| US 7,513,689 B2 | ||
| Hydrodynamic bearing device | ||
| Tsutomu Hamada, Hirakata (Japan); Takafumi Asada, Hirakata (Japan); and Hideaki Ohno, Sennan (Japan) | ||
| Assigned to Panasonic Corporation, Osaka (Japan) | ||
| Filed on Aug. 03, 2005, as Appl. No. 11/195,813. | ||
| Claims priority of application No. 2004-229825 (JP), filed on Aug. 05, 2004. | ||
| Prior Publication US 2006/0029313 A1, Feb. 09, 2006 | ||
| Int. Cl. F16C 32/06 (2006.01) | ||
| U.S. Cl. 384—107 [384/100; 384/121; 384/123] | 14 Claims |
| 1. A hydrodynamic bearing device comprising:
a sleeve having a bearing bore with a dynamic pressure generating groove formed on an inner surface of the bearing bore, the
dynamic pressure generating groove being defined by at least one crest portion adjacent to the dynamic pressure generating
groove;
a shaft disposed in the bearing bore of the sleeve in a relatively rotatable manner;
a thrust flange disposed on an end of the shaft;
a thrust member opposed to the thrust flange;
a dynamic pressure generating groove formed on at least one of opposing surfaces of the thrust flange and the thrust member;
and
working fluid filled in a gap between the shaft and the bearing bore, and between the thrust flange and the thrust member,
the sleeve being a sintered body including a sintering material containing at least one selected from a group containing iron,
an iron alloy, copper and a copper alloy, such that pores in the at least one crest portion adjacent to the dynamic pressure
generating groove of the sintered body are independent pores in which respective neighboring pores do not communicate with
each other, and a diameter of the independent pores is smaller than each of a width and a depth of the at least one crest
portion adjacent to the dynamic pressure generating groove.
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