Theoretical Analysis of Interference of Teeth in Strain Wave Gearing

This paper deals with a theoretical analysis of the inteference in a strain wave gearing (commonly known as a harmonic drive), which is a compact, light-weight mechanical device capable of high speed reduction as well as high mechanical advantage in a single stage. The analysis is carried out in a plane perpendicular to the input and output axes, and in a no load state. The involute profiles of teeth are simplified to straight lines. When the flexible spline is deformed into an oval shape by the wave generator, it is assumed that a neutral line exists there, which maintains the same length as that prior to deformation. The number of teeth causing interference at the same time in a strain wave gearing is found by the analysis, which changes with a period of one pitch of the circular spline.