The functions of vacuum pump oil are as follows:
1: Play the role of working medium: the working principle of the pump is to first pump the system to 10-2Pa by rotating the vacuum pump. The oil is heated and boiled, and the gas molecules in the system are continuously brought to the pump by the ejected oil vapor flow at a high speed. When the gas density reaches the working range of the mechanical vacuum pump, it will be pumped out, so as to gradually obtain a high vacuum.
2: The exhaust valve is sealed with pump oil, which can prevent the atmosphere from returning to the pump through the exhaust valve and ensure good air tightness when the exhaust valve is closed.
3: The pump oil penetrates into the pump glue through the oil circuit, the exhaust valve and the assembly gap, and plays a role in lubricating, sealing and cooling the various moving parts of the pump, such as rotors, rotary vanes, bearings and shaft seals, as well as friction surfaces.
4: The pump oil can fill the harmful space and reduce the high-pressure residual gas in it, thereby greatly reducing the influence of the harmful space on the ultimate vacuum.
5: When the vacuum degree is high, the amount of gas entering the suction space is very small, and the compressed gas pressure still cannot push the exhaust valve sheet. At this time, the exhaust valve plate can be pushed open by means of the pump oil, so that the pumped gas can be discharged smoothly.
6: During the use of the heat transfer oil pump, since the vacuum pump oil directly enters the pump body cavity, when the vacuum pump is running, as the gas pressure gradually decreases, the pump temperature gradually increases. Molecular components with high saturated vapor pressure in the oil can evaporate into the vacuum space, which not only affects the ultimate pressure of the vacuum pump, but also diffuses back to the vacuum system, pollutes the vacuum system, and directly affects the acquisition of ultimate vacuum.
It can be seen from the above points that the vacuum pump oil plays the role of lubrication, sealing and cooling in the pump body.
