The hazards and solutions of axial force produced by pipeline pumps

Harm of axial force produced by pipeline pump

If the liquid pressure on both sides of the impeller does not count the cross-sectional area of the shaft or the influence of the impeller rotation on the pressure distribution, the force acting on the impeller is the difference between the force on the disc and the force on the wheel cover, which is transformed into a calculation formula It is the product of the difference between the outlet pressure and the inlet pressure and the area of the impeller wheel cover. Because the outlet pressure is always greater than the inlet pressure, when the centrifugal pump rotates, there must be a force along the axis and pointing to the inlet acting on the rotor.

The unbalanced axial force will increase the working load of the thrust bearing, which is detrimental to the bearing. At the same time, the axial force causes the pump rotor to move to the suction port, causing vibration and may cause the impeller mouth ring friction to damage the pump body.

Solution to axial force generated by pipeline pump

For pipeline pumps, the outlet pressure is much greater than the inlet pressure, and it is an effective method to eliminate the axial force by balancing force.

1. Pipeline pumps generally adopt a symmetrical installation of balance disc and impeller. Single-stage pumps generally have balance holes on the impeller. Of course, there is also a way to install balance blades on the impeller disc to balance the axial force.

2. Although what we require is to eliminate the axial force, if it is completely eliminated, it will also cause the rotor to become unstable during rotation. Therefore, when designing, 30% of the amount will be designed for the bearing to offset it. This is why it is more The non-driving end bearing of stage pump is usually the cause of angular contact bearing, because it can be used to withstand large axial forces.