Computer Simulation of Tooth Engagement of Strain Wave Gearing

Abstract

A program to simulate the state of tooth engagement of strain wave gearing (commonly known as harmonic drive gearing) was developed with a personal computer for the purpose of determining quantitatively the number of teeth in active engagement of the gearing. This program is able to analyze the orthogonal and static state of tooth engagement in the cross section of the gearing. With the use of such a program, the states of tooth engagement were simulated for three kinds of strain wave gearings. From the results obtained, the following conclusions are drawn. The number of teeth in contact increased as the load torque increased. The percentage of teeth in contact was approximately 6%11% (at no load), and 10%17% (at rated load), and the new teeth which came into contact upon increased load torque appeared to be asymmetrical with respect to the major axis of the wave generator, and biased in the opposite direction of the load torque.