【目的】为有效抑制内置式永磁同步电动机(IPMSM)的振动噪声，提升其运行的平稳性及可靠性，探讨了通过改变气隙长度优化IPMSM振动噪声的方法。【方法】本研究选取一台应用于拉丝机的8极48槽IPMSM作为研究对象。采用有限元法对电机运行时的径向电磁力和切向电磁力进行了计算与分析，并对力波进行了二维傅里叶分解，深入分析了其主要力波的阶次及频率。在此基础上，运用Workbench开展了电机的模态分析及振动噪声仿真分析，重点对比了不同气隙长度下电机的振动加速度及A加权声压级云图，揭示了振动噪声特性的变化规律。考虑了转子静态偏心对径向电磁力波的影响，分析了转子偏心距离2 mm条件下径向电磁力的阶次变化。【结果】仿真结果表明，气隙长度适当增大可在一定程度上降低电机的振动噪声水平以及齿槽转矩的幅值；同时，气隙的增大不可避免地削弱了主磁场强度，导致电机的输出转矩会随着气隙的增大而减小。转子静态偏心情况下会对电磁力的空间阶次产生影响，但是不会改变电磁力的时间阶次。【结论】实际设计中需在降噪效果与转矩性能之间进行综合权衡，且转子偏心对电机的电磁振动噪声的影响较大，在电机制造和使用中避免转子偏心的情况。

[Objective] To effectively mitigate the vibration and noise of interior permanent magnet synchronous motor (IPMSM) and enhance its operational stability and reliability, this study explores the method of optimizing IPMSM vibration and noise by altering the air gap length. [Methods] An 8-pole 48-slot IPMSM applied in a wire drawing machine was selected as the research subject. The radial and tangential electromagnetic forces during motor operation were calculated and analyzed using the finite element method, and the force waves were subjected to two-dimensional Fourier decomposition to thoroughly investigate the order and frequency of the primary force waves. Based on this, modal analysis and vibration noise simulation analysis of the motor were conducted using Workbench, with a focus on comparing the vibration acceleration and a-weighted sound pressure level contour maps under different air gap lengths, revealed the variation patterns of vibration and noise characteristics. Taking into account the influence of the static eccentricity of the rotor on the radial electromagnetic force waves, the order changes of the radial electromagnetic force under the condition of a 2 mm eccentricity of the rotor were analyzed. [Results] The simulation results indicated that appropriately increasing the air gap length could reduce the motor’s vibration and noise levels as well as the amplitude of cogging torque to a certain extent. At the same time, the increase in air gap inevitably weakened the main magnetic field strength, led to a decrease in the motor’s output torque as the air gap increases. When the rotor was in a state of static eccentricity, it had an impact on the spatial order of the electromagnetic force, but it did not change the temporal order of the electromagnetic force. [Conclusion] In practical design, a comprehensive trade-off between noise reduction and torque performance is required. Additionally, rotor eccentricity significantly impacts the electromagnetic vibration and noise of the motor, so it must be avoided during both manufacturing and operation.