Matsushita Electric Industrial Co., Ltd.

Yasuo Saeki

Katsunori Sakuragi

Takao Yoshitsugu

Hideshi Fukutani

Takafumi Asada

Hiroaki Saito

Fluid bearing equipment which is free from lockup or seizure which may occur due to a deficiency of a lubricating fluid when the equipment is operated at a high rotation speed in a high temperature environment. The fluid bearing equipment is arranged such that maximum pressure generating portions of dynamic pressure generating grooves provided in a thrust-side dynamic pressure generating portion are located closer to the outer circumference of a stationary thrust plate than a radially middle position of the thrust-side dynamic pressure generating portion. With this arrangement, the lockup and seizure of a motor can be prevented which may otherwise occur due to a deficiency of the lubricating fluid when the equipment is operated at a high rotation speed in a high temperature environment.

Fluid bearing equipment

In a spindle device mounted to a disc driving apparatus, a mist seal which blocks a mist of lubricating fluid, an oil seal which prevents the lubricating fluid from flowing out, and an oil pool which prevents surplus fluid from flowing out, are combined and disposed so that the lubricating fluid from a dynamic-pressure-fluid bearing is prevented from flowing out or splashing into a clean space. As a result, inconveniences such as a head crush or a head absorption can be avoided, and a reliable spindle device is realized.

Spindle device having a dynamic-pressure-fluid bearing

A hydrodynamic bearing which prevents a lubricating fluid from scattering out of the dynamic pressure generating portion. The bearing includes radial spacing d of a gap at an open end of the thrust-side dynamic pressure generating portion, whose value is greater than a spacing of the thrust-side dynamic pressure generating portion, as measured relative to the thrust direction. Scattering of lubricating fluid from the open end of the thrust-side dynamic pressure generating portion is therefore prevented even when the bearing rotates at a high speed in a high temperature envivronent.

Hydrodynamic bearing device

It is an object of the present invention to provide a hydrodynamic bearing which is highly reliable and capable of preventing a lubricant contained therein from flowing out of the bearing. In the hydrodynamic bearing, lower and upper end portions of a stationary shaft are properly spaced from a sleeve and a thrust plate, respectively, and an air channel is provided inside the stationary shaft with one end thereof opening to a space defined between an outer circumferential portion of the stationary shaft and the sleeve and with the other end thereof communicating with the outside. Thus, the hydrodynamic bearing has a highly reliable construction which can assuredly prevent the flow-out of the lubricant.

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Tottori-ken, Japan

Yasuo Saeki