Multi-speed planetary transmission

• US 10,323,722 B2
• Filed: 09/28/2016
• Issued: 06/18/2019
• Est. Priority Date: 09/28/2016
• Status: Active Grant

• Current Assignee: Allison Transmission Incorporated (Allison Transmission Holdings Incorporated)
• Original Assignee: Allison Transmission Incorporated (Allison Transmission Holdings Incorporated)
• Inventors: Schoolcraft, Brian, Raszkowski, James
• Primary Examiner(s): Holmes, Justin
• Application Number:
  US15/278,694
• Publication Number:
  US 20180087611A1
• Time in Patent Office: 993 Days
• Field of Search: None
• CPC Class Codes: F16H 2003/445 without permanent connection between the input and the set of orbital gears
• CPC Class Codes: F16H 2200/0065 the gear ratios comprising nine forward speeds
• CPC Class Codes: F16H 2200/0069 the gear ratios comprising ten forward speeds
• CPC Class Codes: F16H 2200/2012 with four sets of orbital gears
• CPC Class Codes: F16H 2200/2046 with six engaging means
• CPC Class Codes: F16H 3/66 composed of a number of gear trains without drive passing from one train to another

Abstract

A multi-speed transmission including a plurality of planetary gearsets and a plurality of selective couplers to achieve at least nine forward speed ratios is disclosed. The plurality of planetary gearsets may include a first planetary gearset, a second planetary gearset, a third planetary gearset, and a fourth planetary gearset. The plurality of selective couplers may include a number of clutches and a number of brakes. The multi-speed transmission may have four planetary gearsets and six selective couplers. The six selective couplers may include four clutches and two brakes.

Claims

1. A transmission comprising:

at least one stationary member;

an input member rotatable relative to the at least one stationary member;

a plurality of planetary gearsets operatively coupled to the input member, each planetary gearset of the plurality of planetary gearsets including a sun gear, a plurality of planet gears operatively coupled to the sun gear, a planet carrier operatively coupled to the plurality of planet gears, and a ring gear operatively coupled to the plurality of planet gears, the plurality of planetary gearsets including a first planetary gearset, a second planetary gearset, a third planetary gearset, and a fourth planetary gearset;

a plurality of selective couplers operatively coupled to the plurality of planetary gearsets, each of the plurality of selective couplers having an engaged configuration and a disengaged configuration, the plurality of selective couplers including a first number of clutches and a second number of brakes, the first number being greater than the second number; and

an output member rotatable relative to the at least one stationary member, and operatively coupled to the input member through the plurality of planetary gearsets, wherein the input member is operatively coupled to the plurality of planetary gearsets only through a subset of the first number of clutches, the subset including a first clutch, a second clutch, and a third clutch, wherein

the first clutch, when engaged, fixedly couples the input member to a first group of the plurality of planetary gearsets,

the second clutch, when engaged, fixedly couples the input member to a second group of the plurality of planetary gearsets,

the third clutch, when engaged, fixedly couples the input member to a third group of the plurality of planetary gearsets,

each of the first planetary gearset, the second planetary gearset, the third planetary gearset, and the fourth planetary gearset are included in at least one of the first group of the plurality of planetary gearsets, the second group of the plurality of planetary gearsets, and the third group of the plurality of planetary gearsets, and

the second clutch, when engaged, fixedly couples the input member to the planet carrier of the first planetary gearset and to the planet carrier of the third planetary gearset.

2. The transmission of claim 1, wherein the first clutch, when engaged, fixedly couples the input member to the planet carrier of the second planetary gearset and to the ring gear of the fourth planetary gearset;

and the third clutch, when engaged, fixedly couples the input member to the sun gear of the first planetary gearset.

