US 7,727,102 B2Granted

8-speed transmission

AssigneeGM Global Technology Operations LLC

InventorsAndrew W. Phillips, Clinton E. Carey, James M. Hart, Scott H. Wittkopp, Madhusudan Raghavan

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Abstract

The transmission has a plurality of members that can be utilized in powertrains to provide eight forward speed ratios and one reverse speed ratio. The transmission includes four planetary gear sets having five torque-transmitting devices, two fixed interconnections and two grounded members. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The five torque-transmitting devices provide interconnections between various gear members, and are operated in combinations of three to establish at least eight forward speed ratios and at least one reverse speed ratio.

Claims11

Dependent claims

A multi-speed transmission comprising:

an input member;
an output member;
first, second, third and fourth planetary gear sets each having first, second and third members;
a first interconnecting member continuously connecting said second member of said first planetary gear set with said third member of said second planetary gear set;
a second interconnecting member continuously connecting said first member of said second planetary gear set with said third member of said third planetary gear set;
said third member of said first planetary gear set and said second member of said second planetary gear set being continuously connected with a stationary member;
and
five torque-transmitting devices for selectively interconnecting said members of said planetary gear sets with other members of said planetary gear sets, said five torque-transmitting devices being engaged in combinations of three to establish at least eight forward speed ratios and at least one reverse speed ratio between said input member and said output member.

5 more elements

A multi-speed transmission comprising:

an input member;
an output member;
first, second, third and fourth planetary gear sets each having a sun gear member, planet carrier assembly member and ring gear member;
said input member being continuously interconnected with said planet carrier assembly member of said third planetary gear set;
said output member being continuously interconnected with said planet carrier assembly member of said fourth planetary gear set;
said ring gear member of said first planetary gear set and said planet carrier assembly member of said second planetary gear set being continuously connected with a stationary member;
a first interconnecting member continuously connecting said planet carrier assembly member of said first planetary gear set with said ring gear member of said second planetary gear set;
a second interconnecting member continuously connecting said sun gear member of said second planetary gear set with said ring gear member of said third planetary gear set;
a first torque-transmitting device selectively connecting said sun gear member of said first planetary gear set with said ring gear member of said fourth planetary gear set;
a second torque-transmitting device selectively connecting said planet carrier assembly member of said first planetary gear set with said planet carrier assembly member of said fourth planetary gear set;
a third torque-transmitting device selectively connecting said planet carrier assembly member of said third planetary gear set with said ring gear member of said fourth planetary gear set;
a fourth torque-transmitting device selectively connecting said sun gear member of said third planetary gear set with said sun gear member of said fourth planetary gear set;
a fifth torque-transmitting device selectively connecting said sun gear member of said third planetary gear set with said ring gear member of said fourth planetary gear set;
said torque-transmitting devices being engaged in combinations of three to establish at least eight forward speed ratios and at least one reverse speed ratio between said input member and said output member.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/844,368Filed 24 Aug 2007 · us provisional application
Priority: 30 Mar 2007
Published: US 2008/0242472 A12 Oct 2008
Granted: 1 Jun 2010
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

F16H 3/666
Composed of a number of gear trains without drive passing from one train to another: with intermeshing orbital gears
F16H 2200/006
Characterised by the number of forward speeds: the gear ratios comprising eight forward speeds
F16H 2200/2012
Characterised by the number of sets of orbital gears: with four sets of orbital gears
F16H 2200/2043
Characterised by the engaging friction means not of the freewheel type, e.g. friction clutches or brakes: with five engaging means