Vacuum pump is a kind of industrial equipment which provides vacuum environment. It can be divided into traditional vacuum pump and oil-free vacuum pump according to the working medium. Oil free vacuum pump can be divided into several categories:
1. Dry vacuum pump: the dry vacuum pump refers to the vacuum pump that is not suitable for any oil and liquid in the pump cavity and can discharge air directly, such as claw pump, reciprocating piston pump, screw pump, oil-free rotary vane pump, etc.
The claw type oil-free vacuum pump belongs to the variable volume vacuum pump, and uses the multi-stage claw type rotor in series, so it can maintain the compression ratio, speed and dynamic balance for a long time. The compression ratio of claw pump is higher in high pressure area because of less counter current along the axial direction. The suction and exhaust port of claw pump is arranged on the end wall of the pump cavity, which is convenient for multi-stage connection and has smooth air passage. The extraction process of claw vacuum pump is divided into four strokes, and a pair of conjugate counter rotating claw rotors do continuous work of suction and exhaust.
The working principle of the screw pump is similar to that of the screw compressor. The left screw and the right screw of a pair of rectangular sections want to mesh. The pumping process of screw vacuum pump consists of four processes: suction, compression start, compression start, compression end and exhaust.
Oil free rotary vane pump, working principle is basically the same as that of rotary vane pump. The material for selecting vane is self-lubricating material, such as graphite. At the same time, in order to reduce gas leakage, the oil-free vane pump generally adopts multiple vane structures.
2. Roots type vacuum pump: Roots type vacuum pump uses two 8-shaped rotors to rotate in the pump shell for vacuumizing, which is generally used as a booster vacuum pump, and its principle is similar to roots blower.
Roots vacuum pump is divided into ordinary type and direct exhaust type. The ordinary roots vacuum pump needs to be directly connected with the front-end mechanical pump to discharge into the atmosphere, while the direct air roots vacuum pump does not need to connect with the front-end mechanical pump.
3. Oil free reciprocating vacuum pump: the reciprocating vacuum pump uses the reciprocating linear motion of the piston in the cylinder to vacuumize, and the piston is driven by the crank connecting rod mechanism through the motor. The oil-free reciprocating vacuum pump adopts self-lubricating materials. There is no need to add lubricating oil to the piston ring, sealing ring and cylinder to realize the oil-free inside the cavity. In addition, an oil separation chamber is added between the cylinder and the body to further prevent the leakage of lubricating oil in the body from entering the cylinder and prevent the pump chamber from being polluted by oil.
4. Turbo molecular pump: turbo molecular pump is a mechanical pump that can obtain ultra-high vacuum by relying on the high-speed rotating rotor carrying gas molecules. The molecular pump is mainly divided into ultra-high vacuum pump and high vacuum pump, which can not be directly discharged into the atmosphere, but also needs to be directly connected to the mechanical pre-stage pump.
We provide several oil-free vacuum pumps. Most types of oil-free vacuum pumps are selected from the top manufacturers in the industry, including vacuum system, dry vacuum pump, diaphragm pump and water vacuum cleaner. Oil free vacuum pump eliminates the need for additional accessories, and is a low maintenance cost, efficient and usually low noise vacuum pump.
Oil free vacuum pump is a kind of mechanical vacuum pump which can run without any oil. The utility model has the advantages of simple structure, easy operation, convenient maintenance and no environmental pollution. It is widely used in gas analysis, physical and chemical experiments, high efficiency vacuum filling of various liquid injection bottles, air tightness test of object surface in vacuum, leak test of various containers in vacuum. Most of the filtration experiments in the laboratory are widely used.