Continuously variable transmission

A method of manufacturing a system for generating axial force in a continuously variable transmission (CVT) having a central shaft, the method comprising:

• mounting a torsion spring coaxially about the central shaft of the CVT;
• coupling a torsion disc to the torsion spring, the torsion disc adapted to partially constrain the torsion spring;
• forming a first load cam disc having a plurality of ramps, the first load cam disc operationally coupled to the torsion disc;
• and
• configuring a plurality of rollers to be energized by the first load cam disc, wherein the torsion disc comprises:
• a disc having a first side, a second side, an outer periphery, and an inner bore;
• an annular recess formed on the first side of the disc;
• a plurality of splines formed on the inner bore;
• a first shoulder formed on the disc and configured to support the first load cam disc;
• a second shoulder formed on the disc and configured to support the torsion spring, wherein the second shoulder rises from the first shoulder away from the first side reaching a maximum height measured from the first side, wherein the second shoulder rises from the first shoulder and then falls toward the inner bore.

A system for generating axial force in a continuously variable transmission (CVT), the system comprising:

• an input disc;
• an output disc;
• a plurality of traction rollers disposed between the input disc and the output disc;
• a first load cam disc having a plurality of ramps;
• a torsion spring coupling the first load cam disc and the input disc;
• a first set of rollers, disposed between the first load cam disc and the input disc, adapted to be energized by the first load cam disc, and configured to transmit axial force to the input disc;
• a second load cam disc having a plurality of ramps;
• a second set of rollers, disposed between the second load cam disc and the output disc, adapted to be energized by the second load cam disc, and configured to transmit axial force to the output disc;
• and
• a torsion disc operably coupled to the input disc, wherein the torsion disc comprises
• a disc having a first side, a second side, an outer periphery, and an inner bore;
• an annular recess formed on the first side of the disc;
• a plurality of splines formed on the inner bore;
• a first shoulder formed on the disc and configured to support the first load cam disc;
• a second shoulder formed on the disc, wherein the second shoulder rises from the first shoulder away from the first side reaching a maximum height measured from the first side, wherein the second shoulder rises from the first shoulder and then falls toward the inner bore in a convex shape.