1.Electrical reasons pump motor ：
The motor is the main equipment of the unit, the imbalance of the internal magnetic force and other electrical systems, often cause vibration and noise. Such as asynchronous motor in operation, the rotor tooth harmonic magnetic flux as a result of the interaction between stator and rotor radial alternating magnetic pull, or large synchronous motor in operation, the rotor magnetic center is inconsistent or in all directions of air gap difference exceeds the allowable deviation, may cause the vibration and noise of motor cycle.
2. Mechanical reasons ：
The motor and pump rotation parts quality imbalance, poor quality, installation, crudely made unit axis asymmetry, swing to exceed the allowable value, mechanical strength and stiffness, poor parts of the bearing and sealing parts wear damage, and the critical speed of pump and turbine natural frequency resonance has been caused, will produce strong vibration and noise. The.
3. Hydraulic reasons ：
The pump inlet velocity and pressure distribution, import and export pump working fluid pressure pulsation, liquid flow and drift and flow separation, caused by non quota conditions and various causes of pump cavitation, are common causes of pump unit vibration. The pump starts and stops, the valve opening and closing, water pipelines and emergency shutdown caused by the conditions of changing the dynamic transition process of the dramatic changes in the pressure and the water hammer effect, also often leads to pump and unit vibration.
4. Hydraulic and other reasons ：
The unit inlet design is reasonable or not, and the unit supporting the pump submergence properly, and the unit startup and shutdown order is not reasonable, will cause the deterioration of water conditions, produce vortex cavitation induced or aggravated unit and pump vibration. The destruction of the flow siphon vacuum unit at boot time, if the air entrainment hump, the formation of long siphon; flap unit door design is not reasonable, open and shut, constantly hit the door; rigid reasons such as poor uneven subsidence of foundation or foundation support of pumps and motors, it will cause the unit vibration.
