| US 7,492,548 B2 | ||
| Hydrodynamic bearing device and disk rotating apparatus | ||
| Takafumi Asada, Osaka-fu (Japan); Hiroaki Saito, Ehime-ken (Japan); Takao Yoshitsugu, Ehime-ken (Japan); Keigo Kusaka, Ehime-ken (Japan); Hiroyuki Kiriyama, Ehime-ken (Japan); and Daisuke Ito, Osaka-fu (Japan) | ||
| Assigned to Matsushita Electric Industrial Co., Ltd., Osaka (Japan) | ||
| Appl. No. 10/554,473 PCT Filed Apr. 13, 2004, PCT No. PCT/JP2004/005277 § 371(c)(1), (2), (4) Date May 26, 2006, PCT Pub. No. WO2004/094848, PCT Pub. Date Nov. 04, 2004. |
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| Claims priority of application No. 2003-120025 (JP), filed on Apr. 24, 2003; and application No. 2003-176481 (JP), filed on Jun. 20, 2003. | ||
| Prior Publication US 2006/0274448 A1, Dec. 07, 2006 | ||
| Int. Cl. G11B 17/02 (2006.01) | ||
| U.S. Cl. 360—99.08 | 8 Claims |
| 1. A hydrodynamic bearing device comprising:
a sleeve having a bearing bore into which a shaft is rotatably inserted;
a cover plate which is provided such that a reservoir for storing lubricant or air is defined in the vicinity of one end portion
of the bearing bore;
a substantially dislike flange which is secured to one end portion of the shaft and has one face confronting one end face
of the sleeve in the vicinity of the other end portion of the bearing bore;
a thrust plate which is provided so as to confront the other face of the flange and seal a region including the one end face
of the sleeve; and
at least one communication path extending from the reservoir of the cover plate toward an outer surface of the flange;
wherein first and second dynamic pressure generating grooves of a herringbone pattern are arranged in a direction along an
axis of the shaft on at least one of an inner peripheral surface of the bearing bore of the sleeve and an outer peripheral
surface of the shaft;
wherein a third dynamic pressure generating groove of a herringbone pattern is provided on at least one of opposed faces of
the flange and the thrust plate and a fourth dynamic pressure generating groove of a herringbone pattern is provided on at
least one of the one face of the flange and the one end face of the sleeve;
wherein clearances between the shaft and the sleeve and between the flange and the thrust plate including the first, second,
third and fourth dynamic pressure generating grooves are filled with lubricant;
wherein one of the sleeve and the shaft is mounted on a stationary base and the other of the sleeve and the shaft is mounted
on a rotary member;
wherein when “S1” denotes a dimension of a radial clearance between the shaft and the sleeve at the time the axis of the shaft is held in
alignment with a central axis of the bearing bore, “S2” denotes a dimension of a clearance between the shaft and an inner periphery of the cover plate and “S3” denotes a dimension of clearance between an inner peripheral portion of the cover plate and the other end face of the sleeve,
and wherein the dimension S1 is made smaller than the dimensions S2 and S3.
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