Continuously variable transmission

• US 20050229731A1
• Filed: 03/31/2005
• Published: 10/20/2005
• Est. Priority Date: 04/01/2004
• Status: Active Grant

• Current Assignee: BHSCI LLC
• Original Assignee: BHSCI LLC
• Inventors: Zheng, Ning, Parks, Albert Harold
• Granted Patent: US 7,624,656 B2
• Time in Patent Office: Days
• US Class Current: 74/122
• CPC Class Codes: B62M 11/06 with spur gear wheels B62M11/14 takes precedence
• CPC Class Codes: F16H 29/04 in which the transmission ratio is changed by adjustment of a crank, an eccentric, a wobble-plate, or a cam, on one of the shafts
• CPC Class Codes: F16H 29/20 the intermittently-acting members being shaped as worms, screws, or racks
• CPC Class Codes: Y10T 74/1503 Rotary to intermittent unidirectional motion
• CPC Class Codes: Y10T 74/1518 Rotary cam drive
• CPC Class Codes: Y10T 74/1836 Rotary to rotary

Abstract

A torque transfer mechanism for use as a continuously variable transmission that includes an input shaft, a cam member, a torque-splitting mechanism cooperating with the cam member, and a torque output assembly for coupling the torque splitting mechanism to an output shaft when there is substantially zero relative velocity between the moving parts to be disconnected to minimize torque feedback to the input shaft.

Claims

1. A rotary force transfer device, comprising:

a housing having a cam mounted thereon;

a central axle rotatably mounted in the housing and configured to receive an input torque;

a torque-split mechanism comprising reciprocating means driven by the central axle and the eccentricity of the cam to split torque from the central axle;

a control mechanism coupled to the housing for controlling the torque-split mechanism; and

a clutch mechanism selectively coupling the reciprocating means to an output.

2. The device of claim 1, wherein the reciprocating means comprise one from among a pair of rocker arms and a shuttle assembly.

3. The device of claim 1 wherein the clutch mechanism couples the central axle to the output in a 1:

1 ratio when there is zero relative velocity between moving parts in the reciprocating means.

4. The device of claim 1, wherein the cam has an annular shape and is mounted over the central axle to pivot into and out of axial alignment with the central axle in response to the control mechanism, thereby changing a ratio of rotational input to rotational output.

5. The device of claim 1 wherein the reciprocating means comprise a first rocker assembly rotatably mounted to the central axle and a second rocker assembly rotatably mounted to the central axle and independent of the first rocker assembly, the first and second rocker assemblies each including a follower configured to ride on the cam.

6. The device of claim 1 wherein the reciprocating means comprise a shuttle assembly including a shuttle carrier mounted on the axle to rotate with the axle and a shuttle mechanism mounted over the axle to rotate independent of the axle and in cooperation with the shuttle carrier and the cam.

7. The device of claim 6 wherein the shuttle mechanism cooperates with the cam and shuttle carrier to move in a direction transverse to the longitudinal axis of the central axle when the central axle rotates and the cam is out of axial alignment with the central axle.

8. The device of claim 7 wherein the shuttle mechanism comprises a first shuttle member and a second shuttle member each cooperating with the cam and the shuttle carrier to move independent of each other in a direction transverse to the longitudinal axis of the central axle.

9. The device of claim 8 wherein the clutch member selectively couples the first and second shuffle members to the output when the first and second shuttle members are at a substantially zero velocity relative to the output to minimize a torque feedback to a user.

10. A mechanical cam and clutch continuously variable transmission, comprising:

a housing;

a torque input shaft rotatably mounted in the housing;

a cam mounted to the housing and configured to move in a direction transverse to a longitudinal axis of the input shaft;

a device for moving the cam relative to the longitudinal axis of the input shaft;

a torque transfer mechanism comprising a shuttle carrier mounted on the input shaft to rotate with the input shaft, a shuttle assembly mounted over the shaft and cooperating with the shuttle carrier and the cam, the shuttle assembly including a shuttle follower mounted over the input shaft to rotate independent of the input shaft, and first and second torque transfer shafts rotatably mounted over the input shaft and coaxial with each other and with the input shaft, each of the first and second torque transfer shafts having a coupling device on a first end of the shaft for coupling the torque transfer shaft to the shuttle follower, and each shaft having a clutch input device at a second end thereof; and

a clutch output device configured to alternately connect the clutch input devices on the second end of the first and second shafts to an output shaft.

11. The device of claim 10 wherein the clutch output device is configured to be coupled to the output shaft at a zero relative velocity between the first and second shafts and the output shaft.

12. The device of claim 10 wherein the shuttle follower comprises at least one follower device for following the cam during rotation of the shuttle follower to cause the shuttle follower to move back and forth in a path that is transverse to the longitudinal axis of the input shaft.

13. The device of claim 10 wherein each coupling device on the first and second shafts comprises a pinion gear configured to cooperate with a rack gear mounted on the shuttle follower and configured to rotate the respective shaft about the longitudinal axis of the input shaft in both a clockwise and counterclockwise direction in response to the shuttle follower cooperating with the cam.

