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) comprising:
a plurality of tiltable balls, configured angularly about a longitudinal axis of the CVT;
a traction ring in contact with the balls, the traction ring mounted coaxially about the longitudinal axis;
a cam loader operationally coupled to the traction ring, the cam loader having a cam loader diameter, the cam loader mounted coaxially about the longitudinal axis;
a thrust bearing operationally coupled to the cam loader, the thrust bearing having a bearing diameter, the thrust bearing mounted coaxially about the longitudinal axis; and
wherein the bearing diameter is less than about 90 percent of the cam loader diameter.
2 . The CVT of claim 1 , wherein the thrust bearing comprises a needle bearing.
3 . The CVT of claim 1 , wherein the thrust bearing comprises a ball bearing.
4 . The CVT of claim 1 , wherein the thrust bearing comprises a cylindrical roller bearing.
5 . The CVT of claim 1 , wherein the bearing diameter is less than about 80 percent of the cam loader diameter.
6 . The CVT of claim 1 , wherein the bearing diameter is less than about 70 percent of the cam loader diameter.
7 . The CVT of claim 1 , wherein the bearing diameter is less than about 60 percent of the cam loader diameter.
8 . The CVT of claim 1 , wherein the bearing diameter is less than about 50 percent of the cam loader diameter.
9 . The CVT of claim 1 , wherein the bearing diameter is less than about 40 percent of the cam loader diameter.
10 . The CVT of claim 1 , wherein the bearing diameter is less than about 30 percent of the cam loader diameter.
11 . The CVT of claim 1 , wherein the bearing diameter is less than about 20 percent of the cam loader diameter.
12 . The CVT of claim 1 , wherein the bearing diameter is less than about 10 percent of the cam loader diameter.
13 . The CVT of claim 1 , wherein the bearing diameter is between 30 and 70 percent of the cam loader diameter.
14 . The CVT of claim 1 , wherein the bearing diameter is between 40 and 60 percent of the cam loader diameter.
15 . A load cam and thrust reaction bearing assembly for a continuously variable transmission (CVT), the load cam and thrust bearing assembly comprising:
a cam loader having a cam loader diameter;
a thrust reaction bearing having a bearing diameter; and
wherein the bearing diameter is selected in relationship to the cam loader diameter to minimize bearing drag recirculation in the CVT.
16 . The load cam and thrust reaction bearing assembly of claim 15 , wherein the bearing diameter is less than about 90 percent of the cam loader diameter.
17 . The load cam and thrust reaction bearing assembly of claim 15 , wherein the bearing diameter is between 30 and 70 percent of the cam loader diameter.
18 . The load cam and thrust reaction bearing assembly of claim 15 , wherein the bearing diameter is between 40 and 60 percent of the cam loader diameter.
19 . The load cam and thrust reaction bearing assembly of claim 15 , wherein the bearing diameter is less than about 80 percent of the cam loader diameter.
20 . The load cam and thrust reaction bearing assembly of claim 15 , wherein the bearing diameter is less than about 70 percent of the cam loader diameter.