Development and experimental study of the external compression vacuum pump with the three-lobe rotor profile

The paper considers a two-rotor external compression vacuum pump with the three-lobe rotor profile. This profile has certain advantages compared to the traditional two-lobe profile and provides lower gas flow from the outlet to the inlet, as well as the more uniform pumping. Computation was conducted in the ANSYS CFX software package with different values of gas pressure at the rotors’ inlet and their rotation speed. Experimental dependences of the rotors’ speed of action were obtained on the gas pressure at the inlet. Speed profiles and features of gas flow in the pump working cavity were considered. Comparison of the calculated and experimental data showed that they agreed within the 10% limit. When working with the exhaust into atmosphere, a pump with the three-lobe rotors provided almost 2 times higher ratio of the outlet and inlet pressures than a pump with the two-lobe rotors. The data obtained would be used in design and development of the domestic pumps and multistage units based on the Roots-type stages.
EDN: NIRNTL, https://elibrary/nirntl

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