Transmission with double-sun, one ring, and double-annular gear coplanar gear set

1. A transmission comprising:

a first gear set having:

a first sun gear member rotatable about a first axis of rotation; wherein the first sun gear member has a radially outward-facing surface defining outer teeth;

a second sun gear member rotatable about the first axis of rotation; wherein the second sun gear member has a radially outward-facing surface defining outer teeth;

a carrier member;

a ring gear member radially outward of and concentric with the first sun gear member and the second sun gear member and rotatable about the first axis of rotation; wherein the ring gear member has a radially inward-facing surface defining inner teeth;

a first annular gear supported by the carrier member and having a radially inward-facing surface defining inner teeth and a radially outward-facing surface defining outer teeth; wherein the first annular gear is rotatable about a second axis of rotation that rotates about the first axis of rotation; wherein the inner teeth of the first annular gear mesh with the outer teeth of the first sun gear member;

a second annular gear supported by the carrier member and having a radially inward-facing surface defining inner teeth and a radially outward-facing surface defining outer teeth; wherein the second annular gear is rotatable about a third axis of rotation that rotates about the first axis of rotation; and wherein the inner teeth of the second annular gear mesh with the outer teeth of the first annular gear and with the outer teeth of the second sun gear member, and the outer teeth of the second annular gear mesh with the inner teeth of the ring gear member.

2. The transmission of claim 1 , further comprising:

a first set of cluster bearings positioned between the first annular gear and the carrier member to permit relative rotation thereof; and

a second set of cluster bearings positioned between the second annular gear and the carrier member to permit relative rotation thereof.

3. The transmission of claim 1 , further comprising:

a shaft extending from the first sun gear member; wherein the carrier member has an opening through which the shaft extends and is rotatably supported by the carrier member to establish the first axis of rotation;

wherein the carrier member has a first eccentric hub supporting the first annular gear to define the second axis of rotation; and

wherein the carrier member has a second eccentric hub supporting the second annular gear to define the third axis of rotation.

4. The transmission of claim 3 , wherein the first eccentric hub extends axially from the second eccentric hub.

5. The transmission of claim 3 , wherein the second sun gear member has an opening through which the shaft extends and is rotatably supported by the second sun gear member; and wherein the first sun gear member is positioned axially between the second sun gear member and the carrier member.

6. The transmission of claim 1 , further comprising:

a second gear set having a sun gear member, a ring gear member, and a carrier member;

a stationary member;

wherein the sun gear member of the second gear set is continuously grounded to the stationary member;

an input member continuously interconnected with the ring gear member of the second gear set;

an output member continuously interconnected with the ring gear member of the first gear set;

five torque-transmitting-mechanisms including:

a first torque-transmitting mechanism selectively engageable to interconnect the carrier member of the first gear set with the carrier member of the second gear set;

a second torque-transmitting mechanism selectively engageable to ground the second sun gear member of the first gear set to the stationary member;

a third torque-transmitting mechanism selectively engageable to ground the first sun gear member of the first gear set to the stationary member;

a fourth torque-transmitting mechanism selectively engageable to interconnect the first sun gear member of the first gear set to the carrier member of the second gear set;

a fifth torque-transmitting mechanism selectively engageable to interconnect the input member with the second sun gear member of the first gear set; and

wherein the five torque-transmitting mechanisms are selectively engageable in different combinations to establish six forward speed ratios and a reverse speed ratio of the input member to the output member.

7. The transmission of claim 6 , wherein shifts between adjacent ones of the six forward speed ratios are single transition shifts.

8. A transmission comprising:

a first gear set having:

a first sun gear member rotatable about a first axis of rotation; wherein the first sun gear member has a radially outward-facing surface defining outer teeth;

a second sun gear member rotatable about the first axis of rotation; wherein the second sun gear member has a radially outward-facing surface defining outer teeth;

a carrier member having a first eccentric hub and a second eccentric hub defining a second axis of rotation and a third axis of rotation, respectively;

a ring gear member radially outward of and concentric with the first sun gear member and the second sun gear member and rotatable about the first axis of rotation; wherein the ring gear member has a radially inward-facing surface defining inner teeth;

a first annular gear supported by the carrier member on the first eccentric hub and having a radially inward-facing surface defining inner teeth and a radially outward-facing surface defining outer teeth; wherein the first annular gear is rotatable about the second axis of rotation; wherein the inner teeth of the first annular gear mesh with the outer teeth of the first sun gear member;

a second annular gear supported by the carrier member on the second eccentric hub and having a radially inward-facing surface defining inner teeth and a radially outward-facing surface defining outer teeth; wherein the second annular gear is rotatable about the third axis of rotation; wherein the inner teeth of the second annular gear mesh with the outer teeth of the first annular gear and the outer teeth of the second sun gear member, and the outer teeth of the second annular gear mesh with the inner teeth of the ring gear member;

wherein meshing of the first sun gear member with the first annular gear, meshing of the first annular gear with the second annular gear, and meshing of the second annular gear with the ring gear member all occur in a first plane that is perpendicular to the first axis of rotation; and

wherein meshing of the second sun gear member with the second annular gear, and meshing of the second annular gear with the ring gear member occur in a second plane that is perpendicular to the first axis of rotation.

