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. 25, 2012
Filed:
Jul. 09, 2009
Tetsuro Ohbayashi, Osaka, JP;
Takeshi Shoji, Osaka, JP;
Tetsuro Ohbayashi, Osaka, JP;
Takeshi Shoji, Osaka, JP;
Osaka Vacuum, Ltd., , JP;
Abstract
An object is to provide a turbomolecular pump with rotor and stator blades alternatively arranged that can prevent collision between the adjacent rotor and stator blades due to air inrush, which may take place due to vacuum break in a system operation, prevent excessive centrifugal force to a hub portion of a rotor, and further enhance pumping performance. A blade cross sectional profile taken along the circumferential direction of each of the rotor blades of a rotor blade stage has an upstream portion curved convexly backward in a rotational direction of the rotor and a downstream portion curved convexly forward in the rotational direction of the rotor, thereby forming the blade cross sectional profile into an S-shape or inversed S-shape.