| Harmonic Drive is a mid-50s of the 20th century with its unique advantages in the aerospace and other high precision mechanical transmission occasions has been widely used, but in the course of its use is gradually exposed their deficiencies. One of the main components harmonic gear wheel is a thin flexible shell, in the work to bear the role of alternating stress, prone to fatigue failure, which is harmonic gear transmission accuracy and service life are greatly affected. Harmonic Gear for the above-mentioned problems, to raise as much as possible harmonic gear transmission accuracy and to extend its service life, uses the finite element method to the strength and flexibility flexible wheel housing on the alternating stress analysis.Firstly, the elastic theory to derive the soft bye load stress and strength check calculation formula, and to B3-160 type universal harmonic gear reducer cylindrical cup-shaped flexible wheel, for example, to design type in the four-force wave generator parameters under the same two soft round: cylindrical cup-shaped flexible wheel and bell-shaped flexible wheel. In the three-dimensional modeling software Pro/ENGINEER to create two forms of the geometric model of the flexible wheel and to simplify the actual situation, and then imported into finite element analysis software ANSYS, the finite element model generation. By Solid186 unit to sweep meshing ring gear, so soft tooth ring on the cell as much as possible for the rules of hexahedral, flexible round barrel and flange Solid187 cell free mesh, can improve accuracy to calculate model closer to reality.Second, under the module in ANSYS Multiphysics two forms of the flexible wheel for static stress analysis. The results showed that: the maximum stress occurred at two forms of flexible round ring gear and the four force-type wave generator with the contact area, approximately within±25°; the ring gear stress gradient around the smaller; smooth tube body part in the direction of stress along the flexible wheel bus decreases; due to the boundary effect of, flexible wheel flange and the shaft connecting the stress has gradually increased, so soft and round the ring gear flange is the most concentrated part of the stress; in the subject to the same static load, bell-shaped stress distribution flexible wheel, can reduce the stress concentration of the life of the flexible wheel. Finally, based on modal analysis theory, two forms of soft round obtained mode shapes and natural frequencies. The results showed that: two forms of the first 10 rounds of soft modal ideal, consistent with the theory, of which the first four vibration mode of the frequency distribution is reasonable, but the bell-shaped flexible wheel of the value of natural frequencies on the order of corresponding to cylindrical cup slightly larger than the natural frequency of the value of flexible wheel, and its adjacent natural frequencies of the different little bell-shaped flexible wheel base greater than the frequency 455.91Hz round cylindrical cup soft baseband 407.27Hz, better The four forces acting away from the wave generator and the wheel gear and the load just the vibration caused in order to avoid the resonance phenomenon.Therefore, the bell-shaped flexible wheel can reduce the stress concentration, expand life; its natural frequency bandwidth, can avoid resonance for harmonic structure of the flexible wheel for gear drive improvements, optimization and design of a useful theoretical and technical support.
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