Study On Lifting Arm Of EBZ220Roadheader In Analysis Of Load, Stress And Strain And Structural Improvement

There is no doubt that excavation and actual mining are important parts of the coal production in the coal industry. Since the rapid excavation of the tunnel is the key technology of high yield of measures to ensure the mine production, mining technology and equipment level will directly affect the coal mine production and safety. The lifting arm, as an important component part of the boom-type roadheader which is the main excavation equipment for underground tunnel construction, bearing the whole cutting part and connecting the turning platform and the lift cylinder, is under the complex stress.With poor working conditions, arduous tasks and inconvenience maintenance, the whole machine will not work if the lifting arm fails when operating,which will seriously affect the efficiency of the enterprise and cause great economic losses. As a result, it is necessary to analyze the lifting arm based on modern means of simulation and do some structural improvements in the weak areas of the original design to improve the stability and reliability of the roadheader.This paper mainly studies the dynamics of the lifting arm in three typical operating conditions based on themultibody mechanical system dynamics and elastic dynamics theory. The solid models of key components and assembly of the roadheader are built in UG, by adopting which into ADAMS the rigid dynamic model of the roadheader is established. The kinematics and multi-body dynamics test analysis of the virtual prototype model verifies that this method is not appropriate for the model.The rigid-flexible coupling system of roadheader is established in ADAMS via importing the modal neutral file for lifting arm blexible body generated by ANSYS. According to the actual working environment of the roadheader, three typical conditions are simulated (side to side cutting, swinging up and down cutting, and drilling). By means of rigid-flexible coupled dynamics simulation analysis of this system, the load curve of lifting arm hinge joints and stress and deformation animation of the flexible body, as well as stress time history curve of keypoints are obtained. The analysis shows that the strength near the hole where the lifting arm and the lift cylinder connecting is relatively weak.Structural improvement is made in the final and reanalysis is also done with the improved lifting arm.Since the rigid-flexible coupling dynamics analysis method of the roadheader,product quality and fatigue life of some components can be early predicted by the time history of dynamic characteristics, which is obtained by the means of creating a virtual prototype model and studying in simulated actual working conditions during the design stage of the whole machine. Simultaneously, the method can also provide a reference in the area of engineering machinery and construction machinery.