Pump noise basically contains: caused by pump operation, the noise of the pump running caused by pipeline resonant noise, pump operation flow movement and the rattle noise.
As the motor noise, there are three main aerodynamic noise, mechanical noise and electromagnetic noise. When the motor is working, the air flow noise of the cooling air and the high speed rotating blade noise of the fan are formed by the air dynamic noise. Mechanical noise contains bearing noise and motor rotor unbalance rotor "trench harmonic force" caused by structure vibration and generate noise. Electromagnetic noise is by between the stator and the rotor pump noise caused by alternating electromagnetic force, magnetostriction outward transfer of primary way is air transfer and solid borne sound.
