Multi-speed transmission with stacked planetary gear sets
A multi-speed transmission is provided that has three planetary gear sets that have a plurality of members positioned to establish only two gear planes. Six torque-transmitting mechanisms are selectively engagable in different combinations to connect different members of the planetary gear sets with an input member, an output member, a stationary member, and one another to establish seven forward speed ratios and a reverse speed ratio. One of the gear planes is established by the first and the second planetary gear sets. The second planetary gear set is positioned concentric with and radially-outward of the first planetary gear set, and the first and second planetary gear sets share a member.
1. A multi-speed transmission comprising:
an input member;
an output member;
a stationary member;
three planetary gear sets having a plurality of members positioned to establish only two gear planes; and
six torque-transmitting mechanisms selectively engagable in different combinations to connect different members of the planetary gear sets with the input member, the output member, the stationary member, and one another to establish seven forward speed ratios and a reverse speed ratio.
2. The multi-speed transmission of claim 1 , wherein a first and a second of the three planetary gear sets are radially stacked, with the second planetary gear set being radially outward of the first planetary gear set to establish a first of the two gear planes; wherein a first of the plurality of members is shared as a ring gear member of the first planetary gear set and a sun gear member of the second planetary gear set.
3. The multi-speed transmission of claim 2 , wherein the plurality of members include a ring gear member of the second planetary gear set, a sun gear member of the third planetary gear set, a carrier member of the first planetary gear set, and a carrier member of the second planetary gear set; and further comprising:
a first interconnecting member continuously connecting the carrier member of the first planetary gear set with the carrier member of the second planetary gear set; and
a second interconnecting member continuously connecting the ring gear member of the second planetary gear set for common rotation with the sun gear member of the third planetary gear set.
4. The multi-speed transmission of claim 3 , wherein the plurality of members include a ring gear member of the third planetary gear set; wherein the input member is continuously connected for common rotation with the first of the plurality of members; and wherein the output member is continuously connected for common rotation with the ring gear member of the third planetary gear set.
5. The multi-speed transmission of claim 1 , wherein the output member is concentric with the input member and the transmission is a front wheel-drive transmission.
6. A multi-speed transmission comprising:
an input member;
an output member;
a first, a second, and a third planetary gear set; wherein the first and second planetary gear sets are radially stacked with respect to one another with a first member common to both; and
six torque-transmitting mechanisms selectively engagable in different combinations to establish seven forward speed ratios and a reverse speed ratio.
7. The multi-speed transmission of claim 6 , wherein the first member common to both the first and the second planetary gear sets is a ring gear member of the first planetary gear set and a sun gear member of the second planetary gear set.
8. The multi-speed transmission of claim 6 , further comprising:
a first interconnecting member continuously connecting a second member of the first planetary gear set for common rotation with a second member of the second planetary gear set.
9. The multi-speed transmission of claim 6 , further comprising:
a second interconnecting member continuously connecting a third member of the second planetary gear set for common rotation with a member of the third planetary gear set.
10. The multi-speed transmission of claim 6 , wherein the input member is continuously connected for common rotation with the first member of the first and second planetary gear sets; and wherein the output member is continuously connected for common rotation with the first member of the third planetary gear set.
11. The multi-speed transmission of claim 6 , further comprising:
a stationary member; and wherein one of the six torque-transmitting mechanisms is selectively engagable to ground a third member of the first planetary gear set to the stationary member.
12. The multi-speed transmission of claim 6 , further comprising:
a stationary member; and wherein one of the six torque-transmitting mechanisms is selectively engagable to ground a third member of the second planetary gear set to the stationary member.
13. The multi-speed transmission of claim 6 , further comprising:
a stationary member; and wherein one of the six torque-transmitting mechanisms is selectively engagable to ground a third member of the third planetary gear set to the stationary member.
14. The multi-speed transmission of claim 6 , further comprising:
a stationary member; and wherein one of the six torque-transmitting mechanisms is selectively engagable to ground a second member of the first planetary gear set and a second member of the second planetary gear set to the stationary member.
15. The multi-speed transmission of claim 6 , wherein one of the six torque-transmitting mechanisms is selectively engagable to connect a third member of the third planetary gear set for common rotation with the first member of the first and second planetary gear sets.
16. The multi-speed transmission of claim 6 , wherein one of the six torque-transmitting mechanisms is selectively engagable to connect a second member of the second planetary gear set for common rotation with a third member of the third planetary gear set.
17. The multi-speed transmission of claim 6 , wherein the output member is concentric with the input member and the transmission is a front wheel-drive transmission.
18. The multi-speed transmission of claim 6 , wherein the first and second planetary gear sets and concentric with the input member and the transmission is a rear wheel-drive transmission.