Design And Study Of Tester For Shearer Height-adjustment Based On Similarity Theory

In the current, the drum shearer is the major mining equipment used in coal mine. The automatic adjustment height technology for shearer drum is the key to realize automation in comprehensive mechanized coal mining. At present, the automatic height adjustment technology was mostly researched by theoretical analysis and simulation, and the experimental research was insufficient. Due to the special working condition of the working surface, the relevant experimental research can not be carried out by the actual working condition of the drum shearer, so it is necessary to design and study of tester for shearer height-adjustment.This paper simply described the composition structure of the drum shearer. It elaborated on the present situation of the drum shearer model tests and presented the overall design scheme of the tester. One type of thin seam drum shearer was selected as prototype. The similarity criterions between the tester and prototype were deduced based on similarity theory, and the correlative parameters of the tester were determined. Picks arrangement on helical vanes and drum plate were accomplished. Using SolidWorks software, the 3D model of the parts of the simulated spiral drum was established. Cutting force on simulated spiral drum was analyzed and calculated. The power combination of general inverter with common 3-phase motor was adopted in cutting dynamic system. Combined with the requirement of the simulated rocker arm length and deceleration ratio, the secondary gear deceleration device was designed. Using SolidWorks software, the 3D modeling of the cutting power system has been completed. The hydraulic system of the tester for shearer height-adjustment was designed. The hydraulic system of the tester includes electro-hydraulic proportional hydraulic circuit for height-adjustment, electro-hydraulic proportional haulage hydraulic circuit, manual control hydraulic circuit and high pressure fluid supply hydraulic circuit. The electro-hydraulic proportional height-adjustment hydraulic circuit is the core of the tester. According to the actual height-adjustment work of the tester, the center of the drum at the highest point, the median and the lowest point were selected to calculate the load on height-adjustment cylinder and the structure parameter of height-adjustment cylinder such as work pressure, mounting distance and cylinder diameter were determined. The pressure difference and cylinder feed flow of the height-adjustment cylinder in three height-adjustment works were calculated. Then, type selection of electro-hydraulic proportional directional value was completed according to flow adjusting curves of the proportional value. After the type selection of hydraulic power units major components, design of hydraulic manifold block and oil tank, integration design of hydraulic power units was completed. All things considered such as stability of the barycenter, vibration and lateral cutting force, overall design of the tester was accomplished.The above results show that the designed tester for shearer height-adjustment can meet the requirements of the similarity criterions to achieve cutting motion, haulage motion and height-adjustment motion. The design of electro-hydraulic proportional height-adjustment hydraulic system explored the application of electro-hydraulic proportional technique in shearer drum automatic height-adjustment. The design and study of the tester laid the foundation for further research.