Second-Generation RADIALcvt Continuously Variable Transmission Simulation and Test Results 06-13-02-0011

The RADIALcvt is a traction drive continuously variable transmission (CVT) implemented in a new novel radial configuration mechanical assembly. The RADIALcvt functions as a multi-parallel power path (at least six) type of CVT, which consists of only one steel-on-steel, line contact, traction drive interface in each power path. A constant input radius on the traction drive input makes it possible to use a constant clamping force, which is provided by mechanical springs, thus eliminating the need for a hydraulic control system. The RADIALcvt has a very large radius variation on the traction drive output, which provides the ratio variation. The test and simulation results of the first RADIALcvt prototype was published in [1] and presented mechanical efficiencies above 90%. This article presents the simulation and test results of the second-generation RADIALcvt prototype, which presents mechanical efficiencies above 94% and includes measured parameters of mechanical efficiency, slip, traction curves, and ratio torque at different loads while providing excellent partial load versus mechanical efficiency properties. A methodology for predicting the efficiency map using the no load torque loss is also proposed.