| The high-precision harmonic drive is an indispensable core basic component for reliable and precise operation of the robot,and 75% of the market is monopolized by the Japanese harmonic drive system.The domestic harmonic reducer has the problems of low transmission accuracy and short life,which is difficult to meet the major demand for high-performance harmonic reducers of the explosive growth of the robot industry.A key reason for the above problem is that the existing harmonic drive spatial conjugate tooth surface design method does not take into account the spatial characteristics of the tapered deformation of the flexspline.Therefore,based on the finite element analysis of the tapered deformation of the flexspline,this paper introduces the radial deformation function into the spatial conjugate kinematics model of the harmonic drive.Considering the processing technology of the flexspline and circular spline tooth,a design method of the spatial conjugate tooth surface is proposed.The meshing characteristics and contact characteristics of the designed tooth profile were compared and analyzed to verify the correctness of the proposed method.It provides a theoretical basis for the design of the spatial tooth profile of the harmonic drive,which has important academic significance and engineering application value.Main research contents of the thesis are as follows:(1)According to the composition and transmission principle of harmonic gear transmission,the design and verification of the prototype of the double arc tooth profile harmonic drive are completed,the structural parameters of each part of the harmonic drive are determined,and the three-dimensional model of the part is established And complete the assembly of the whole machine,which provides a basis for the subsequent analysis of the spatial taper deformation law of the flexible wheel;(2)Based on the finite element method,the deformation of the flexspline is analyzed,and the deformation law of the flexspline is obtained.The radial deformation function of the flexspline is introduced to establish the spatial conjugate kinematics model of the harmonic drive,and the spatial conjugate tooth profile that conforms to the deformation law of the flexspline is obtained.Based on the principle of eliminating meshing interference,the available tooth profiles are selected for the sections with overlapping and self-intersecting conjugate tooth profiles.The flexspline tooth profile of the designed cross section is used as the tooth profile of the cog teeth of all cross sections,and the geometric design of the flexspline tooth surface is carried out by reasonably adjusting the displacement of each cross section tooth profile;(3)Establish a simulation analysis model of harmonic drive assembly and meshing motion considering the spatial taper deformation of the flexspline,and conduct the assembly state,motion trajectory,meshing backlash and coincidence degree of the harmonic drive using this space tooth surface analysis;(4)The finite element method was used to establish the contact finite element model of the double-arc harmonic drive including the flexible bearing,and The performance indexes such as deformation,stress,coincidence degree,contact area,load distribution and transmission error between the flexspline neutral surface and flexible bearing with common spur gear tooth profile and space conjugate tooth surface are comparatively analyzed,which fully verifies the correctness of the method. |
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