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:
Oct. 27, 2020
Filed:
Sep. 26, 2016
Hitachi Automotive Systems, Ltd., Hitachinaka-shi, Ibaraki, JP;
Atsushi Sato, Yokote, JP;
Keisuke Kitamura, Atsugi, JP;
Mitsuaki Abe, Yokote, JP;
Tetsuya Yonezawa, Yokote, JP;
Tatsuyoshi Maruyama, Atsugi, JP;
Osamu Yoshida, Yokohama, JP;
Kenji Kagami, Machida, JP;
HITACHI AUTOMOTIVE SYSTEMS, LTD., Hitachinaka-Shi, JP;
Abstract
In a power steering device equipped with a rack shaft constructed by joining a first member having rack teeth and a second member serving as a ball screw shaft on which a ball screw groove is formed, a grinding process of the ball screw groove is performed on the second member by causing a grindstone to rotate and move along a rotation axis of the second member, while causing the second member to rotate about an axis of the second member as the rotation axis. The grinding process is performed so as to satisfy a specified machining condition 'g/(5×p)<w<g/p', where w is a rotational speed of the second member during grinding of the ball screw groove, g is a rotational speed of the grindstone during grinding of the ball screw groove, and p is a circumferential length of one circumference of the ball screw groove around the rotation axis.