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:
Sep. 06, 2011
Filed:
Nov. 09, 2005
Isamu Tsubono, Ushiku, JP;
Junichi Tamamoto, Kasumigaura, JP;
Makoto Yamakado, Tsuchiura, JP;
Tooru Takahashi, Hiratsuka, JP;
Yukio Sudo, Aikawa, JP;
Isamu Tsubono, Ushiku, JP;
Junichi Tamamoto, Kasumigaura, JP;
Makoto Yamakado, Tsuchiura, JP;
Tooru Takahashi, Hiratsuka, JP;
Yukio Sudo, Aikawa, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Revolving rollers, each provided on an outer peripheral surface thereof with revolving roller grooves extending therearound, are caused to mesh with a rack rod thread of a central rack rod with an axial angle over a lead angle of the rack rod thread and arranged for rotation on a holder member to be twisted. The holder member is rotated round the rack rod by a motor to translate the rack rod. A large thrust can be generated while ensuring a high reliability since a high efficiency is achieved by realizing rolling contact in set points of mesh of the rack rod thread and the revolving roller grooves, points of mesh are made planar, and interference in other points than the points of mesh can be suppressed. Also, play can be restricted by assembling the revolving rollers to the rack rod thread while applying torque in a direction, in which the axial angle is increased.