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:
Mar. 13, 2012
Filed:
Mar. 19, 2007
Takeki Shirai, Tokyo, JP;
Yuji Tachikake, Tokyo, JP;
Soshi Miyahara, Tokyo, JP;
Masahiko Yoshino, Tokyo, JP;
Takashi Sakuyama, Tokyo, JP;
Lina Teng, Tokyo, JP;
Tsutomu Togashi, Tokyo, JP;
Takeki Shirai, Tokyo, JP;
Yuji Tachikake, Tokyo, JP;
Soshi Miyahara, Tokyo, JP;
Masahiko Yoshino, Tokyo, JP;
Takashi Sakuyama, Tokyo, JP;
Lina Teng, Tokyo, JP;
Tsutomu Togashi, Tokyo, JP;
THK Co., Ltd., Tokyo, JP;
Abstract
A ball screw device having a novel ball circulation structure suitable for a screw shaft with a large lead, optimum for downsizing and weight saving of a nut member, capable of being manufactured at low cost, and capable of exhibiting high reliability even under severe use conditions. In a ball screw device where a screw shaft and a nut member are screwed to each other through an intermediation of a large number of balls, a no-load ball path which forms an infinite circulation path for the balls is constituted by a no-load ball groove spirally formed in an inner peripheral surface of a through-hole of the nut member and by a pair of direction change grooves which communicatively couple a load rolling groove and the no-load ball groove to each other so as to complete the infinite circulation path as a closed loop.