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:
Dec. 16, 2008
Filed:
Dec. 29, 2005
Andreas Kull, Donaueschingen, DE;
Andreas Kull, Donaueschingen, DE;
Minebea Co., Ltd., Nagano-ken, JP;
Abstract
The invention relates to a fluid dynamic bearing system particularly to rotatably support a spindle motor to drive the disk(s) of a hard disk drive. The bearing system comprises a bearing sleeve and a shaft accommodated in a bore in the bearing sleeve and rotatably supported with respect to the bearing sleeve, the surfaces of the bearing sleeve and of the shaft, which face each other and are separated by a bearing gap () filled with a bearing fluid, forming at least one first radial bearing region. According to the invention the diameter of the shaft is chosen such that the relationship between the bearing distance, i.e. the distance of the fixing point of the shaft to the first radial bearing region, and the diameter of the shaft is equal to or less than 0.9, and that the diameter of the shaft is preferably 3 mm to 5 mm. This provision causes the resonance frequency of the bearing to shift to a higher, uncritical frequency range.