14. The device of claim 13 wherein the shuttle follower comprises a first shuttle follower member and a second shuttle follower member each cooperating with the cam and the shuttle carrier to move independent of each other in a direction transverse to the longitudinal axis of the input shaft.

15. A vehicle, comprising:

A rotary force transfer device, comprising;

a housing;

a central axle rotatably mounted in the housing and configured to receive an input torque;

a torque-split mechanism comprising a cam coupled to the central axle and a reciprocating means driven by eccentricity of the cam to the central axle to split torque from the central axle;

a control mechanism coupled to the housing for controlling the torque-split mechanism; and

a clutch mechanism selectively coupling the reciprocating means to an output.

16. The device of claim 15, wherein the reciprocating means comprise one from among a pair of rocker arms and a shuttle assembly.

17. The device of claim 16 wherein the clutch mechanism couples the central axle to the output in a 1:

1 ratio when there is zero relative velocity between moving parts in the reciprocating means.

18. The device of claim 15, wherein the cam has an annular shape and is mounted over the central axle to pivot into and out of axial alignment with the central axle in response to the control mechanism, thereby changing a ratio of rotational input to rotational output.

19. The device of claim 15 wherein the reciprocating means comprise a first rocker assembly rotatably mounted to the central axle and a second rocker assembly rotatably mounted to the central axle and independent of the first rocker assembly, the first and second rocker assemblies each including a follower configured to ride on the cam.

20. The device of claim 15 wherein the reciprocating means comprise a shuttle assembly including a shuttle carrier mounted on the axle to rotate with the axle and a shuttle mechanism mounted over the axle to rotate independent of the axle and in cooperation with the shuttle carrier and the cam.

21. The device of claim 20 wherein the shuttle mechanism cooperates with the cam and shuttle carrier to move in a direction transverse to the longitudinal axis of the central axle when the central axle rotates and the cam is out of axial alignment with the central axle.

22. The device of claim 21 wherein the shuttle mechanism comprises a first shuttle member and a second shuttle member each cooperating with the cam and the shuttle carrier to move independent of each other in a direction transverse to the longitudinal axis of the central axle.

23. The device of claim 22 wherein the clutch member selectively couples the first and second shuttle members to the output when the first and second shuttle members are at a substantially zero velocity relative to the output to minimize a torque feedback to a user.

24. A machine, comprising:

a prime mover supplying a torque input;

a torque input shaft rotatably mounted in a housing;

a cam mounted to the housing and configured to move in a direction transverse to a longitudinal axis of the input shaft;

a device for moving the cam relative to the longitudinal axis of the input shaft;

a torque transfer mechanism comprising a shuttle carrier mounted on the input shaft to rotate with the input shaft, a shuttle assembly mounted over the shaft and cooperating with the shuttle carrier and the cam, the shuttle assembly including a shuttle follower mounted over the input shaft to rotate independent of the input shaft, and first and second torque transfer shafts rotatably mounted over the input shaft and coaxial with each other and with the input shaft, each of the first and second torque transfer shafts having a coupling device on a first end of the shaft for coupling the torque transfer shaft to the shuttle follower, and each shaft having a clutch input device at a second end thereof; and

a clutch output device configured to alternately connect the clutch input devices on the second end of the first and second shafts to an output shaft.

25. The device of claim 24 wherein the clutch output device is configured to be coupled to the output shaft at a zero relative velocity between the first and second shafts and the output shaft.

26. The device of claim 24 wherein the shuttle follower comprises at least one follower device for following the cam during rotation of the shuttle follower to cause the shuttle follower to move back and forth in a path that is transverse to the longitudinal axis of the input shaft.

27. The device of claim 24 wherein each coupling device on the first and second shafts comprises a pinion gear configured to cooperate with a rack gear mounted on the shuttle follower and configured to rotate the respective shaft about the longitudinal axis of the input shaft in both a clockwise and counterclockwise direction in response to the shuttle follower cooperating with the cam.

28. The device of claim 27 wherein the shuttle follower comprises a first shuttle follower member and a second shuttle follower member each cooperating with the cam and the shuttle carrier to move independent of each other in a direction transverse to the longitudinal axis of the input shaft.

29. A torque transfer mechanism, comprising:

an input shaft;

a cam member;

a torque split assembly operatively coupled to the cam member and configured to split the input torque into a first output torque and a second output torque; and

a torque output assembly coupled to the torque split assembly and configured to couple the first output torque to an output shaft and to couple the second output torque to the output shaft when there is zero relative velocity between moving parts of the torque split assembly to be coupled to the output shaft.

30. The mechanism of claim 29 wherein the cam member is configured to move into and out of axial alignment with a longitudinal axis of the input shaft and wherein the torque split assembly comprises a shuttle follower configured to follow the cam when the shuttle follower rotates about the longitudinal axis of the input shaft and to reciprocate in a direction transverse to the longitudinal axis of the input shaft when the cam member is eccentric with respect to the input shaft to thereby vary the ratio of input shaft rotation to output shaft rotation and when the cam member is not eccentric with respect to the input shaft to otherwise to provide a 1:

1 ratio of input shaft rotation to output shaft rotation.