EIGHT SPEED AUTOMATIC TRANSMISSION
First Claim
1. An automatic transmission comprising, in combination,an input member,an output member,a transmission housing having a first wall, a second wall and a third wall extending between said first and said second walls,a first, a second, a third and a fourth planetary gear assembly disposed within said transmission housing, wherein said first planetary gear assembly is adjacent said first wall, said second planetary gear assembly is adjacent said first planetary gear assembly, said fourth planetary gear assembly is adjacent said second planetary gear assembly and said third planetary gear assembly is between said fourth planetary gear assembly and said second wall, each of said planetary gear assemblies including a sun gear member, a ring gear member and a planet carrier member supporting a plurality of planet gears meshing with said sun gear member and said ring gear member,wherein said input member is coupled to said planet carrier of said first planetary gear assembly, said output member is coupled to said planet carrier of said third planetary gear assembly, said ring gear member of said third planetary gear assembly is coupled to said planet carrier of said fourth planetary gear assembly, said sun gear member of said first planetary gear assembly is coupled to said sun gear member of said fourth planetary gear assembly, said sun gear member of said second planetary gear assembly is coupled to said sun gear member of said third planetary gear assembly and said ring gear member of said first planetary gear assembly is coupled to said planet carrier of said second planetary gear assembly,wherein said transmission housing has a first area radially inward from an outer periphery of said planetary gear assemblies and axially bounded by said first wall and said first planetary gear assembly, a second area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said first and said second planetary gear assemblies, a third area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said second and said fourth planetary gear assemblies, a fourth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said fourth and said third planetary gear assemblies, a fifth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said third planetary gear assembly and said second wall, and a sixth area between said outer periphery of said planetary gear assemblies and said third wall and axially bounded by said first wall and said second wall,a first clutch selectively engageable between said planet carrier of said first planetary gear assembly and said sun gear member of said second planetary gear assembly,a second clutch selectively engageable between said sun gear member of said second planetary gear assembly and said planet carrier of said second planetary gear assembly,a third clutch selectively engageable between said ring gear member of said second planetary gear assembly and said ring gear member of said third planetary gear assembly,a first brake selectively engageable between said sun gear member of said fourth planetary gear assembly and said transmission housing,a second brake selectively engageable between said ring gear member of said fourth planetary gear assembly and said transmission housing,wherein said first clutch is located in one of said first, second and sixth areas, said second clutch is located in one of said first, second and sixth areas, said third clutch is located in one of said second, third, fourth and sixth areas, said first brake is located in one of said first, fifth and sixth areas and said second brake is located in one of said first, fifth and sixth areas,wherein said clutches and brakes are selectively engageable to establish at least eight forward speed ratios and one reverse speed ratio between said input member and said output member.
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Accused Products
Abstract
An eight speed automatic transmission is provided having an input member, an output member, four planetary gear sets and five torque transmitting devices. Three of the planetary gear sets are simple and one planetary gear set is compound. Each of the plurality of planetary gear sets has first, second and third members: a sun gear, a ring gear and a planet carrier having a plurality of planet gears rotatably disposed thereon. Three of the torque transmitting devices are clutches and two of the devices are brakes. Eight embodiments of the transmission having different arrangements of the planetary gear sets, clutches and brakes are disclosed.
