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:
Feb. 02, 2010
Filed:
Dec. 20, 2006
Ming Feng, Kyoto, JP;
Satoru Sodeoka, Kyoto, JP;
Ming Feng, Kyoto, JP;
Satoru Sodeoka, Kyoto, JP;
Nidec Corporation, Kyoto, JP;
Abstract
A bearing assembly for use in an electric motor minimizes the generation of a negative pressure. In the bearing assembly, gaps are formed between a shaft provided with a flange portion, a ring member mounted on the shaft, and a sleeve member with a through hole formed therein are continuously filled with lubrication oil. When a rotor rotates, the rotor is supported by a fluid dynamic pressure. In the bearing assembly, herringbone grooves are formed in an upper surface of the flange portion of the shaft fixed to a base plate. When the sleeve member rotates with respect to the shaft, ends of all of the herringbone grooves and the through hole are superposed on each other sequentially. Thus, the lubrication oil can be efficiently supplied to an outer peripheral region in the thrust dynamic pressure bearing mechanism in which the negative pressure is most prone to be generated, and generation of the negative pressure can be efficiently minimized.