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:
May. 16, 2006
Filed:
Dec. 31, 2002
Toshiharu Kajita, Gunma, JP;
Toshiharu Kajita, Gunma, JP;
NSK Ltd., Tokyo, JP;
Abstract
A ball screw having: a screw shaft having a spiral ball rolling groove; a ball nut having a ball rolling groove corresponding to the ball rolling groove; and a large number of balls interposed between the ball rolling grooves so as to roll freely; wherein the ball rolling groove of at least one of the screw shaft and the ball nut is ground so that a maximum value component of a number of undulation peaks per lead in the ball rolling groove is not in a range of from 0.95 nm to 1.05 nm centered on an integral multiple nm of a number m of load balls per lead calculated by an expression: in which P is a distance between centers of the adjacent load balls disposed at substantially equal intervals in the ball rolling groove, dis a ball pitch circle diameter, and L is a lead.