Characteristic Analysis And Optimization Design Of Disc Type Permanent Magnet Eddy Current Coupling

At present,more and more customers have accepted and applied the permanent magnetic transmission equipment because of its many characteristics in field of transmission and speed regulation,.The modified version of the permanent magnet eddy current speed regulating equipment—windings permanent magnet speed control equipment has been listed as the latest product of energy saving and consumption reduction recommended product by the Ministry of industry and information of China.It can be seen that the permanent magnet eddy current speed control equipment has attracted the attention of the national functional department.In this paper,a comprehensive analysis and research on the disk permanent magnetic eddy current speed control equipment,from the product type,the working principle,the energy saving principle,the key parameter and so on,the analysis and comparison is carried out.The eddy current coupling with slotted conductor disk is researched and optimization.A simple methord is used to inhibition of the cogging torque and torque ripple,which is caused by the magnetic slot.The Halbach magnetic array is also applied to the permanent magnet eddy coupling,which further reduced the torque ripple.In the end,the torque density and the cost performance are improved effectively.The main work of the paper is as follows:Firstly,the principle and structure of the device and the its speed regulating equipment are introduced.From a number of aspects,such as speed regulation,working environment,life,costperformance,starting performance,etc.A comprehensive comparison is made with the frequency converter and the hydraulic coupler.Secondly,the expression of air gap magnetic density and torque of the device is derived.The relationship between the thickness of the copper conductor disk,the structure of the magnetic pole,the speed of the rotation difference and the torque,the axial force and the loss are studied by the FEM simulation.Through the electromagnetic thermal coupling analysis,the temperature of the copper conductor disk is simulated.It provides a great help for the optimization design of the traditional device.Last,a lot analysis and research of the equipment with a slotted copper conductor disk,which change the energy of the magnetic field distributed along the circumference.Thus,the device produces a large value of the cogging torque whichcaused torque ripple and deterioration the stability of the system.A simple method which change the slot number is used to improve this unfavourable situation.The principle of this method is analyzed.The simulation analysis is carried out to verify the correctness of the measure use the finite element method.Comparison of the torque fluctuation at different slot number,when there is no common divisor between slot number and pole number,can reduce the cogging torque.In the case of low transfer speed,this method does not achieve the desired effect.A Halbach array is proposed to solve this unfavourable phenomenon.It has been found that this method has a good effect whether the equipment is working at low transfer speed or high transfer speed.A device with separated magnetic pole is study to analysis its merits and drawbacks.Finally,an orthogonal method is used to optimize the improved disc type permanent magnet eddy current coupling to promote its performance.