Abstract
This paper describes a new method of profile design for strain wave gearing. At present there is a strong market demand for this device having improved performance. Especially, improved load capabilities are desired. The main elements covering load capabilities of strain wave gearing devices are the tooth bottom rim of the flexible external gear and the inner rolling contact surface of the wave generator, particularly, the fatigue strength at locations in the vicinity of the major axis thereof. The object of the present study is to reduce the stresses produced at these two locations. The principles of this method are based on two approaches. The one is the continuous meshing of teeth in the principal perpendicular section by satisfying the extend Euler-Savary's theorem. The latter condition is satisfied by the tooth contact condition along the tooth trace. Using these steps, we will get the useful guidance to profile design of this device.
