CONTINUOUSLY VARIABLE TRANSMISSION
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”) having a central axis, the CVT comprising:
a plurality of balls distributed in a plane about the central axis, each having a bore through it that forms a tiltable axis of rotation of the ball;
an input disc rotatable about the central axis and contacting a first point on each of the balls;
an output disc rotatable about the central axis and contacting a second point on each of the speed adjusters;
a generally cylindrical idler annularly rotatable about the longitudinal axis and contacting a third point on each ball;
a plurality of generally cylindrical axles having two ends, wherein one spindle is positioned in the bore of each ball; and
a plurality of needle roller bearings positioned between each ball and its respective axle, wherein the needle roller bearings are adapted to allow the balls to rotate relative to their respective axles and are fixed in their positions inside their respective balls.
2 . The CVT of claim 1 , further comprising a torsion disc adapted to transfer torque to the input disc, wherein the torsion disc comprises a splined bore and is coupled to a splined shaft.
3 . The CVT of claim 2 , further comprising an axial force generation assembly adapted to transfer torque from the torsion disc to the input disc.
4 . The CVT of claim 3 , wherein the axial force generation assembly comprises at least one load cam disc.
5 . The CVT of claim 4 , wherein the load cam disc comprises ramps.
6 . (canceled)
7 . (canceled)
8 . The CVT of claim 3 , wherein the axial force generation assembly comprises at least one ball thrust bearing.
9 . (canceled)
10 . The CVT of claim 2 , wherein the torsion disc comprises a recess for receiving a bearing.
11 . (canceled)
12 . (canceled)
13 . A method of manufacturing a continuously variable transmission (“CVT”), the method comprising:
providing a plurality of spherical rollers;
providing an input disc and an output disc;
providing and idler mounted coaxially mounted about a main shaft of the CVT;
placing the spherical rollers in frictional contact with the input disc and output disc;
placing the spherical rollers in frictional contact with the idler;
providing a torsion disc adapted to transfer torque to the input disc, wherein the torsion disc comprises a splined bore; and
coupling a splined shaft to the torsion disc.
14 . The method of claim 12 , further comprising the step of providing an axial force generation assembly adapted to transfer torque from the torsion disc to the input disc.
15 . The method of claim 14 , wherein the axial force generation assembly comprises at least one load cam disc.
16 . The CVT of claim 15 , wherein the load cam disc comprises ramps.
17 . The method of claim 12 , further comprising the step of adapting the torsion disc with a recess for receiving a bearing.
18 . The CVT of claim 14 , wherein the axial force generation assembly comprises at least one ball thrust bearing.
19 . (canceled)
20 . A method of using a continuously variable transmission (“CVT”), the method comprising:
providing a plurality of spherical rollers;
providing an input disc and an output disc;
providing and idler mounted coaxially mounted about a main shaft of the CVT;
placing the spherical rollers in frictional contact with the input disc and output disc;
placing the spherical rollers in frictional contact with the idler;
providing a torsion disc adapted to transfer torque to the input disc, wherein the torsion disc comprises a splined bore; and
coupling a splined shaft to the torsion disc.
21 . The method of claim 19 , further comprising the step of providing an axial force generation assembly adapted to transfer torque from the torsion disc to the input disc.
22 . The method of claim 21 , wherein the axial force generation assembly comprises at least one load cam disc.
23 . The method of claim 19 , further comprising the step of adapting the torsion disc with a recess for receiving a bearing.
24 . The method of claim 19 , where the CVT is used in a vehicle.
25 . (canceled)
26 . (canceled)
27 . (canceled)
28 . (canceled)
29 . The method of claim 19 , where the CVT is used in a power generator.
30 . The method of claim 19 , further comprising providing a mechanism to change the ratio of input speed to output speed of the CVT.