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:
Nov. 17, 2015
Filed:
Dec. 14, 2011
Hiroyuki Yamada, Tokyo, JP;
Isao Hayase, Tokyo, JP;
Hiroyuki Yamada, Tokyo, JP;
Isao Hayase, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a roller screw () having a screw shaft (), a plurality of rollers () that roll on a flank face () of the screw shaft; and a cage () that rotatably houses the plurality of rollers, a plurality of roller groups () each having a plurality of rollers arranged at equal intervals while contacting with the same flank face along a spiral groove of the screw shaft for one lead are provided, and the plurality of roller groups are arranged at intervals in the axial direction of the screw shaft. With this configuration, the size of the nut portion in the axial direction of the screw shaft can be prevented from being bloated, and the load distribution in a circumferential direction of the screw shaft can be uniformized.