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Citations
63 Claims
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1. An automatic transmission comprising, in combination,
an input member, an output member, a transmission housing having a first wall, a second wall and a third wall extending between said first and said second walls, a first, a second, a third and a fourth planetary gear assembly disposed within said transmission housing, wherein said first planetary gear assembly is adjacent said first wall, said second planetary gear assembly is adjacent said first planetary gear assembly, said fourth planetary gear assembly is adjacent said second planetary gear assembly and said third planetary gear assembly is between said fourth planetary gear assembly and said second wall, each of said planetary gear assemblies including a sun gear member, a ring gear member and a planet carrier member supporting a plurality of planet gears meshing with said sun gear member and said ring gear member, wherein said input member is coupled to said planet carrier of said first planetary gear assembly, said output member is coupled to said planet carrier of said third planetary gear assembly, said ring gear member of said third planetary gear assembly is coupled to said planet carrier of said fourth planetary gear assembly, said sun gear member of said first planetary gear assembly is coupled to said sun gear member of said fourth planetary gear assembly, said sun gear member of said second planetary gear assembly is coupled to said sun gear member of said third planetary gear assembly and said ring gear member of said first planetary gear assembly is coupled to said planet carrier of said second planetary gear assembly, wherein said transmission housing has a first area radially inward from an outer periphery of said planetary gear assemblies and axially bounded by said first wall and said first planetary gear assembly, a second area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said first and said second planetary gear assemblies, a third area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said second and said fourth planetary gear assemblies, a fourth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said fourth and said third planetary gear assemblies, a fifth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said third planetary gear assembly and said second wall, and a sixth area between said outer periphery of said planetary gear assemblies and said third wall and axially bounded by said first wall and said second wall, a first clutch selectively engageable between said planet carrier of said first planetary gear assembly and said sun gear member of said second planetary gear assembly, a second clutch selectively engageable between said sun gear member of said second planetary gear assembly and said planet carrier of said second planetary gear assembly, a third clutch selectively engageable between said ring gear member of said second planetary gear assembly and said ring gear member of said third planetary gear assembly, a first brake selectively engageable between said sun gear member of said fourth planetary gear assembly and said transmission housing, a second brake selectively engageable between said ring gear member of said fourth planetary gear assembly and said transmission housing, wherein said first clutch is located in one of said first, second and sixth areas, said second clutch is located in one of said first, second and sixth areas, said third clutch is located in one of said second, third, fourth and sixth areas, said first brake is located in one of said first, fifth and sixth areas and said second brake is located in one of said first, fifth and sixth areas, wherein said clutches and brakes are selectively engageable to establish at least eight forward speed ratios and one reverse speed ratio between said input member and said output member.
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9. An automatic transmission comprising, in combination,
an input member, an output member, a transmission housing having a first wall, a second wall and a third wall extending between said first and said second walls, a first, a second, a third and a fourth planetary gear assembly disposed within said transmission housing, wherein said first planetary gear assembly is adjacent said first wall, said third planetary gear assembly is adjacent said first planetary gear assembly, said second planetary gear assembly is adjacent said third planetary gear assembly and said fourth planetary gear assembly is between said second planetary gear assembly and said second wall, each of said planetary gear assemblies including a sun gear member, a ring gear member and a planet carrier member supporting a plurality of planet gears meshing with said sun gear member and said ring gear member, wherein said input member is coupled to said planet carrier of said first planetary gear assembly, said output member is coupled to said planet carrier of said third planetary gear assembly, said ring gear member of said third planetary gear assembly is coupled to said planet carrier of said fourth planetary gear assembly, said sun gear member of said first planetary gear assembly is coupled to said sun gear member of said fourth planetary gear assembly, said sun gear member of said second planetary gear assembly is coupled to said sun gear member of said third planetary gear assembly and said ring gear member of said first planetary gear assembly is coupled to said planet carrier of said second planetary gear assembly, wherein said transmission housing has a first area radially inward from an outer periphery of said planetary gear assemblies and axially bounded by said first wall and said first planetary gear assembly, a second area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said first and said third planetary gear assemblies, a third area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said third and said second planetary gear assemblies, a fourth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said second and said fourth planetary gear assemblies, a fifth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said fourth planetary gear assembly and said second wall, and a sixth area between said outer periphery of said planetary gear assemblies and said third wall and axially bounded by said first wall and said second wall, a first clutch selectively engageable between said planet carrier of said first planetary gear assembly and said sun gear member of said second planetary gear assembly, a second clutch selectively engageable between said sun gear member of said second planetary gear assembly and said planet carrier of said second planetary gear assembly, a third clutch selectively engageable between said ring gear member of said second planetary gear assembly and said ring gear member of said third planetary gear assembly, a first brake selectively engageable between said sun gear member of said fourth planetary gear assembly and said transmission housing, a second brake selectively engageable between said ring gear member of said fourth planetary gear assembly and said transmission housing, wherein said first clutch is located in one of said first, second and sixth areas, said second clutch is located in one of said second, third, fourth and sixth areas, said third clutch is located in one of said third, fourth, fifth and sixth areas, said first brake is located in one of said first, fifth and sixth areas and said second brake is located in one of said first, fifth and sixth areas, wherein said clutches and brakes are selectively engageable to establish at least eight forward speed ratios and one reverse speed ratio between said input member and said output member.
