Patents Assigned to Pfeiffer Vacuum GmbH
  • Patent number: 5893702
    Abstract: A gas friction pump including a rotor located in the pump housing and formed of a plurality of coaxial first cylindrical elements, and a stator located in the housing and formed of a plurality of second cylindrical elements coaxial with the first cylindrical elements and surrounding respective first cylindrical elements, with the first cylindrical elements or the second cylindrical elements having smooth inner and outer surfaces, and another ones of the first cylindrical elements and the second cylindrical elements have a plurality of parallel discharge channels formed on their inner and outer surfaces, arranged one beneath another and separated by a respective plurality of webs, the parallel discharge channels defining a plurality of parallel discharge chambers forming a plurality of parallel operating pumping chambers for pumping gas form the suction port to the discharge port.
    Type: Grant
    Filed: August 5, 1997
    Date of Patent: April 13, 1999
    Assignee: Pfeiffer Vacuum GmbH
    Inventors: Armin Conrad, Heinrich Lotz, Carsten Reese