FRICTION VACUUM PUMP

摘要

A friction vacuum pump has at least one turbomolecular pump stage (2) joined at its pressure side to a screw pump stage (4). In order to improve the pump properties, a filling stage (3) is arranged between the turbomolecular pump stage (2) and the screw pump stage (4) and has blades (13) whose length corresponds at the suction side to the active length of the blades at the pressure side of the turbomolecular pump stage (2) and at the pressure side to the depth of the suction-side area of the screw (14) of the screw stage (4).