Research On Starting Characteristics Of Belt Conveyor Based On Permanent Magnet Eddy Current Transmission

Belt conveyor is one of the main equipments in coal mine transportation.Its working environment is complex,frequent startup,and it is prone to problems such as slippage,silt belts,and broken belts,which need to be solved in engineering applications.In this dissertation,a double disc magnetic coupler is used to replace the traditional speed regulating device,which reduces the dynamic tension of the conveyor belt during the startup process and realizes the smooth start of the belt conveyor.First,according to the structure of the magnetic coupler,the mathematical model of the magnetic circuit analysis method is used to establish a mathematical model of double disc magnetic coupler and the speed-regulating cylindrical magnetic coupler.And use Matlab Simulink software to build two types of magnetic coupler simulation models,compare and analyze the performance of two magnetic couplers under the same volume.The results show that the double disc magnetic coupler has high speed regulation accuracy,large torque transmission,and shows better speed regulation performance.Secondly,build a double disc magnetic coupler experimental platform.According to the working environment and working conditions of the belt conveyor in the mine,the soft-start,overload protection and permanent magnet temperature rise characteristics of the double disc magnetic coupler are tested.The experimental results show that the double disc magnetic coupler has a time-delay characteristic during startup,which reduces the load on the drive motor;When overloaded,the overload time of the drive motor is reduced,and the phenomenon that the motor stops due to overload is eliminated,Exhibits better soft-start and overload protection performance;But when it is operated for a long time with a small air gap,it is likely to cause the permanent magnet to fail at high temperature.This dissertation continues to establish the GA-BP algorithm to predict the working temperature of permanent magnets.The correlation between the predicted value and the test value is r=0.99795,and the error is small.It can effectively avoid the dangerous working state of the double disc magnetic coupler.Thirdly,According to the magnetic transmission structure and principle of mining belt conveyor,the system equivalent dynamic model,the dynamic model of each component,and the discrete finite element model of the belt conveyor system are established.In this way,the system torque transfer model and the discrete dynamic equation of the belt conveyor system are determined.It can get the speed,acceleration,displacement and dynamic tension of the conveyor belt at any time and at any position.Finally,using the simulation technology of AMEsim and Simulink software to build a simulation model of a belt conveyor based on the dual disc magnetic coupling drive.The starting characteristics of the belt conveyor with fixed parameters under different operating conditions and different starting times are analyzed.The simulation results show that the double disc magnetic coupler can meet the normal startup of the belt conveyor under no-load,half-load and full-load conditions,and the conveyor belt speed fluctuation is small during startup and the startup process is stable Within a reasonable start-up time,the double disc magnetic coupler can effectively reduce the starting tension of the belt conveyor,avoid problems such as startup slippage,broken belts and silted belts,and prolong the service life of the belt conveyor.Figure[59]table[2]references[72]...