The jumping in synchronous belt drives occurs on the driven pulley when the number of the driving and the driven pulley teeth is the same and the wrapping angle of the belt on both pulleys is π radian. However, when the pulley rotates at quite a low speed (2 rpm), overload is rapidly applied on the driven pulley which causes jumping on the driving pulley. Jumping over of the synchronous belt drives is caused by the belt teeth climbing on the pulley teeth in combination with elastic deformation of the belt and the supporting shafts and bearings. Belt teeth climbing starts from the slack side belt in both of the driving pulley jumping and the driven pulley jumping. The belt tooth climbing progresses from the slack side to the tight side belt. Theses facts can be conformed by the simulation of dynamic finite element analysis. In this study, "ABAQUS/Explicit" and "ABAQUS/Standard" were used for the simulation.
