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. 12, 2009
Filed:
Jun. 30, 2006
Takeyoshi Yamamoto, Ehime, JP;
Takeyoshi Yamamoto, Ehime, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A spindle motor includes a shaft including a core spindle member with a large and a small diameter portions and an encircling annulus member attached to the small diameter portion; a rotor hub attached to the large diameter portion; a bearing member; a radial bearing portion provided with first dynamic pressure creating grooves and formed between the outer peripheral surface of the encircling annulus member and the inner peripheral surface of the bearing member; a thrust bearing portion provided with second dynamic pressure creating grooves and formed between a lower end of the encircling annulus member and the bottom of the bearing member; a first opening formed at a radially inner side of the thrust bearing portion; a second opening formed at a radially outer side of the large diameter portion; and a communication hole continuously formed from the first opening to the second opening.