Dual Drive continuously variable transmission

• US 6,398,679 B1
• Filed: 09/14/1999
• Issued: 06/04/2002
• Est. Priority Date: 09/14/1998
• Status: Expired due to Fees

• Current Assignee: Albert W. Brown
• Original Assignee: Albert W. Brown
• Inventors: Brown, Albert W.
• Primary Examiner(s): Bucci, David A.
• Assistant Examiner(s): Charles, Marcus
• Application Number:
  US09/395,467
• Time in Patent Office: 994 Days
• Field of Search: 474/34, 474/35, 474/33, 474/36, 474/17, 474/8, 474/18, 474/28, 474/69, 474/14
• US Class Current: 474/35
• CPC Class Codes: F16H 2009/163 Arrangements of two or more belt gearings mounted in parallel, e.g. for increasing transmittable torque
• CPC Class Codes: F16H 2061/66295 characterised by means for controlling the geometrical interrelationship of pulleys and the endless flexible member, e.g. belt alignment or position of the resulting axial pulley force in the plane perpendicular to the pulley axis
• CPC Class Codes: F16H 37/08 with differential gearing
• CPC Class Codes: F16H 37/0846 CVT using endless flexible members
• CPC Class Codes: F16H 55/56 of which the bearing parts are relatively axially adjustable
• CPC Class Codes: F16H 9/16 using two pulleys, both built-up out of adjustable conical parts
• CPC Class Codes: Y10S 29/044 Vacuum
• CPC Class Codes: Y10T 29/49826 Assembling or joining
• CPC Class Codes: Y10T 29/4984 Retaining clearance for motion between assembled parts

Abstract

A continuously variable transmission has dual driving connections extending between a first shaft and a second shaft. The driving connections generally include a drive pulley, a driven pulley and a belt. The pulleys each comprise a fixed portion and an axially moveable portion. Movement between the two portions changes an effective diameter of the pulley. The moveable portions of the drive pulley are positioned next to one another on the first shaft and the moveable portions are interposed between the fixed portions of the drive pulleys. The fixed portions of the driven pulleys, on the other hand, are interposed between the moveable portions. The driven pulleys are free to rotate relative to the second shaft. A differential is positioned between the fixed portions of the driven pulleys, connects the two fixed portions and transfers the torque from the driven pulleys to the second shaft.

Claims

1. A continuously variable transmission comprising a first shaft supporting two first pulleys, said two first pulleys each comprising a fixed disk portion and a moveable disk portion whereby axial movement of said moveable disk portions along said first shaft relative to said fixed disk portions changes an effective diameter of said two first pulleys, said moveable disk portions of said two first pulleys being interposed along said first shaft between said fixed disk portions of said two first pulleys, a synchronizing member connecting said moveable disk portions such that the effective diameters of said two first pulleys are maintained substantially equal by said synchronizing member, at least a portion of each of said moveable disk portions being axially moveable between said first shaft and at least a portion of each corresponding fixed disk portion of said fixed disk portions, said at least a portion of each of said moveable disk portions being dynamically keyed to said first shaft using a plurality of balls positioned within a substantially cylindrical race formed between said moveable disk portions and said first shaft.

2. The transmission of claim 1, wherein said synchronizing member is pivotably secured to said first shaft.

3. The transmission of claim 1 further comprising a second shaft, two second pulleys being journalled on said second shaft, and a pair of belts connecting said two second pulleys to said two first pulleys.

4. The transmission of claim 2, wherein said synchronizing member comprises two beams.

5. The transmission of claim 3 further comprising a differential positioned between said two second pulleys.

6. The transmission of claim 1, wherein said two second pulleys each comprise a fixed pulley half, said differential being connected to said two fixed pulley halves.

7. A continuously variable transmission comprising a first shaft supporting two first pulleys, said two first pulleys each comprising a fixed disk portion and a moveable disk portion whereby axial movement of said moveable disk portions along said first shaft relative to said fixed disk portions changes an effective diameter of said two first pulleys, said moveable disk portions of said two first pulleys being interposed along said first shaft between said fixed disk portions of said two first pulleys, a synchronizing member connecting said moveable disk portions such that the effective diameters of said two first pulleys are maintained substantially equal by said synchronizing member, a piston being connected to each of said moveable disk portions, said stationary disk portions being interposed between said piston and said moveable disk portion of each of said two first pulleys, a chamber at least partially defined by said stationary disk portion and said piston, and axial movement of said moveable disk portion relative to said stationary disk portion being at least partially controlled by a pressure within said chamber.

8. The transmission of claim 7, wherein at least a portion of said moveable disk portion is axially moveable between at least a portion of said fixed disk portion and said first shaft.

9. The transmission of claim 7, wherein said synchronizing member is pivotably secured to said first shaft.

10. The transmission of claim 7, wherein at least a portion of said moveable disk portion is axially moveable between at least a portion of said fixed disk portion and said first shaft.

11. The transmission of claim 7 further comprising a second shaft, two second pulleys being journalled on said second shaft, and a pair of belts connecting said two second pulleys to said two first pulleys.

