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A new rolling traction CVT design based on spherical torque transfer components has been developed by Motion Technologies, LLC. Improved efficiencies and significantly improved power densities have been demonstrated. Ratio control of this CVT is very simple, in contrast with more complex controls required for other rolling traction type CVTs. Both the single cavity and dual cavity designs of the Motion CVT have coaxial input and output shafts. The input and/or output may also be offset to accommodate other automobile drivelines. These characteristics, combined with low manufacturing cost, make the Motion CVT a very reasonable option for automotive and other vehicle applications.

An attractive new CVT design has been introduced that is a variation of the Kopp variator, currently used in some industrial applications. A prototype of the transmission has been tested and modeled by Southwest Research Institute in efforts to optimize performance over the full range of operating conditions. Analytical predictions and experimental results at steady state are presented that demonstrate higher efficiencies and power capacities with the new design, yielding possible feasibility in a number of vehicle and industrial applications. The traction and power loss prediction is made using models that include evaluation of creep, spin and side slip in the contact patch as well as the influence of asperity contact through the fluid film. Overall, efficiency levels are higher than the Kopp variator and axial load requirements are lower. Additionally, analytical predictions of the transmission performance yield reasonably good agreement with experimental data.

Infinitely variable transmission (IVT) characteristics are typically obtained by utilizing a planetary gear set in a split-power transmission configuration. The spherical traction CVT developed by Fallbrook Technologies is kinematically analogous to a variable planetary gear set. The combinations of multiple inputs, outputs, and different internally parallel architectures combine to create hundreds of CVT, IVT, and/or split-power configurations. The variable planetary configuration is inherently power dense and creates a compact, low cost IVT, potentially without the need for dual paths. The control of this novel variator is inherently stable because ratio control is independent of load.