Causes of vibration of FRP fan

When we operate the FRP fan, there will be a phenomenon - the fan itself has vibration, and what causes the vibration of the distance?
1. The common causes are imbalance of impeller, pulley, coupling or motor of FRP fan.
2. When the pulley is not communicating or the length of the belt is not uniform, the belt is worn, there are hard points, the pulley is not aligned, or the adjustable distance between the grooves of the pulley is not equal, so that the V-belt can be sent out to induce vibration.
3. The shaft is not straight, the keyway has local weakness (middle rotation rotor), the shaft movement is not round or the shaft system size is insufficient, which causes the shaft to induce vibration.
4. The bearing is cracked and asymmetric, the bearing has dirt, the bearing is deformed (compressed), the bearing is unable to conduct automatic alignment freely, and the bearing induced vibration will be caused by the shape caused by the positioning screw or the mixture of grease / oil.
5. The impeller assembly of FRP fan has defects (runout), friction, misalignment and resonance, which will cause vibration of fan structure.
6. Insufficient support (resonance), loose or missing anchor bolt, loose access door, panel creaking, etc. and vibration caused by vortex shedding of fan with exhaust pipe.
7. Motor eccentricity (Electrical and Mechanical) produces vibration.
8. Vibration due to pneumatic source.
What is resonance?
1. Resonance occurs when the working frequency is consistent with the natural frequency of the system.
2. Vibration energy is stored and amplified.
3. Peak amplitude is controlled by amplitude reduction. (partial reduction of oil in sleeve bearing is possible).
4. It is difficult to avoid using variable speed drive on spring fan.
Consequences of resonance:
1. Mechanical source transmits force to fan and system
2. Impact load generated by pneumatic source (load may cause fatigue failure of fan blades, especially on axial-flow fans and high-pressure centrifugal fans)
3. Surge causes a wide range of air pressure changes
4. Increase noise