Miniaturized Design Of Harmonic Reducer And Optimization Analysis Of Key Components

Harmonic gear transmission is a key field in China's high-tech industry.Its superior performance is related to the rapid development of emerging robotics,cutting-edge weapons and equipment,and aerospace,etc.However,the technology and materials have been blocked by other countries.Therefore,the independent research of high-precision and high-rigidity harmonic reducers is a key issue to be solved urgently in the field of precision instruments in China.To obtain a high-performance harmonic reducer,it is necessary to optimize the structure and parameters of its core components,especially to deepen the research on the deformation mechanism and mechanical properties of the flexspline.In order to expand the application range of the harmonic reducer,it is necessary to miniaturize and integrate the harmonic reducer.Optimizing the various indicators of the small flexspline and proposing a targeted size compensation scheme is of great significance for improving the performance and life of the reducer.In this paper,a certain type of industrial robot joint harmonic reducer is taken as the research object.Based on the response surface test method,the parametric finite element model of the harmonic reducer is established,and the scheme of harmonic reducer miniaturized design is explored,and the structural of its core components are optimized.The main research contents are as follows:(1)Research on deformation mechanism and mechanical properties of flexspline.Based on the ring theory,the deformation mechanism of the flexspline and the stress and strain under load were analyzed,and the key parameters affecting the mechanical properties were explored.The differential model of the elastic ring of the flexspline was established.The differential equation of the elastic ring was theoretically studied,and the differential equation was corrected.(2)Establish a parametric model of the flexspline and wave generator,then analyze its deformation behavior and stress property.Based on the response surface method,the key components such as the flexspline and wave generator were designed and parametrically modeled.The comparison between the model with tooth and non-tooth was verified.And the deformation characteristics and the stress conditions of the flexspline in all directions were comprehensively analyzed.And the influence of the structural parameters of the flexible wheel on the deformation and stress under the meshing state is analyzed.(3)Research on miniaturized design of harmonic reducer.The effects of four factors(radius,radial deformation,length to diameter ratio and thickness to diameter ratio)were studied,and the coupling effects of multiple parameters on stress and stiffness were analyzed.Then the size compensation method in the miniaturized design process of the harmonic reducer was obtained according to the sensitivity of each parameter to the stress,and the results were regression fitted by the least squares method.(4)Optimize the structure of the core components of the harmonic reducer.The key rounded structures of the flexspline were optimized at first.Then the drafting feature was designed at the bottom of flexspline and the improvement of mechanical properties was analyzed.Secondly,the design scheme of non-standard elliptical cam was explored,and the parametric analysis method with universality was proposed.Finally,the model was further optimized,and the harmonic reducer model including the the rigid wheel and flexspline with tooth was established to analyze the influence of the structural parameters of the flexspline on the stress and deformation under the meshing state,which laid a foundation for the optimal design of the harmonic reducer under the meshing characteristics of the flexspline and rigid wheel.