What is the reason for the vibration noise of the motor?

An important characteristic of the micro DC motor is the vibration and noise of the motor, and the brushless motor has relatively stricter noise requirements. And through the noise and vibration, it can also judge whether the motor is working properly. The order of the reasons for the vibration noise of the motor should be:

1. Mechanical vibration noise, which is generated by the unbalance of the rotor, produces vibration at the same rotational speed frequency or multiple frequencies (multiple frequencies), which can be seen from the FFT (noise spectrum)

2. Electromagnetic vibration noise is generally caused by unbalanced electromagnetic force or uneven magnetic field, as well as magnetic noise caused by magnetic density saturation or air gap eccentricity.

3. Bearing abnormal sound, abnormal bearing assembly or wear will produce abnormal bearing natural sound. The abnormal sound of the bearing is usually reflected in the noise FFT, and the noise value appears at the frequency doubling point (frequency doubling at the rotational speed frequency).

4. Fluid noise, especially motors with fans. If the fan or rotor causes ventilation, it is difficult to avoid noise. Sometimes the gear of the iron core will also cause noise, and the blades will also cause resonance of other parts, etc.

5. Noises caused by other foreign objects, poor assembly, etc. are usually easier to distinguish.

The above is the reason and order of the noise generated by the motor, I hope it will help you. For more micro-motor information, please continue to pay attention to us.