vacuum pump oil viscosity selection range and principle
The viscosity of vacuum pump oil is one of the important factors of vacuum pump performance. The viscosity of liquid is the resistance of liquid flow, or internal friction of liquid. The greater the viscosity, the greater the resistance of the movement speed of various parts, the higher the temperature rise, and the greater the power loss; if the viscosity is too small, the sealing performance of the pump will become worse, causing gas leakage and vacuum deterioration. Therefore, it is very important to select the viscosity of vacuum pump oil for various types of vacuum pumps.
1. The higher the pump speed, the lower the viscosity of the selected oil.
2. The greater the linear velocity of the pump rotor, the lower the viscosity of the selected oil.
3. The more precise the machining accuracy of the pump parts or the smaller the clearance between the friction parts, the lower the viscosity of the selected oil.
4. When the vacuum pump is used at high temperature, the viscosity of oil should be selected.
5. For the vacuum pump with cooling water circulation, the vacuum pump oil with low viscosity is generally selected.
7. For other types of vacuum pumps, the corresponding oil products can be selected according to their speed, processing accuracy and limit vacuum.
Recommended viscosity range of vacuum pump oil:
1. Piston vacuum pump (W type) can be used with general oil, V100, V150 viscosity grade oil.
2. Rotary vane vacuum pump (2x type) uses v68, V100 viscosity grade oil.
3. Direct coupled (high speed) rotary vane vacuum pump (2XZ type) uses v46, v68 viscosity grade oil.
4. Slide valve vacuum pump (H type) uses v68, V100 viscosity grade oil.
5. The remaining cycloid vacuum pump (YZ, YZR) uses V100, V150 viscosity grade oil.
6. The gear transmission system of Roots vacuum pump (mechanical booster pump) can be lubricated with V32, v46 lyborg vacuum pump oil.
In addition, it is necessary to purchase vacuum pump oil from regular manufacturers. When producing vacuum pump oil, some manufacturers directly use base oil without distillation and cutting, and then sell it as products after adding ordinary antioxidant
(1) Although the product can also be used as vacuum pump oil to a certain extent, it will greatly prolong the vacuum pumping time in the process of use;
(2) Ordinary antioxidants are easy to oxidize and decompose in high temperature to form acid substances, produce peculiar smell and pollute the environment. At the same time, the oil products are also easy to be oxidized and deteriorated, and the service life is shortened;
(3) The limit pressure and saturated vapor pressure can not reach the quality standard, which affects the limit vacuum degree of vacuum pump.