Working principle of air-cooled Roots vacuum pump

The structure of ZJQ series air-cooled Roots vacuum pumps is as shown in the Figure. In the pump cavity, two rotor (two blades or multi blades) mounted on a pair of parallel axes, the transmission ratio is 1 for a pair of gears with synchronous rotation opposite to each other. In between the rotor and the rotor, between the inner wall the pump shell, maintaining a certain gap, can achieve high speed operation. Compared with the ZJ series Roots vacuum pump, ZJQ series air-cooled Roots vacuum pump with reflux in the side of the pump body position design, the gas into the pump chamber cooling to cool the rotor, the rotor temperature is maintained within the specified scope the ZJQ series of air-cooled Roots vacuum pump can withstand higher pressure (up to 90kPa) without overheating.

Working principle of air-cooled Roots vacuum pump 　　

Figures (a) ~ (f) ZJQ are working process of air-cooled Roots vacuum pump:　

As Figure (a), in the rotation process, the top of the pump cavity becomes larger, the gas is inhaled; when rotating to the Figure (b), right from the entrance into the V0 rotor pump gas volume; when transferred to the Figure (c), right V0 cavity and the return line is connected, the exhaust side pressure higher than the V0 cavity, so the exhaust gas is cooled after heat exchanger flow to the V0 cavity; when transferred to the Figure (d), a V0 volume of gas left rotor; when transferred to the Figure (e) and (f), the left side of the V0 cavity and the return line is connected, V0 cavity cooled gas return flow to the left; when to continue to Figure (a), the reflux cavity communicates with the exhaust port on the right side of the Figure to continue; (c) when the initial gas discharged from the pump with the right rotor enclosed gas reflux together. The rotor spindle rotates a circle, 6 gases in volume of V0 are discharged.