Working principle of reciprocating vacuum pump

Reciprocating vacuum pump (referred to as reciprocating pump), also known as piston vacuum pump, belongs to one of the low vacuum acquisition equipment. Compared with rotary vane vacuum pump, it can be made into a pump with high pumping speed; Compared with the water ring vacuum pump, the efficiency is slightly higher. The main disadvantages of this type of pump are complex structure, large volume, and large vibration during operation. It can be replaced by liquid ring vacuum pump in many cases.

The working principle of reciprocating vacuum pump:

The structure of the reciprocating vacuum pump: the main components are the cylinder and the piston which do reciprocating linear movement, the piston is driven by the crank connecting rod mechanism (including the cross head) to complete. In addition to the above main components, the reciprocating vacuum pump also has important components such as exhaust valve and suction valve, as well as auxiliary components such as frame, crankcase, dynamic seal and static seal.

When the reciprocating vacuum pump is running, it is driven by the motor and the action of the crank connecting rod mechanism to make the piston in the cylinder reciprocate. When the piston moves from the left end to the right end in the cylinder, the density of the gas in the cylinder decreases due to the increasing volume of the left chamber of the cylinder, and the pumping process is formed. At this time, the gas in the pumped container enters the left chamber of the reciprocating vacuum pump through the suction valve. When the piston reaches the rightmost position, the left chamber of the cylinder is completely filled with gas. Then the piston moves from the right end to the left end, and the suction valve is closed.

The gas in the reciprocating vacuum pump cylinder is gradually compressed with the movement of the station piston from right to left, when the pressure of the gas in the cylinder reaches or is slightly greater than one atmospheric pressure, the exhaust valve is opened, and the gas is discharged into the atmosphere to complete a working cycle. When the piston moves left to right again, it repeats the previous cycle, and so on, and finally reaches a stable equilibrium pressure in the pumped container.

In order to improve the pumping efficiency, the suction valve and exhaust valve are generally provided at both ends of the reciprocating vacuum pump cylinder, and then the suction and exhaust ports at both ends of the cylinder are connected in parallel with pipes.