Screw Pump Of Technology

At present, the development of various vacuum pumps is increasingly affected by vacuum applications. The general vacuum system can not meet the requirements of clean and oil-free corrosion resistance. Therefore, in recent years, the market demand of dry vacuum pumps is very large. Vacuum products have been replaced. A large number of oil-free vacuum systems have been replaced by oil-free vacuum systems. Clean vacuum system instead.

Dry screw vacuum pump has become the preferred vacuum acquisition equipment in the microelectronics, semiconductor, pharmaceutical, precision processing and other industries in Europe, the United States and Japan due to its superior performance. On the basis of screw compressor, Japan developed the multi-head rotor profile of vacuum pump very early and put it into the market. Several German vacuum equipment companies have gradually developed rotor profiles with constant pitch and variable pitch, and have done a lot of research on rotor and body cooling.

The structure of dry screw pump:

The structure of screw vacuum pump is mainly composed of screw rotor, shell, cooling cycle and sealing material. The drive shaft is connected with the active rotor, and the driven rotor is rotated by the synchronous gear. A cooling water channel is opened on the shell to cool the rotor and the exhaust temperature, and the synchronous gear and the bearing oil are lubricated. The bearing and housing are sealed by seals to achieve an oil-free effect. The dry screw vacuum pump is similar to the oil-free screw compressor in sealing and lubrication.

Key technical problems of screw pumps:

The exhaust port of the general vacuum pump is mechanically sealed, and the inlet side is commonly used with double lip seals. In the transmission mode, the current general is the direct-connected motor, with a coupling and rotor connection, very few belt or chain drive. The exhaust temperature of constant pitch screw pump is very high (about 110 degrees) because of no internal compression process. If the cooling effect is not good, the rotor and casing will deform, affecting the sobbing effect. So the cooling casing is an indispensable link, and water cooling is the most common method. Through cooling water on the outer side of the bearing body, the cooling shell can be cooled and the rotor can be cooled. The water cooling of the rotor inside the rotor increases the life of the rotor and achieves a good cooling effect. But the structural design (two stage) requires a certain level of technical and processing support. Water cooling sometimes can not achieve cooling effect, so usually near the exhaust end of the rotor cooling gas (mostly nitrogen).

Now the mainstream screw vacuum pumps abroad use this method. This method has several advantages: firstly, it can cool the rotor casing and reduce the exhaust temperature; secondly, when the gas contains particulate matter, it can prevent the deposition of particulate matter or chemical reaction causing explosion.