Development of a Method for Analyzing CVT Casing Radiated Noise Induced by Belt Excitation Forces 2005-01-1460

Finite element analysis methods have so far been developed for studying automotive transmission gear mesh noise, but no such methods exist for analyzing the noise caused by excitation forces from the steel belt used in continuously variable transmissions (CVTs). The principal reason for that is because studies of such belt-induced noise have yet to show clearly how belt excitation forces should be input into a finite element model.

In an effort to resolve that problem, we developed a belt tester comprising a steel belt and pulley system and used it to measure pulley vibration caused by belt excitation forces. Belt excitation forces were found in a reverse calculation from the experimentally measured vibration and the results calculated with a finite element model of the belt tester. The result was then input into a finite element model of a CVT, and a prediction was made of the CVT casing vibration. An acoustic simulation program was then used to predict the radiated noise level from the casing surface. Comparisons were then made with experimental data to determine the validity of the calculated casing vibration and radiated noise level. A good correlation was seen between the calculated and measured results for the casing vibration and reasonably good agreement was obtained with respect to the radiated noise level.