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. 23, 2005
Filed:
Nov. 28, 2003
Shin-ichi Hirasawa, Kanagawa, JP;
Yukio Adachi, Kanagawa, JP;
Takeshi Yoshitome, Kanagawa, JP;
WAKO Industrial Co Ltd, Tokyo, JP;
Abstract
A hydraulic oil filtration apparatuscomprises an actuation control valve V, a pump-pressure oil passage, a connection oil passage, a tank oil passage, a return filter, a drain oil passage, a drain filterand an aspirator structure. The actuation control valve V controls to charge and discharge a hydraulic actuator A such as a boom cylinderand travel motors with hydraulic oil from a hydraulic pump P, which is connected through the pump-pressure oil passageto the actuation control valve V The hydraulic actuator A is connected with the actuation control valve V by the connection oil passage, and the actuation control valve V is connected to a tank T by the tank oil passage, in which the return filteris provided. The part of the tank oil passagedownstream with respect to the return filteris connected to the hydraulic pump P by the drain oil passage, in which the drain filteris provided. The aspirator structureis positioned at the junction between the tank oil passageand the drain oil passage, so that leakage oil in the drain oil passageis drawn by the flow of the discharged oil through the tank oil passageand led to the drain filter