Patent Number: 6,168,374

Title: Friction vacuum pump

Abstract: The present invention relates to a friction vacuum pump having 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 it is proposed that a filling stage (3) be arranged between the turbomolecular pump stage (2) and the screw pump stage (4) that 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 region of the screw (14) of the screw stage (4).

Inventors: Stolle; Robert (Cologne, DE), Odendahl; Heinz-Dieter (Cologne, DE), Beyer; Christian (Cologne, DE)

Assignee: Leybold Vakuum GmbH

International Classification: F04D 19/04 (20060101); F04D 19/00 (20060101); F04C 23/00 (20060101); F01D 001/36 ()

Expiration Date: 01/02/2018