| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharger with high delivery capability, showing more favorable evacuating action. SOLUTION: A compressive medium discharger, in particular, a dry operation vacuum pump comprises at least two shafts provided with rotors 4 designed as spiral contour bodies 4 with their sectional shapes meshed with each other like gears during rotation, running in non-contact with each other and having leads of the spiral contour bodies lessened as tending from an entrance to an exit. The spiral contour bodies 4 are designed in two lines, and leads S1, S3 at the entrance ends and the exit ends of the spiral contour bodies 4 are kept constant and an intermediate lead S2 is continuously lessened as tending from the wide lead S1 at the entrance end to the narrow lead S3 at the exit end.
|
