Dynamics During Speed Ratio Change of a Double Roller Full Toroidal Traction Drive

The dynamics of the speed ratio change process of a double roller full toroidal variator (DFTV) is presented. Speed ratio variation process is observed by finding settling time and efficiency during the ratio variation. A numerical model is developed and simulated using computer software. Contact analyses between roller and discs are based on Hertz theory. The traction and spin moment coefficients are estimated using elasto-hydrodynamic lubrication (EHL) theory. Equation for maximum acceleration of output shaft is derived in terms of maximum output torque. Finally, a procedure to obtain maximum efficiency keeping certain dynamic speed ratio change requirements is discussed.