Justification of geometrical parameters of lining plates for a belt conveyor drive drum

Belt conveyors are widely used in mining industry in open-pit and underground mining for moving bulkload in horizontal and inclined directions to the sites of processing. In order to create the best conditions of frictional contact between a belt and a drum, various methods of drive drum lining are used. The main lining material is rubber of different grades, providing proper coefficient of friction of a belt with a drum (within the range of 0.6-0.62). A drive drum lining material must have high wear resistance, thermal resistance, mechanical strength, ability not to accumulate electric charges on the surface and not to generate dangerous concentrations of toxic components (for example, chlorine gases, carbon monoxide) when heated. The use of ceramic lining opens up great opportunities for increasing lining durability and useful life of high capacity heavy-duty conveyors. The paper presents the results of the study of stress-strain state of belt conveyor drive drum ceramic lining plates. We used Solid Work Simulation environment in the study on the basis of the accepted analytical model of plate-belt contact for drive drum with diameter D = 1250 mm, belt width L = 1000 mm, and the belt entering branch tension value Se = 25400 daN with regard to the value, direction, and nature of the acting loads. On the basis of stress-strain analysis of alumina ceramics lining plates, the favorable geometrical parameters of the plate cleats (projections) and the required properties of lining material ensuring the proper load-carrying capacity at the contact with the belt rubber facing were found. It was established that a plate cleat diameter for heavy duty conditions should be not less than 4.5 mm and its end round R should be within the limits of 0.5-0.6 mm, and, in the base, 0.3-0.4 mm at a cleat height of 1.0-1.4 mm in order to prevent stress concentration in hazardous sections. It was also established that alumina ceramics bending strength must be no less than 350 MPa for effective functioning of rubber-ceramic lining. Simulation of a plate stress-strain state on exposure to alternating loads made it possible to identify characteristic areas with maximum stress concentration, which were foci of crack nucleation. Thus, it became possible to predict lining useful life.