Analysis Of The Stress Of Flexspline In Harmonic Gear Drive By Finite Element Method

Because harmonic gear drive have many merits such as big ratio of transmission, small volume and light weight, high drive accuracy, little return difference and so on, it has been applied successfully to many fields including aerospace, atomic reactor and high-energy accelerator, radar system, robot, military field, optical instrument and general machine. Though almost all fields involved harmonic gear drive have been studied by many domestic and foreign scholars, a lot of works still require to do. Such as the problem of fatigue strength and precision of flexspline, which mainly influence the life of harmonic drive is one of the most important research in harmonic gear drive. So it is very significant to study harmonic gear drive. This article mainly study the fatigue strength and displacement of flexspline by using of finite element method.Firstly, the theory and characteristic of harmonic gear is described in this article. Based on the experimental result, the stress and displacement of flexspline are analyzed. The expressions of the fatigue strength of flexspline is obtained. This is the basic theory in studying of flexspline. The displacement of flexspline is large, this is a large displacement of geometry non-linear problem.Then, according to achievements and shortages that have been achieved on study of harmonic drive at the present time, by applying elastic theory, non-linear finite element method and the techniques of CAD/CAE, a 3-D model of flexspline is established. The model is analyzed by finite element contact method in order to gain stress and displacement of flexspline. The load of flexspline tooth is calculated. The stress and displacement of flexspline under the load is analyzed. Comparison of the stress and displacement of flexspline is done under different wave generators. The stress and displacement curves of flexspline are obtained. The results show: cam and disk wave generators are better then the roller wave generator.At last, on the basis of the model in above paragraphs, some important geometrical parameters of flexspline are analyzed and the recommendatory values of these parameters are given based on the changes of flexspline's stress and displacement. This can help the designers to design the flexspline. The rotation angle of flexspline tooth is calculated, which gives much help to research the precision of harmonic gear. The...