There are electromagnetic, mechanical and aerodynamic noises chiefly. It is motor bearing noise that has most problems and is most difficult to solve.

• 电机噪声的主要类型有电磁噪声、机械噪声、空气动力噪声等,其中出现问题最多的、最不好解决的是机械噪声中的电机轴承噪声。