Continuously variable transmission

• US 7,686,729 B2
• Filed: 02/08/2008
• Issued: 03/30/2010
• Est. Priority Date: 02/28/2003
• Status: Expired due to Fees

• Current Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Original Assignee: Fallbrook Technologies Incorporated
• Inventors: Miller, Donald C, Allen, David J, Smithson, Robert A.
• Primary Examiner(s): Nguyen; Ninh H
• Application Number:
  US12/028,732
• Publication Number:
  US 20080132373A1
• Time in Patent Office: 781 Days
• Field of Search: 475/189, 475/196, 475/215, 475/219, 476/36, 476/37, 476/38
• US Class Current: 475/189
• CPC Class Codes: B62M 11/04 of changeable ratio
• CPC Class Codes: B62M 11/14 with planetary gears
• CPC Class Codes: B62M 9/08 involving eccentrically- mounted or elliptically-shaped driving or driven wheel; with expansible driving or driven wheel
• CPC Class Codes: F16H 15/28 with external friction surface
• CPC Class Codes: F16H 15/40 in which two members co-operative by means of balls, or rollers of uniform effective diameter, not mounted on shafts
• CPC Class Codes: F16H 15/50 Gearings providing a continuous range of gear ratios
• 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
• CPC Class Codes: F16H 15/52 in which a member of uniform effective diameter mounted on a shaft may co-operate with different parts of another member
• CPC Class Codes: F16H 2037/088 Power split variators with summing differentials, with the input of the CVT connected or connectable to the input shaft
• CPC Class Codes: F16H 2037/101 Power split variators with one differential at each end of the CVT
• CPC Class Codes: F16H 37/084 at least one power path being a continuously variable transmission, i.e. CVT
• CPC Class Codes: F16H 37/0853 CVT using friction between rotary members having a first member of uniform effective diameter cooperating with different parts of a second member
• CPC Class Codes: F16H 37/086 CVT using two coaxial friction members cooperating with at least one intermediate friction member
• CPC Class Codes: F16H 61/6649 characterised by the means for controlling the torque transmitting capability of the gearing
• CPC Class Codes: F16H 63/067 mechanical actuating means
• CPC Class Codes: Y10T 29/49464 Assembling of gear into force transmitting device
• CPC Class Codes: Y10T 408/65 Means to drive tool

Abstract

A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

Claims

1. A transmission comprising:

a first disc mounted coaxially about a longitudinal axis of the transmission;

a plurality of tiltable balls placed angularly about the longitudinal axis and in contact with the first disc;

a second disc mounted coaxially about the longitudinal axis of the transmission and in contact with the plurality of tiltable balls;

an idler placed radially inward of, and in contact with, the plurality of tiltable balls;

a cage operably coupled to the plurality of balls;

wherein at least two of the first disc, second disc, idler, and cage are adapted to receive a power input; and

wherein at least one of the first disc, second disc, idler and cage is adapted to provide a power output.

2. The transmission of claim 1, further comprising a planetary gearset operably coupled to at least one of the first disc, second, disc, idler, and cage.

3. The transmission of claim 1, wherein at least two of the first disc, second disc, idler, and cage are adapted to provide a power output.

4. The transmission of claim 1, wherein the first disc is nonrotatable.

5. The transmission of claim 1, wherein the first disc is adapted to rotate freely without transferring power.

6. The transmission of claim 1, wherein the cage is nonrotatable.

7. The transmission of claim 1, wherein the cage is adapted to rotate freely without transferring power.

8. The transmission of claim 1, wherein the idler is nonrotatable.

9. The transmission of claim 1, wherein the idler is adapted to rotate freely without transferring power.

10. A transmission comprising:

a first disc mounted coaxially about a longitudinal axis of the transmission;

a plurality of tiltable balls placed angularly about the longitudinal axis and in contact with the first disc;

a second disc mounted coaxially about the longitudinal axis of the transmission and in contact with the plurality of tiltable balls;

an idler placed radially inward of, and in contact with, the plurality of tiltable balls;

a cage operably coupled to the plurality of balls;

wherein one of the first disc, second disc, idler, and cage is adapted to receive a power input; and

wherein at least two of the first disc, second disc, idler and cage are adapted to provide a power output.

11. The transmission of claim 10, wherein at least three of the first disc, second disc, idler and cage are adapted to provide a power output.

12. The transmission of claim 10, wherein the first disc is nonrotatable.

13. The transmission of claim 10, wherein the first disc is adapted to rotate freely without transferring power.

14. The transmission of claim 10, wherein the cage is nonrotatable.

15. The transmission of claim 10, wherein the cage is adapted to rotate freely without transferring power.

16. The transmission of claim 10, wherein the idler is nonrotatable.

17. The transmission of claim 10, wherein the idler is adapted to rotate freely without transferring power.

18. A transmission comprising:

a first disc mounted coaxially about a longitudinal axis of the transmission;

a plurality of tiltable balls placed angularly about the longitudinal axis and in contact with the first disc;

a second disc mounted coaxially about the longitudinal axis of the transmission and in contact with the plurality of tiltable balls;

an idler placed radially inward of, and in contact with, the plurality of tiltable balls;

a cage operably coupled to the plurality of balls;

wherein at least three of the first disc, second disc, idler, and cage are adapted to receive a power input; and

wherein one the first disc, second disc, idler and cage is adapted to provide a power output.

19. The transmission of claim 18, further comprising a planetary gearset coupled to at least one of the first disc, second disc, idler, and cage.

20. The transmission of claim 18, further comprising a planetary gearset coupled to at least two of the first disc, second disc, idler, and cage.