Structural Optimization And Fatigue Sensitivity Analysis Of Hat-type Flexispline

The harmonic drive,which relies on the elastic deformation of the flexispline,solves the contradictory problem between the large transmission ratio and the structure size,and has become the focus of attention in the field of aerospace exploration,artificial intelligence and military field.However,because the flexispline needs to bear cyclic alternating stresses of a thousand times per minute,its fatigue strength and service life seriously restrict the transmission performance of the harmonic.Therefore,it is of great significance to analyze the response trend of the structural parameters of flexisplines,to carry out the research on the structural optimization and fatigue sensitivity of flexisplines.According to the school-enterprise cooperation project,this article takes the hat-type SHF14 series harmonic reducer as the research object,and uses the theoretical deduction,the numerical calculation and the finite element imitation truth combination method to carry on the related research,the main research content is as follows:1.Based on the contact of the hat-type flexispline with the wave generator,the structural parameters affecting the deformation and stress distribution of the flexispline are analyzed under the condition of the structural deflection theory and the fatigue strength formula,and the similarities and differences between them and the traditional cup structure are compared,and the following directions are pointed out.2.In order to research the deformation and equivalent stress of the hat-type flexispline,this paper establishes the parametric assembly model of hat-type flexispline and wave generator in Creo2.0 software,and then imports it into ANSYS Workbench by using the joint simulation interface.By defining the nonlinear behavior of friction and penetration between the contact surfaces of the two components,also the observation path is set in the key area.It is found that the maximum deformation and the position of the equivalent stress of the hat-type flexispline are similar to the cup-type flexispline,but the stress amplitude of the hat-type flexispline can not be ignored at the transition round angle,and the angle radius should be studied in the later period.3.According to the maximum deformation displacement and equivalent stress of the hat-type flexispline structure,the response trend of the three structural parameters(length diameter ratio,wall thickness and round corner radius)induced by the upper chapter is studied.Subsequently,response surface methodology and BBD experimental sample pointdesign were used to optimize the structure.Finally,the tooth wear resistance,fatigue strength and structural stability of the optimized parameters are checked,and the design drawings are given.4.Using modal module and fatigue tool to analyze the modal and fatigue sensitivity of optimized structure,the result shows the trend consistency between structural optimization and fatigue sensitivity,and proves the rationality of the optimization and provides reference for improving the fatigue life of the flexispline.