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17. An automatic transmission comprising, in combination,
an input member, an output member, a transmission housing having a first wall, a second wall and a third wall extending between said first and said second walls, a first, a second, a third and a fourth planetary gear assembly disposed within said transmission housing, wherein said first planetary gear assembly is adjacent said first wall, said fourth planetary gear assembly is adjacent said first planetary gear assembly, said second planetary gear assembly is adjacent said fourth planetary gear assembly and said third planetary gear assembly is between said second planetary gear assembly and said second wall, each of said planetary gear assemblies including a sun gear member, a ring gear member and a planet carrier member supporting a plurality of planet gears meshing with said sun gear member and said ring gear member, wherein said input member is coupled to said planet carrier of said first planetary gear assembly, said output member is coupled to said planet carrier of said third planetary gear assembly, said ring gear member of said third planetary gear assembly is coupled to said planet carrier of said fourth planetary gear assembly, said sun gear member of said first planetary gear assembly is coupled to said sun gear member of said fourth planetary gear assembly, said sun gear member of said second planetary gear assembly is coupled to said sun gear member of said third planetary gear assembly and said ring gear member of said first planetary gear assembly is coupled to said planet carrier of said second planetary gear assembly, wherein said transmission housing has a first area radially inward from an outer periphery of said planetary gear assemblies and axially bounded by said first wall and said first planetary gear assembly, a second area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said first and said fourth planetary gear assemblies, a third area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said fourth and said second planetary gear assemblies, a fourth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said second and said third planetary gear assemblies, a fifth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said third planetary gear assembly and said second wall, and a sixth area between said outer periphery of said planetary gear assemblies and said third wall and axially bounded by said first wall and said second wall, a first clutch selectively engageable between said planet carrier of said first planetary gear assembly and said sun gear member of said second planetary gear assembly, a second clutch selectively engageable between said sun gear member of said second planetary gear assembly and said planet carrier of said second planetary gear assembly, a third clutch selectively engageable between said ring gear member of said second planetary gear assembly and said ring gear member of said third planetary gear assembly, a first brake selectively engageable between said sun gear member of said fourth planetary gear assembly and said transmission housing, a second brake selectively engageable between said ring gear member of said fourth planetary gear assembly and said transmission housing, wherein said first clutch is located in any of said areas, said second clutch is located in one of said first, second, third, fourth and sixth areas, said third clutch is located in one of said third, fourth, fifth and sixth areas, said first brake is located in one of said first, second, fifth and sixth areas and said second brake is located in one of said first, second, fifth and sixth areas, wherein said clutches and brakes are selectively engageable to establish at least eight forward speed ratios and one reverse speed ratio between said input member and said output member.
