Granted Patent B2

US 7,749,125 · App. 11/774,697 · Granted Jul 6, 2010

Abstract

Claims (49)

1. 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;

said first member of said first planetary gear set and said second member of said second planetary gear set being continuously connected with a stationary member;

a first interconnecting member continuously connecting said third member of said second planetary gear set with said third member of said third planetary gear set;

a second interconnecting member continuously connecting said first member of said third planetary gear set with said first member of said fourth planetary gear set;

a third interconnecting member continuously connecting said third member of said first planetary gear set with said second member of said fourth planetary gear set; and

five torque-transmitting devices, wherein each of said five 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 five 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 five torque-transmitting devices is operable for selectively connecting said third member of said first planetary gear set with said stationary member.

3. The transmission of claim 2 , wherein a second of said five torque-transmitting devices is operable for selectively connecting said second member of said first planetary gear set with said first member of said second planetary gear set.

4. The transmission of claim 3 , wherein a third of said five torque-transmitting devices is operable for selectively connecting said first member of said second planetary gear set with said third member of said fourth planetary gear set.

5. The transmission of claim 4 , wherein a fourth of said five torque-transmitting devices is operable for selectively connecting said second member of said third planetary gear set with said third member of said fourth planetary gear set.

6. The transmission of claim 5 , wherein a fifth of said five torque-transmitting devices is operable for selectively connecting said first member of said third planetary gear set with said third member of said fourth planetary gear set.

7. The transmission defined in claim 1 , wherein said first torque-transmitting device comprises a brake, and said second, third, fourth and fifth torque-transmitting devices comprise clutches.

8. The transmission of claim 1 , wherein said first, second and third members of said first, second, third and fourth planetary gear sets comprise a sun gear member, a planet carrier assembly member and a ring gear member, respectively.

9. The transmission of claim 1 , wherein said input member is continuously connected with said first member of said second planetary gear set, and said output member is continuously connected with said second member of said third planetary gear set.

10. The transmission of claim 1 , wherein said second member of said second planetary gear set is a double-pinion carrier.

11. 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;

said input member being continuously connected with said first member of said second planetary gear set; and said output member being continuously connected with said second member of said third planetary gear set;

said first member of said first planetary gear set and said second member of said second planetary gear set being continuously connected with a stationary member;

a first interconnecting member continuously connecting said third member of said second planetary gear set with said third member of said third planetary gear set;

a second interconnecting member continuously connecting said first member of said third planetary gear set with said first member of said fourth planetary gear set;

a third interconnecting member continuously connecting said third member of said first planetary gear set with said second member of said fourth planetary gear set;

a first torque-transmitting device selectively connecting said third member of said first planetary gear set with a stationary member;

a second torque-transmitting device selectively connecting said second member of said first planetary gear set with said first member of said second planetary gear set;

a third torque-transmitting device selectively connecting said first member of said second planetary gear set with said third member of said fourth planetary gear set;

a fourth torque-transmitting device selectively connecting said second member of said third planetary gear set with said third member of said fourth planetary gear set;

a fifth torque-transmitting device selectively connecting said first member of said third planetary gear set with said third member of said fourth planetary gear set; and

said five 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.

12. The transmission of claim 11 , wherein said first, second and third members of said first, second, third and fourth planetary gear sets comprise a sun gear member, a planet carrier assembly member and a ring gear member, respectively.

13. 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 sun gear member of said second planetary gear set, and said output member being continuously interconnected with said planet carrier assembly member of said third planetary gear set;

said sun 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 ring gear member of said second planetary gear set with said ring gear member of said third planetary gear set;

a second interconnecting member continuously connecting said sun gear member of said third planetary gear set with said sun gear member of said fourth planetary gear set;

a third interconnecting member continuously connecting said ring gear member of said first planetary gear set with said planet carrier assembly member of said fourth planetary gear set;

a first torque-transmitting device selectively connecting said ring gear member of said first planetary gear set with said stationary member;

a second torque-transmitting device selectively connecting said planet carrier assembly member of said first planetary gear set with said sun gear member of said second planetary gear set;

a third torque-transmitting device selectively connecting said sun gear member of said second planetary gear set with said ring gear member of said fourth planetary gear set;

a fourth 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 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; and

said five 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.

Assignments (11)