Based On Rigid-flexible Coupling Dynamics Analysis Of Excavator Joint Friction Pair Face Contact Perfor Mance Analysis

Excavator,as one of the most typical construction machinery,plays an irreplaceable role in social production and life and engineering application.China’s excavator started a little later than foreign countries,but with the rise of Chinese manufacturing in recent years,China’s excavator products gradually began to go to the world.Therefore,it is becoming more and more important to improve the quality of excavators and build the core competitiveness and brand recognition of Chinese excavators.The working device of excavator is an important load bearing system in excavator’s daily work.In order to study the working device of excavator,this paper adopts rigid-flexible coupling dynamics analysis theory and finite element analysis method to study the overall strength of excavator working device and the performance of joint friction pair,and explores a theoretical method to study the performance of excavator working device.（1）Based on modal method and Lagrange method,the mathematical model of rigid-flexible coupling dynamics of excavator working device was established,and the deformation motion equation of working device was derived;The working conditions and modes of excavator excavation are summarized,and the conventional classical working conditions of bucket excavation are selected for dynamic analysis.At the same time,the external load of excavator is calculated,which is the basis of dynamic simulation.（2）Based on the virtual prototype technology,the rigid-flexible coupling dynamics simulation of the excavator’s working device was carried out,and the loads of the three important joints of the excavator,the partial loads of the arm-base joints and the angular velocity data were obtained.The joint load curves were compared.The results show that the rigid-flexible coupling curve is more realistic.At the same time,the strength of the flexible body boom and bucket rod is checked to get the dynamic change of the dangerous area and the dangerous node of the flexible body.（3）The strain flower stress experiment was designed to verify the dynamic stress of boom and bucket rod based on the rigid-flexible coupling dynamic analysis results.The results show that the rigid-flexible coupling simulation is consistent with the experimental curve trend,and there is little difference in numerical value.The oscillation degree of rigid-flexible coupling exceeds the experimental curve in some parts of heavy load.This shows that the error of rigid-flexible coupling will increase in the case of large load and deformation.In this case,the rigid-flexible coupling theory needs to be further improved.（4）Taking the joint load of rigid-flexible coupling dynamics analysis as the external load,the finite element analysis on the end face of the joint friction pair is carried out to analyze its performance,including strength analysis,fatigue analysis and wear analysis.The results of finite element analysis show that the maximum contact pressure of the left and right face is far less than the maximum pressure limit of the material,and the material is safe.In the contact form,the outer surface of the end face bears the main contact pressure,and the wear also extends from the outer surface to the inner surface.The left end face is more likely to be damaged than the right end face,The fatigue life of the left end face is calculated,and the fatigue point is located in the area directly below the end face,which is consistent with the wear position.Figure [50] Table [5] Reference [100]...