Continuously variable transmission

• US 7,909,727 B2
• Filed: 08/20/2007
• Issued: 03/22/2011
• Est. Priority Date: 10/05/2004
• Status: Expired due to Fees

• Current Assignee: Enviolo BV
• Original Assignee: Fallbrook Technologies Incorporated
• Inventors: Poth, Wesley R, Lohr, Charles B, Simister, Matthew P, Smithson, Robert A, Nichols, Jon M, Thomassy, Fernand A, Dawe, Daniel J, Miller, Donald C, Armstrong, Oronde J, Pohl, Brad P
• Primary Examiner(s): Joyce; William C
• Application Number:
  US11/842,021
• Publication Number:
  US 20080039270A1
• Time in Patent Office: 1,310 Days
• Field of Search: 476/36, 476/38
• US Class Current: 476/36
• 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 continuously variable transmission (“

CVT”

) comprising a plurality of ball-leg assemblies; and

a shaft comprising;

an elongated body having a first end, a middle portion, and a second end,

a central bore through the main axis of the elongated body, said bore extending from the first end and terminating beyond the middle portion of the body,

a flange coupled to the elongated body and located between the middle portion and the first end,

wherein the flange is adapted to couple to, and axially fix the position of, a stator of the continuously variable transmission,

a pair of slots communicating the central bore with the outside diameter of the shaft, and

wherein the sizes of the slots are chosen to provide shift stops for selectively determining a tilt angle range of each ball-leg assembly with respect to the central bore.

2. The shaft of claim 1, further comprising a key seat located proximate to the second end.

3. The shaft of claim 1, wherein the flange and the elongated body are one integral piece.

4. The shaft of claim 1, wherein the flange is threaded onto the elongated body.

5. The shaft of claim 1, wherein the flange is press fit onto the elongated body.

6. The shaft of claim 1, wherein the slots are located proximate to the middle portion of the shaft.

7. The shaft of claim 1, wherein the flange further comprises a shoulder for supporting the bore of a stator of the CVT.

8. A method of manufacturing a shaft for a continuously variable transmission (“

CVT”

) having a plurality of ball-leg assemblies, the method comprising;

forming an elongated body having a first end, a middle portion, and a second end;

forming a central bore through the main axis of the elongated body, said bore extending from the first end and terminating beyond the middle portion of the body;

forming a flange located between the middle portion and the first end;

wherein the flange is adapted to couple to, and axially fix the position of, a stator of the continuously variable transmission;

forming a pair of slots communicating the central bore with the outside diameter of the shaft;

determining a tilt angle range for the plurality of ball leg assemblies; and

choosing appropriate dimensions and locations of the slots to provide shift stops for each ball-leg assembly with respect to the central bore.

9. The method of claim 8, further comprising the step of forming a key seat proximate to the second end.

10. The method of claim 8, wherein the flange and the elongated body are formed of one integral piece.

11. The method of claim 8, wherein the flange is formed to be threaded onto the elongated body.

12. The method of claim 8, wherein the flange is press fit onto the elongated body.

13. The method of claim 8, wherein the slots are formed proximate to the middle portion of the shaft.

14. The method of claim 8, wherein the step of forming a flange further comprises the step of forming a shoulder for supporting the bore of a stator of the CVT.

15. The method of claim 14, wherein the shoulder and the flange are formed from one integral piece.