Abstract
The fatigue failure mechanism has been investigated for the rubber CVT (continuously variable transmission) belts. There are three major failure modes, namely the adhesive rubber failure, the backing rubber failure and the bottomland failure. Especially, the adhesive rubber failure is the important mode to strengthen the rubber CVT belts, because the failure is hard to find out during the driving. The authors have revealed that the adhesive rubber failure is further branched into two failure initiation types, i.e. the interface de-bonding and the surface-crack initiation. In this study, the authors focused on the surface-crack initiation type. The damage for the surface-crack initiation was accumulated by the shearing between the belt cord and the belt side-surface, where the torque was transformed by the friction between the belt and pulley. The extent of the shearing stress was estimated by a simplified mechanical model, which was proposed basing on Euler's theory for the friction.
