Formation of elastohydrodynamic liquid film of mechanical seal-

Formation of Elastohydrodynamic Liquid Film of Mechanical Seal

　2017-06-13　　

The formation of mechanical seal elasto-fluid liquid film:

The contact pressure in the contact area of u200bu200bthe white ceramic mechanical seal is very high, but an oil film may be formed. The favorable conditions are as follows:

1. There is an oil wedge function in a populated area, which can generate fluid dynamic pressure: [Figure 2-53(b)];

2. The elastohydrodynamic liquid film is often thin (usually only about 0.5-1 twisted meters), and the resistance encountered during flow is large, and it is not easy to discharge;

3. The fluid in the contact area is subject to high pressure, its viscosity is very large, because the viscosity of lubricating oil increases with the increase in pressure, the relationship is usually (where u/u2 are atmospheric pressure and pressure, respectively) Lower oil viscosity; a is viscosity-pressure coefficient; p is oil pressure);

4. The length of the contact area is very small, about 0.5-1mm. At a tangential speed of 1m/s, the time for the lubricating oil to pass through the contact area is 0.5-1ms, which is very fast.

In summary, the elastic oil film of the towel is very thin, and the viscosity of the oil becomes very large under high pressure, and the higher the pressure, the greater the viscosity, so the oil in the contact area is not easy to be squeezed out. Even if it is possible to be squeezed out, it has to go through a certain period of time, and the lubricating oil passes through the contact area very quickly, and there is not enough time for the contact pressure to squeeze out the oil. Under these favorable conditions, an elastic oil film can be established.　　448.html,

The pressure distribution mode of the mechanical seal at each point in the contact area 　　 the shape and pressure distribution of the mechanical seal elastic fluid oil film