The Dynamic Characteristic Analysis And Research Of The Harmonic Drive With Three-wave Wavegenerator

The harmonic gear drive has been widely applied in a wide range of fields owing to its unparalleled advantages over other drives. However, its actual applications are subjected to various restrictions because of the multiple-bent of the flexspline, great stress and high requirement on the performance of the materials in the process of engagement. Considering that the performance of the harmonic flexspline made of plastics is better than that made of steel under light load, the author of the paper presents a thorough study of the harmonic gear drive with three-wave wavegenerator made of plastics.In line with the movement distortion characteristics of the harmonic gear drive with three-wave wavegenerator and by adopting the theory of the movement of force for elastic thin shell, the author, (1). derives the formulae for calculating the distortion and stress on the acting surface of flexspline load in the drive process of the harmonic gear drive with three-wave wavegenerator; (2) analyzes and compares the performance of plastic and steel products under light load drive and calculates the probably reached limit of drive ratio for both types of flexsplines under the same load; (3) applies the harmonic gear drive with three-wave wavegenerator to the small-sized multiple-revolution electric device of valves by taking into consideration of the low limit of the drive ratio for the harmonic gear drive with three-wave wavegenerator made of plastics, improves the design on the main drive mechanism of the traditional small-sized multiple-revolution electric device of valves, and validates through examples the feasibility for the harmonic gear drive with three-wave wavegenerator made of plastics to be applied to the small-sized multiple-revolution electric device of valves. Finally the author performs calculations on the two types of the flexsplines of the harmonic gear with three-wave wavegenerator by using the finite element method and analyzes the causes for the errors. The research shows that the harmonic gear drive with three-wave wavegenerator causes great distortion and stress, but if the material for the flexspline is properly chosen, this disadvantage will be offset and the scope of application for the harmonic gear drive will be expanded. However, it should be noticed that as a new type of drive that has just started in China, the harmonic gear drive with three-wave wavegenerator made of plastics still has many open problems to solve by means of a thorough study so that the drive can find a wider application.