Abstract:
The screw drum is the direct mechanism of the shearer cutting coal and rock. The optimization design of geometric parameters and cutting strategy of screw drum has an important impact on improving coal loading performance of drum. The existing optimization design schemas of the screw drum based on the finite element method and the two-dimensional discrete element method are mostly based on a single factor or part factors. The influence of multiple design variables on the coal loading performance of the screw drum is not comprehensively considered. It is difficult to obtain the optimal solution of the geometric parameters and kinematic parameters simultaneously. In order to solve this problem, based on the test results of the physical and mechanical properties of coal, the coupling model of the shearer's screw drum cutting coal wall is established by using discrete element analysis software EDEM. The numerical simulation of coal loading performance of the shearer's screw drum is carried out. The single-factor method is used to analyze the influence of the spiral angle, diameter, hub diameter, cutting depth, drum rotation rate and traction speed of the screw drum on the coal loading performance. The three factors and three levels orthogonal test of the screw drum is designed based on the results of discrete element analysis. Through range analysis, the influence of geometric parameters of drum diameter, drum hub diameter and spiral rise angle, and kinematic parameters of cutting depth, drum rotation rate and traction speed on the coal loading performance of the screw drum is reduced in turn. According to the orthogonal test results, the optimal geometric parameters of the screw drum are 13° spiral rise angle, 1300 mm drum diameter and 475 mm drum hub diameter. The optimal cutting strategy is that the cutting depth is 600 mm, the drum rotation rate is 58 r/min, and the traction speed is 8 m/min. Under the optimal parameters, the coal loading rate of the screw drum is 76.39%, which is 15.82% higher than before.