A vacuum pump refers to a device or equipment that uses a mechanical, physical, chemical, or physical-chemical method to evacuate a pumped container to obtain a vacuum. Generally speaking, a vacuum pump is a device that uses various methods to improve, generate, and maintain a vacuum in an enclosed space.
According to the working principle of vacuum pumps, vacuum pumps can basically be divided into two types, namely gas capture pumps and gas transfer pumps. It is widely used in metallurgy, chemical industry, food, electronic coating and other industries.
The two rotors of the vacuum pump are relatively synchronized by a pair of high-precision gears. The drive shaft is connected to the motor through a coupling. There are two main types of drive structure arrangements: one is that the motor and gear are placed on the same side of the rotor as shown in the figure. The driven rotor is directly driven by the gear at the motor end. In this way, the torsional deformation of the driving rotor shaft is small, and the gap between the two rotors will not change due to the large torsional deformation of the driving shaft, so the gap between the rotors is running. The process is even. The biggest disadvantages of this transmission method are: a. There are three bearings on the drive shaft, which increases the processing and assembly difficulties of the pump, and the disassembly and adjustment of the gear is inconvenient; b. The overall structure is uneven, and the center of gravity of the pump is biased to the motor and gear Box side.
(1) There is a large pumping speed in a wide pressure range;
(2) The rotor has good geometric symmetry, so the vibration is small and the operation is stable. There is a gap between the rotors and between the rotor and the casing. No lubrication is required, and the friction loss is small. The driving power can be greatly reduced, so that a higher speed can be achieved.
(3) There is no need to seal and lubricate with oil in the pump cavity, which can reduce the pollution of vacuum system by oil vapor;
(4) There is no compression in the pump cavity, and there is no exhaust valve. Simple and compact structure, insensitive to dust and water vapor in the pumped gas;
(5) The compression is relatively low, and the effect of pumping hydrogen gas is poor;
(6) The surface of the rotor is a more complex curved cylindrical surface, which is difficult to process and inspect.