Research On The Design And Calculation Method Of Belt Conveyor Pulley

The pulley is the main part of the belt conveyor,which has the functions of tightening,driving and changing direction.The pulley is subjected to very large tension and torque.Sometimes the belt tension can reach up to several million Newton.The unreasonable design of the pulley will lead to the fracture of the pulley shaft and the cracking of the weld,and these pulley failures bring huge losses to the enterprises.A more accurate pulley design and calculation method can reduce these failures caused by unreasonable design effectively,and it is the main route to improve the lifetime and reliability of the pulley.The surface loading expression of the pulley is related to the accuracy of the pulley design.The paper analyzed the axial and circumferential load distribution at pulley shell surface due to the belt tension,on the basis of structural relationship between belt and pulley,and gave the axial load distribution at pulley shell surface which is conforming to the practical situation.The transfer matrix based finite element method is applied to the design and calculation of the pulley,and reconsidered the shell’s circumferential displacement.Obtained the exact solution of the Hamiltonian equation through the accurate numerical integration method,and obtained the stress value at any position of the pulley.Program the design and calculation algorithm of the pulley with MATLAB 2014.Through comparing the calculation results of the drive pulley model of variable cross-section web with the ANSYS,the accuracy of the algorithm is verified.Obtained some relation curves between the stress and the circular angle of the cylinder on key positions,such as the central position of the shell,the connection of the web and the shell,the connection between the central cylinder and the end-disk.The results show that the circumferential stress of the pulley is the largest,the axial stress is the next,and the shear stress is 0.Compare with the finite element result,the maximum stress error is less than 15%.The parameterized modeling of the pulley is realized by using the macro command of ANSYS APDL.It has been validated that the finite element model was correct by comparing the calculation of finite element model with Lange’s experimental result.It also analyzed the maximum stress on pulley shell affected by varying wrap angle under the same tension and pulley structure.The result showed that the maximum stress on pulley shell at the wrap angle within the range of 40～120° was significantly higher than it at the wrap angle of 180°.According to the design of the end-disk,it analyzed the stress conditions on axial and radial cross sections of pulley shell,and verified that there was a minimum stress zone near the position of web,and the cycled number of stress was two in this position when the pulley completed one revolution,so it can be used as the optimal weld position.Considering the influence of the gravity component on the combined pressure,the equal effect force is used as the main index to measure the stress level.Obtained the relationship between the equivalent stress and the circumferential angle on the position of the outside of the shell centre,the inside of the shell connected with the web when the situation of the conveying belt is in the horizontal arrangement at the wrap angle within the range of 20～240°.Discusses parameters influence on the maximum stress of shell such as the pulley thickness and the web distance,pulley width,and draw the maximum stress curve of different parameters.To improve the pulley structure,compared with the simulation analysis and calculation,the optimization scheme is given.