Research On Impact Dynamics Of Cutting Part Of Coal Mining Machine And Parametric Design Method Of Torque Axi

The drum electric traction shearer is the main equipment of fully mechanized mining face,which has the advantages of high efficiency,high reliability and long working life.The cutting part is the main working mechanism of the shearer,which is composed of transmission system,cutting motor and electrical system,mainly for coal cutting and coal falling.Torque shaft is the key parts of the cutting part of the shearer.Its main functions include : on the one hand,it plays the role of transmission power,flexible start and elastic buffer of the transmission system of the cutting part.On the other hand,when the shearer is overloaded,the torque shaft breaks itself and plays the role of protecting the cutting motor.But in some cases,when the shearer overload torque shaft failed to break in accordance with the design requirements,resulting in damage to the shearer,thereby affecting production.In the process of cutting coal body by shearer drum,due to the complexity of coal body,the drum will be subject to changing resistance and resistance torque,and the speed of drum and cutting motor will also fluctuate.In view of the problem that the previous dynamic analysis of the torque shaft of the shearer cutting part did not consider the mechanical-electric coupling characteristics of the cutting part,taking a certain type of shearer as an example,the influence of mechanical-electric coupling characteristics on the load of the torque shaft was studied.Firstly,the dynamic characteristics of the cutting part are theoretically deduced and simulated.Based on the dynamic model of the cutting motor and the transmission system of the cutting part,the mechanical-electric coupling model of the cutting part of the shearer is constructed.Then,LS-DYNA was used to simulate the process of drum cutting coal body,and the load characteristics of drum were analyzed.Finally,the rigid-flexible coupling and mechanical-electric coupling dynamics simulation analysis of the cutting part is carried out by ADAMS and SIMULINK,and the influence of mechanical-electric coupling on the torque shaft load is studied.In order to study the parametric design method and breaking conditions of the torque shaft,a parametric design method of the torque shaft is proposed by using the finite element analysis software ANSYS Workbench and modeling software.Based on Workbench and Matlab,the structure that the torque shaft can break exactly under a given load is studied.Based on the fatigue damage theory,the fatigue life of the torque shaft was analyzed by ANSYS n Code,and the fatigue damage and fatigue life of the torque shaft were obtained.Through this study,it can be concluded that the mechanical and electrical coupling has an inhibitory effect on the load of the torque shaft.The average load torque of the torque shaft is reduced by 6.32%,and the maximum is reduced by 14.87%.Due to the influence of mechanical-electric coupling characteristics,when the torque shaft runs stably,the speed fluctuates up and down at the rated speed of the motor;the maximum amplitude of the torque shaft mainly occurs in the middle section and the unloading groove,which can be optimized to enhance the strength of the torque shaft.When the torque shaft is subjected to the rated torque of three times the motor,the arc radius of the unloading groove that the torque shaft can just twist is 24.33 mm,and when the torque shaft is subjected to the rated torque of five times the motor,the arc radius of the unloading groove that the torque shaft can just twist is18.43 mm.The minimum number of cycles of the torque shaft is 1.247e10,and the fatigue life is long.Under normal conditions,the damage of the torque shaft is mainly overload torsion.