8-speed transmission
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 three planetary gear sets, six torque-transmitting devices, a split sun gear, two fixed interconnections and a grounded member. The powertrain includes an engine and torque converter that is continuously connected to one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six torque-transmitting devices provide interconnections between various gear members, and the transmission housing, and are operated in combinations of two to establish eight forward speed ratios and one reverse speed ratio.
1. A multi-speed transmission comprising:
an input member;
an output member;
first, second and third planetary gear sets each having first, second and third members and wherein the first member of one of said planetary gear sets is split into first and second portions;
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 first planetary gear set with said first member of said third planetary gear set;
said third member of said first planetary gear set being continuously connected with a stationary member; and
six torque-transmitting devices, wherein each of said six torque-transmitting devices selectively interconnects said members of said planetary gear sets with said stationary member or with other members of said planetary gear sets, said six torque-transmitting devices being engaged in combinations of two to establish at least eight forward speed ratios and at least one reverse speed ratio between said input member and said output member.
2. The transmission of claim 1 , wherein a first of said six torque-transmitting devices is operable for selectively connecting said second member of said third planetary gear set with said stationary member.
3. The transmission of claim 2 , wherein a second of said six torque-transmitting devices is operable for selectively connecting said first member of said first planetary gear set with said stationary member.
4. The transmission of claim 3 , wherein a third of said six torque-transmitting devices is operable for selectively connecting said first member of said first planetary gear set with said second member of said second planetary gear set.
5. The transmission of claim 4 , wherein the first member of said one of said planetary gear sets is the first member of said second planetary gear set, and wherein a fourth of said six torque-transmitting devices is operable for selectively connecting said first member of said first planetary gear set with said second portion of said first member of said second planetary gear set.
6. The transmission of claim 5 , wherein a fifth of said six torque-transmitting devices is operable for selectively connecting said second member of said second planetary gear set with said third member of said third planetary gear set.
7. The transmission of claim 6 , wherein a sixth of said six torque-transmitting devices is operable for selectively connecting said second portion of said first member of said second planetary gear set with said second member of said third planetary gear set.
8. The transmission defined in claim 1 , wherein said first and second torque-transmitting devices comprises brakes, and said third, fourth, fifth and sixth torque-transmitting devices comprise clutches.
9. The transmission of claim 1 , wherein said first, second and third members of said first, second and third planetary gear sets comprise a sun gear member, a planet carrier assembly member and a ring gear member, respectively.
10. The transmission of claim 1 , wherein the first member of said one of said planetary gear sets is the first member of said second planetary gear set, and wherein said input member is continuously connected with said first portion of said first member of said second planetary gear set; and said output member is continuously connected with said third member of said third planetary gear set.
11. The transmission of claim 1 , wherein a connection to one of said torque-transmitting devices extends between said first and second portions of said split first member.
12. A multi-speed transmission comprising:
an input member;
an output member;
first, second and third planetary gear sets each having first, second and third members and wherein the first member of said second planetary gear set is split into first and second portions thereby allowing said second member of said one of said planetary gear sets to be selectively connected to other members of said one planetary gear sets between said first and second portions;
said input member being continuously connected with said first portion of said first member of said second planetary gear set;
said output member being continuously connected with said third member of said third planetary gear set;
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 first planetary gear set with said first member of said third planetary gear set;
said third member of said first planetary gear set being continuously connected with a stationary member;
a first torque-transmitting device selectively connecting said second member of said third planetary gear set with said stationary member;
a second torque-transmitting device selectively connecting said first member of said first planetary gear set with said stationary member;
a third torque-transmitting device selectively connecting said first member of said first planetary gear set with said second member of said second planetary gear set;
a fourth torque-transmitting device selectively connecting said first member of said first planetary gear set with said second portion of said first member of said second planetary gear set;
a fifth torque-transmitting device selectively connecting said second member of said second planetary gear set with said third member of said third planetary gear set;
a sixth torque-transmitting device selectively connecting said first member of said second planetary gear set with said second member of said third planetary gear set; and
said six torque-transmitting devices being engaged in combinations of two to establish at least eight forward speed ratios and at least one reverse speed ratio between said input member and said output member.
13. The transmission of claim 12 , wherein said first, second and third members of said first, second and third planetary gear sets comprise a sun gear member, a planet carrier assembly member and a ring gear member, respectively.
14. A multi-speed transmission comprising:
an input member;
an output member;
first, second and third planetary gear sets each having a sun gear member, planet carrier assembly member and ring gear member and wherein the sun gear member of said second planetary gear set is split into first and second portions thereby allowing said planet carrier assembly member of said second planetary gear set to be selectively connected to other members of said planetary gear sets between said first and second portions;
said input member being continuously interconnected with said first portion of said sun gear member of said second planetary gear set;
said output member being continuously interconnected with said ring gear member of said third planetary gear set;
said ring gear member of said first 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 first planetary gear set with said sun gear member of said third planetary gear set;
a first torque-transmitting device selectively connecting said planet carrier assembly member of said third planetary gear set with said stationary member;
a second torque-transmitting device selectively connecting said sun gear member of said first planetary gear set with said stationary member;
a third torque-transmitting device selectively connecting said sun gear member of said first planetary gear set with said planet carrier assembly member of said second planetary gear set;
a fourth torque-transmitting device selectively connecting said sun gear member of said first planetary gear set with said second portion of said sun gear member of said second planetary gear set;
a fifth torque-transmitting device selectively connecting said planet carrier assembly member of said second planetary gear set with said ring gear member of said third planetary gear set;
a sixth torque-transmitting device selectively connecting said second portion of said sun gear member of said second planetary gear set with said planet carrier assembly member of said third planetary gear set;
said six torque-transmitting devices being engaged in combinations of two to establish eight forward speed ratios and one reverse speed ratio between said input member and said output member.