ADD:No.789,liming South Road,RongCheng City,Shandong Province,China.
Cause of electromagnetic noise
Electromagnetic noise is one of the main sources of noise for motor. In multi pole motor or low noise motor, the electromagnetic noise is very prominent. In general, it increases with the increase of motor power, and it is the root of noise increase when load occurs. The noise is closely related to the electromagnetic design parameters of the motor. If the design is not proper, the electromagnetic noise will be very obvious, and it may become the most important noise source beyond the other noise (ventilation and mechanical noise).
There are a series of harmonic magnetic field and magnetic field of motor air gap in the magnetic field interaction of tangential force, resulting in tangential electromagnetic torque, will produce radial force with the change of time and space. In general, there is a variety of frequency and frequency of the rotating radial electromagnetic force wave in the air gap of the motor. Each radial force wave acts on the stator and rotor core respectively, causing the radial deformation of stator core and frame and rotor to change periodically with time. That is to say, vibration occurs. The vibration frequency is the frequency of force wave action. Because the stiffness of the rotor core is very large, the vibration of the rotor is very small, so the vibration of the stator core and the frame is generally considered. Electromagnetic noise is mainly caused by the vibration of the stator that causes the ambient air pulsation.