How to prolong the service life of mechanical sealsMechanical seals

How to prolong the service life of mechanical seal

2020-06-13 13:58

1 Grooving on the end face:

It is difficult to maintain a liquid film between mechanical friction surfaces at high speed and high pressure, and the film is usually destroyed by frictional heat at high pressure and speed. In this case, enhanced lubrication in the form of slotting is very effective. Rings and retaining rings can be grooved, usually in a more wear-resistant material. The ring and retaining ring should not be grooved at the same time, as this will reduce the lubrication effect. In order that possible dust or debris will not enter the friction surface, the sealing of the liquid flow is in the forward direction of the centrifugal force (outward flow), the grooves in the retaining ring are opened to avoid the introduction of dirt centrifugally forcing the friction surface. Conversely, when the liquid flows in the opposite direction (flow) by the centrifugal force, the groove should open in the ring, and the centrifugal force helps throw the dirt from the tank.

The small grooves on the friction surface are rectangular, wedge-shaped, or other different shapes. The slots should not be made too many or too deep, otherwise the risk of information leakage may increase. Seals

2 pressure lubrication:

The so-called hydrostatic lubrication directly introduces the lubricating fluid to the friction surface to function as a lubricant. The lubricating oil is introduced through a liquid, such as a hydraulic pump, supplied by a separate source of fluid. With a lubricating fluid pressure in phase with the mechanical fluid pressure, this form is also commonly referred to as a hydrostatic pressure seal.

For the mechanical sealing of gas medium, effective measures should be taken to establish gas film lubrication, such as using different gas static pressure controlled film mechanical equipment seals or solid lubrication, that is, using self-lubricating materials as the moving ring or static ring. As long as economic conditions permit, these gas medium working conditions should be converted to liquid as the medium condition as much as possible, which is convenient for lubrication and sealing.

3 side eccentricity:

In general mechanical seals, the center of the moving ring, the center of the static ring and the center line of the shaft are all on a straight line. When sliding the surface, the ring can be continuously brought into the lubricating fluid for lubrication.

It should be noted that the size of the eccentricity should not be too large, especially for high pressure, the eccentricity will make the pressure on the end face uneven, resulting in uneven wear. For high-speed sealing, do not use a moving ring as an eccentric ring, otherwise the balance of centrifugal force will cause the machine to vibrate.