Minebea Company, Limited

Toshimitsu Horiuchi

Andreas Kull

Fumiyasu Higuchi

Naoyuki Kondo

A fluid dynamic pressure bearing device includes a first capillary seal () formed between an outer circumferential surface of a bearing memberand an internal circumferential surface of a seal member (). A second capillary seal portion () is formed between an outer circumferential surface of a shaft member () and a protrusion hole () of the seal member (). A ventilation hole () is formed in a substantially intermediate portion of a side wall of the seal member. A lubricant holding gap () is formed between an inner surface of a top wall () of the seal member () and the upper end surface of the bearing member (). Leakage of lubricant () is suppressed by action of the capillary seal portions (), and the liquid surface is positioned in the first capillary seal portion () above the ventilation hole (), whereby extra lubricant () is filled in the first capillary seal portion () and the lubricant holding gap ().

Fluid dynamic pressure bearing device, spindle motor provided with fluid dynamic pressure bearing device, and recording disk drive device

An apparatus for and a method of construction of a spindle motor having a bearing unit, a rotary shaft, a rotary hub member and an electro-magnetic motor is presented. The rotary shaft has a flange attached at a mid-section in an axial direction, between large and small diameter sections of the rotary shaft. Grooves between the bearing unit, rotary shaft and flange create radial dynamic pressure generating areas, each with as long as possible a span, and thrust dynamic pressure generating areas to both sides of the flange.

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Kitasaku-gun, Japan

Toshimitsu Horiuchi