Second-Generation RADIALcvt Continuously Variable Transmission Simulation and Test Results 06-13-02-0011
This also appears in
SAE International Journal of Passenger Cars - Mechanical Systems-V129-6EJ
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  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.