Dynamic Analysis And Experimental Study Of Flexible Bearings For Harmonic Reducers

Harmonic reducers have the advantages of large transmission ratio,light weight,and high transmission accuracy,and are widely used in fields such as aviation,biomimetic technology,and general machinery.The flexible bearing used in the harmonic reducer is both a load bearing component and an elastic deformation elastic transmission component.Its dynamic performance and service life determine the dynamic characteristics,transmission accuracy and service life of the harmonic reducer.The flexible bearing has thin-walled inner and outer rings,which produce structural elastic deformation under the action of the wave generator cam.Its kinematics Dynamics and experimental research have become one of the urgent difficulties in the development of high-performance harmonic reducers.This article adopts the multi body dynamics method to study the static and dynamic characteristics of flexible bearings with different wave generator cams under various working conditions.A flexible bearing performance test bench that conforms to the load characteristics of flexible bearings is developed and constructed,providing reference for studying the mechanical characteristics of flexible bearings in harmonic reducers.Firstly,using multi body dynamics methods and simulation analysis techniques,a rigid body dynamics model for flexible bearings was established,taking into account the dynamic contact effect between steel balls and flexible ring raceways.Based on this,a rigid flexible coupling dynamics model for flexible bearings and a rigid flexible coupling dynamics model for cam flexible bearings of different types of wave generators were established,taking into account the structural elastic deformation effect of thin-walled rings.In response to the elastic deformation problem of flexible bearings,the influence of the elastic deformation of thin-walled rings on the internal load distribution,deformation,and contact characteristics of bearings was studied.According to the theory of standard elliptical cam contour curve,the theoretical curve and simulation curve of the steel ball were compared and analyzed,and the modal vibration characteristics of the thin-walled ring were analyzed.Then,the load distribution and deformation characteristics of the flexible bearing were analyzed under the action of standard elliptical cams and double eccentric circular arc cams,and the influence of wave generator cams with different contour curves on the motion and contact characteristics of the flexible bearing was studied.Aiming at different transmission modes of different harmonic reducers,under two typical transmission modes of fixed flexspline and output flexspline,the kinematic and contact characteristics of the cam flexible bearing of the wave generator are compared and analyzed,and the dynamic response characteristics of the cam flexible bearing of the typical wave generator under different transmission modes are discussed.Finally,based on the working load and harmonic elastic deformation characteristics of flexible bearings used in harmonic reducers,the functional requirements of the harmonic reducer performance test bench were analyzed.A flexible bearing performance test bench was developed and constructed that can apply synchronous time-varying speed drive and synchronous tracking load to the flexible bearings,while meeting the connection between the test process and the harmonic reducer.The mechanical structure and function of the harmonic reducer test bench were designed,A performance test bench for flexible bearings was built,and dynamic response testing instruments were used to conduct dynamic response tests on the flexible bearings.The stress and strain situation of the outer ring of the flexible bearing was analyzed,and the vibration acceleration of the outer ring of the flexible bearing was also studied.