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25. An automatic transmission comprising, in combination,
an input member, an output member, a transmission housing having a first wall, a second wall and a third wall extending between said first and said second walls, a first, a second, a third and a fourth planetary gear assembly disposed within said transmission housing, wherein said second planetary gear assembly is adjacent said first wall, said first planetary gear assembly is adjacent said second planetary gear assembly, said fourth planetary gear assembly is adjacent said first planetary gear assembly and said third planetary gear assembly is between said fourth planetary gear assembly and said second wall, each of said planetary gear assemblies including a sun gear member, a ring gear member and a planet carrier member supporting a plurality of planet gears meshing with said sun gear member and said ring gear member, wherein said input member is coupled to said planet carrier of said first planetary gear assembly, said output member is coupled to said planet carrier of said third planetary gear assembly, said ring gear member of said third planetary gear assembly is coupled to said planet carrier of said fourth planetary gear assembly, said sun gear member of said first planetary gear assembly is coupled to said sun gear member of said fourth planetary gear assembly, said sun gear member of said second planetary gear assembly is coupled to said sun gear member of said third planetary gear assembly and said ring gear member of said first planetary gear assembly is coupled to said planet carrier of said second planetary gear assembly, wherein said transmission housing has a first area radially inward from an outer periphery of said planetary gear assemblies and axially bounded by said first wall and said second planetary gear assembly, a second area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said second and said first planetary gear assemblies, a third area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said first and said fourth planetary gear assemblies, a fourth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said fourth and said third planetary gear assemblies, a fifth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said third planetary gear assembly and said second wall, and a sixth area between said outer periphery of said planetary gear assemblies and said third wall and axially bounded by said first wall and said second wall, a first clutch selectively engageable between said planet carrier of said first planetary gear assembly and said sun gear member of said second planetary gear assembly, a second clutch selectively engageable between said sun gear member of said second planetary gear assembly and said planet carrier of said second planetary gear assembly, a third clutch selectively engageable between said ring gear member of said second planetary gear assembly and said ring gear member of said third planetary gear assembly, a first brake selectively engageable between said sun gear member of said fourth planetary gear assembly and said transmission housing, a second brake selectively engageable between said ring gear member of said fourth planetary gear assembly and said transmission housing, wherein said first clutch is located in one of said first, second and sixth areas, said second clutch is located in one of said first, second and sixth areas, said third clutch is located in one of said second, fourth and sixth areas, said first brake is located in one of said first, fifth and sixth areas and said second brake is located in one of said first, fifth and sixth areas, wherein said clutches and brakes are selectively engageable to establish at least eight forward speed ratios and one reverse speed ratio between said input member and said output member.
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32. An automatic transmission comprising, in combination,
an input member, an output member, a transmission housing having a first wall, a second wall and a third wall extending between said first and said second walls, a first, a second, a third and a fourth planetary gear assembly disposed within said transmission housing, wherein said second planetary gear assembly is adjacent said first wall, said third planetary gear assembly is adjacent said second planetary gear assembly, said first planetary gear assembly is adjacent said third planetary gear assembly and said fourth planetary gear assembly is between said first planetary gear assembly and said second wall, each of said planetary gear assemblies including a sun gear member, a ring gear member and a planet carrier member supporting a plurality of planet gears meshing with said sun gear member and said ring gear member, wherein said input member is coupled to said planet carrier of said first planetary gear assembly, said output member is coupled to said planet carrier of said third planetary gear assembly, said ring gear member of said third planetary gear assembly is coupled to said planet carrier of said fourth planetary gear assembly, said sun gear member of said first planetary gear assembly is coupled to said sun gear member of said fourth planetary gear assembly, said sun gear member of said second planetary gear assembly is coupled to said sun gear member of said third planetary gear assembly and said ring gear member of said first planetary gear assembly is coupled to said planet carrier of said second planetary gear assembly, wherein said transmission housing has a first area radially inward from an outer periphery of said planetary gear assemblies and axially bounded by said first wall and said second planetary gear assembly, a second area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said second and said third planetary gear assemblies, a third area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said third and said first planetary gear assemblies, a fourth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said first and said fourth planetary gear assemblies, a fifth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said fourth planetary gear assembly and said second wall, and a sixth area between said outer periphery of said planetary gear assemblies and said third wall and axially bounded by said first wall and said second wall, a first clutch selectively engageable between said planet carrier of said first planetary gear assembly and said sun gear member of said second planetary gear assembly, a second clutch selectively engageable between said sun gear member of said second planetary gear assembly and said planet carrier of said second planetary gear assembly, a third clutch selectively engageable between said ring gear member of said second planetary gear assembly and said ring gear member of said third planetary gear assembly, a first brake selectively engageable between said sun gear member of said fourth planetary gear assembly and said transmission housing, a second brake selectively engageable between said ring gear member of said fourth planetary gear assembly and said transmission housing, wherein said first clutch is located in one of said first, second and sixth areas, said second clutch is located in one of said first, second and sixth areas, said third clutch is located in one of said second, third, fourth, fifth and sixth areas, said first brake is located in one of said first, fifth and sixth areas and said second brake is located in one of said fifth and sixth areas, wherein said clutches and brakes are selectively engageable to establish at least eight forward speed ratios and one reverse speed ratio between said input member and said output member.
