Analysis of the causes of water pump vibration

Analysis of the causes of pump vibration There are many reasons for the vibration of the unit and the pump room building. Some factors are both connected and interacted. In summary, there are four main reasons.

Electrical

The motor is the main equipment of the unit. The imbalance of the magnetic force inside the motor and the imbalance of other electrical systems often cause vibration and noise. For example, when the asynchronous motor is running, the radial alternating magnetic pull between the stator and the rotor is generated by the interaction of the stator and rotor teeth harmonic magnetic flux, or when the large synchronous motor is running, the magnetic force centers of the stator and rotor are inconsistent or the air gaps in all directions are different. Exceeding the allowable deviation value, etc., may cause the motor to vibrate periodically and make noise.

Mechanical

The quality of the rotating parts of the motor and the water pump is unbalanced, shoddy, and the installation quality is poor, the axis of the unit is asymmetric, the swing exceeds the allowable value, the mechanical strength and rigidity of the parts are poor, the bearing and sealing parts are worn and damaged, and the critical speed of the pump is related to the unit. The resonance caused by the natural frequency all the time will generate strong vibration and noise.

Hydraulic

Uneven flow rate and pressure distribution at the inlet of the pump, pressure pulsation of the working liquid at the inlet and outlet of the pump, liquid bypass, bias flow and de-flow, non-rated operating conditions and pump cavitation caused by various reasons are all common causes of pump unit vibration. s reason. The sudden pressure change and water hammer effect in the water pipeline caused by the dynamic transition process such as the start and stop of the pump, the opening and closing of the valve, the change of the working condition and the emergency shutdown of the accident also often lead to the vibration of the pump room and the unit.

Hydraulic and other aspects

The unreasonable design of the water inlet channel of the unit or the incompatibility with the unit, the improper submersion depth of the pump, and the unreasonable sequence of starting and stopping the unit will deteriorate the water inlet conditions, generate vortices, induce cavitation or aggravate the vibration of the unit and pump room. When the unit that destroys the siphon vacuum cut-off is started, if the air in the hump section is difficult to carry, the siphon will take too long; The uneven subsidence of the foundation of the pump and motor or the poor rigidity of the foundation will also cause the unit to vibrate.