| US 7,527,432 B2 | ||
| Hydrodynamic bearing type rotary device and recording and reproduction apparatus including the same | ||
| Takafumi Asada, Osaka (Japan); Hiroaki Saito, Ehime (Japan); and Daisuke Ito, Osaka (Japan) | ||
| Assigned to Panasonic Corporation, Osaka (Japan) | ||
| Filed on Jul. 25, 2006, as Appl. No. 11/492,166. | ||
| Claims priority of application No. 2005-364050 (JP), filed on Dec. 16, 2005. | ||
| Prior Publication US 2007/0140605 A1, Jun. 21, 2007 | ||
| Int. Cl. F16C 32/06 (2006.01) | ||
| U.S. Cl. 384—107 [384/119] | 20 Claims |
| 1. A hydrodynamic bearing type rotary device, comprising:
a sleeve having a bearing hole;
a shaft placed in the bearing hole so as to be relatively rotatable;
a seal cap fixed to one side in an axial direction of the sleeve;
a thrust plate fixed to the other side in the axial direction of the sleeve;
a radial bearing portion having radial dynamic pressure generating grooves on at least one of an outer peripheral surface
of the shaft and an inner peripheral surface of the sleeve;
a circular first fluid reservoir which communicates with the radial portion, and is formed between at least two of the sleeve,
the shaft, and the thrust plate on the other side in the axial direction of the sleeve;
a circular second fluid reservoir which communicates with the radial bearing portion, and is formed between the sleeve and
the seal cap;
a communication hole formed in the sleeve which communicates the first and the second fluid reservoirs; and
a lubricating fluid held between the sleeve, the shaft, the seal cap and the thrust plate,
wherein a capillary pressure in the first fluid reservoir is higher than a capillary pressure in the second fluid reservoir.
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