3. The transmission of claim 1, wherein the first clutch, when engaged, fixedly couples the input member to the planet carrier of the second planetary gearset and to the planet carrier of the fourth planetary gearset;

the second clutch, when engaged, fixedly couples the input member to the planet carrier of the first planetary gearset and to the planet carrier of the third planetary gearset; and

the third clutch, when engaged, fixedly couples the input member to the sun gear of the third planetary gearset.

4. The transmission of claim 1, wherein the first clutch, when engaged, fixedly couples the input member to the ring gear of the third planetary gearset and to the planet carrier of the fourth planetary gearset;

the second clutch, when engaged, fixedly couples the input member to the planet carrier of the first planetary gearset and to the planet carrier of the second planetary gearset; and

the third clutch, when engaged, fixedly couples the input member to the sun gear of the first planetary gearset.

5. The transmission of claim 1, wherein the output member is fixedly coupled to the fourth planetary gearset.

6. The transmission of claim 5, wherein the output member is further fixedly coupled to the third planetary gearset.

7. The transmission of claim 5, wherein the plurality of selective couplers includes the first clutch, the second clutch, the third clutch, a fourth clutch, a first brake fixedly coupled to the at least one stationary member, and a second brake fixedly coupled to the at least one stationary member.

8. The transmission of claim 7, wherein each of the first planetary gearset, the second planetary gearset, the third planetary gearset, and the fourth planetary gearset is a simple planetary gearset.

9. The transmission of claim 8, wherein the plurality of selective couplers are selectively engaged in a plurality of combinations to establish at least nine forward speed ratios and at least one reverse speed ratio between the input member and the output member, each of the plurality of combinations having at least three of the plurality of selective couplers engaged.

10. The transmission of claim 8, further comprising:

a first interconnector which fixedly couples the sun gear of the fourth planetary gearset, the ring gear of the third planetary gearset, and the ring gear of the second planetary gearset together;

a second interconnector which fixedly couples the planet carrier of the second planetary gearset to the planet carrier of the fourth planetary gearset;

a third interconnector which fixedly couples the sun gear of the first planetary gearset to the sun gear of the second planetary gearset; and

a fourth interconnector which fixedly couples the planet carrier of the first planetary gearset to the planet carrier of the third planetary gearset.

11. The transmission of claim 10, wherein

the first brake, when engaged, fixedly couples the sun gear of the first planetary gearset and the sun gear of the second planetary gearset to the at least one stationary member;

the second brake, when engaged, fixedly couples the ring gear of the first planetary gearset to the at least one stationary member;

the first clutch, when engaged, fixedly couples the input member to the planet carrier of the second planetary gearset and to the planet carrier of the fourth planetary gearset;

the second clutch, when engaged, fixedly couples the input member to the planet carrier of the first planetary gearset and to the planet carrier of the third planetary gearset;

the third clutch, when engaged, fixedly couples the input member to the sun gear of the third planetary gearset; and

the fourth clutch, when engaged, fixedly couples the ring gear of the first planetary gearset to the sun gear of the third planetary gearset.

12. The transmission of claim 8, further comprising:

a first interconnector which fixedly couples the ring gear of the third planetary gearset to the planet carrier of the fourth planetary gearset;

a second interconnector which fixedly couples the ring gear of the first planetary gearset to the sun gear of the fourth planetary gearset;

a third interconnector which fixedly couples the sun gear of the second planetary gearset to the sun gear of the third planetary gearset; and

a fourth interconnector which fixedly couples the planet carrier of the first planetary gearset to the planet carrier of the second planetary gearset.

13. The transmission of claim 12, wherein

the first brake, when engaged, fixedly couples the sun gear of the second planetary gearset and the sun gear of the third planetary gearset to the at least one stationary member;

the second brake, when engaged, fixedly couples the ring gear of the second planetary gearset to the at least one stationary member;

the first clutch, when engaged, fixedly couples the input member to the ring gear of the third planetary gearset and to the planet carrier of the fourth planetary gearset;

the second clutch, when engaged, fixedly couples the input member to the planet carrier of the first planetary gearset and to the planet carrier of the second planetary gearset;

the third clutch, when engaged, fixedly couples the input member to the sun gear of the first planetary gearset; and

the fourth clutch, when engaged, fixedly couples the sun gear of the first planetary gearset to the ring gear of the second planetary gearset.

