Load capacity of mechanical seal-

Load capacity of mechanical seal
　2017-06-11　　
Bearing capacity of mechanical seal:
The bearing capacity of small metal bellows mechanical seal refers to the ability of the hydrostatic seal fluid film (Jinghan pad) to withstand an external load, and its value should be equal to the external load it can withstand: it is the pressure difference in the corresponding fluid chamber; A is the effective cross-sectional area of u200bu200bthe chamber, that is, the projection surface of the chamber perpendicular to the external load direction; the gap.
When there is disturbance, the fluid film bleach h becomes thinner and the average pressure of the fluid film increases. The fluid film has positive rigidity and the hydrostatic pressure seal (such as mechanical seal) works stably. Flashing means that the pressure of the fluid film increases, and the force of the fluid medium of the seal ring does not change. Therefore, the pressure of the fluid film is greater than the pressure of the medium, and the mechanical sealing surface is restored to its original position and the fluid film is thickened. This shows that the seal has positive stiffness. The positive stiffness seal produces a restoring force and has the ability to restore the fluid film to its original thickness. Seals such as grooved orifice type, radially convergent conical indium, and radially convergent step surface type have positive rigidity, and the fluid film between the sealing surfaces has sufficient anti-interference ability. The radial expansion cone type seal has negative Rigidity. When the load increases, the thickness of the fluid film increases, which will cause the sealing surface to open and fail; when the load decreases, the thickness of the fluid film decreases, and the sealing surface will come into contact. Therefore, the sealing operation with negative stiffness is unstable.　　434.html,

The bearing capacity of the hydrostatic pad of the mechanical seal and the calculation formula for the stiffness of the fluid film 　　 the influence of the positive and negative stiffness of the mechanical seal fluid