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:
Oct. 18, 2011
Filed:
Feb. 28, 2008
Ikuo Yamamoto, Kashiwara, JP;
Takatoshi Sakata, Yamatotakada, JP;
Ikuo Yamamoto, Kashiwara, JP;
Takatoshi Sakata, Yamatotakada, JP;
JTEKT Corporation, Osaka-shi, JP;
Abstract
In an electric pump unit, communication between arcuate ports provided in correspondence with a discharge side and a suction side of an internal gear pump is selectively permitted and prohibited in correspondence with movement of a spool of a relief valve. If fluid pressure at the discharge side of the internal gear pump becomes greater than or equal to a predetermined value, the spool moves across an inner arc of one of the arcuate ports corresponding to the suction side of the internal gear pump and from a position at which the spool prohibits the communication between the arcuate ports to a position at which the spool permits the communication. As the spool moves away from the position at which the spool blocks the communication between the arcuate ports, the opening degree of the relief valve changes in accordance with a downward convex curve.