Mechanical seal refers to a device for preventing fluid leakage is formed by at least one pair of end faces perpendicular to the rotation axis under the action of the fluid pressure and the compensating mechanism elastic force (or magnetic force) and the auxiliary seal. The elastic loading mechanism and the auxiliary seal are mechanical seals of the metal bellows. We call them metal bellows seals. In the light seal, there is also a rubber bellows for auxiliary sealing. The rubber bellows has limited elastic force, and generally needs to be supplemented with a spring to satisfy the loading elasticity.
Mechanical seals are shaft seals for rotating machinery. Such as centrifugal pumps, centrifuges, reactors and compressors. Since the drive shaft runs through the inside and outside of the device, there is a circumferential gap between the shaft and the device. The medium in the device leaks outward through the gap. If the pressure inside the device is lower than atmospheric pressure, the air leaks into the device, so there must be a A shaft seal that prevents leakage. There are many types of shaft seals. Because mechanical seals have the advantages of less leakage and long life, the world's mechanical seals are the most important shaft seals in these equipments.
The main components
Moving ring, static ring, cooling device and compression spring (depending on the specific equipment).
Auxiliary seal
Sealing ring (O-shaped, X-shaped, U-shaped, wedge-shaped, rectangular flexible graphite, PTFE coated rubber O-ring, etc.).
Elastic compensation mechanism
Spring, push ring.
Spring seat and key or various screws.
Classification
Divided into single end, double end; balanced, unbalanced
