Screw-type vacuum pump has at least two adjacent chambers directly interconnected by check valve with throughflow direction towards pressure side and formed by continuous valve passage

摘要

The screw-type vacuum pump has two meshing screw rotors(12,14) defining chambers(20-22) with respective volumes which become smaller in the direction of feed. At least two adjacent chambers are directly interconnected by a check valve(41a,41b) with throughflow direction towards the pressure side. The check valve is formed by a continuous valve passage, and the check valve in longitudinal section is constructed asymmetrically in such a way that it has different throughflow characteristics in both flow directions.