CONTINUOUSLY VARIABLE PLANETARY GEAR SET

• US 20070270269A1
• Filed: 08/07/2007
• Published: 11/22/2007
• Est. Priority Date: 08/11/2003
• Status: Active Grant

• Current Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Original Assignee: Fallbrook Technologies Incorporated
• Inventors: Allen, David, Miller, Donald, Smithson, Robert, Birchak, Jeffrey
• Granted Patent: US 7,727,110 B2
• Time in Patent Office: Days
• US Class Current: 475/189
• CPC Class Codes: B62D 5/0409 Electric motor acting on the steering column
• CPC Class Codes: B62D 5/0475 Controlling other elements
• 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 15/52 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 37/084 at least one power path being a continuously variable transmission, i.e. CVT
• CPC Class Codes: F16H 61/6649 characterised by the means for controlling the torque transmitting capability of the gearing
• CPC Class Codes: Y10S 903/918 Continuously variable
• CPC Class Codes: Y10S 903/945 Characterized by control of gearing, e.g. control of transmission ratio
• CPC Class Codes: Y10S 903/951 Assembly or relative location of components
• CPC Class Codes: Y10T 74/19251 Control mechanism
• CPC Class Codes: Y10T 74/19555 Varying speed ratio
• CPC Class Codes: Y10T 74/1956 Adjustable

Abstract

A continuously variable planetary gear set is described having a generally tubular idler, a plurality of balls distributed radially about the idler, each ball having a tiltable axis about which it rotates, a rotatable input disc positioned adjacent to the balls and in contact with each of the balls, a rotatable output disc positioned adjacent to the balls opposite the input disc and in contact with each of the balls such that each of the balls makes three-point contact with the input disc, the output disc and the idler, and a rotatable cage adapted to maintain the axial and radial position of each of the balls, wherein the axes of the balls are oriented by the axial position of the idler.

Claims

1. A method of controlling a continuously variable transmission (CVT) of a vehicle, the CVT having a plurality of balls supported on an idler that is mounted coaxially about a longitudinal axis of the CVT and radially inward of the plurality of balls, the method comprising:

detecting a speed of the vehicle;

determining a first transmission ratio based at least in part upon the detected speed; and

adjusting the axis of rotation of the balls to shift a transmission ratio of the CVT to the first transmission ratio.

2. The method of claim 1, further comprising adjusting an axial position of the idler.

3. The method of claim 2, further comprising adjusting the axial position of the idler simultaneously with the adjusting of the axis of rotation of the balls.

4. The method of claim 1, further comprising determining a position of an accelerator pedal of the vehicle, and further comprising determining the first transmission ratio based at least in part upon the determined position of the accelerator pedal.

5. The method of claim 1, further comprising receiving a CVT transmission mode, and further comprising determining the first transmission ratio based at least in part upon the received CVT transmission mode.

6. The method of claim 5, wherein the CVT transmission mode comprises an automatic CVT transmission mode.

7. The method of claim 5, wherein the CVT transmission mode comprises a manual CVT transmission mode.

8. A continuously variable drive train system comprising:

a continuously variable transmission (CVT) comprising;

a plurality of balls arrayed angularly about a longitudinal axis, at least some of the plurality of balls having a respective axis of rotation; and

a substantially cylindrical component mounted coaxially about the longitudinal axis, the cylindrical component located radially inward of the balls and configured to support a rolling motion of the balls;

a microcomputer configured to receive signals, process the signals, and output command signals;

a speed sensor configured to provide to the microcomputer signals indicative of an output speed;

wherein the microcomputer is configured to determine, based at least in part upon the signal indicative of the output speed, and output a signal indicative of a desired transmission ratio for the CVT;

means for receiving the output signal indicative of the desired transmission ratio; and

means for adjusting the axis of rotation of the plurality of balls to adjust a transmission ratio of the CVT to the desired transmission ratio, wherein the means for adjusting the axis of rotation are in communication with the means for receiving the output signal indicative of the desired transmission ratio.

9. The continuously variable drive train system of claim 8, further comprising means for adjusting an axial position of the cylindrical component.

10. The continuously variable drive train system of claim 8, further comprising a pedal sensor configured to provide to the microcomputer a signal indicative of a position of an accelerator pedal.

11. The continuously variable drive train system of claim 10, wherein the microcomputer is further configured to determine and output the signal indicative of the desired transmission ratio for the CVT based at least in part upon the signal indicative of the position of the accelerator pedal.

12. The continuously variable drive train system of claim 8, further comprising means for determining a selected transmission mode and providing a signal indicative of a selected transmission mode to the microcomputer.

13. The continuously variable drive train system of claim 12, wherein the microcomputer is further configured to determine and output a signal indicative of the desired transmission ratio based at least in part upon the signal indicative of the selected transmission mode.

14. The continuously variable drive train system of claim 13, wherein the selected transmission mode comprises a manual transmission mode.

15. The continuously variable drive train system of claim 8, wherein the means for receiving the output signal indicative of the desired transmission ratio comprises a motor controller.

16. The continuously variable drive train system of claim 8, wherein the means for adjusting the axis of rotation of the plurality of balls comprises a motor.

17. A system for controlling a transmission ratio in a drive train, the system comprising:

a plurality of balls arrayed angularly about a longitudinal axis, each of the balls having an axis of rotation;

a cylindrical component configured to provide radial support for the balls and located radially inward of the balls;

a first sensor configured to detect an output speed;

means for determining a desired transmission ratio based at least in part on the detected output speed;

a motor configured to facilitate an adjustment in the axis of rotation of the balls to, thereby, achieve the desired transmission ratio; and

a motor controller, in communication with the means for determining the desired transmission ratio, the motor controller configured to command the motor to facilitate the adjustment in the axis of rotation of the balls.

18. The system of claim 17, wherein the means for determining a desired transmission ratio comprises a microprocessor.

19. The system of claim 18, wherein the means for determining a desired transmission ratio comprises a look up table.

20. The system of claim 17, wherein the means for determining a desired transmission ratio and the motor controller are coupled integrally.