Simulation And Experimental Research On Mechanical Performance Of Hollow Harmonic Flexible Wheel

Harmonic reducer has the characteristics of high transmission ratio,high transmission accuracy,high load capacity,compact structure and transmission particularity,and is widely used in the fields of robotics and aerospace.Because the harmonic reducer relies on the periodic elastic deformation of the flexspline to transmit motion and torque,the flexspline bears periodic and repeated loads for a long time,so the flexspline is the most prone to fatigue failure component in the harmonic reducer,and only the flexspline breaks It accounts for more than 60% of the total failure of the harmonic reducer,which has restricted the development of the harmonic reducer.Therefore,it is necessary to conduct a detailed study on the mechanical characteristics of the flexspline to break through the key technology of the harmonic drive structure design.In this paper,the hollow harmonic reducer is the research object,and the static and dynamic mechanical performance numerical simulation and experimental test research are carried out,including:According to the theory of harmonic transmission,the deformation closed curve equations corresponding to different forms of wave generator flexspline are derived,as well as the calculation formula for the load between the flexspline teeth,the load between the flexspline teeth and the load torque,the tooth modulus,and the tooth pressure angle.Positive correlation,negative correlation with gear ring width,meshing interval angle,and neutral surface radius;use the safety factor method to check the fatigue strength of the flexspline of the studied model,and perform structural instability analysis at the same time to study the fatigue strength and stability of the object all meet the design requirements.Using SOLIDWORKS to carry out three-dimensional simulation modeling of the harmonic reducer,using ANSYS and Hyper Mesh co-simulation to simulate the assembly-no-load-load load condition of the harmonic reducer,and study the flexible harmonic reducer considering the assembly prestress and load.The characteristics of wheel deformation and stress distribution;at the same time,the deformation and stress data of each section of the flexible wheel are extracted,and the weak links in the structural design of the flexible wheel are identified.According to the circumferential and radial deformation of the flexspline,it is found that the flexspline is spatially deformed,which is expressed as the space deflection caused by the circumferential deformation and the space warpage caused by the radial deformation.The specific structure optimization of the research object is given based on the characteristics of the deformation Design.In terms of dynamic characteristics,the torsional stiffness performance,dynamic performance and fatigue life performance of the flexspline of the harmonic reducer are studied.According to the simulation test of positive and negative loading,the torsional stiffness of the flexspline is calculated,which verifies that the torsional stiffness of the model meets the characteristics of high torque and low hysteresis;through free calculation modal analysis,it is found that the excitation frequency of the flexspline is much lower than the inherent frequency,there is no resonance,the model has good dynamic performance;In addition,using Fe-safe software,based on the nominal stress method to predict the life of the harmonic reducer flexspline,and plot the fatigue life and safety factor of the flexspline under different load conditions Based on this curve,the recommended working load interval of the flexspline is proposed.The ARAMIS three-dimensional optical deformation measurement system and the LMS Test.Lab data acquisition system are used to carry out the experimental test of the harmonic reducer flexible wheel.Measure the deformation of the flexspline during the assembling process of the wave generator,and the relative error between the simulation results and the experimental test results is small;the modal test is performed on the flexspline,and the measured modes of the flexspline correspond well to the simulation.,The maximum relative error between the natural frequency of the flexible wheel simulation and the experimental test result is 10.35%,which verifies the accuracy and precision of the modeling and simulation methods,and has certain engineering application value.