| The Permanent Magnet Synchronous Electric Spindle(PMSES)has the advantages of high power density,high efficiency and reliable operation.However,there are influence of its vibration and noise on its comprehensive performance.Therefore,It is necessary to study the vibration and noise of the PMSES.Different material properties affect electrical force,which produces electromagnetic vibration and noise of the PMSES.There are two factors resulting in electromagnetic vibration and noise of the PMSES.The one is magnitude of the space harmonics and the time harmonics of the radial electromagnetic force produced by the air-gap magnetic flux density.The other one is the approaching degree between the space harmonics and the time harmonics frequencies of the radial electromagnetic force and the modal frequency of the stator system.This dissertation takes the 4-pole 18-slot PMSES as the research object,based on the theory of electromagnetism.The research is conducted by the analytical method and the finite element method as following:The modal analysis is conducted by finite element software,considering the equivalent model of stator core,the equivalent model of winding,and setting up the reasonable contact.The study shows that the adding of winding,casing and end cover can make the deformation of stator smaller and the radial modal frequencies rise.Secondly,the two-dimensional electromagnetic field of PMSES is modeled and solved by finite element analysis software.The magnetic flux density,magnetic field distribution,and electromagnetic density image in the air-gap is obtained.Then,radial electromagnetic force on the inner surface of the stator and tangential electromagnetic force on the surface of rotor is calculated by the Maxwell stress tensor method.The results of harmonic analysis and spectrum analysis are conducted which show that the low harmonic of the radial electromagnetic force on the inner surface of the stator is the main cause of the electromagnetic vibration and noise.Finally,Based on the research of the two-dimensional electromagnetic field with different iron loss values of the stator silicon steel sheet,the influence discipline of different iron loss of the stator silicon steel sheet on the electromagnetic torque and torque ripple is found.According to different casing material of the PMSES model is analyzed,the influence discipline of main material properties-Elastic modulus and density parameters to the inherent frequencies of the PMSES is obtained.A method of avoiding resonance and reducing noise by changing the material properties is presented.And then the effect of different casing materials on vibration and noise is analyzed.It provides a reference for the design of PMSES with high performance,low vibration and noise. |
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