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:
Dec. 16, 1997
Filed:
Jul. 11, 1996
Masao Shinoda, Zama, JP;
Chishiro Yamashina, Fujisawa, JP;
Shimpei Miyakawa, Oiso-machi, JP;
Yuichi Usami, Fujisawa, JP;
Ebara Corporation, Tokyo, JP;
Abstract
A hydraulic servovalve controls the direction of flow of a working fluid and a flow rate of a working fluid between a plurality of ports. The hydraulic servovalve includes a spool axially movably disposed in a valve body for changing a direction of a working fluid and varying a flow rate of the working fluid, a sleeve disposed in the valve body and having a spool hole for housing the spool, a pair of hydrostatic bearings disposed in the sleeve around respective opposite end portions of the spool, and a plurality of windows defined in the sleeve as control orifices for controlling a flow rate of a working fluid. The hydraulic servovalve further includes a fluid passageway communicating between the supply port and the control port through one of the windows, and a fluid passageway communicating between the control port and the return port through the other of the windows.