14. A transmission comprising:

at least one stationary member;

an input member rotatable relative to the at least one stationary member;

a plurality of planetary gearsets operatively coupled to the input member, each of the plurality of planetary gearsets including a first gearset component, a second gearset component, and a third gearset component, the plurality of planetary gearsets including a first planetary gearset, a second planetary gearset, a third planetary gearset, and a fourth planetary gearset;

an output member operatively coupled to the input member through the plurality of planetary gearsets and rotatable relative to the at least one stationary member, the output member is fixedly coupled to the second gearset component of the fourth planetary gearset;

a first interconnector which fixedly couples the first gearset component of the second planetary gearset, the first gearset component of the third planetary gearset, and the first gearset component of the fourth planetary gearset together;

a second interconnector which fixedly couples the third gearset component of the fourth planetary gearset to the second gearset component of the second planetary gearset;

a third interconnector which fixedly couples the third gearset component of the first planetary gearset to the third gearset component of the second planetary gearset;

a fourth interconnector which fixedly couples the second gearset component of the first planetary gearset to the second gearset component of the third planetary gearset; and

a plurality of selective couplers, wherein the plurality of selective couplers includes;

a first selective coupler which, when engaged, fixedly couples the first gearset component of the second planetary gearset, the first gearset component of the third planetary gearset, and the first gearset component of the fourth planetary gearset to the at least one stationary member;

a second selective coupler which, when engaged, fixedly couples the third gearset component of the third planetary gearset to the at least one stationary member;

a third selective coupler which, when engaged, fixedly couples the input member to the third gearset component of the fourth planetary gearset and to the second gearset component of the second planetary gearset;

a fourth selective coupler which, when engaged, fixedly couples the input member to the second gearset component of the first planetary gearset and to the second gearset component of the third planetary gearset;

a fifth selective coupler which, when engaged, fixedly couples the input member to the first gearset component of the first planetary gearset; and

a sixth selective coupler which, when engaged, fixedly couples the first gearset component of the first planetary gearset to the third gearset component of the third planetary gearset.

15. The transmission of claim 14, wherein each of the first planetary gearset, the second planetary gearset, the third planetary gearset, and the fourth planetary gearset is a simple planetary gearset.

16. The transmission of claim 15, wherein the first gearset component of the first planetary gearset is a first sun gear, the first gearset component of the second planetary gearset is a second sun gear, the first gearset component of the third planetary gearset is a third sun gear, the first gearset component of the fourth planetary gearset is a fourth sun gear, the second gearset component of the first planetary gearset is a first planet carrier, the second gearset component of the second planetary gearset is a second planet carrier, the second gearset component of the third planetary gearset is a third planet carrier, the second gearset component of the fourth planetary gearset is a fourth planet carrier, the third gearset component of the first planetary gearset is a first ring gear, the third gearset component of the second planetary gearset is a second ring gear, the third gearset component of the third planetary gearset is a third ring gear, and the third gearset component of the fourth planetary gearset is a fourth ring gear.

17. The transmission of claim 14, wherein the at least one stationary member includes a housing, the housing having a first end and a second end, wherein

the input member is accessible proximate the first end of the housing;

the output member is accessible proximate the second end of the housing;

the first planetary gearset is positioned between the first end of the housing and the second planetary gearset;

the second planetary gearset is positioned between the first planetary gearset and the third planetary gearset;

the third planetary gearset is positioned between the second planetary gearset and the fourth planetary gearset; and

the fourth planetary gearset is positioned between the third planetary gearset and the second end of the housing.

