The Vacuum pump is a stand-alone pump model. In fact, it is a pump like any other pump: there is a liquid part, a shaft seal and a bearing bracket (or two bearing brackets). Just like any pump, a vacuum pump generates underpressure on the suction side (suction effect) and overpressure on the pressure side (pressure effect). The difference with a "normal" pump is that a vacuum pump uses the suction side, so to speak the underpressure. A vacuum pump is specifically designed and built to provide the best and highest possible underpressure (vacuum). The pump housing is shaped in such a way that the inlet provides a good negative pressure (read suction pressure).
The maximum achievable underpressure or vacuum is a space in which no air or other gas is present. The pressure in that space is (almost) Pascal. Vacuum is a space with lower pressure than the pressure of the outside air. This then ranges from 0 to 1 bar or between 0 and 100,000 Pa, in technology we speak of 0 bar to -1 bar of course compared to the outside air. Take into account that the outside air (commonly called air pressure) can vary and is generally indicated in millibars. On average, it is assumed that the outside air pressure is approximately 1000 millibars.
In fact, vacuum pumps can be divided into two groups;
1. The pumps that “use” a liquid to create the vacuum.
2. The pumps that do not “use” liquid to create the vacuum.
Also in this type of pump, the pump can be divided into three parts:
