The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 28, 2004
Filed:
Jan. 29, 2003
Mats Stellnert, Farsta, SE;
Delaval Holding AB, Tumba, SE;
Abstract
A vacuum pump of the rotary vane type, comprises a casing ( ) having a cylindrical inner wall surface ( ), a first ( ′) and a second ( ′) end wall at opposite sides of said casing defining a fluid cavity therein, fluid inlet ( ) and outlet ( ) ports in open communication with said fluid cavity, and a rotor ( ′) extending between said end walls carried by a drive shaft ( ) for rotation about an axis eccentric to said casing inner wall surface, said rotor being provided with a plurality of longitudinally extending radial slots ( ) about the periphery thereof. Further, there are provided a plurality of vanes ( ), each being radially slidably carried within a respective of said slots. The invention comprises that at least one of said end walls and said rotor comprise, at oppositely facing surfaces, an annular recess ( ″) and an annular rib ( ″), respectively, said rib and recess being interengaging so as to define a radial clearance ( ′) and an axial seal ( ′), respectively, between said at least one of said end walls and said rotor, and that the rotor/drive shaft combination is axially biased.