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. 28, 2003
Filed:
Jul. 06, 2001
Hiroshi Yamamoto, Kawasaki, JP;
Hiroyuki Tokunaga, Hiratsuka, JP;
Komatsu Ltd., Tokyo, JP;
Abstract
A subject of the present invention is to provide a water based hydraulic fluid and a hydraulic pressure device able to prevent burning and wearing in a sliding portion of a member constructed by an iron-based material as much as possible. Therefore, the water based hydraulic fluid relative to the invention contains copper ions for forming a film on addendum surfaces of a drive gear and a driven gear constructed by the iron-based material. A gear pump as the hydraulic pressure device relative to the invention uses the water based hydraulic fluid containing metallic ions for forming the film on the addendum surfaces of the drive gear and the driven gear constructed by the iron-based material.