18. A transmission comprising:

at least one stationary member;

an input member rotatable relative to the at least one stationary member;

a plurality of planetary gearsets operatively coupled to the input member, each planetary gearset of the plurality of planetary gearsets including a sun gear, a plurality of planet gears operatively coupled to the sun gear, a planet carrier operatively coupled to the plurality of planet gears, and a ring gear operatively coupled to the plurality of planet gears, the plurality of planetary gearsets including a first planetary gearset, a second planetary gearset, a third planetary gearset, and a fourth planetary gearset;

a plurality of selective couplers operatively coupled to the plurality of planetary gearsets, each of the plurality of selective couplers having an engaged configuration and a disengaged configuration, the plurality of selective couplers including a first number of clutches and a second number of brakes, the first number being greater than the second number;

a first interconnector which fixedly couples the sun gear of the second planetary gearset, the sun gear of the third planetary gearset, and the sun gear of the fourth planetary gearset together; and

an output member rotatable relative to the at least one stationary member and operatively coupled to the input member through the plurality of planetary gearsets, wherein the input member is operatively coupled to the plurality of planetary gearsets only through a subset of the first number of clutches, the subset including a first clutch, a second clutch, and a third clutch, wherein

the first clutch, when engaged, fixedly couples the input member to a first group of the plurality of planetary gearsets,

the second clutch, when engaged, fixedly couples the input member to a second group of the plurality of planetary gearsets,

the third clutch, when engaged, fixedly couples the input member to a third group of the plurality of planetary gearsets, and

each of the first planetary gearset, the second planetary gearset, the third planetary gearset, and the fourth planetary gearset are included in at least one of the first group of the plurality of planetary gearsets, the second group of the plurality of planetary gearsets, and the third group of the plurality of planetary gearsets.

19. The transmission of claim 18, further comprising:

a second interconnector which fixedly couples the planet carrier of the second planetary gearset to the ring gear of the fourth planetary gearset;

a third interconnector which fixedly couples the ring gear of the first planetary gearset to the ring gear of the second planetary gearset; and

a fourth interconnector which fixedly couples the planet carrier of the first planetary gearset to the planet carrier of the third planetary gearset.

20. The transmission of claim 19, wherein the plurality of selective couplers includes

a first brake fixedly coupled to the at least one stationary member which, when engaged, fixedly couples the sun gear of the second planetary gearset, the sun gear of the third planetary gearset, and the sun gear of the fourth planetary gearset to the at least one stationary member;

a second brake fixedly coupled to the at least one stationary member which, when engaged, fixedly couples the ring gear of the third planetary gearset to the at least one stationary member;

the first clutch which, when engaged, fixedly couples the input member to the planet carrier of the second planetary gearset and to the ring gear of the fourth planetary gearset;

the second clutch which, when engaged, fixedly couples the input member to the planet carrier of the first planetary gearset and to the planet carrier of the third planetary gearset;

the third clutch which, when engaged, fixedly couples the input member to the sun gear of the first planetary gearset; and

a fourth clutch which, when engaged, fixedly couples the ring gear of the third planetary gearset to the sun gear of the first planetary gearset.

21. The transmission of claim 20, wherein the output member is fixedly coupled to the fourth planetary gearset.

22. The transmission of claim 21, wherein each of the first planetary gearset, the second planetary gearset, the third planetary gearset, and the fourth planetary gearset is a simple planetary gearset.

23. The transmission of claim 22, wherein the at least one stationary member includes a housing, the housing having a first end and a second end, wherein

the input member is accessible proximate the first end of the housing;

the output member is accessible proximate the second end of the housing;

the first planetary gearset is positioned between the first end of the housing and the second planetary gearset;

the second planetary gearset is positioned between the first planetary gearset and the third planetary gearset;

the third planetary gearset is positioned between the second planetary gearset and the fourth planetary gearset; and

the fourth planetary gearset is positioned between the third planetary gearset and the second end of the housing.