Sensitivity Analysis of Torque Transmission Efficiency of a Half-Toroidal CVT

In this research a computer model based on elasto hydrodynamic fluid film lubrication is developed in order to calculate the torque transmission efficiency of a half-toroidal CVT variator. Validation of this model is verified by comparing the experimental and the model results. Sensitivity of torque transmission efficiency to eleven parameters is investigated. These parameters are: dimensionless roller curvature, aspect ratio, half cone angle, fluid viscosity index, pressure constant for Roelands model, input rotational velocity, absolute viscosity at atmospheric pressure, Young modulus of disks and power rollers, Poisson ratio of disks and power rollers, number of power rollers and variator cavity radius. The fractional factorial design 2^{k- p} is employed for sensitivity analysis. It is believed that variator aspect ratio, pressure constant for Roelands model, absolute viscosity at atmospheric pressure, input rotational velocity and Poisson ratio are the factors which have more than 10% effect on torque transmission efficiency.