CONTINUOUSLY VARIABLE TRANSMISSION

• US 20100173743A1
• Filed: 06/06/2008
• Published: 07/08/2010
• Est. Priority Date: 06/11/2007
• Status: Active Grant

• Current Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Original Assignee: Fallbrook Technologies Incorporated
• Inventors: Armstrong, Oronde J., Nichols, Jon M., Dawe, Daniel J.
• Granted Patent: US 8,641,577 B2
• Time in Patent Office: Days
• US Class Current: 476/38
• CPC Class Codes: F16H 15/28 with external friction surface
• 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: Y10T 29/49464 Assembling of gear into force transmitting device

Abstract

Inventive embodiments are directed to components, subassemblies, systems, and/or methods for continuously variable transmissions (CVT). In one embodiment, a main axle is adapted to receive a shift rod that cooperates with a shift rod nut to actuate a ratio change in a CVT. In another embodiment, an axial force generating mechanism can include a torsion spring, a traction ring adapted to receive the torsion spring, and a roller cage retainer configured to cooperate with the traction ring to house the torsion spring. Various inventive power roller-leg assemblies can be used to facilitate shifting the ratio of a CVT. Embodiments of a hub shell and a hub cover are adapted to house components of a CVT and, in some embodiments, to cooperate with other components of the CVT to support operation and/or functionality of the CVT. Among other things, shift control interfaces and braking features for a CVT are disclosed.

Claims

1-5. -5. (canceled)

6. A continuously variable transmission (CVT) comprising:

a plurality of power roller-leg assemblies each having a skew-shift reaction roller; and

a single-piece carrier having a substantially cylindrical hollow body, the carrier operably coupled to each of the power roller-leg assemblies, wherein each of the power roller-leg assemblies are arranged at least in part on an interior of the hollow body, the carrier configured to contact each of the skew-shift reaction rollers on the interior of the hollow body.

7. The CVT of claim 6, further comprising a first support axle coupled to a first end of the carrier, the first support axle extending axially from a first exterior surface of the carrier.

8. The CVT of claim 6, further comprising a second support axle coupled to a second end of the carrier, the second support axle extending axially from a second exterior surface of the carrier.

9. A carrier for a continuously variable transmission (CVT), the carrier comprising:

a generally cylindrical hollow body having a first end and a second end;

a first support axle coupled to the first end, the first support axle extending axially from a first end exterior surface;

a second support axle coupled to the second end, the second support axle extending axially from a second end exterior surface;

a plurality of openings arranged radially about the outer periphery of the cylindrical hollow body;

a first plurality of radial grooves formed on a first end interior surface;

a second plurality of radial grooves formed on a second end interior surface; and

wherein the first and second pluralities of radial grooves is each configured to couple to a respective plurality of skew-shift reaction rollers of the CVT.

10. The carrier of claim 9, wherein at least one opening is configured to facilitate the installation of an idler assembly of the CVT.

11. The carrier of claim 9, wherein the first and second plurality of radial grooves comprise a substantially toriconical profile.

12. The carrier of claim 9, wherein the first and second plurality of radial grooves comprise a substantially hemi-spherical profile.

13. A power input assembly for a continuously variable transmission (CVT), the power input assembly comprising:

a cam driver having a first face, a second face, and an inner bore, wherein the first face has a plurality of ramps;

a torsion plate operably coupled to the cam driver;

a plurality of pawls operably coupled to the torsion plate, each of the pawls operably coupled to the inner bore of the cam driver; and

wherein the pawls are configured to facilitate a transfer of torque from the torsion plate to the cam driver in a first direction.

14. The power input assembly of claim 13, wherein the cam driver comprises a plurality of teeth located on the inner bore, the plurality of teeth configured to engage the pawls.

15. The power input assembly of claim 14, wherein the plurality of teeth and the plurality of pawls are configured to couple so as to minimize an angular rotation of the torsion plate in the first direction.

16. A power input assembly for a continuously variable transmission (CVT), the power input assembly comprising:

a traction ring;

a load cam roller cage operably coupled to the traction ring, the load cam roller cage having a plurality of load cam rollers;

a load cam driver operably coupled to the load cam roller cage, the load cam driver having a plurality of ramps operably coupled to the load cam rollers, the load cam driver having a groove formed on an outer circumference; and

a torsion spring coupled to the load cam roller cage and to the load cam driver, the torsion spring located in the groove of the load cam driver.

17. The power input assembly of claim 16, further comprising a bearing coupled to the load cam driver, wherein the bearing is operably coupled to a housing of the CVT.

18. A method of assembling a continuously variable transmission (CVT) having a plurality of power roller-leg assemblies, a housing cover, and a traction ring coupled to each of the power roller-leg assemblies, the method comprising:

providing a roller cage operably coupled to the traction ring;

providing a drive washer operably coupled to the roller cage;

installing a shim between the drive washer and the housing cover; and

wherein the shim is configured to provide an axial pre-load force of the CVT.

19. The method of claim 18, further comprising selecting a shim having a size corresponding to an axial pre-load force of the CVT.

20. A shifter interface assembly for a continuously variable transmission (CVT) having a main axle, the shifter interface assembly comprising:

a shift rod arranged at least in part in a hollow bore of the main axle;

a ball bearing coupled to the shift rod and to the main axle; and

a shift retainer nut coupled to the ball bearing and coupled to the main axle.

21. The shifter interface assembly of claim 20, wherein the ball bearing further comprises a bearing race integral with the shift rod.

22. The shifter interface assembly of claim 20, wherein the ball bearing further comprises a bearing race integral with the shift retainer nut.

23. (canceled)

24. A shifter interface assembly for a continuously variable transmission (CVT) having a main axle arranged along a longitudinal axis, the shifter interface assembly comprising:

a shift rod having and elongated body, the shift rod positioned in a hollow bore of the main axle wherein at least a portion of the shift rod is enclosed by the main axle;

a clip coupled to the shift rod;

a first groove formed on the shift rod, the first groove configured to receive an o-ring;

a second groove formed on the shift rod, the second groove configured to receive the clip;

wherein the shift rod and the main axle are configured relative to each other such that the first groove is located inside the hollow bore of the main axle and the second groove is located outside of the hollow bore.

25. The shifter interface assembly of claim 24, further comprising a shift retainer nut coupled to the clip and coupled to the main axle.

26-27. -27. (canceled)

28. An anti-rotation washer for a continuously variable transmission (CVT), the CVT coupled to a frame of a bicycle, the anti-rotation washer comprising:

an elongated body having a first face and a second face;

a reaction arm extending from the first face, the reaction arm configured to engage the frame;

a plurality of friction teeth formed on the first face;

a first bore located on one end of the elongated body, the first bore having at least one flat surface adapted to engage the CVT; and

a second bore located on a second end of the elongated body, the second end at a distal location from the first end, the second bore adapted to engage the frame.