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. 01, 2006
Filed:
May. 17, 2005
Masato Kageyama, Tochigi, JP;
Yukio Shoji, Tochigi, JP;
Nobumi Yoshida, Tochigi, JP;
Komatsu, Ltd., Tokyo, JP;
Abstract
In a hydraulic machine, hydraulic pump failure is detected and the pump lifespan is estimated before the pump failure occurs. The discharge pressure, oil temperature, and drain filter differential pressureare measured, a correlative relationshipbetween the filter differential pressure and the discharge pressure is determined, and a representative filter differential pressureis calculated from this correlative relationship. Using an oil temperature-differential pressure correlation function, the representative differential pressure valueis corrected so that the variable componentcaused by the oil temperatureis eliminated therefrom. The long-term trend and the short-term trend of the increase over time of the corrected differential pressure is calculated. A pump failure is predicted or the pump lifespan is estimated based on the degree of deviation between the long-term trend and the short-term trend.