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:
Nov. 21, 2017
Filed:
Jun. 06, 2017
Hitachi-ge Nuclear Energy, Ltd., Hitachi-shi, Ibaraki, JP;
Yuuichi Matsushita, Hitachi, JP;
Toshihiro Kodama, Hitachi, JP;
Kiyoshi Harada, Hitachi, JP;
Hirokazu Akatsuka, Hitachi, JP;
Takahiro Tsuchiya, Hitachi, JP;
Hitachi-GE Nuclear Energy, Ltd., Hitachi-shi, JP;
Abstract
A control rod drive mechanism includes an outer tube, a guide tube disposed inside the outer tube, a ball tube, a hollow piston, and an electric motor. A gap between a ball traveling side of the screw shaft and the traveling balls and a gap between the traveling balls and a ball traveling side of the ball nut, having the gap coefficient (A) is given by: A=((2×R−L)−D)÷(2×R−L). The diameter of the traveling balls is determined to satisfy the expression given by A, in which A has the value of more than 0.03 and less than 0.17.