永磁同步电主轴的电磁噪声分析

Analysis on Electromagnetic Noise of Permanent Magnet Synchronous Spindle

为了提高永磁同步电主轴的加工精度、减小振动、降低其电磁噪声,考虑谐波磁动势的影响,推导永磁同步电主轴气隙磁密的解析表达式,提高了永磁同步电主轴径向磁密的计算精度。采用解析法计算径向磁密及其谐波,利用有限元法求解径向电磁力。建立该永磁同步电主轴的三维模型并进行模态分析以及谐响应分析,实测了电主轴的振动加速度。将模型电磁力频率以及模态分析结果与实测振动加速度频谱进行对照,结果表明径向电磁力是引起振动的主要原因,共振是产生噪声的主要因素。通过对永磁体结构的优化,减小了永磁同步电主轴的径向电磁力。通过噪声仿真分析,验证了电主轴结构优化后噪声的降低。

In order to improve the machining accuracy of the permanent magnet synchronous spindle,reduce vibration,reduce its electromagnetic noise,considering the influence of the harmonic magnetomotive force,the analytical expression of the air-gap flux density of the permanent magnet synchronous motor was derived and the calculation accuracy of the radial flux density of the permanent magnet synchronous motor was improved.Radial flux density and its harmonics were calculated by analytic method,and radial electromagnetic force was solved by finite element method.The three-dimensional model of the permanent magnet synchronous spindle was established and mode analysis and harmonic response analysis were carried out.The vibration acceleration of the spindle was measured.The model electromagnetic force frequency and modal analysis results were compared with the measured vibration acceleration spectrum.The results show that the radial electromagnetic force is the main cause of vibration.Resonance is the main factor of noise.By optimizing the structure of the permanent magnets,the radial electromagnetic force of the permanent magnet synchronous motor spindle is reduced.The noise reduction is verified by the noise simulation analysis.