Design And Research Of High Efficiency Cutting Drum For Gangue Coal And Rock

The cutting and crushing of coal and rock is an inevitable phenomenon of mechanized mining and excavation of coal,and it is the result of multi-factor coupling.The screw drum is a key component of the shearer.The structural parameters of the screw drum and the occurrence conditions of the cut coal rock will directly affect the performance of the drum cutting coal.Based on the coal-breaking mechanism of the coal mining machine and the design basis of the drum structure,the occurrence condition of the 4602 working face of Yangcun Coal Mine of Yankuang Group is taken as the prototype,and the screw drum of the MG2×55/250-BW thin coal seam shearer is used as the engineering object.the shearer drum assisted design software developed was used to obtain different pick arrangements(sequential and crossover)and spiral angle of drum(10°/12°/14°/16°)condition of the picking arrangement.Using Pro/E parameterized modeling ability to build screw drums with different structures.EDEM is used to build the discrete element simulation model of coal wall,and the drum model is introduced to simulate the process of cutting coal and rock,and the theoretical calculation is carried out by using the auxiliary design software to verify the feasibility of the simulation.Comparing the different coefficient of solidity of gangue,the drum spiral angle and arrangement of cutting teeth condition of the drum and the coal loading performance,the optimal spiral drum structure parameters under different working conditions are determined.The results show that:The coefficient of solidity of gangue and arrangement of cutting teeth have a great influence on the load condition of the drum.When the coal rock body with good cutting condition is cut(f <3.5),the cross-type screw drum is selected;the cutting condition is general and there is a certain impact coal rock body(3.5< f <6.8),in order to improve the lump coal rate,priority is given to the cross-type screw drum.When the requirement of lump coal rate is not high,in order to improve the life of the screw drum,the sequential screw drum is preferred;the cutting condition is bad.In the case of severely impacted coal and rock body(f > 6.8),in order to ensure the stability of cutting,avoid the use of the crossed screw drums.In addition,the spiral angle of the drum has the greatest influence on the coal loading rate of the drum,the second is the coal rock mass,and the picking arrangement has the least influence.In order to improve the coal loading performance of the screw drum,the spiral angle is about 14°.Based on ANSYS Workbench static analysis,the stress of the optimal structure drum under different working conditions is analyzed.The results show that: The stresses on the drum are from large to small: the contact area of the cutting tooth tip and the front surface of the toothbody,the toothed seat and the end plate welding and the end plate on the end plate;The stress received is significantly higher than the stress on the pick of the blade.In addition,the cross roller participates in the welding of the end plate and the hub near the cutting pick.It can be seen from the worst working conditions that the cutting tooth body meets the requirements of the drum strength and can work safely and reliably.