抄録
In previous paper we have already reported that the noise generation mechanism of synchronous belts is not impact sound due to the collision of the belt and the pulley tooth, but radiated sound from the belt vibration excited by radial displacement caused by the polygonal effect of the pulley and the deformation of the belt at the meshing point. In this paper it is shown that the noise reduction mechanism of helical synchronous belts can be explained by using the above theory with the polygonal effect of the shape projected to a surface at right angle with the pulley axis.
