| Belt conveyor plays a huge role in the coal conveying, storage andtransship processes. In China, the main ascertained coal resources storage typesare inclined type and gentle inclined type. Therefore, it is unavoidable to applythe downwards belt conveyor in the process of underground coal mining andtransport.When the downward belt conveyor is running, if the material glide forceproduced under the action of gravity is greater than the running resistance, thedrive motor will be in the condition of power generation, and the produced antitorque force can be as the conveyor belt braking force.When the parking brake works, the motor counter torque will disappear.The material downward motion law which was caused by the combined actionsof the slide component force and inertia force entirely depends on the dynamiccoupling. The dynamic coupling is produced during the working course ofbraking system, the conveying belt, roller and automatic tensioning system.Thus, the braking system is the key link for the safe operation of the beltconveyor. According to the downward belt conveyor’s existing problem in the braking, based on the comprehensive consideration of various factors, and inorder to realize the smooth and safe braking, this paper designs the downwardbelt conveyor brake damping roller which will be used in the belt conveyor’sspeed control and parking brake.Based on the study of viscoelastic belt’s movement and deformation law onthe rigid roller surface, this paper analyzes the conveyor belt sag resistance, anddraws the impact curve that the factors such as belt speed and roller diameterinfluence on the conveyor belt sag resistance.Combined with the research results, and based on analyzing the conveyorfield condition and braking equipment design goal, this paper completes thedownward belt conveyor brake damping roller layout scheme design and the3Dmodel of the braking roller monomer structure.On the base of the reasonable simplification, this paper has established theviscoelastic belt-rigid roller system model. According to the workbenchdynamic simulation, this paper analyzes of the conveyor belt strain anddeformation state under the roller brake force, and applying the ResponseSurface Optimization module, this paper analyzes the sensitivity of themaximum strain and deformation influence that the belt speed, the rollerdiameter, the conveyor belt positive pressure, roller rotating friction coefficientand other factors affect the conveyor belt. Through the optimization analysis,this paper has obtained a reasonable range of the roller diameter and the rollershaft and the roller friction coefficient on the maximum strain. By using multi-body dynamics software RecurDyn, this paper has builtdownward belt conveyor virtual prototype model, and based on this virtualprototype, the paper compares and studies the single point brake and brakingroller brake in terms of the simulation of braking effectiveness and the belttension. Combined the simulation analysis results and the tension theoreticalcalculation, the optimal plan of the layout of the braking roller is obtained. |
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