Patent · US Expired

Multi-stage molecular pump

US4893985A · kind A · utility

13Cited by
5References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 15, 1988
Grant dateJan 16, 1990
Priority date
Expiry dateAug 15, 2008

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF04D19/044
  • WIPO fieldEngines, pumps, turbines
  • WIPO sectorMechanical engineering

Abstract

A molecular pump of the Hollweck type is composed of a plurality of stages in order to improve the pumping characteristics. Rotor and stator consist of different portions which are provided alternately with helical grooves and with smooth outer and inner surfaces respectively. The cooperating surfaces of the individual rotor and stator portions are tapered.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.