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40. An automatic transmission comprising, in combination,
an input member, an output member, a transmission housing having a first wall, a second wall and a third wall extending between said first and said second walls, a first, a second, a third and a fourth planetary gear assembly disposed within said transmission housing, wherein said second planetary gear assembly is adjacent said first wall, said third planetary gear assembly is adjacent said second planetary gear assembly, said fourth planetary gear assembly is adjacent said third planetary gear assembly and said first planetary gear assembly is between said fourth planetary gear assembly and said second wall, each of said planetary gear assemblies including a sun gear member, a ring gear member and a planet carrier member supporting a plurality of planet gears meshing with said sun gear member and said ring gear member, wherein said input member is coupled to said planet carrier of said first planetary gear assembly, said output member is coupled to said planet carrier of said third planetary gear assembly, said ring gear member of said third planetary gear assembly is coupled to said planet carrier of said fourth planetary gear assembly, said sun gear member of said first planetary gear assembly is coupled to said sun gear member of said fourth planetary gear assembly, said sun gear member of said second planetary gear assembly is coupled to said sun gear member of said third planetary gear assembly and said ring gear member of said first planetary gear assembly is coupled to said planet carrier of said second planetary gear assembly, wherein said transmission housing has a first area radially inward from an outer periphery of said planetary gear assemblies and axially bounded by said first wall and said second planetary gear assembly, a second area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said second and said third planetary gear assemblies, a third area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said third and said fourth planetary gear assemblies, a fourth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said fourth and said first planetary gear assemblies, a fifth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said first planetary gear assembly and said second wall, and a sixth area between said outer periphery of said planetary gear assemblies and said third wall and axially bounded by said first wall and said second wall, a first clutch selectively engageable between said planet carrier of said first planetary gear assembly and said sun gear member of said second planetary gear assembly, a second clutch selectively engageable between said sun gear member of said second planetary gear assembly and said planet carrier of said second planetary gear assembly, a third clutch selectively engageable between said ring gear member of said second planetary gear assembly and said ring gear member of said third planetary gear assembly, a first brake selectively engageable between said sun gear member of said fourth planetary gear assembly and said transmission housing, a second brake selectively engageable between said ring gear member of said fourth planetary gear assembly and said transmission housing, wherein said first clutch is located in one of said first, second and sixth areas, said second clutch is located in one of said first, second and sixth areas, said third clutch is located in one of said second, third, fourth and sixth areas, said first brake is located in one of said fifth and sixth areas and said second brake is located in one of said third, fourth, fifth and sixth areas, wherein said clutches and brakes are selectively engageable to establish at least eight forward speed ratios and one reverse speed ratio between said input member and said output member.
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48. An automatic transmission comprising, in combination,
an input member, an output member, a transmission housing having a first wall, a second wall and a third wall extending between said first and said second walls, a first, a second, a third and a fourth planetary gear assembly disposed within said transmission housing, wherein said fourth planetary gear assembly is adjacent said first wall, said first planetary gear assembly is adjacent said fourth planetary gear assembly, said second planetary gear assembly is adjacent said first planetary gear assembly and said third planetary gear assembly is between said second planetary gear assembly and said second wall, each of said planetary gear assemblies including a sun gear member, a ring gear member and a planet carrier member supporting a plurality of planet gears meshing with said sun gear member and said ring gear member, wherein said input member is coupled to said planet carrier of said first planetary gear assembly, said output member is coupled to said planet carrier of said third planetary gear assembly, said ring gear member of said third planetary gear assembly is coupled to said planet carrier of said fourth planetary gear assembly, said sun gear member of said first planetary gear assembly is coupled to said sun gear member of said fourth planetary gear assembly, said sun gear member of said second planetary gear assembly is coupled to said sun gear member of said third planetary gear assembly and said ring gear member of said first planetary gear assembly is coupled to said planet carrier of said second planetary gear assembly, wherein said transmission housing has a first area radially inward from an outer periphery of said planetary gear assemblies and axially bounded by said first wall and said fourth planetary gear assembly, a second area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said fourth and said first planetary