12. The transmission of claim 8, wherein said at least a portion of each of said moveable disk portions is dynamically keyed to said first shaft.

13. The transmission of claim 9, wherein said synchronizing member comprises two beams.

14. The transmission of claim 10, wherein said at least a portion of each of said moveable disk portions being dynamically keyed to said first shaft.

15. The transmission of claim 11 further comprising a differential positioned between said two second pulleys.

16. The transmission of claim 15, wherein said two second pulleys each comprise a fixed pulley half, said differential being connected to said two fixed pulley halves.

17. A continuously variable transmission comprising a first shaft supporting two first pulleys, said two first pulleys each comprising a fixed disk portion and a moveable disk portion whereby axial movement of said moveable disk portions along said first shaft relative to said fixed disk portions changes an effective diameter of said two first pulleys, said moveable disk portions of said two first pulleys being interposed along said first shaft between said fixed disk portions of said two first pulleys, a synchronizing member connecting said moveable disk portions such that the effective diameters of said two first pulleys are maintained substantially equal by said synchronizing member, a second shaft extending generally parallel to said first shaft, two second pulleys being journalled on said second shaft, a pair of belts connecting said two second pulleys to said two first pulleys, a differential positioned between said two second pulleys, said two second pulleys each comprising a fixed pulley half, said differential being connected to said two fixed pulley halves and said differential being connected to a chain drive.

18. A continuously variable transmission comprising a first shaft supporting two first pulleys, said two first pulleys each comprising a fixed disk portion and a moveable disk portion whereby axial movement of said moveable disk portions along said first shaft relative to said fixed disk portions changes an effective diameter of said two first pulleys, said moveable disk portions of said two first pulleys being interposed along said first shaft between said fixed disk portions of said two first pulleys, a synchronizing member connecting said moveable disk portions such that the effective diameters of said two first pulleys are maintained substantially equal by said synchronizing member, a second shaft extending generally parallel to said first shaft, two second pulleys being journalled on said second shaft, a pair of belts connecting said two second pulleys to said two first pulleys and said first shaft and said second shaft each forming a flow lumen for hydraulic fluids.

19. A continuously variable transmission comprising a first shaft supporting two first pulleys, said two first pulleys each comprising a fixed disk portion and a moveable disk portion whereby axial movement of said moveable disk portions along said first shaft relative to said fixed disk portions changes an effective diameter of said two first pulleys, said moveable disk portions of said two first pulleys being interposed along said first shaft between said fixed disk portions of said two first pulleys, a synchronizing member connecting said moveable disk portions such that the effective diameters of said two first pulleys are maintained substantially equal by said synchronizing member, a second shaft extending generally parallel to said first shaft, two second pulleys being journalled on said second shaft, a pair of belts connecting said two second pulleys to said two first pulleys and said two first pulleys and said two second pulleys being hydraulically actuated.

20. The transmission of claim 19, wherein said synchronizing member is pivotably secured to said first shaft.

21. The transmission of claim 19, wherein at least a portion of said moveable disk portion is axially moveable between at least a portion of said fixed disk portion and said first shaft.

22. The transmission of claim 19 further comprising a second shaft, two second pulleys being journalled on said second shaft, and a pair of belts connecting said two second pulleys to said two first pulleys.

23. The transmission of claim 20, wherein said synchronizing member comprises two beams.

24. The transmission of claim 21, wherein said at least a portion of each of said moveable disk portions being dynamically keyed to said first shaft.

25. The transmission of claim 22 further comprising a differential positioned between said two second pulleys.

26. The transmission of claim 25 wherein said two second pulleys each comprise a fixed pulley half, said differential being connected to said two fixed pulley halves.

27. A continuously variable transmission comprising a first belt assembly and second belt assembly extending between a first shaft and a second shaft, said first belt assembly comprising a first first-shaft pulley, a first second-shaft pulley and a first belt, said second belt assembly comprising a second first-shaft pulley, a second second-shaft pulley and a second belt, said first first-shaft pulley and said second first-shaft pulley each comprising a moveable first-shaft sheave portion and a fixed first-shaft sheave portion, said moveable first-shaft sheave portions being capable of movement along an axis of said first shaft, said first second-shaft pulley and said second second-shaft pulley each comprising a fixed second-shaft sheave portion and a moveable second-shaft sheave portion, said moveable second-shaft sheave portion being capable of movement along an axis of said second shaft, said moveable first-shaft sheave portions being connected by a mechanical linkage to equalize said movement along said axis of said first shaft between said first first-shaft pulley and said second first-shaft pulley, a differential connecting said fixed second-shaft sheave portions to said second shaft, and a piston being attached to each moveable first-shaft sheave portion, said piston propelling said moveable first-shaft sheave portion along said axis of said first shaft relative to said fixed first-shaft sheave portion.

28. The transmission of claim 27, wherein said fixed first-shaft sheave portion is interposed between said moveable first-shaft sheave portion and at least a portion of said piston.

29. The transmission of claim 27, wherein said moveable first-shaft sheave portions are dynamically splined to said first shaft.

