Continuously variable transmission and engine

• US 7,285,068 B2
• Filed: 10/25/2005
• Issued: 10/23/2007
• Est. Priority Date: 10/25/2005
• Status: Expired due to Fees

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Inventors: Hosoi, Yukiharu
• Primary Examiner(s): Wright; Dirk
• Application Number:
  US11/259,496
• Publication Number:
  US 20070093345A1
• Time in Patent Office: 728 Days
• Field of Search: 475/189, 476/38
• US Class Current: 475/189
• CPC Class Codes: F16H 15/503 in which two members co-operate by means of balls or rollers of uniform effective diameter, not mounted on shafts

Abstract

A continuously variable transmission features an inner ring and an outer ring. Each of the inner ring and the outer ring is split into a first portion and a second portion. At least two balls are positioned between the inner ring and the outer ring. The at least two balls also are positioned between the first and second portions of the inner and outer ring. The at least two balls rotate with rotation of the input shaft. As the distance between the first and second portions of the outer ring changes, the at least two balls move to a smaller radius of travel or a larger radius of travel. The rotation of the balls is transmitted to an output shaft. The input shaft and the output shaft are directly connectable through a one-way clutch to allow engine braking and/or push starting of the associated engine. A dedicated lubrication system also can be provided.

Claims

1. An engine and continuously variable transmission assembly comprising a continuously variable transmission, the transmission comprising a transmission input shaft having an axial direction, the transmission input shaft being coupled to an engine crankshaft, the transmission input shaft receiving rotation from the engine crankshaft, an inner ring comprising a first half and a second half, the inner ring first half and the inner ring second half being generally aligned in the axial direction of the transmission input shaft, the inner ring first half and the inner ring second half being joined for rotation with the transmission input shaft, an outer ring comprising a first half and a second half, the outer ring first half and the outer ring second half being located radially outward from the inner ring, the outer ring first half and the outer ring second half being generally aligned in the axial direction of the transmission input shaft, the outer ring first half and the outer ring second half being generally restrained from rotating around the axis of the transmission input shaft, a plurality of transmitting balls rollable between the inner ring and the outer ring, a plurality of driven rollers interposed between the transmitting balls and in contact with the transmitting balls, a roller supporting member carrying the driven rollers, the roller supporting member being rotatable around the axis of the transmission input shaft, a transmission output shaft connected to the roller supporting member and a wheel driving transmission member, the transmission output shaft being rotatable around the axis of the transmission input shaft, and a speed changing mechanism coupled to the outer ring such that the distance between the first outer ring half and the second outer ring half can be adjusted, adjustment of the distance between the first outer ring half and the second outer ring half varying the rotational speed of the driven rollers around the inner ring, wherein the transmission output shaft has a generally cylindrical portion, the transmission input shaft extending at least partway into the generally cylindrical portion, and a one-way clutch connecting the transmission output shaft and the transmission input shaft such power can be transmitted through the one-way clutch from the transmission output shaft to the transmission input shaft, the one-way clutch being positioned within the generally cylindrical portion.

2. The assembly of claim 1, wherein the transmission input shaft comprises an internal lubricant passage that extends from an end of the transmission input shaft to a position on the outer periphery thereof that corresponds to the transmitting balls, the internal lubricant passage being connected to a lubricant supply device.

3. The assembly of claim 1, wherein a first end portion of transmission input shaft is generally parallel to an engine drive shaft, the transmission input shaft meshing with the engine drive shaft.

4. The assembly of claim 3, wherein the balls are positioned about a second end portion of the transmission input shaft.

5. The assembly of claim 4, wherein the generally cylindrical portion of the transmission output shaft and the one-way clutch are disposed between the first end portion and the second end portion of the transmission input shaft.

6. The assembly of claim 5, wherein the wheel driving transmission member is positioned on the generally cylindrical portion of the transmission output shaft.

7. The assembly of claim 6, wherein the wheel driving transmission member comprises a sprocket.

8. The assembly of claim 1, wherein a first end portion of the transmission input shaft is connected coaxially to an engine drive shaft.

9. The assembly of claim 8, wherein the balls are positioned around an intermediate portion of the transmission input shaft.

10. The assembly of claim 9, wherein the generally cylindrical portion of the transmission output shaft and the one-way clutch are positioned at a second end portion of the transmission input shaft.

11. The assembly of claim 10, wherein the wheel driving transmission member is disposed on the generally cylindrical portion.

12. The assembly of claim 11, wherein the wheel driving transmission member is a sprocket.

13. An engine and continuously variable transmission assembly comprising a continuously variable transmission, the transmission comprising a transmission input shaft having an axial direction, the transmission input shaft being driven by an engine crankshaft, an inner ring mounted to the transmission input shaft, the inner ring comprising a first half and a second half, at least two balls being positioned between the first half and the second half of the inner ring, the inner ring first half and the inner ring second half being joined for rotation with the transmission input shaft, the at least two balls also being positioned between the inner ring and an outer ring, the outer ring comprising a first half and a second half, the at least two balls being positioned between the outer ring first half and the outer ring second half, a roller interposed between two adjacent balls of the at least two balls, the roller contacting both of the adjacent balls, the roller being mounted on a roller supporting member, the roller supporting member being rotatable around the axis of the transmission input shaft, a transmission output shaft connected to the roller supporting member, a wheel driving transmission member connected to the transmission output shaft, the transmission output shaft being rotatable around the axis of the transmission input shaft, a one-way clutch connecting the transmission input shaft and the transmission output shaft, and a speed changing mechanism coupled to the outer ring such that the distance between the first outer ring half and the second outer ring half can be adjusted with adjustment of the distance between the first outer ring half and the second outer ring half varying the rotational speed of the roller around the inner ring.

14. The assembly of claim 13, wherein the first half of the inner ring is integrally formed with the transmission input shaft.

15. The assembly of claim 13, wherein the first half of the inner ring and the second half of the inner ring urged together by a biasing member.

16. The assembly of claim 13, wherein the transmission output shaft has a generally cylindrical portion and the transmission input shaft extends at least partway into the generally cylindrical portion.

17. The assembly of claim 16, wherein the one-way clutch is positioned within the generally cylindrical portion of the transmission output shaft.