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. 01, 2020
Filed:
Aug. 21, 2018
Jtekt Corporation, Osaka, JP;
Masashi Yamaguchi, Toyota, JP;
JTEKT CORPORATION, Osaka, JP;
Abstract
In a ball screw device, an inner peripheral rolling groove of a nut includes, between openings of mounting holes, a constant pitch circle diameter region where a pitch circle diameter is constant and gradually-changing pitch circle diameter regions where the pitch circle diameter gradually increases, in the ranges from opposite ends of the constant pitch circle diameter region to the respective openings. At least the constant pitch circle diameter region has a surface hardness greater than or equal to a predetermined value, among the constant pitch circle diameter region and the gradually-changing pitch circle diameter regions excluding edges at the boundaries between the respective openings and the inner peripheral rolling groove, and the edges at the boundaries between the respective openings and the inner peripheral rolling groove have a surface hardness less than the predetermined value.