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:
Feb. 04, 2003
Filed:
Apr. 06, 2001
Tomoyoshi Okamura, Minori, JP;
Kouichi Irie, Tsuchiura, JP;
Taiji Hashimoto, Tsuchiura, JP;
Hitoharu Kimura, Chiyoda, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A pump, comprising: an impeller having blades; and a casing for storing the impeller therein, on an inner surface of which, confronting to the impeller, are formed plural numbers of shallow grooves in a direction of pressure gradient of fluid, around a periphery thereof, wherein the fluid being increased up in pressure by the blades flows within the grooves in a reverse direction, directing to an upstream side, so as to spout out at a place where re-circulations occur when the flow rate is low in amount. Also, an outlet angle of the blade is set to be within a region from 30 degree to 90 degree. Further, preferably, front guide vanes are provided, so that a direction of absolute flow at an outlet of the impeller is directed into an axial direction of the pump at an amount of designed flow rate.