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. 24, 2011
Filed:
Oct. 09, 2003
Tatsuya Hayashi, Kuwana, JP;
Kiyotaka Kusunoki, Kuwana, JP;
Tatsuya Hayashi, Kuwana, JP;
Kiyotaka Kusunoki, Kuwana, JP;
NTN Corporation, Osaka-Fu, JP;
Nidec Corporation, Kyoto, JP;
Abstract
A hydrodynamic bearing device has favorable bearing performance and long endurance life. A thrust bearing part of the hydrodynamic bearing device has a second thrust surface. In the second thrust surface, a dynamic pressure generating groove area having a plurality of dynamic pressure generating grooves is formed in at least a part thereof in a radial direction. The action of dynamic pressure of lubricating oil increases the pressure in a thrust bearing clearance between an end of a flange part of an axial member and the second thrust surface, to support the axial member in an axial direction in a non-contact manner. The dynamic pressure generating groove area of the second thrust surface is formed by press working. The difference in height between the inner and outer peripheral edges of the surface of the dynamic pressure generating groove area regulated between or equal to 0 and 2 μm.