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:
Jan. 06, 2015
Filed:
Feb. 28, 2012
Hiroyuki Noda, Kuwana, JP;
Natsuhiko Mori, Kuwana, JP;
Tetsuya Kurimura, Kuwana, JP;
Isao Komori, Ama-gun, JP;
Masaharu Hori, Kuwana, JP;
Kimihiko Bito, Kuwana, JP;
Toshiyuki Mizutani, Kuwana, JP;
Hiroyuki Noda, Kuwana, JP;
Natsuhiko Mori, Kuwana, JP;
Tetsuya Kurimura, Kuwana, JP;
Isao Komori, Ama-gun, JP;
Masaharu Hori, Kuwana, JP;
Kimihiko Bito, Kuwana, JP;
Toshiyuki Mizutani, Kuwana, JP;
NTN Corporation, Osaka-shi, JP;
Abstract
An inner peripheral surface and a lower end surface of a bearing sleeve made of a sintered metal are each formed into a smooth cylindrical surface or a flat surface that does not have a dynamic pressure generating portion. Thus, a step of forming the dynamic pressure generating portion can be omitted from a manufacturing step of the bearing sleeve, and cost of dies can be markedly reduced. Further, the inner peripheral surface of the bearing sleeve is formed into the smooth cylindrical surface, and hence a radial dynamic pressure generating portion is formed on an outer peripheral surface of a shaft member. However, the outer peripheral surface of the shaft portion is accessible to tools, and hence the radial dynamic pressure generating portion can be formed easily with high accuracy. As a result, accuracy of a radial bearing gap is enhanced so that a bearing rigidity is enhanced.