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:
Sep. 23, 2008
Filed:
Oct. 06, 2005
Masakazu Kurata, Kanagawa, JP;
Mizuo Otaki, Kanagawa, JP;
Masakazu Kurata, Kanagawa, JP;
Mizuo Otaki, Kanagawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In an oil pump employing a cam ring, and inner and outer rotors in meshed-engagement, two housings are provided at opposite ends of the cam ring. A plurality of volume chambers are defined between inner and outer teeth of the rotors. Two axial holes are formed in the cam ring. A first one of the axial holes is positioned corresponding to a mesh portion having a minimum volume, whereas the second axial hole is positioned corresponding to a trap portion having a maximum volume. A suction port and a discharge port are formed at least in one of the housings and are open to the volume chambers between the mesh and trap portions. All are positioned at a line symmetry of an axis line between the mesh and trap portions. At least one of the two axial holes is formed as a slot extending along the axis lines.