Engine braking system for continuously variable transmission

• US 10,641,366 B2
• Filed: 12/22/2016
• Issued: 05/05/2020
• Est. Priority Date: 12/22/2016
• Status: Active Grant

• Current Assignee: Polaris Industries Incorporated (Polaris Inc.)
• Original Assignee: Polaris Industries Incorporated (Polaris Inc.)
• Inventors: Kuhl, Amery D., Ripley, Anthony J., Nelson, Stephen L.
• Primary Examiner(s): Dondero, William E
• Assistant Examiner(s): Reese, Robert T
• Application Number:
  US15/388,221
• Publication Number:
  US 20180180141A1
• Time in Patent Office: 1,230 Days
• CPC Class Codes: F16H 55/56 of which the bearing parts are relatively axially adjustable
• CPC Class Codes: F16H 55/563 actuated by centrifugal masses
• CPC Class Codes: F16H 61/21 Providing engine brake control
• CPC Class Codes: F16H 61/66245 using purely mechanical sensing or control means
• CPC Class Codes: F16H 9/18 only one flange of each pulley being adjustable

Abstract

A continuously variable clutch (CVT) is disclosed which is operable in a first direction to transfer power from a power source to ground engaging members of a vehicle, and in a second direction where the ground engaging members brake and/or drive the engine. The CVT has a braking assembly having a thrust member positioned over a drive clutch shaft and adjacent an outer sheave of the drive clutch. A flanged sleeve is operatively coupled to the drive clutch shaft and generally positioned intermediate the inner and outer sheaves of the drive clutch, with a portion of the flanged sleeve being adjacent the thrust member. The flanged sleeve is fixed relative to the drive clutch shaft when operating in the first direction and is cooperable with the thrust member to move the flanged member axially relative to the drive clutch shaft and towards the inner sheave when operating in the second direction.

Claims

1. A continuously variable transmission (CVT), comprising:

a drive clutch having inner and outer sheaves rotatably coupled to a drive clutch shaft;

a driven clutch having inner and outer sheaves rotatably coupled to a driven clutch shaft;

a one-way clutch;

a flanged sleeve operatively coupled to the drive clutch shaft and generally positioned intermediate the inner and outer sheaves of the drive clutch, with the one-way clutch positioned over the flanged sleeve, wherein the flanged sleeve is rotatably fixed relative to the drive clutch shaft when operating in a first direction, and wherein the flanged sleeve is moveable axially relative to the drive clutch shaft and moveable towards the outer sheave of the drive clutch when operating in a second direction; and

a thrust member operative to move the flanged sleeve axially upon rotation of the flanged sleeve in the second direction, wherein the thrust member is a thrust plate positioned adjacent to an inner surface of the inner sheave of the drive clutch.

2. The CVT of claim 1, wherein the flanged sleeve comprises a flange portion and a collar portion, the collar portion being positioned over the drive clutch shaft and the flange portion being positioned adjacent to the inner sheave of the drive clutch.

3. The CVT of claim 2, wherein the inner sheave of the drive clutch includes a recess to receive the flanged sleeve.

4. The CVT of claim 3, wherein the thrust member is positioned in the recess to cooperate with the collar portion to move the flanged sleeve axially upon rotation of the flanged sleeve in the second direction.

5. The CVT of claim 4, further comprising a belt coupled between the drive clutch and the driven clutch, and positioned over the one-way clutch.

6. The CVT of claim 4, wherein the inner and outer sheaves of the drive clutch rotate relative to the one-way clutch when rotating in the first direction.

7. The CVT of claim 6, wherein the flanged sleeve and the thrust member cooperate to move the flanged sleeve axially.

8. The CVT of claim 7, wherein the flanged sleeve and the thrust member include cooperating cams used to move the flanged sleeve axially.

9. The CVT of claim 8, wherein the cooperating cams are rotary cams.

10. The CVT of claim 8, wherein the cooperating cams are on an end face of the flanged sleeve and facing the inner sheave.

11. The CVT of claim 10, wherein the flanged sleeve is comprised of forged steel.

12. The CVT of claim 1, further comprising a bearing positioned between the flanged sleeve and the drive clutch shaft.

13. The CVT of claim 1, wherein the drive clutch shaft is provide in plural pieces.

14. The CVT of claim 1, wherein the thrust member has at least two interactive portions that are spaced apart from each other around a base and interface with the flanged sleeve.

15. The CVT of claim 14, wherein the flanged sleeve includes at least two interactive portions that are spaced apart and interact with the at least two interactive portions of the thrust member.

16. The CVT of claim 15, wherein the at least two interactive portions of the flanged sleeve and the thrust member are ramped surfaces that cooperate with each other to move the flanged sleeve axially.

17. The CVT of claim 14, wherein the flanged sleeve includes at least two interactive portions that interact with the base of the thrust member.

18. The CVT of claim 17, wherein the base of the thrust member includes at least two openings, and wherein the at least two interactive portions of the flanged sleeve are lugs that are spaced in radial cooperation with the at least two openings of the thrust member.

19. A continuously variable transmission (CVT), comprising:

a drive clutch having inner and outer sheaves rotatably coupled to a drive clutch shaft;

a driven clutch having inner and outer sheaves rotatably coupled to a driven clutch shaft;

a thrust member positioned over the drive clutch shaft and adjacent the inner sheave of the drive clutch, the thrust member having at least two interactive portions that are spaced apart from each other around a base, and the base including at least two openings; and

a flanged sleeve operatively coupled to the drive clutch shaft and generally positioned intermediate the inner and outer sheaves of the drive clutch, with a portion of the flanged sleeve being adjacent the thrust member, the flanged sleeve including at least two interactive portions that interact with the base of the thrust member, the at least two interactive portions of the flanged sleeve being lugs that are spaced in radial cooperation with the at least two openings of the thrust member,

wherein the flanged sleeve is rotatably fixed relative to the drive clutch shaft when operating in a first direction and is cooperable with the thrust member to move the flanged sleeve axially relative to the drive clutch shaft and towards the outer sheave when operating in a second direction and wherein the at least two interactive portions of the thrust member interface with the flanged sleeve.

20. The CVT of claim 19, wherein the flanged sleeve comprises a flange portion and a collar portion, the collar portion being positioned over the drive clutch shaft and the flange portion being positioned adjacent to the inner sheave of the drive clutch.

21. The CVT of claim 20, wherein the inner sheave of the drive clutch includes a recess to receive the flanged sleeve.

22. The CVT of claim 21, further comprising a one-way clutch positioned over the collar portion of the flanged sleeve.

23. The CVT of claim 22, wherein the thrust member is positioned in the recess to cooperate with the collar portion to move the flanged sleeve axially upon rotation of the flanged sleeve in the second direction.

24. The CVT of claim 23, further comprising a belt coupled between the drive clutch and the driven clutch, and positioned over the one-way clutch.

25. The CVT of claim 23, wherein the inner and outer sheaves of the drive clutch rotate relative to the one-way clutch when rotating in the first direction.

26. The CVT of claim 25, wherein the flanged sleeve and the thrust member include cooperating cams to move the flanged sleeve axially.

27. The CVT of claim 26, wherein the cooperating cams are rotary cams.

28. The CVT of claim 26, wherein the cooperating cams are on an end face of the flanged sleeve and facing the inner sheave.

29. The CVT of claim 28, wherein the flanged sleeve is comprised of forged steel.

30. The CVT of claim 28, further comprising a bearing positioned between the flanged sleeve and the drive clutch shaft.