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. 08, 2011
Filed:
Jun. 15, 2007
Takafumi Asada, Osaka, JP;
Hiroyuki Kiriyama, Ehime, JP;
Hiroaki Saito, Ehime, JP;
Daisuke Ito, Osaka, JP;
Takafumi Asada, Osaka, JP;
Hiroyuki Kiriyama, Ehime, JP;
Hiroaki Saito, Ehime, JP;
Daisuke Ito, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A hydrodynamic bearing type rotary device is configured to prevent air from being trapped inside a bearing and causing the bearing to have oil film rupture and NPPR to deteriorate. In the device, a flange having a shape substantially like a disc is provided integrally with a shaft near its lower portion. A sleeve having a bearing hole is fitted to the shaft so as to be relatively rotatable. Hydrodynamic grooves are provided on at least one of an outer periphery of the shaft and an inner periphery of the sleeve. The flange forms a thrust bearing surface with a lower end surface of the sleeve. Hydrodynamic grooves are provided on at least one of the lower surface of the sleeve and an upper surface of the flange. During rotation of the bearing, the hydrodynamic grooves circulate the lubricant. Capillary pressures at respective portions in the lubricant circulation path have different magnitudes. The principle that air tends to move toward the portion having a smaller capillary pressure is utilized to make it difficult for the air to be trapped inside the bearing and to smoothly discharge the air.