| The planetary frame of the cutting part of the shearer is the key part of the transmission system of the cutting part.Due to the randomness and mutation of the coal seam change,the load of the drum fluctuates violently,so that the planetary frame is subjected to complex and changeable loads for a long time.It is easy to break the planetary frame,which seriously affects the starting rate,safety and reliability of the shearer.In this paper,the planetary gear of the cutting part of MG1000/2500-WD large mining height shearer is taken as the research object,and the electromechanical coupling dynamic model of the cutting part is established.The influence of electromechanical coupling on the dynamic response of the two-stage planetary gear of the cutting part is analyzed,the fatigue life of the two-stage planetary gear of the cutting part is predicted,and the structural parameters of the planetary gear are optimized.Firstly,the three-dimensional CAD software is used to establish the geometric model of the shearer drum and the coal wall,and the grid division and parameter setting are imported into LS＿DYNA.Then the solver is called to solve the problem,and the drum load of the shearer is obtained,which lays the foundation for the follow-up work.Based on the multi-body dynamics theory,the dynamic simulation model of the transmission system of the shearer cutting unit was established in ADAMS.The working load of the drum obtained from the simulation of coal and rock cutting was added at the center of the drum.The three-phase asynchronous motor model of the cutting unit was established in Simulink.The electromechanical coupling dynamic simulation model of the cutting unit was established through the data interface between ADAMS and Simulink.By comparing the simulation results under electromechanical coupling and constant speed input,the influence of electromechanical coupling on the dynamic response of the cutting part is studied.Secondly,based on the flexible multi-body system modeling theory,the rigid-flexible coupling dynamic model of the cutting part of the flexible two-stage planetary frame is established by using Mechanical APDL and ADAMS.The rigid-flexible coupling dynamic simulation of the cutting part considering and without considering the electromechanical coupling is carried out respectively.The stress distribution and variation law of the two-stage planetary carrier of the cutting part under the two conditions are compared and analyzed.At the same time,the maximum stress time history curve of the two-stage planetary carrier in the stable operation stage is extracted as the load spectrum of the fatigue analysis.Then,ANSYS Workbench is used for static analysis of the two-stage planetary frame.The obtained finite element results and the fatigue load spectrum obtained above are imported into n Code Design Life.Based on the cumulative fatigue damage theory,the fatigue life of the two-stage planetary frame is analyzed,and the fatigue life distribution nephogram of the two-stage planetary frame is obtained.Finally,the parametric model of two-stage planetary carrier is established.Based on the static analysis and fatigue life analysis of planetary carrier,the sample points are selected by central composite design method,and the response surface model of planetary carrier is established.The multi-objective optimization is carried out with the minimum mass and maximum stress of the planet carrier as the optimization objectives,and the optimal solution is obtained and the accuracy of the response surface model is verified,which provides a direction for the optimization design of the planet carrier. |
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