| 摘要 |
<p>The present invention provides a vacuum pump attaining less loss at the tip end of the rotor blade arranged on the inlet port side, thus improving discharge capabilities. A rotor body (61) includes multiple stages of rotor blades (62), each comprising a plurality of open-ended blades. The uppermost rotor blade (62a) formed on the rotor body (61) is located in a position corresponding to a conical portion (13) in a casing 10. The tip end of the rotor blade (62a) is inclined at the same angle as an inclination angle of the conical portion (13). Accordingly, gas molecules accelerated at the tip end of the rotor blade (62a) in a gas molecular region are unlikely to impinge on the casing (10), and are prevented from staying so that deterioration in discharge capabilities at the tip end can be suppressed. The uppermost rotor blade (62a) is located at the conical portion 13, making it possible to effectively transport the gas molecules toward the outer periphery of the second and following rotor blades (62). <IMAGE></p> |
