摘要 |
<p>A turbo-molecular pump evacuates gas with a rotor (R) that rotates at a high speed. The turbo-molecular pump comprises a casing (10), a stator (5) fixedly mounted in the casing and having stator blades (38), a rotor (R) rotatably provided in the casing and having rotor blades (30) alternating with the stator blades, and a radial turbine blade pumping section (L2) having a spiral ridge-groove section provided on at least one of surfaces, facing each other, of the stator blade and the rotor blade. At least one of the stator blade and the rotor blade which are located at a first stage of the radial turbine blade pumping section has such a shape that at least one of the stator blade and the rotor blade is smaller in thickness in a direction of gas flow. <IMAGE></p> |