission housing, and wherein the first clutch is located in one of the first, second, third, and fourth areas, the second clutch is located in one of the first, second, third, and fourth areas, the first brake is located in one of the first, second, and sixth areas, the second brake is located in one of the first, second, third, and sixth areas, the third brake is located in one of the first, second, third, and sixth areas, and the fourth brake is located in one of the third, fourth, fifth, and sixth areas, and wherein the clutches and brakes are selectively engageable to establish at least nine forward speed ratios and one reverse speed ratio between the input member and the output member. |
