Continuously variable transmission

Abstract

Inventive embodiments are directed to components, subassemblies, systems, and/or methods for continuously variable transmissions (CVT). In one embodiment, a main axle is adapted to receive a shift rod that cooperates with a shift rod nut to actuate a ratio change in a CVT. In another embodiment, an axial force generating mechanism can include a torsion spring, a traction ring adapted to receive the torsion spring, and a roller cage retainer configured to cooperate with the traction ring to house the torsion spring. Various inventive idler-and-shift-cam assemblies can be used to facilitate shifting the ratio of a CVT. Embodiments of a hub shell and a hub cover are adapted to house components of a CVT and, in some embodiments, to cooperate with other components of the CVT to support operation and/or functionality of the CVT. Among other things, shift control interfaces and braking features for a CVT are disclosed.

What is claimed is: 
     
         1 . A power input assembly comprising:
 an input driver having a first end and a second end, wherein the first end comprises a splined surface, and wherein the second end comprises at least two torque transfer extensions; and   a torque transfer key having at least two torque transfer tabs configured to mate with the at least two torque transfer extensions.   
     
     
         2 . The power input assembly of  claim 1 , wherein the second end of the input driver comprises torque transfer key retention surfaces. 
     
     
         3 . The power input assembly of  claim 1 , wherein the torque transfer key comprises at least two surfaces adapted to ensure concentricity with the at least two torque transfer extensions. 
     
     
         4 . The power input assembly of  claim 3 , wherein the torque transfer key comprises an outer surface having a set of threads. 
     
     
         5 . The power input assembly of  claim 3 , wherein the torque transfer key comprises an outer surface having a set of splines.