How mechanical seals work

In the use of some equipment, the medium will leak through the gap, which will have some impact on the normal use of the equipment and the use effect. In order to avoid this problem, a shaft seal device to prevent leakage is needed. This device is our mechanical seal. How does it achieve the sealing effect?

The working principle of the mechanical seal: It relies on a pair or several pairs of end faces that are perpendicular to the shaft for relative sliding under the action of the fluid pressure and the elastic force (or magnetic force) of the compensation mechanism to keep fit and cooperate with auxiliary seals to prevent leakage. Shaft seal device.

The commonly used mechanical seal structure is composed of static ring (static ring), rotating ring (moving ring), elastic element spring seat, set screw, rotating ring auxiliary sealing ring and stationary ring auxiliary sealing ring, etc. The anti-rotation pin is fixed on the gland to prevent the stationary ring from turning.

Rotating rings and stationary rings are often also called compensating rings or non-compensating rings depending on whether they have axial compensation capability.

For equipment such as centrifugal pumps, centrifuges, reactors and compressors, since the drive shaft runs through the inside and outside of the equipment, there is a circumferential gap between the shaft and the equipment, and the medium in the equipment leaks out through the gap. If the pressure in the equipment is lower than atmospheric pressure, the air leaks into the equipment, so there must be a shaft sealing device to prevent leakage.