9. The transmission of claim 8 , further comprising:

a first set of cluster bearings positioned between the first annular gear and the carrier member to permit relative rotation thereof; and

a second set of cluster bearings positioned between the second annular gear and the carrier member to permit relative rotation thereof.

10. The transmission of claim 8 , further comprising:

a shaft extending from the first sun gear member; wherein the carrier member has an opening in which the shaft is rotatably supported to establish the first axis of rotation.

11. The transmission of claim 10 , wherein the ring gear member has a hub with an opening in which the shaft is rotatably supported so that the first sun gear member and the second sun gear member are positioned axially between the carrier member and the hub of the ring gear member.

12. The transmission of claim 8 , wherein the first eccentric hub extends axially from the second eccentric hub.

13. The transmission of claim 8 , further comprising:

a second gear set having a sun gear member, a ring gear member, and a carrier member;

a stationary member;

wherein the sun gear member of the second gear set is continuously grounded to the stationary member;

an input member continuously interconnected with the ring gear member of the second gear set;

an output member continuously interconnected with the ring gear member of the first gear set;

five torque-transmitting mechanisms including:

a first torque-transmitting mechanism selectively engageable to interconnect the carrier member of the first gear set with the carrier member of the second gear set;

a second torque-transmitting mechanism selectively engageable to ground the second sun gear member of the first gear set to the stationary member;

a third torque-transmitting mechanism selectively engageable to ground the first sun gear member of the first gear set to the stationary member;

a fourth torque-transmitting mechanism selectively engageable to interconnect the first sun gear member of the first gear set to the carrier member of the second gear set;

a fifth torque-transmitting mechanism selectively engageable to interconnect the input member with the second sun gear member of the first gear set; and

wherein the five torque-transmitting mechanisms are selectively engageable in different combinations to establish six forward speed ratios and a reverse speed ratio of the input member to the output member.

14. The transmission of claim 13 , wherein shifts between adjacent ones of the six forward speed ratios are single transition shifts.

15. A transmission comprising:

a first gear set having:

a first sun gear member rotatable about a first axis of rotation; wherein the first sun gear member has a radially outward-facing surface defining outer teeth;

a second sun gear member rotatable about the first axis of rotation; wherein the second sun gear member has a radially outward-facing surface defining outer teeth;

a carrier member;

a ring gear member radially outward of and concentric with the first sun gear member and the second sun gear member, and rotatable about the first axis of rotation; wherein the ring gear member has a radially inward-facing surface defining inner teeth;

a first annular gear supported by the carrier member and having a radially inward-facing surface defining inner teeth and a radially outward-facing surface defining outer teeth; wherein the first annular gear is rotatable about a second axis of rotation that rotates about the first axis of rotation; wherein the inner teeth of the first annular gear mesh with the outer teeth of the first sun gear member;

a second annular gear supported by the carrier member and having a radially inward-facing surface defining inner teeth and a radially outward-facing surface defining outer teeth; wherein the second annular gear is rotatable about a third axis of rotation that rotates about the first axis of rotation; and wherein the inner teeth of the second annular gear mesh with the outer teeth of the first annular gear and the outer teeth of the second sun gear member, and the outer teeth of the second annular gear mesh with the inner teeth of the ring gear member;

a first set of cluster bearings positioned between the first annular gear and the carrier member to permit relative rotation thereof;

a second set of cluster bearings positioned between the second annular gear and the carrier member to permit relative rotation thereof;

a second gear set having a ring gear member, a carrier member, and a sun gear member;

an input member continuously interconnected with the ring gear member of the second gear set;

an output member continuously interconnected with the ring gear member of the first gear set;

a stationary member;

five torque-transmitting mechanisms including:

a first torque-transmitting mechanism selectively engageable to interconnect the carrier member of the first gear set with the carrier member of the second gear set;

a second torque-transmitting mechanism selectively engageable to ground the second sun gear member of the first gear set to the stationary member;

a third torque-transmitting mechanism selectively engageable to ground the first sun gear member of the first gear set to the stationary member;

a fourth torque-transmitting mechanism selectively engageable to interconnect the first sun gear member of the first gear set to the carrier member of the second gear set;

a fifth torque-transmitting mechanism selectively engageable to interconnect the input member with the second sun gear member of the first gear set; and

wherein the five torque-transmitting mechanisms are selectively engageable in different combinations to establish six forward speed ratios and a reverse speed ratio of the input member to the output member.

16. The transmission of claim 15 , wherein shifts between adjacent ones of the five forward speed ratios are single transition shifts.