Analysis And Calculation For Magnetic Field And Properties Of A High-Performance Coaxial Magnetic Gear

Because of the realization of uncontested transmission,the magnetic gear offers not only the rotation speed and direction changing,but also advantages such as physical isolation,vibration isolation,friction reduction and automatic overload protection,which was more and more popular in wind power generation, transportation,petrochemical,and so on.The High-performance coaxial Magnetic Gear could offer high transmission performance for enhances the utilization ratio of permanent magnets,so it is a hot research subject at home and abroad.This paper will care out structure design and theoretical analysis of the High-performance Magnetic Gear,which offer significant theoretical meaning and application.In this paper,based on the theory of magnetic field modulation,four kinds of operation forms of High-performance Magnetic Gears are proposed,and their application occasions are discussed,and then the structures of these forms are designed.Furthermore,two structures scheme of modulation pole-pieces are proposed.In this paper,based on the distribution of vector potential of magnetic field,the Laplace Equations of magnetic field due to either magnetic rotor modulated by the modulation pole-pieces are established and their boundary conditions are assured by using the boundary equivalent surface current method of permanent magnet.For the solution of the Laplace Equation,the distribution equations of magnetic field due to the magnetic rotors are obtained.After the figuring out of the distribution equations of magnetic field,the torque of the outer magnetic rotor can be calculated by current magnetic force principle.By the same way,the torque of the inner magnetic rotor is calculated,too.Thus,the problem of torque calculation can be solved by the method above.According to the magnetic field distribution,the induction current is obtained by using electromagnetic induction principle,and the current heat loss and the efficiency are consequently obtained.In this paper,the FEA method is applied on the magnetic field of the high-performance magnetic gear by Ansoft Maxwell 2D.Firstly,the static analysis is used for the calculation of magnetic field distribution,which can explain the principle of transmission.Secondly,the transient analysis is applied to obtain the max transmission torque and the torque loss of the both inner and outer magnetic rotor.At last,according to the torque and the loss,the variation of efficiency for the high-performance magnetic gear is obtained.The results of torque and efficiency can be used to provide the consult for the design and optimum.