Research On Tooth Profile Design And Meshing Performance Of Harmonic Gear Transmission Based On Improved Kinematics Method

In the background of "intelligent manufacturing 2025",the domestic robot industry is booming.As an important part of robot joint,harmonic reducer’s meshing performance plays a vital role in the performance of robot.The difference between the research of harmonic reducer in China and abroad is mainly reflected in the high-precision transmission.How to improve the high-precision,high stability,high strength and high life of harmonic reducer is the key to the research of harmonic reducer.In this paper,starting from the tooth profile and meshing characteristics of harmonic drive,taking the new flexible tooth profile as the research object,around the angle relationship and conjugate theory of harmonic drive,combined with MATLAB and finite element simulation analysis,the new flexible tooth profile design,tooth profile space modification and parameter optimization are carried out,so as to improve the meshing performance and transmission stability of harmonic drive.The main tasks are as follows:Firstly,the composition and basic principle of harmonic drive are described in detail,and several basic assumptions of harmonic drive are put forward,based on which the subsequent tooth profile design is carried out.Based on the geometric model of harmonic drive,the angle relationship of each component is studied,and the common tangent double circular arc flexible tooth profile is designed.The meshing mechanism of improved kinematics of harmonic drive is deduced.Based on the improved kinematics method,the conjugate steel tooth profile is solved,and the conjugate numerical solution is obtained by least square arc fitting.Secondly,the meshing characteristics of harmonic drive are analyzed,the threedimensional elastic contact finite element model of harmonic drive is established,and the transient dynamic analysis steps and methods of harmonic drive are studied.The stress and deformation of harmonic drive are analyzed in different working conditions,and the transmission law of stress change in transient state is explored.Based on the common tangent double arc tooth profile as the research object,and combined with the meshing characteristics of S-shaped tooth profile,a new flexible tooth profile is designed,and the meshing backlash of several tooth profiles and the stress of flexible gear during transmission meshing are co MPared to verify the meshing backlash and equivalent stress of the new flexible tooth profile The advantages of the system.Then,three kinds of tooth thickness modification schemes are put forward based on flexible tooth thickness modification,and the optimal selection scheme is selected through analysis and co MParison.Combined with the finite element method,the thickness of the tooth profile at the front and rear end of the main section is adjusted,and the modification amount of the front and rear sections is solved,so that the flexible tooth profile can mesh with the steel tooth profile at the three section ends without interference.Considering the deformation of the tooth profile in the transient analysis,the equidistant compensation modification of the new flexible tooth profile is carried out based on the new flexible tooth profile.At the same time,the compensation formula of flexible gear profile modification is put forward,and the corresponding modification amount is calculated by combining with the finite element quantitative analysis.Then,the meshing situation of flexible gear and steel gear profile before and after modification is analyzed,and it is concluded that the tooth profile modification can improve the meshing of steel flexible gear to a certain extent;the stress situation of flexible gear in three states,i.e.unmodified shape state,tooth thickness modification state and tooth profile modification state,is analyzed,and the conclusion is drawn Flexible gear tooth thickness modification and tooth profile modification can effectively improve the bearing capacity of flexible gear.Finally,the influencing factors of flexspline stress are analyzed,the different stress performance of Flexspline in no-load and load state is studied,and the tooth profile parameter factor of flexspline is determined;the influence law of single tooth profile parameter on flexspline stress is explored;the influence law of interaction between different parameter factors on flexspline stress is explored based on design expert response surface method,which is the premise of verifying the feasibility of the experimental model In order to minimize the maximum stress of the flexspline,the optimal parameters of the flexspline are obtained.