Zhang Meichen, Zhao Lijuan, Shi Baisheng
College of Mechanical Engineering, Changshu Institute of Technology, Suzhou, 215500, People's Republic of China.
College of Mechanical Engineering, Liaoning Technical University, Fuxin, 123000, People's Republic of China.
Sci Rep. 2024 Apr 24;14(1):9438. doi: 10.1038/s41598-024-60262-9.
The cutting and crushing of coal and rock containing gangue is the result of the coupling effect of multiple factors. The geometric parameters of the working mechanism, the kinematic parameters of the shearer, and the physical and mechanical properties of the coal and rock to be cut all affect the cutting and crushing process of the shearer. To study the coal falling trajectory of cutting coal and rock using a spiral drum, optimal cutting parameters were obtained, efficient cutting using a spiral drum was achieved, and analysis of the coal falling trajectory and strength of the drum of a shearer based on bidirectional coupling technology was proposed based on particle discrete element contact theory and virtual prototype technology. The discrete element method multi-flexible body dynamics two-way coupling method was used to obtain cutting and interactive information about the spiral drum for a complex coal seam with gangue. The cutting conditions of the spiral drum under different cutting depths, rotational speeds, and traction speeds were determined. The movement status of coal and rock particles was monitored under different working conditions. Coal falling trajectory equations for the coal and rock particles were compiled under different working conditions, and the coal falling trajectory curve was drawn. The optimal coal loading rate was used as the measurement standard for the coal falling trajectory, and the optimal coal falling trajectory of the drum was obtained through full factor experiments. The load of the drum and pick was extracted, their stress and deformation were analyzed, and fatigue life analysis was performed on the pick with the highest stress. The results indicate that the maximum deformation occurs on the cutting teeth that are cutting hard gangue. The stress of the tooth seat is mainly concentrated at the root of the tooth seat, and its maximum equivalent stress is less than the yield limit value of the selected material. Therefore, the material selection and structural design of the drum are safe and reliable. By building a coal mining machine cutting coal and rock experimental platform and monitoring the working status of the designed spiral drum, it meets the usage requirements. Based on industrial experiments conducted underground, the measured average coal loading rate of the shearer drum was 46.31%, achieving stable operation and verifying that the designed drum of the shearer has an efficient cutting ability.
含矸煤岩的截割破碎是多种因素耦合作用的结果。工作机构的几何参数、采煤机的运动参数以及待截割煤岩的物理力学性质都会影响采煤机的截割破碎过程。为研究采用螺旋滚筒截割煤岩时的煤炭抛落轨迹，获得了最优截割参数，实现了螺旋滚筒的高效截割，并基于颗粒离散元接触理论和虚拟样机技术，提出了基于双向耦合技术的采煤机滚筒煤炭抛落轨迹及强度分析方法。采用离散元法多柔体动力学双向耦合方法，获取了含矸复杂煤层螺旋滚筒的截割及相互作用信息。确定了不同截割深度、转速和牵引速度下螺旋滚筒的截割工况。监测了不同工况下煤岩颗粒的运动状态。编制了不同工况下煤岩颗粒的煤炭抛落轨迹方程，并绘制了煤炭抛落轨迹曲线。以最优装煤率作为煤炭抛落轨迹的衡量标准，通过全因素试验得到了滚筒的最优煤炭抛落轨迹。提取了滚筒和截齿的载荷，分析了其应力和变形，并对应力最大的截齿进行了疲劳寿命分析。结果表明，截割硬矸石的截齿变形最大。齿座应力主要集中在齿座根部，其最大等效应力小于所选材料的屈服极限值。因此，滚筒的材料选择和结构设计安全可靠。通过搭建采煤机截割煤岩试验平台，监测所设计螺旋滚筒的工作状态，其满足使用要求。基于井下工业试验，测得采煤机滚筒平均装煤率为46.31%，实现了稳定运行，验证了所设计的采煤机滚筒具有高效截割能力。
