Multi-speed transmission having a reduction planetary gear set

Patent metadata

Field	Value
Publication number	US-2016245372-A1
Application number	US-201514627588-A
Country	US
Kind code	A1
Filing date	Feb 20, 2015
Priority date	Feb 20, 2015
Publication date	Aug 25, 2016
Grant date	—

Abstract

A transmission is provided having an input member, an output member, two planetary gear sets one of which is a selectively speed reducing gear set, another two planetary gear sets that may be stacked or nested to form a planetary gear set assembly, 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 stacked or nested planetary gear set assembly has a carrier member for rotatably supporting a first plurality of pinion gears and a second plurality of pinion gears, a ring gear and a common gear member. The torque transmitting devices include clutches and brakes.

First claim

1 . A transmission comprising:
an input member; an output member; a planetary gear set assembly having a first member, a second member, a third member and a fourth member; a first planetary gear set having a first, a second and a third member; a first interconnecting member continuously interconnecting the second member of the planetary gear set assembly with the first member of the first planetary gear set; a second planetary gear set having a first, a second and a third member; a second interconnecting member continuously interconnecting the second member of the first planetary gear set with the third member of the second planetary gear set and wherein the second planetary gear set is configured to selectively reduce a rotational speed of the output member relative to a rotational speed of the second interconnecting member; and seven torque transmitting mechanisms selectively engageable to interconnect at least one of the members of the planetary gear set assembly, one of the members of the first and second planetary gear sets with at least one other of the members of the planetary gear set assembly, one other of the members of the first and second planetary gear sets, the input member, the output member and the stationary member, and wherein the torque transmitting mechanisms are selectively engageable in combinations of at least three to establish a plurality of 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 a first of the seven torque transmitting mechanisms is selectively engageable to interconnect the third member of the planetary gear set assembly with the third member of the first planetary gear set and the input member.

3 . The transmission of claim 2 wherein a second of the seven torque transmitting mechanisms is selectively engageable to interconnect the fourth member of the planetary gear set assembly with the third member of the first planetary gear set and the input member.

4 . The transmission of claim 3 wherein a third of the seven torque transmitting mechanisms is selectively engageable to interconnect the fourth member of the planetary gear set assembly with the second member of the first planetary gear set and the third member of the second planetary gear set.

5 . The transmission of claim 4 wherein a fourth of the seven torque transmitting mechanisms is selectively engageable to interconnect the second member of the first planetary gear set and the third member of the second planetary gear set with the output member.

6 . The transmission of claim 5 wherein a fifth of the seven torque transmitting mechanisms is selectively engageable to interconnect the second member of the second planetary gear set with the output member to reduce a rotational speed of the output member relative to a rotational speed of the second interconnecting member.

7 . The transmission of claim 6 wherein a sixth of the seven torque transmitting mechanisms is selectively engageable to interconnect the third member of the planetary gear set assembly with the stationary member.

8 . The transmission of claim 7 wherein a seventh of the seven torque transmitting mechanisms is selectively engageable to interconnect the first member of the planetary gear set assembly with the stationary member.

9 . The transmission of claim 1 wherein the first member of the planetary gear set assembly is a sun gear, the second member of the planetary gear set assembly is a ring gear, the third member of the planetary gear set assembly is a carrier member, the fourth member of the planetary gear set assembly is a common gear, the second members of the first and second planetary gear sets are carrier members, the third members of the first and second planetary gear sets are sun gears and the first members of the first and second planetary gear sets are ring gears.

10 . The transmission of claim 9 wherein the common member is formed as a unitary gear member having an outer surface and an inner surface, wherein the outer surface has a plurality of gear teeth and the inner surface has a plurality of gear teeth.

11 . The transmission of claim 10 wherein the unitary gear member meshes with a first plurality of pinion gears rotatably supported by the carrier member of the planetary gear set assembly and a second plurality of pinion gears rotatably supported by the carrier member of the planetary gear set assembly.

12 . A transmission comprising:
an input member; an output member; a planetary gear set assembly having a first member, a second member, a third member and a fourth member; a first planetary gear set having a first, a second and a third member; a second planetary gear set having a first, a second and a third member, wherein the second planetary gear set is a speed reducing gear set; a first interconnecting member continuously interconnecting the second member of the planetary gear set assembly with the first member of the first planetary gear set; a second interconnecting member continuously interconnecting the second member of the first planetary gear set with the third member of the second planetary gear set and wherein the second planetary gear set is configured to selectively reduce a rotational speed of the output member relative to a rotational speed of the second interconnecting member; and seven torque transmitting mechanisms selectively engageable to interconnect at least one of the members of the planetary gear set assembly, one of the members of the first and second planetary gear sets with at least one other of the members of the planetary gear set assembly, one other of the members of the first and second planetary gear sets, the input member, the output member and the stationary member, and wherein the torque transmitting mechanisms are selectively engageable in combinations of at least three to establish a plurality of forward speed ratios and at least one reverse speed ratio between the input member and the output member.

13 . The transmission of claim 12 wherein a first of the seven torque transmitting mechanisms is selectively engageable to interconnect the third member of the planetary gear set assembly with the third member of the first planetary gear set and the input member.

14 . The transmission of claim 13 wherein a second of the seven torque transmitting mechanisms is selectively engageable to interconnect the fourth member of the planetary gear set assembly with the third member of the first planetary gear set and the input member.

15 . The transmission of claim 14 wherein a third of the seven torque transmitting mechanisms is selectively engageable to interconnect the fourth member of the planetary gear set assembly with the second member of the first planetary gear set and the third member of the second planetary gear set.

16 . The transmission of claim 15 wherein a fourth of the seven torque transmitting mechanisms is selectively engageable to interconnect the second member of the first planetary gear set and the third member of the second planetary gear set with the first member of the second planetary gear set.

17 . The transmission of claim 16 wherein a fifth of the seven torque transmitting mechanisms is selectively engageable to interconnect the first member of the second planetary gear set with the stationary member to reduce a rotational speed of the output member relative to a rotational speed of the second interconnecting member.

18 . The transmission of claim 17 wherein a sixth of the seven torque transmitt

Assignees

• Gm Global Tech Operations Llc

Inventors

• Hart James M

Classifications

• F16H2200/2048

  with seven engaging means · CPC title

• F16H2200/0086

  the gear ratios comprising two reverse speeds · CPC title

• F16H2200/0078

  the gear ratio comprising twelve or more forward speeds · CPC title

• F16H3/666 Primary

  with intermeshing orbital gears (F16H3/663 takes precedence) · CPC title

• F16H2200/2097

  comprising an orbital gear set member permanently connected to the housing, e.g. a sun wheel permanently connected to the housing · CPC title