Study On Peening Technology And Fatigue Life Of Flexible Drive Parts Of Harmonic Reducer

Harmonic gear drive is widely used in robot.In the transmission process,it deformed due to the load and the meshing load.Therefore,the service life of the flexible wheel often determines the harmonic reducer's service life.As a widely used surface strengthening technology,shot peening can significantly improve the anti-fatigue performance of the material surface.It is an important strengthening process to delay the fatigue failure of the material.In order to further enhance the service life of the soft wheel,this article explores the effect of shot peening on soft round.Combining with the experiments of orthogonal test and comprehensive analysis method to optimize the soft round shot peening process parameters.At the same time,studied the distribution of residual stress under different shot peening technology,the change of the surface roughness under various process parameters.And the relationship between the maximum residual stress and the roughness of the s-n curve research shot peening process on the influence of the soft wheel fatigue life.The main research contents of this paper are as follows:The finite element simulation model of shot peening process was established,and the reliability of the model was verified through comparison between experiment and simulation.In this process,the surface residual stress was taken as the standard rather than the maximum residual stress,and the integrity of parts was preserved.On this basis,the selection of the projectile velocity,the projectile diameter,coefficient of friction and impact times as factors of orthogonal experiment simulation analysis,and the surface residual compressive stress,the maximum residual compressive stress,the maximum depth of the residual compressive stress value,residual compressive stress layer depth of value analysis.The result think that pill granule radius and speed impact on the effect of shot peening is larger,the coefficient of friction and collision frequency is smaller;With the increase of pellet velocity and diameter,the maximum residual compressive stress,maximum residual stress depth and the depth of residual stress layer increased significantly.The optimal process parameters are: the diameter of the projectile is 1.2mm,the impact velocity is 120m/s,the impact frequency is 2 times,and the friction coefficient is 0.2.As before,is still the first experiments to validate the finite element model,then to study blasting parameters on the influence law of workpiece surface roughness after shot peening by ABAQUS.Quantitative analysis of various parameters on the workpiece surface roughness,including coverage with shot number instead,and the correlation of the residual stress and the roughness is studied,found that the maximum residual stress value,the maximum depth of the residual stress and surface roughness are a linear positive correlation,which affect the shot peening speed compared with coverage more.Even if the maximum residual stress value and the maximum residual stress depth are taken as the target,the required residual stress depth value can be well inhibited by increasing the speed of shot peening.By modifying the key words,the stress results after shot peening were imported into the flexible wheel,and the fatigue life was analyzed by fe-safe under the condition of establishing s-n curve.The results show that: In this study,the fatigue life of the flexible wheel was increased by 66%.The influence of shot peening parameters on fatigue life was optimized.When the residual stress was small,the surface roughness had a great influence on fatigue life,and when the residual stress was large,the residual stress dominated.With the increase of surface.