Dynamic Analysis And Active Control Of Discordance Between Wire Ropes On Multi-point Winding Hoisting System

With the development of world economy and society, the demand for mineral resources has been growing. Our country now is turning to the deep mining within the earth, and mining the super deep well of which the well depth will reach more than1500 meters. At present, the mine hoisting equipment mainly adopts single rope winding hoist and friction hoist, which both cannot meet the needs of the super deep well for “super deep” and “heavy load” lifting. The topology structure of multi-rope lifting is expected to become an effective type of super well lifting equipment. At the same time, the ropes may make inconsistent movement since the exist of physical properties’ difference, the dynamic deformation and the winding error of ropes, which leads to the sharply rising of tension difference and huge swings of hoisting system,thus affecting the service life and safety of hoisting ropes. For double rope winding hoist, one type of multi-point and multi-layer winding hoist,the phenomenon is defined as “discordance between wire ropes on multi-point winding hoisting system”in this paper, and short for “discordance between wire ropes”. In order to control the discordance between the ropes of multi-point winding hoisting system, first the mechanism of discordance is studied, and the dynamic response, the ropes’ tension and tension difference between ropes are analyzed. Then a tension balance device is designed to adjust the tension between wire ropes, and the control characteristics is also studied.In this paper, our study mainly includes the following three aspects:(1)The Rayleigh method is used to deal with the mass of the wire rope while the rope is equivalent to a viscoelastic body with damping and variable stiffness, thus the longitudinal vibration model of a multi-point hoisting system model is established,and the numerical solution of the model is proceeded through programming by Matlab.And at last, the conveyance’s velocity and acceleration curves over time and the ropes’ tension, the tension difference curves over time are obtained.(2)The discrete methods is applied to describe the wire rope as a series of masses coupled by generalized force, and the dynamics software is adopted to static modeling and dynamic modeling of multi-point winding hoisting system, and the ropes’ tension,tension difference under the static and dynamic conditions are analyzed. Then the dynamic response of the conveyance obtained by software is compared to numericalsolution in order to verify the validity of the mathematical model; At last, the dynamic model of the hoisting system under unsteady conditions is established to analysis the response characteristics.(3)An active tension balance device is designed for controlling the discordance between wire ropes, and the mechanical-hydraulic coupling simulation analysis of the device is proceeded, and the given displacement signal from hydraulic simulation system is compared with actual displacement signal from dynamics simulation system,which is to verify the validity of the coupled simulation model established.Meanwhile the changes of ropes’ tension, tension difference and the hydraulic cylinder’s pressure and flow rate are acquired, and the results are further analyzed,which is to verify the effectiveness of the control system of the coupling simulation model established.