Theoretical-Experimental Determination of CVT Power Losses Due to Rubber V-belt Vibrations

Abstract

The article proposes a solution of determining power losses caused only by rubber V-belt vibrations in continuously variable transmission (CVT). The analysis was performed on the basis of a mathematical model and experimental data. The article includes the results of experimental tests of vibrations of a transmission belt driven by a two-stroke engine. A contactless measurement was performed by a high-speed camera and a time-lapse image analysis was performed in dedicated software. This new approach in the discussed research area allows obtaining results impossible to receive with other measurement methods. The mathematical model applied is an axially moving, with constant velocity, Euler-Bernoulli beam, the nonlinear effects and longitudinal vibrations are ignored. It was assumed that the material of the belt obeyed the Voigt-Kelvin rheological model. The method of determining the coefficients describing the damping properties of the belt is also discussed. The equivalent bending damping coefficient was determined based on the analysis of the damped free vibrations of the cantilever beam, made of the belt segment. The CVT power losses for fixed working conditions were obtained after numerical calculations with the use of procedures of the IMSL® C package.