Study on shearer drum structure design and coal-breaking performance based on multi-impact picks for hard coal

摘要

Aiming at the low efficiency of traditional mechanical cutting methods in hard coal seams, a multi-impact cutting technology was proposed, which was to design a hydraulic system inside the drum. In this paper, by analyzing the working process of the multi-impact drum, the corresponding mechanical model was established and the overall research plan was determined. A simulation experiment explored the working performance of the multi-impact drum under the action of multiple factors in cutting different hardnesses, using different impact frequencies and different drum speeds. The simulation results showed that the drum speed has the greatest influence on coal-breaking performance, followed by coal hardness, and the impact frequency of picks has the least influence on coal-breaking performance. In addition, a discrete element coal-breaking experiment with a traditional drum was carried out. The simulation results showed that the multi-point impact drum can improve coal-breaking performance by more than 20 compared with traditional drum in terms of coal-breaking capacity and cutting specific energy consumption. Finally, a simplified multi-impact drum industrial cutting test was carried out. The test results showed that the cutting resistance of the multi-impact drum was about 17.22 lower than when there was no impact. Considering that the simplified multi-impact cutting drum had a reduced impact pre-cracking effect on the coal, it can be considered that the results of the industrial test and the discrete element simulation test were still relatively consistent. The multi-impact cutting drum had good working performance under hard coal conditions.