gear assemblies, a third area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said first and said second planetary gear assemblies, a fourth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said second and said third planetary gear assemblies, a fifth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said third planetary gear assembly and said second wall, and a sixth area between said outer periphery of said planetary gear assemblies and said third wall and axially bounded by said first wall and said second wall, a first clutch selectively engageable between said planet carrier of said first planetary gear assembly and said sun gear member of said second planetary gear assembly, a second clutch selectively engageable between said sun gear member of said second planetary gear assembly and said planet carrier of said second planetary gear assembly, a third clutch selectively engageable between said ring gear member of said second planetary gear assembly and said ring gear member of said third planetary gear assembly, a first brake selectively engageable between said sun gear member of said fourth planetary gear assembly and said transmission housing, a second brake selectively engageable between said ring gear member of said fourth planetary gear assembly and said transmission housing, wherein said first clutch is located in one of said first, second, third, fourth and fifth areas, said second clutch is located in one of said third, fourth and sixth areas, said third clutch is located in one of said third, fourth, fifth and sixth areas, said first brake is located in one of said first, second, fifth and sixth areas and said second brake is located in one of said first, second, fifth and sixth areas, wherein said clutches and brakes are selectively engageable to establish at least eight forward speed ratios and one reverse speed ratio between said input member and said output member.
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56. An automatic transmission comprising, in combination,
an input member, an output member, a transmission housing having a first wall, a second wall and a third wall extending between said first and said second walls, a first, a second, a third and a fourth planetary gear assembly disposed within said transmission housing, wherein said fourth planetary gear assembly is adjacent said first wall, said second planetary gear assembly is adjacent said fourth planetary gear assembly, said first planetary gear assembly is adjacent said second planetary gear assembly and said third planetary gear assembly is between said first planetary gear assembly and said second wall, each of said planetary gear assemblies including a sun gear member, a ring gear member and a planet carrier member supporting a plurality of planet gears meshing with said sun gear member and said ring gear member, wherein said input member is coupled to said planet carrier of said first planetary gear assembly, said output member is coupled to said planet carrier of said third planetary gear assembly, said ring gear member of said third planetary gear assembly is coupled to said planet carrier of said fourth planetary gear assembly, said sun gear member of said first planetary gear assembly is coupled to said sun gear member of said fourth planetary gear assembly, said sun gear member of said second planetary gear assembly is coupled to said sun gear member of said third planetary gear assembly and said ring gear member of said first planetary gear assembly is coupled to said planet carrier of said second planetary gear assembly, wherein said transmission housing has a first area radially inward from an outer periphery of said planetary gear assemblies and axially bounded by said first wall and said fourth planetary gear assembly, a second area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said fourth and said second planetary gear assemblies, a third area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said second and said first planetary gear assemblies, a fourth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said first and said third planetary gear assemblies, a fifth area radially inward from said outer periphery of said planetary gear assemblies and axially bounded by said third planetary gear assembly and said second wall, and a sixth area between said outer periphery of said planetary gear assemblies and said third wall and axially bounded by said first wall and said second wall, a first clutch selectively engageable between said planet carrier of said first planetary gear assembly and said sun gear member of said second planetary gear assembly, a second clutch selectively engageable between said sun gear member of said second planetary gear assembly and said planet carrier of said second planetary gear assembly, a third clutch selectively engageable between said ring gear member of said second planetary gear assembly and said ring gear member of said third planetary gear assembly, a first brake selectively engageable between said sun gear member of said fourth planetary gear assembly and said transmission housing, a second brake selectively engageable between said ring gear member of said fourth planetary gear assembly and said transmission housing, wherein said first clutch is located in one of said first, fourth and fifth areas, said second clutch is located in one of said second, third, fourth and sixth areas, said third clutch is located in one of said second, fifth and sixth areas, said first brake is located in one of said first and sixth areas and said second brake is located in one of said first, fifth and sixth areas, wherein said clutches and brakes are selectively engageable to establish at least eight forward speed ratios and one reverse speed ratio between said input member and said output member.
Specification