Introduce the difference between rotating and stationary forms in mechanical seals

Mechanical seal refers to a device that prevents fluid leakage by at least one pair of end faces perpendicular to the axis of rotation under the action of fluid pressure and the elastic force (or magnetic force) of the compensation mechanism and the cooperation of auxiliary seals to keep fit and slide relative to each other.


The difference between a rotary mechanical seal and a static mechanical seal is whether the spring of the mechanical seal rotates with the shaft. For example, if the spring rotates with the shaft, it is a rotary mechanical seal, and if it does not rotate with the shaft, it is a static mechanical seal;


The elastic element device of the rotary mechanical seal is simple and the radial size is small. It is a commonly used structure, but it is not suitable for high-speed conditions; it is used in common mechanical seals and has the characteristics of good sealing performance and extremely long service life;


Static mechanical seal, because the spring does not follow the shaft rotation, so it is not affected by centrifugal force, it is often used in high-speed mechanical seal equipment, in addition to being suitable for high-speed mechanical seals, it is also often used in bellows mechanical seals in high-temperature media It is a mechanical seal with high stability in special working conditions.


Generally, rotary mechanical seals are used as common seals, but when the shaft diameter is large, the rotating speed is high, and the sealing peripheral speed reaches 25m/s, due to the large centrifugal force generated by the spring and other rotating components, the dynamic The balance requirement is high, and the stirring power consumption is also large, so a static mechanical seal should be selected. It depends on the situation to decide which seal to use.