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:
Apr. 17, 2012
Filed:
Jan. 07, 2009
Yoshiyuki Abe, Nihonmatsu, JP;
Yoshiyuki Abe, Nihonmatsu, JP;
NOK Corporation, Tokyo, JP;
Abstract
A hydraulic cylinder includes a cylinder having a shaft hole, a piston inserted into the shaft hole so as to have clearance with respect to an inner circumferential surface of the shaft hole, and seal members arranged in annular grooves formed in an inner circumference of the shaft hole to seal an annular gap between the inner circumference of the shaft hole and the piston, wherein in the hydraulic cylinder in which cavitation could occur in a portion of the clearance accompanying motion of the piston, an expansion part obtained by expanding a portion of a sidewall surface of the annular grooves on an inner circumferential edge side outward from an arrangement area of the seal members is provided to make a distance from a location where cavitation occurs to the seal members longer by a space formed by the expansion part.