Abstract
This paper presents an analytical and experimental study on the belt vibration of a rubber V-belt CVT during speed-ratio change. On the basis of the motion characteristics of the CVT, the major components are modeled as an instantaneous flexible four-bar linkage for the determination of the belt vibration. The free-span of the axially moving belt is considered as the flexible coupler link, while the variable-diameter driving and driven sheaves are modeled as the crank and rocker links, respectively. The equation of motion, governing the dynamic behavior of the free-span of the belt in transverse direction, is derived by employing a mixed variational principle. The geometrical boundary and initial conditions are determined from the physical configuration of a practical CVT system. A parametric study on the natural frequencies of the belt is then performed by using assumed-modes method. Meanwhile, the length of the free-span of the belt is simultaneously established from contact analysis. Finally, a dynamometer is constructed for verifying the proposed theoretical development and the results of computer simulation. Parameters which may result in the change of dynamic behavior are also investigated experimentally. Favorable comparisons between the analytical and experimental results are obtained.