Study On Sidewise Dynamics Of Belt Conveyor

The belt conveyor has played an important role in the bulk material transportation, the sidewise dynamics affects the stable operation of the belt conveyor, and the paper carries on the comprehensive study on the sidewise dynamics of the belt conveyor by taking the excitation sources as the starting point.(1) The excitation sources resulting in the sidewise deviation of the belt conveyor is analyzed. The excitation sources, such as the quality problems, the belt itself joint misalignment and the unbalanced distribution of the temperature field are analyzed, the distribution law of the excitation source resulted from the belt structure characteristics is obtained. The sidewise excitations caused by the imbalanced operation of the left roller and the right roller, the roller dip, the nonverticalness of the shaft and the belt center line, the inclination of the roller bracket are researched, the action mechanism and the characteristics of the idler excitation are analyzed. The sidewise excitation caused by the unenough straightness and the horizontality of the bracket, such as the left-right bending of the bracket, the up-down fluctuation, are analyzed, and the action mechanism is studied. The sidewise excitation caused by the partial load, the inconsistency of the pulley diameter, the nonverticalness of the pulley shaft and the conveyor shaft are researched, the action law is analyzed. The sidewise deviation of the belt is the consequence of the all exciations.(2) The action mechanism of the centripetal force source preventing the belt from the sidewise deviation is researched. The aligning principles, such as the roll anteversion, the conic aligning idler, the vertical automatic aligning idler, the curve rotary body aligning idler, the hanging aligning idler, the hanging series aligning idler group, are researched. The action mechanism of the restoring force causing the belt back is studied. The producing mechanism for the restoring force of the belt and the material itself is analyzed, the calculation method is studied, and the sidewise movement laws are determined. The research shows that the sidewise movement of the belt is co-produced by the excitation resulting in the belt deviation and the centripetal force preventing the belt from the sidewise deviation.(3) Taking the excitation sources for the sidewise deviation together, the nonlinear dynamics continuous model for the sidewise movement of belt is constructed, the sidewise dynamics equation of the belt was deduced, and the boundary condition is determined; according to the actual situation, the model is simplified, the analytical solution is given, the modal analysis is performed, the sidewise bending stiffness of the belt, the belt tension, the restoring force are the key elements impacting the sidewise stable operation of the belt conveyor.(4) The finite element discrete unit model of the belt is constructed, according to the specific conditions, the boundary conditions are determined and the state equation of belt sidewise movement is deduced. According to different working conditions, the sidewise dynamics characteristics of the belt conveyor is simulated, the sidewise movement characteristics and the laws of the belt are revealed, which provides the theoretical basis for the prevention and control of belt deviation.(5) The dynamic model of the aligning idler is constructed, the aligning properties of the vertical aligning idler and the curve rotary body aligning idler are analyzed, and the hysteresis properties are revealed. The relation between the aligning force and the rotatory angle of the stable aligning idler is proposed. The hydraulic(pneumatic) servo automatic aligning equipment is designed, the control system model of the system is constructed, the simulation is performed, and the stability for aligning is analyzed, the comparison simulation research on the properties of the hydraulic(pneumatic) servo automatic aligning equipment and the vertical aligning idler is performed, the result shows that the aligning property of the hydraulic(pneumatic) servo automatic aligning equipment is obviously better than that of the vertical aligning idler, and the hysteresis property is avoided.(6) The experiment platform and the experiment system are designed by employing the belt conveyor of the large mining equipment research center, the belt deviation test is completed, the test result is coincident with the simulation result, the correctness of the theory model is verified. The superiority of the hydraulic(pneumatic) servo automatic aligning equipment beyond the vertical aligning idler is validated.