Research On Preload Setting And Preload Combination Structure Of Shearer Hydraulic Rod

Hydraulic rod is one of the important auxiliary parts of the shearer,the four hydraulic rods of the shearer are used with high-strength nuts,and the working is equipped with a certain preload,and the size of the preload is the key controllable factor to ensure the integrity of the whole machine.In this paper,the external load of hydraulic rod under different working conditions is solved,the initial preload force of hydraulic rod is set according to the critical slit state of the preload combination,and the reliability of the preload combination structure is simulated and analyzed,on this basis,the size and installation mode of hydraulic rod components are optimized.The specific research content is as follows:Firstly,the external load of the drum under different working conditions is determined by EDEM discrete element simulation,the external load of the drum is transferred to the four hydraulic rods by establishing the shearer space force system balance equation system,and the working load of the four hydraulic rods is solved by Matlab calculation program.On the basis of considering the critical load,preload,working load,residual preload,stiffness C_bof the hydraulic tie bar and fuselage stiffness C_m,the preload coefficient of the hydraulic rod is preliminarily set 0.5～1.1.Secondly,the contact pressure and seam condition of the joint surface of the fuselage under different preload coefficients obtained by ANSYS software.When the preload coefficient Z is 0.8,it meets the engineering design requirements of the critical slit width and strength of the preload combination structure,the n Code software is used to obtain the variation relationship between quasi-static and vibration fatigue life and preload force at the transition fillet corner of the hydraulic rod,and then the prestressed mode analysis and harmonious response analysis of the hydraulic rod assembly are carried out,and the trend of the natural frequency change of the first six orders of the four hydraulic rods with the preload force is investigated,and the deformation and stress response of the tie-rod under the influence of frequency excitation are investigated.Finally,through parametric modeling and simulation,the influence of the radius at the transition fillet corner of the hydraulic rod on the fatigue life is analyzed,and the fitting formula between the two is obtained.On the basis of the previous vibration characteristic analysis,the reliability of the hydraulic rod assembly is optimized by the scheme of adding nylon shock absorbing sleeve,which avoids the excitation frequency of 23.91Hz caused by the bursting effect of shearer tooth picking on coal blocks,and analyzes the resonance reliability of tie-rod,which effectively solves the problem of hydraulic rod resonance failure.