Study on Wide Ratio Range Toroidal IVT 2011-01-2032
The author describes a wide ratio range, half-toroidal, continuously variable transmission (CVT) and discusses how this CVT can contribute to improved fuel economy for passenger vehicles. Technologies that have been applied to improve the CVT are first discussed where the author describes how a higher traction coefficient can expand the ratio range of the toroidal variator. Then, improvements to the infinitely variable transmission (IVT) are discussed. Details on how the IVT has two driving modes and an infinite ratio range are discussed; with further details on factors that can improve fuel economy by expanding the over drive ratio. In order to expand the overdrive ratio of the IVT, the author mounted a newly developed, wide ratio range variator and adopted a direct-drive mode for the high-speed driving mode of the IVT. The author finally describes the process used to determine the final gear ratio of the IVT and the calculation results of fuel consumption of the vehicle as it relates to the IVT.