Multi-speed transmission
View Patent ↗A 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 first, second and third members. The torque transmitting devices may include clutches and brakes. The torque transmitting mechanisms are selectively engageable in combinations of at least two to establish at least eight forward speed ratios and at least one reverse speed ratio between the input member and the output member.
1. A 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 torque transmitting mechanism selectively engageable to interconnect at least one of the second member of the second planetary gear set and the first member of the first planetary gear set with the third member of the fourth planetary gear set;
a second torque transmitting mechanism selectively engageable to interconnect the third member of the second planetary gear set with the second member of the fourth planetary gear set;
a third torque transmitting mechanism selectively engageable to interconnect at least one of the first member of the third planetary gear set and the first member of the fourth planetary gear set with the third member of the fourth planetary gear set;
a fourth torque transmitting mechanism selectively engageable to interconnect at least one of the second member of the third planetary gear set and the output member with the third member of the fourth planetary gear set; and
a fifth torque transmitting mechanism selectively engageable to interconnect the second member of the fourth planetary gear set with a stationary member, and
wherein the torque transmitting mechanisms are selectively engageable in combinations of at least two to establish at least eight forward speed ratios and at least one reverse speed ratio between the input member and the output member.
2. The transmission of claim 1 wherein the first members are sun gears, the second members are carrier members, and the third members are ring gears.
3. The transmission of claim 1 wherein the input member is continuously interconnected with the first member of the first planetary gear set and wherein the output member is continuously interconnected with the second member of the third planetary gear set.
4. The transmission of claim 1 wherein the at least one reverse speed ratio is achieved by engagement of the first and fifth torque transmitting mechanisms.
5. The transmission of claim 4 wherein a first of the at least eight forward speed ratios is achieved by engagement of the fourth and fifth torque transmitting mechanisms.
6. The transmission of claim 5 wherein a second of the at least eight forward speed ratios is achieved by engagement of the third and fifth torque transmitting mechanisms.
7. The transmission of claim 6 wherein a third of the at least eight forward speed ratios is achieved by engagement of the third and fourth torque transmitting mechanisms.
8. The transmission of claim 7 wherein a fourth of the at least eight forward speed ratios is achieved by engagement of the first and third torque transmitting mechanisms.
9. The transmission of claim 8 wherein a fifth of the at least eight forward speed ratios is achieved by engagement of the second and third torque transmitting mechanisms.
10. The transmission of claim 9 wherein a sixth of the at least eight forward speed ratios is achieved by engagement of the first and second torque transmitting mechanisms.
11. The transmission of claim 10 wherein a seventh of the at least eight forward speed ratios is achieved by engagement of the second and fourth torque transmitting mechanisms.
12. The transmission of claim 11 wherein an eighth of the at least eight forward speed ratios is achieved by engagement of the first and fourth torque transmitting mechanisms.
13. The transmission of claim 1 wherein the first member of the first planetary gear set and the second member of the second planetary gear set form a first rotary member, the second member of the first planetary gear set, the first member of the second planetary gear set and the third member of the third planetary gear set form a second rotary member, the first member of the third planetary gear set and the first member of the fourth planetary gear set form a third rotary member, and the third member of the first planetary gear set and the stationary member form a non-rotary member.
14. A transmission comprising:
an input member;
an output member;
first, second, third and fourth planetary gear sets each having a sun gear, a carrier member, and a ring gear, wherein the input member is continuously interconnected with the sun gear of the first planetary gear set and wherein the output member is continuously interconnected with the carrier member of the third planetary gear set;
at least four continuous interconnections from at least one of the sun gears, carrier members, and ring gears to at least one other of the sun gears, carrier members, ring gears, and a stationary member;
a first torque transmitting mechanism selectively engageable to interconnect at least one of the carrier member of the second planetary gear set and the sun gear of the first planetary gear set with the ring gear of the fourth planetary gear set;
a second torque transmitting mechanism selectively engageable to interconnect the ring gear of the second planetary gear set with the carrier member of the fourth planetary gear set;
a third torque transmitting mechanism selectively engageable to interconnect at least one of the sun gear of the third planetary gear set and the sun gear of the fourth planetary gear set with the ring gear of the fourth planetary gear set;
a fourth torque transmitting mechanism selectively engageable to interconnect at least one of the carrier member of the third planetary gear set and the output member with the ring gear of the fourth planetary gear set; and
a fifth torque transmitting mechanism selectively engageable to interconnect the carrier member of the fourth planetary gear set with the stationary element, and
wherein the torque transmitting mechanisms are selectively engageable in combinations of at least two to establish at least eight forward speed ratios and at least one reverse speed ratio between the input member and the output member.
15. The transmission of claim 14 wherein a first interconnecting member continuous interconnecting the sun gear of the first planetary gear set with the carrier member of the second planetary gear set, a second interconnecting member continuous interconnecting the carrier member of the first planetary gear set with the sun gear of the second planetary gear set and the ring gear of the third planetary gear set, a third interconnecting member continuously interconnecting the sun gear of the third planetary gear set with the sun gear of the fourth planetary gear set, and a fourth interconnecting member continuously interconnecting the ring gear of the first planetary gear set with the stationary member.
16. The transmission of claim 15 wherein the at least one reverse speed ratio is achieved by engagement of the first and fifth torque transmitting mechanisms.
17. The transmission of claim 15 wherein a first of the at least eight forward speed ratios is achieved by engagement of the fourth and fifth torque transmitting mechanisms.
18. The transmission of claim 15 wherein a second of the at least eight forward speed ratios is achieved by engagement of the third and fifth torque transmitting mechanisms.
19. The transmission of claim 15 wherein a third of the at least eight forward speed ratios is achieved by engagement of the third and fourth torque transmitting mechanisms.
20. The transmission of claim 15 wherein a fourth of the at least eight forward speed ratios is achieved by engagement of the first and third torque transmitting mechanisms.
21. The transmission of claim 15 wherein a fifth of the at least eight forward speed ratios is achieved by engagement of the second and third torque transmitting mechanisms.
22. The transmission of claim 15 wherein a sixth of the at least eight forward speed ratios is achieved by engagement of the first and second torque transmitting mechanisms.
23. The transmission of claim 15 wherein a seventh of the at least eight forward speed ratios is achieved by engagement of the second and fourth torque transmitting mechanisms.
24. The transmission of claim 15 wherein an eighth of the at least eight forward speed ratios is achieved by engagement of the first and fourth torque transmitting mechanisms.