Efficiency of the drag stage application in the multistage turbomolecular vacuum pump.

A method for calculating the main parameters of a multistage turbomolecular vacuum pump (TMP) providing the main pumping parameters, including the ultimate pressure, the pumping speed, and compression ratio in the molecular gas flow regime has been developed. As a result of the calculation of the main parameters of multistage TMP according to the proposed method, the pumping curve of the drag stage was obtained. The pumping curve of TMP was also obtained taking into account the influence of the main parameters of the drag stage in the molecular regime of gas flow. [ABSTRACT FROM AUTHOR]