The screw vacuum pump is a pumping device that uses a pair of screws to perform synchronous high-speed reverse rotation in the pump casing to generate suction and exhaust. It is a replacement product for oil-sealed vacuum pumps. On gas occasions with a small amount of dust, it is widely used in domestic pharmaceutical, chemical, semiconductor, and other enterprises that require a high clean vacuum.
The use of a screw vacuum pump
The two screws are corrected by fine dynamic balance, supported by bearings, and installed in the pump casing. There is a certain gap between the screws, so when the pump is working, there is no friction between each other, the operation is stable, the noise is low, and the working chamber does not need lubrication. Therefore, the dry screw pump can pump out the gas containing a large amount of water vapor and a small amount of dust, the ultimate vacuum is higher, the power consumption is lower, and it has the advantages of energy-saving and maintenance-free. It is a replacement product for an oil-sealed vacuum pump.
Advantages of screw vacuum pumps
The development of various vacuum pumps is more and more affected by vacuum applications. The general vacuum system cannot meet the requirements of being clean, oil-free, and corrosion-resistant. Therefore, in recent years, the market demand for dry vacuum pumps is very large, and vacuum products have been updated. At the same time, a large number of oil-based vacuum systems have been replaced by oil-free vacuum systems. Almost every large vacuum company abroad produces various types of dry vacuum pumps. The screw vacuum pump is a non-contact dry pump and is an ideal type of pump that appeared in the early 1990s. Its pumping speed range The advantages of a wide, simple, and compact structure, no friction, long service life, low energy consumption, and no oil pollution of the pumping cavity components can be widely used.
Due to its superior performance, the dry screw vacuum pump has become the preferred vacuum obtaining equipment in microelectronics, semiconductors, pharmaceuticals, precision machining, and other industries in Europe, America, and Japan. On the basis of screw compressors, Japan developed a multi-head rotor for vacuum pumps very early. line and put it on the market. Several German vacuum equipment companies have also gradually developed constant-pitch and variable-pitch rotor profiles, and have done a lot of research on rotor and body cooling.
Structure of screw vacuum pump
The drive shaft is connected to the driving rotor and drives the driven rotor to rotate through the synchronizing gear. A cooling water channel is opened on the casing to cool the rotor and the temperature of the exhaust port. The synchronizing gear and bearing are lubricated with oil, and the inside of the bearing and casing is sealed. Parts to seal for oil-free effect. Dry screw vacuum pumps are similar in sealing and lubrication structure to oil-free screw compressors. Generally, mechanical seals are used on the exhaust end of vacuum pumps, and double lip seals are usually used on the intake side. In terms of transmission mode, the most common is a direct-connected motor, which is connected to the rotor with a coupling, and very few are driven by a belt or a transmission chain. Since the equal-pitch screw pump has no internal compression process, the exhaust temperature is very high. If the cooling effect is not good, the rotor and the casing will be deformed, which will affect the pumping effect. Cooling the casing is an indispensable part, and water cooling is the most common method. Passing cooling water on the outside of the casing body and the bearing can achieve the purpose of cooling the casing and then cooling the rotor.
