Dynamics And Dynamic Strength Analysis Of The Working Device Of The Hydraulic Shovel

In view of the high carrying capacity and efficiency of the hydraulic excavator,and the relatively research is few in China.Therefore,the working device of a 12 bar 3 DOF large shovel hydraulic excavator is studied and analyzed in this paper.The dynamic characteristics and dynamic strength of the working device are mainly analyzed.1?The kinematic modeling of the working device is carried out through the D-H method.The positive solution and the inverse solution of position are simulated under two conditions of mixed mining and horizontal shovel,and the results are in accordance with the actual situation.The analysis results of angular velocity and angular acceleration indicate that the joint of bucket rod has the greatest influence on the position of the bucket end,and the working device has good kinematics response,which lays the foundation for dynamic analysis.2?The dynamic model of the working device is established by the principle of virtual work,and the change curves of the driving force of three groups of hydraulic cylinders are obtained under the working condition of the horizontal push shovel.The results show that the tangent mining resistance has the greatest impact on the driving force.The change trend of driving force reveals the law of the end position of the bucket and the change of the load.The dynamic simulation of the working device is carried out by using ADAMS.Two kinds of results arc compared and analyzed.The error is within a reasonable range,and the correctness of the two dynamic models and analysis results is proved.3?The structure characteristics of the working device are studied and analyzed with ANSYS,especially the modal analysis and the harmonic analysis of the arm and the bucket.The free and constrained modes of boom and bucket are analyzed respectively,and the analysis results show that the frequency and deformation of bucket rod are slightly larger than that of boom.Through harmonic response analysis,it is concluded that the frequency and amplitude of resonance of boom and bucket rod are easy to occur,which provides a reference for structural optimization.4?Combined with ANSYS and ADAMS,the dynamic strength of the working device under the typical operating conditions and the impact load is analyzed.The results show that the change of working condition causes driving force shock,and the impact load has more influence on boom than bucket rod.The size and time of the impact load have great influence on the stress of the component.The longer the action time is,the longer the shock time is;the greater the impact load,the greater the amplitude of the shock.