Continuously variable transmission

• US 8,920,285 B2
• Filed: 12/10/2012
• Issued: 12/30/2014
• Est. Priority Date: 10/05/2004
• Status: Active Grant

• Current Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Original Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Inventors: Smithson, Robert A, Pohl, Brad P, Armstrong, Oronde J, Miller, Donald C, Dawe, Daniel J, Thomassy, Fernand A, Poth, Wesley R, Nichols, Jon M, Lohr, Charles B, Simister, Mathew P
• Primary Examiner(s): Joyce, William C
• Application Number:
  US13/710,304
• Publication Number:
  US 20130095977A1
• Time in Patent Office: 750 Days
• Field of Search: 476 36- 38, 476/40, 476/42
• US Class Current: 476/38
• CPC Class Codes: B62M 23/00 Transmissions characterised by use of other elements; Other transmissions
• CPC Class Codes: B62M 9/00 Transmissions characterised by use of an endless chain, belt, or the like cycle chain guards B62J13/00
• CPC Class Codes: F16H 15/28 with external friction surface
• 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: Y10T 29/49462 Gear making
• CPC Class Codes: Y10T 29/49464 Assembling of gear into force transmitting device
• CPC Class Codes: Y10T 29/49467 Gear shaping
• CPC Class Codes: Y10T 29/4984 Retaining clearance for motion between assembled parts

Abstract

A continuously variable transmission (CVT) having a main shaft configured to support and position various components of the CVT. Shift cam discs cooperate with ball-leg assemblies to shift the transmission ration of the CVT. Load cam discs, a torsion disc, rolling elements, and a hub cap shell are configured to generate axial force, transmit torque, and manage reaction forces. In one embodiment, a splined input shaft and a torsion disc having a splined bore cooperate to input torque into the variator of the CVT. Among other things, various ball axles, axle-ball combinations, and reaction force grounding configurations are disclosed. In one embodiment, a CVT having axial force generation means at both the input and output elements is disclosed.

Claims

1. A system comprising:

a continuously variable transmission (CVT) comprising;

an input disc arranged along a longitudinal axis of the CVT,

an output disc arranged along the longitudinal axis of the CVT,

a plurality of balls arranged between, and in contact with, the input disc and the output disc, each ball provided with an adjustable tiltable axis of rotation, and

an idler located radially inward of the balls, the idler arranged between the input disc and the output disc, each ball in contact with the idler; and

an input torque system comprising;

an input shaft having a splined flange,

a torsion disc having a splined bore, and

a spring coupled to the torsion disc, wherein the torsion disc comprises a plurality of holes adapted to receive one end of the spring, the torsion disc configured to fasten one end of the spring so as to facilitate the adjustment of an axial pre-load between the balls, the input disc, the output disc, and the idler, and wherein the splined flange and splined bore are adapted to couple together operationally to transmit torque from the input shaft to the torsion disc.

2. The system of claim 1, wherein the splined flange comprises at least two splines.

3. The system of claim 2, wherein the splined flange comprises a key seat for receiving a key adapted to transfer torque to the input shaft.

4. The system of claim 1, wherein the splined bore comprises at least two splines.

5. The system of claim 1, wherein the torsion disc comprises a recess for receiving a bearing race.

6. The system of claim 5, wherein the bearing race is integral with the torsion disc.

7. The system of claim 1, further comprising a first load cam disc coupled to the torsion disc.

8. The system of claim 7, further comprising a second load cam disc adapted to couple to the input disc.

9. The system of claim 8, further comprising rollers between the first load cam disc and the second load cam disc.

10. The system of claim 9, wherein the rollers are spherical.

11. The system of claim 9, wherein the rollers are cylindrical.

12. The system of claim 9, wherein the first load cam disc comprises ramps.

13. The system of claim 9, wherein the second load cam disc comprises ramps.

14. A system comprising:

a continuously variable transmission (CVT) comprising

an input disc arranged along a longitudinal axis of the CVT,

an output disc arranged along the longitudinal axis of the CVT,

a plurality of balls arranged between, and in contact with, the input disc and the output disc, each ball provided with an adjustable tiltable axis of rotation, and

an idler located radially inward of the balls, the idler arranged between the input disc and the output disc, each ball in contact with the idler;

an input torque system comprising

an input shaft having a splined flange,

a torsion disc having a splined bore,

a spring coupled to the torsion disc,

a first load cam disc coupled to the torsion disc,

a second load cam disc adapted to couple to the input disc, and

rollers between the first load cam disc and the second load cam disc, wherein the torsion disc is provided with a plurality of holes adapted to receive one end of the spring, the torsion disc configured to fasten one end of the spring so as to facilitate the adjustment of an axial pre-load between the first load cam disc and the second load cam disc, and wherein the splined flange and the splined bore are adapted to couple together operationally to transmit torque from the input shaft to the torsion disc.

15. The system of claim 14, wherein the first load cam disc comprises ramps.

16. The system of claim 14, wherein the second load cam disc comprises ramps.

17. The system of claim 14, wherein the torsion disc comprises a recess for receiving a bearing race and wherein the bearing race is integral with the torsion disc.