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:
Aug. 09, 2011
Filed:
May. 21, 2007
Applicants:
Norikatsu Hoshina, Kanagawa, JP;
Takao Muto, Tokyo, JP;
Yukio Uchida, Kanagawa, JP;
Jun Soeda, Kanagawa, JP;
Inventors:
Norikatsu Hoshina, Kanagawa, JP;
Takao Muto, Tokyo, JP;
Yukio Uchida, Kanagawa, JP;
Jun Soeda, Kanagawa, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F03C 4/00 (2006.01); F04C 14/18 (2006.01); F04C 2/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A variable displacement vane pump includes a rotor, a cam ring; and a pump casing including first and second side walls disposed on both sides of the cam ring, and a circumferential wall surrounding the cam ring and defining first and second pressure chambers. A pressure introduction groove is formed in a sliding contact surface between the cam ring and one of the first and second side walls, and arranged so that a pressure lower than an outlet pressure is introduced.