30. The transmission of claim 27, wherein said fixed first-shaft sheave portions and said moveable first-shaft sheave portions arc secured together for rotation while allowing relative axial movement.

31. A continuously variable transmission comprising a first belt assembly and second belt assembly extending between a first shaft and a second shaft, said first belt assembly comprising a first first-shaft pulley, a first second-shaft pulley and a first belt, said second belt assembly comprising a second first-shaft pulley, a second second-shaft pulley and a second belt, said first first-shaft pulley and said second first-shaft pulley each comprising a moveable first-shaft sheave portion and a fixed first-shaft sheave portion, said moveable first-shaft sheave portions being capable of movement along an axis of said first shaft, said first second-shaft pulley and said second second-shaft pulley each comprising a fixed second-shaft sheave portion and a moveable second-shaft sheave portion, said moveable second-shaft sheave portion being capable of movement along an axis of said second shaft, said moveable first-shaft sheave portions being connected by a mechanical linkage to equalize said movement along said axis of said first shaft between said first first-shaft pulley and said second first-shaft pulley, a differential connecting said fixed second-shaft sheave portions to said second shaft, and a piston being attached to each moveable second-shaft sheave portion, said piston propelling said moveable second-shaft sheave portion along said axis of said second shaft relative to said fixed second-shaft sheave portion.

32. The transmission of claim 31, wherein said moveable second-shaft sheave portion is interposed between said fixed second-shaft sheave portion and at least a portion of said piston.

33. The transmission of claim 31, wherein a piston is attached to each moveable first-shaft sheave portion, said piston propelling said moveable first-shaft sheave portion along said axis of said first shaft relative to said fixed first-shaft sheave portion.

34. The transmission of claim 33, wherein said fixed first-shaft sheave portion is interposed between said moveable first-shaft sheave portion and at least a portion of said piston that is attached to said moveable first-shaft sheave portion.

35. A continuously variable transmission comprising a first belt assembly and second belt assembly extending between a first shaft and a second shaft, said first belt assembly comprising a first first-shaft pulley, a first second-shaft pulley and a first belt, said second belt assembly comprising a second first-shaft pulley, a second second-shaft pulley and a second belt, said first first-shaft pulley and said second first-shaft pulley each comprising a moveable first-shaft sheave portion and a fixed first-shaft sheave portion, said moveable first-shaft sheave portions being capable of movement along an axis of said first shaft, said first second-shaft pulley and said second second-shaft pulley each comprising a fixed second-shaft sheave portion and a moveable second-shaft sheave portion, said moveable second-shaft sheave portion being capable of movement along an axis of said second shaft, said moveable first-shaft sheave portions being connected by a mechanical linkage to equalize said movement along said axis of said first shaft between said first first-shaft pulley and said second first-shaft pulley, a differential connecting said fixed second-shaft sheave portions to said second shaft, said moveable first-shaft sheave portions being dynamically splined to said first shaft and a set of balls captured within a race defined at an interface between said moveable first-shaft sheave portions and said first shaft forming the dynamically splined connection.

36. A continuously variable transmission comprising a first belt assembly and second belt assembly extending between a first shaft and a second shaft, said first belt assembly comprising a first first-shaft pulley, a first second-shaft pulley and a first belt, said second belt assembly comprising a second first-shaft pulley, a second second-shaft pulley and a second belt, said first first-shaft pulley and said second first-shaft pulley each comprising a moveable first-shaft sheave portion and a fixed first-shaft sheave portion, said moveable first-shaft sheave portions being capable of movement along an axis of said first shaft, said first second-shaft pulley and said second second-shaft pulley each comprising a fixed second-shaft sheave portion and a moveable second-shaft sheave portion, said moveable second-shaft sheave portion being capable of movement along an axis of said second shaft, said moveable first-shaft sheave portions being connected by a mechanical linkage to equalize said movement along said axis of said first shaft between said first first-shaft pulley and said second first-shaft pulley, a differential connecting said fixed second-shaft sheave portions to said second shaft, said fixed first-shaft sheave portions and said moveable first-shaft sheave portions are secured together for rotation while allowing relative axial movement and said fixed first-shaft sheave portions including a slot and said moveable drive sheave portions including a shaft that translates within said slot.

37. The transmission of claim 36, wherein the shaft is a threaded fastener.

38. An axially expandable pulley arrangement comprising a first pulley disk and a second pulley disk, said first disk comprising a first front face, a first back face and a first hub, said second disk comprising a second front face, a second back face and a second hub, said second hub extending at least partially within said first hub, said first back face including a circumferential flange, a piston being positioned within said flange and being slidably connected to said first back face, said piston also being connected to said second hub through an aperture defined in said first hub such that movement of said piston relative to said first pulley disk results in corresponding movement of said second pulley disk relative to said first pulley disk.

39. The pulley arrangement of claim 38, wherein said aperture comprises an elongated slot extending in an axial direction along said first hub.

40. The pulley arrangement of claim 39, wherein a shaft connects said piston and said second hub.

41. The pulley arrangement of claim 40, wherein said shaft is a threaded fastener.