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Mechanical Seal Overview
- Oct 01, 2018 -

A mechanical seal (face seal) is a device used to solve the seal between the rotating shaft and the body. The utility model is characterized in that the fluid pressure of the at least one pair of end faces perpendicular to the rotation axis and the elastic force (or magnetic force) of the compensating mechanism and the auxiliary seal are kept under the fit and relatively slid to form a device for preventing fluid leakage, which is commonly used for pumps, Rotary fluid machines such as compressors and reaction agitators are also used for sealing gearboxes and ship tail shafts. Therefore, the mechanical seal is a universal shaft seal device.

Mechanical seals are available in a variety of configurations, and the most common mechanical seals are end seals. The static ring and the moving ring of the end face seal form a pair of friction pairs, and the friction pair acts to prevent the medium from leaking. It requires a static ring and a moving ring, and has good wear resistance. The moving ring can move flexibly in the axial direction, automatically compensates for the wear of the sealing surface, and makes it fit well with the static ring; the static ring has a floating property and acts as a buffer. . For this reason, the sealing surface is required to have a good processing quality, and the sealing pair has a good bonding property. The basic components constituting the mechanical seal include a static ring, a moving ring, a gland, a push ring, a spring, a positioning ring, a bushing, a moving ring seal ring, and a static ring seal ring bushing seal ring.

The elastic element (spring, bellows) mainly plays the role of pre-tightening, compensation and buffering. It is required to maintain sufficient elasticity at all times to overcome the inertia of the auxiliary seal and the friction and moving ring of the transmission member, and to ensure a good fit of the end seal pair. And the follow-up of the moving ring, the material requires corrosion resistance and fatigue resistance.

Auxiliary seals (0-rings, V-rings, U-rings, wedge rings and profiled rings, etc.) mainly serve as a seal for the stationary and moving rings, as well as for floating and cushioning. The sealing element of the static ring is required to ensure the tightness between the static ring and the gland. The static ring has a certain floating property. The sealing element of the moving ring can ensure the sealing between the moving ring and the shaft or the sleeve and the moving ring. Floating. Materials require heat resistance and the like.

1, the basic structure

1) Face seal friction pair

2) cushioning and tightening mechanism

3) Auxiliary seal (secondary sealed flexible element)

4) Transmission mechanism

2, the basic sealing point

1) End face main sealing point

2) Static ring and end cap auxiliary sealing point

3) moving ring and shaft (sleeve) auxiliary sealing point

4) End cap and pump body connection sealing point