Study On The Two-Way Coupling Mechanism And Wear Characteristics Of Shearer Drum Cutting Coal-Rock With Gangue

Drum is the working mechanism of shearer,which undertakes two tasks of coal cutting and loading,and there is strong coupling behavior between drum and coal-rock.The wear of pick and blade is inevitable,especially in the thin coal seam with gangue,its friction loss is more serious.In order to study the two-way coupling mechanism and wear characteristics of drum cutting coal-rock with gangue,and to improve the cutting-wear performance of drum,supported by the project of National Natural Science Foundation of China "Study on dynamic transfer law and structure evolution theory of drum high-efficiency cutting coal-rock with gangue(51674134)",the key project of Liaoning province "Study on forming track planning and quality control of laser additive remanufacturing of shearer drum(LJ2017ZL001)"and the project of "Software development of shearer spiral drum aided design and load calculation",the related research and achievements are as follows:According to the test results of physical and mechanical properties of coal-rock,uniaxial compression,Brazilian splitting simulation test and neural network were used to calibrate the contact parameters and bonding parameters of irregular coal particles;combined with EDEM and RecurDyn,the DEM-MFBD(Discrete Element Method-Multi Flexible Body Dynamics)coupling model of drum cutting coal-rock with gangue was established.Based on DEM-MFBD simulation,the two-way coupling mechanism and the wear distribution characteristics of pick and blade in drum cutting coal-rock with gangue were studied.The single factor method was used to analyze the influence of coal-rock compressive strength,drum structure parameters and shearer kinematics parameters on drum wear.The results show that:when the compressive strength of coal-rock increases from 30MPa to 50MPa,the average growth rates of pick wear depth and blade wear depth are 41.20%and 19.51%respectively;the traction speed increases from 2m/min to 6m/min,the contact load between particles increases,the average decrease rate of peak coal flow velocity is 10.05%,and the average increase rates of pick wear depth and blade wear depth are 14.595%and 11.12%respectively;the drum rotation speed increases from 70r/min to 110r/min,the contact load between particles decreases,the average increase rate of peak coal flow velocity is 15.26%,the average decrease rate of pick wear depth is 14.57%,and the blade wear depth increases first and then decreases.Drum vibrates along the vertical direction and shakes around its axial direction obviously.There is obvious stress concentration in the pick tip and the end of blade,which is the vulnerable part of drum.When cutting in bad working conditions,the sequential spiral drum should be preferred in consideration of wear.Response surface method was used to analyze the significance and interaction of traction speed,drum rotation speed,spiral angle and pick tip half cone angle on drum wear.The results show that the traction speed has the most significant effect on the wear of spiral drum,and the interaction of traction speed and drum rotation speed on the wear of pick and spiral blade is obvious.The multi-objective optimization model of cutting-wear performance of shearer was constructed,and the traction speed and drum rotation speed were optimized by grades.Principal component analysis(PCA)and probabilistic neural network(PNN)were used to identify the compressive strength of coal-rock quickly and accurately.Based on the principle of vector control,a coordinated speed control system of drum cutting with wear reducing and high efficiency was established and simulated.The results show that the coordinated speed control system can accurately control the traction speed and drum rotation speed,and the control errors are less than 5%.Compared with the traditional traction speed regulation mode,the coordinated speed control system has better cutting-wear performance.The research of this paper can provide a new method for reducing the friction loss of drum and adaptive variable speed cutting,which has certain theoretical significance and engineering application value.This paper has 121 figures,36 tables,147 references.