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. 09, 2003
Filed:
May. 06, 2002
Applicant:
Inventors:
Assignee:
Kabushiki Kaisha Toyota Jidoshokki, Kariya, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F01M 1/00 ;
U.S. Cl.
CPC ...
F01M 1/00 ;
Abstract
A Roots pump rotates a plurality of rotors by a pair of rotary shafts to draw gas. Each rotary shaft extends through a rear housing member of the Roots pump. A plurality of stoppers are located on each rotary shaft to integrally rotate with the corresponding rotary shaft, and prevent oil from entering a fifth pump chamber of the Roots pump. Stoppers have a circumferential surface, respectively. Annular oil chambers collect oil. The oil chambers are located about an axis of the rotary shaft to surround the circumferential surface of the stopper. This effectively prevents oil from entering the pump chamber of the Roots pump.