Torque Analysis And Optimization Of Axial Magnetic Coupling

Magnetic coupling is a non-contact transmission device based on air-gap magnetic field coupling to transmit torque.Compared with mechanical coupling,it has the advantages of strong overload protection ability,low maintenance cost,high reliability,and strong shock absorption ability.Compared with the radial magnetic coupling,the axial magnetic coupling(AMC)has a more compact structure and is more widely used in isolation and sealing occasions.In the thesis,the AMC is the main research object to analyze and optimize the torque characteristics.The main research content is the following aspects:1.A 3D finite element model of the AMC is established,and it is found that the torque is closely related to the air gap flux density,and the expressions of the air gap flux density and torque are quantitatively established.Based on the torque harmonic analysis,it is found that specific harmonic components play a major role in the torque generation,and the end effect will affect the torque transmission capacity.Analyzing and calculating the air gap flux density at different radii,it is found that the harmonic components at the average radius have universal regularity,which can be used for rapid torque analysis and optimization.At the same time,a segmented torque calculation method considering the end effect is proposed.2.The thesis compares the air gap flux sine characteristics,effective air gap flux density content and required yoke thickness of AMC with axial magnetization array,two-segment Halbach array and three-segment Halbach array,and proposes a novel two-segment Halbach structure.It is found that the Halbach array can effectively improve the torque performance,the novel two-segment Halbach array can effectively improve the torque performance of the two-segment Halbach model,and the axial magnetic coupling with three-segment Halbach array(HAMC)has the best torque performance.Compared the finite element simulation results,it is verified that the torque segmented calculation method is suitable for AMC with different Halbach structures.3.The three-segment HAMC is taken to optimize the torque performance with an optimization method combining mathematical model and particle swarm algorithm.In the case of initial torque,the torque density is increased by 7.56% and 7.13% by the constraint optimization method and the multi-objective optimization method.The optimal solution of constrained optimization is selected as the final optimal solution.The constrained optimization method effectively suppresses the harmonic components that are not conducive to torque generation,and improves the utilization of permanent magnets.The parameter analysis of the constrained optimization model is found that the magnetic pole ratio and pole arc coefficient are beneficial to increase the torque density,but are not good to torque increase,and the increase of the magnetic pole thickness can make up for the torque loss.Through the above research content,the effectiveness of torque harmonic analysis and particle swarm optimization methods are verified,and a complete torque characteristic analysis and optimization method is formed,which provides a theoretical basis for subsequent related research.