The quality of vacuum pump oil mainly depends on the viscosity and vacuum degree, and the vacuum degree depends on the value under different temperature conditions. The higher the temperature, the more stable the performance of the vacuum degree is the good oil.
Recommended vacuum pump oil viscosity range
1. Piston vacuum pump (W type) can use ordinary engine oil, and use oil products with viscosity grades of V100 and V150.
2. Rotary vane vacuum pump (type 2X) uses V68, V100 viscosity grade oil.
3. The direct-coupled (high-speed) rotary vane vacuum pump (type 2XZ) uses V46 and V68 viscosity grade oil products
4. The slide valve vacuum pump (type H) selects V68, V100 viscosity grade oil.
5. Trochoidal vacuum pumps (YZ, YZR) use V100, V150 viscosity grade oils.
6. For the lubrication of the gear transmission system of Roots vacuum pump (mechanical booster pump), V32 and V46 vacuum pump oil can be used.
The principle of viscosity selection
Selection of oil viscosity is one of the important factors for vacuum pump performance. The viscosity of a liquid is the resistance to flow of the liquid, or the internal friction of the liquid. The greater the viscosity, the greater the resistance to the speed of movement of various parts,
The temperature increases, and the power loss is large; the viscosity is too small, and the sealing performance of the pump becomes poor, causing gas leakage and vacuum deterioration. Therefore, the selection of oil viscosity for various vacuum pumps is extremely important. The principle of oil viscosity selection is:
1. The higher the speed of the pump, the lower the viscosity of the selected oil.
2. The higher the linear velocity of the rotor of the pump, the lower the viscosity of the selected oil.
3. The finer the machining accuracy of the pump parts or the smaller the gap between the friction parts, the lower the viscosity of the selected oil.
4. When the vacuum pump is used in high temperature conditions, it is advisable to choose a higher viscosity oil.
5. For vacuum pumps with cooling water circulation, it is generally advisable to use oil with lower viscosity.
7. For other types of vacuum pumps, the corresponding oil can be selected according to its speed, processing accuracy, ultimate vacuum, etc.
Viscosity Index and Viscosity
Generally, people think that the more "viscous" the vacuum, the better. In fact, this is not the case. "Thin" and "sticky" are just relative visual inspection and hand feeling of DVC, DVE VG22, 32, and 46, and there is no quantitative data. If the viscosity values of the two oils are the same at 40°C, when the oils are cooled to room temperature, the "thin" oil is better than the "sticky" oil. Because "thin" oils have a higher viscosity index than "sticky" oils. The viscosity of viscous oil changes greatly with the change of temperature, that is, the viscosity index is low, and the viscosity index is an important indicator of vacuum pump oil. Pump oils with a high viscosity index have less variation in viscosity with temperature. Moreover, the cold pump is easy to start and has the effect of significantly saving energy consumption. Especially in summer, as the ambient temperature and the oil temperature in the pump rise, the limit pressure of the oil can maintain a good effect.
Post time: Sep-09-2022
