ENGINE BRAKING SYSTEM FOR CONTINUOUSLY VARIABLE TRANSMISSION

• US 20180180141A1
• Filed: 12/22/2016
• Published: 06/28/2018
• 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.
• Granted Patent: US 10,641,366 B2
• Time in Patent Office: 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 clutch (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 sleeve; and

the flanged sleeve being rotatably fixed relative to the drive clutch shaft when operating in a first direction and being moveable axially relative to the drive clutch shaft and towards the outer sheave when operating in a second direction.

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 1, further comprising a bearing positioned between the flanged sleeve and the drive clutch shaft.

5. The CVT of claim 1, further comprising a thrust member 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.

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

7. The CVT of claim 5, wherein the inner and outer sheaves of the clutch rotate relative to the one-way clutch when rotating in the first direction.

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

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

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

11. The CVT of claim 9, wherein the cams are on an end face of the flanged sleeve and facing the inner sheave.

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

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

25. The CVT of claim 13, further comprising a bearing positioned between the flanged sleeve and the drive clutch shaft.

14. A continuously variable clutch (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 outer sheave of the drive 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 a portion of the flanged sleeve being adjacent the thrust member;

the flanged sleeve being rotatably fixed relative to the drive clutch shaft when operating in a first direction and being cooperable with the thrust member to move the flanged member axially relative to the drive clutch shaft and towards the outer sheave when operating in a second direction.

15. The CVT of claim 14, 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.

16. The CVT of claim 15, wherein the inner sheave of the drive clutch includes a recess to receive the flanged sleeve.

17. The CVT of claim 16, further comprising a one-way clutch positioned over the collar portion of the sleeve.

18. The CVT of claim 17, 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.

19. The CVT of claim 18, further comprising a belt coupled between the drive clutch and the driven clutch, and positioned over the one-way clutch.

20. The CVT of claim 18, wherein the inner and outer sheaves of the clutch rotate relative to the one-way clutch when rotating in the first direction.

21. The CVT of claim 20, wherein the flanged sleeve and the thrust member include cooperating cams to move the flanged member axially.

22. The CVT of claim 21, wherein the cooperating cams are rotary cams.

23. The CVT of claim 21, wherein the cams are on an end face of the flanged sleeve and facing the inner sheave.

24. The CVT of claim 23, wherein the flanged sleeve is comprised of forged steel.

26. A continuously variable clutch (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;

one of the sheaves having a helix fixed to the sheave, the helix having helical surfaces, and the other of the sheaves having engagement members cooperating with the helical surfaces to effect movement of the two sheaves relative to each other; and

the one sheave being comprised of a first material having a density lower than 4 gr/cc and the helix is comprised of a second material having a density greater than 4 gr/cc.

27. The CVT of claim 26, wherein the one sheave is cast aluminum.

28. The CVT of claim 26, wherein the helix is forged steel.

29. The CVT of claim 28, wherein the helix is coupled to the one sheave.

30. The CVT of claim 27, further comprising a driven clutch shaft coupled to the outer sheave of the driven clutch.

31. The CVT of claim 30, wherein the driven clutch shaft is steel and the one sheave is cast to the driven clutch shaft.