Continuously variable transmission
View Patent ↗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.
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.