NEW THEORETICAL METHOD FOR ESTABLISHING INDENTATION ROLLING RESISTANCE

Theoretical analysis indicates an underestimation of the calculated values of resistance of conveyor belts in relation to the measurement results. Disproportions are mainly observed for large mass capacities of conveyors. In this paper previous method for calculations of indentation rolling resistance was improved. Indentation rolling resistance is the main component of motion resistance for conveyors longer than 80 m. The most important impact on rolling resistance have damping factor of belt. This parameter was included in calculations in the new approach, moreover, a defined way of its determination in laboratory conditions was indicated. Another important parameter is the modulus of elasticity affecting the transverse rigidity of the belt. By analyzing elastic energy in bottom cover and cord of the belt new equations (which included construction and belt type) were established. In addition, the impact of the distribution of the loads along the idler on the rolling resistance value was analyzed. On this basis differ-ent equations for calculations of center and side idler was proposed. New theoretical model was verified in both laboratory test and measurements conducted in mine conditions.A series of tests of rolling resistance and damping properties were carried out for belts of various core designs and various rubber of bottom covers. Damping factors and modules of elasticity established in laboratory conditions were applied to new calculations algorithms. Obtained results were compared with measured values. Final verification of the new theoretical model was a comparison of calculated re-sistance with measured values for conveyor in mine. The obtained results have much higher convergence than the previous calculations. The new calculations allows for more accurate dimensioning of the drive and other elements of the belt conveyor.