1958 年 27 巻 2 号 p. 110-115
The profile of rouse rotors of mechanical boosters and leakage through clearances between sliding members are studied. The maximum volume of gas evacuated per revolution of the coupled rotors is found independent of the tooth profile and becomes approximately 4×(rotor diameter) 2 × rotor thickness. As for the leakage, two identical cylinders are assumed to lie parallel with a small known clearance between them through which gas flows by pressure difference. Approximate calculation of the leakage assures that if the clearance between rotors and casing is less than, 0.6 mm, the booster is fit for producing high vacuum.