The shaft seal in a high-efficiency, energy-saving multi-stage pump plays a crucial role in preventing leakage, maintaining performance, and preventing the entry of external contaminants. Its principle is mainly to achieve effective sealing through contact sealing, cooling and lubrication, elastic compensation, and hydrostatic support technologies. To improve the service life and performance of the shaft seal, advanced technologies and designs are also needed, and it needs to work in coordination with other parts of the pump.

I. Functions of the Shaft Seal

In high-efficiency, energy-saving multi-stage pumps, the shaft seal plays a vital role. Its main functions include:

1. Preventing Leakage: The shaft seal effectively prevents the leakage of media from between the pump shaft and the casing, thereby improving system efficiency and safety.

2. Maintaining Performance: A good shaft seal ensures the normal operation of the pump, maintains its stable performance, and extends its service life.

3. Preventing the Entry of External Contaminants: The shaft seal also prevents external contaminants from entering the pump, avoiding damage to the internal parts of the pump.

II. Principle of the Shaft Seal

The principle of the shaft seal is mainly to achieve effective sealing by establishing a sealing surface between the stationary ring and the rotating ring. Specifically, its principle includes the following aspects:

1. Contact Sealing: Contact between the stationary ring and the rotating ring forms a sealing surface to prevent media leakage. This contact can be maintained by springs or other elastic elements.

2. Cooling and Lubrication: The shaft seal usually has a cooling and lubrication system to ensure good contact of the sealing surface and reduce wear.

3. Elastic Compensation: The shaft seal usually uses elastic elements for compensation to cope with changes in the gap between the sealing surfaces caused by thermal expansion, vibration, etc., that may occur during pump operation.

4. Hydrostatic Support: Hydrostatic support inside the shaft seal creates a certain pressure between the sealing surfaces, further improving the sealing effect.

In addition, the shaft seal of a high-efficiency multi-stage pump also uses many advanced technologies and designs, such as using wear-resistant materials and optimizing the sealing structure, to improve its sealing performance and service life. At the same time, the shaft seal of a multi-stage pump also needs to work in coordination with other parts of the pump (such as bearings and sealing rings) to achieve efficient and stable operation of the pump.