Abstract: A fluid injection apparatus for a bearing includes a bearing support surface for supporting the bearing so that a seal space is defined between the support surface and the bearing, a fluid injection passage comprised of an oil tank, a first conduit connecting the oil tank to the seal space, and an injection valve provided in the conduit, a decompression passage comprised of an oil recovery tank, a second conduit connecting the oil recovery tank to the seal space, a vacuum pump connected to the seal space through the oil recovery tank, and a decompression valve provided in the second conduit, and a sequence control unit for evacuating the bearing by closing the injection valve, opening the decompression valve, and turning on the vacuum pump, and then filling the bearing with lubricating oil by turning off the vacuum pump, closing the decompression valve, and opening the injection valve.

Abstract: In a fluid injection apparatus for a fluid dynamic pressure bearing, which uses a vacuum injection method, a maintenance is made easy and costs for the apparatus and the maintenance are reduced. A sequence control unit closes an injecting valve, subsequently opens a decompressing valve, and starts a vacuum pump. Whereupon, an inside of a fluid dynamic pressure bearing is decompressed. If the inside of the fluid dynamic pressure bearing is decompressed, the sequence control unit closes the decompressing valve, subsequently stops the vacuum pump, and opens the injecting valve. Whereupon, a lubricating oil stored in an injection tank is pushed out by the atmospheric pressure, and injected into the inside of the fluid dynamic pressure bearing being decompressed.

Abstract: In a hydraulic bearing motor, by means of dynamic pressure generating grooves provided on a thrust shaft with a larger diameter not only on the end face thereof but also on the shaft surface thereof, pressures generated in oil when rotating a shaft body are made to be applied not only in the axial direction but also in the radial direction with high magnitude. This can provide the hydraulic bearing motor as being capable of satisfying features of exhibiting small NRRO, and vibration and shock resistance even with a thinned hydraulic bearing motor.

Abstract: A hydraulic dynamic pressure bearing motor has a rotational shaft mounted to undergo rotation about a rotational axis and having a shaft section and a flange section. A sleeve has a cavity for receiving the rotational shaft. A cover member is disposed over an open end of the sleeve cavity. A hydraulic dynamic pressure bearing includes minute radial and thrust clearances disposed between outer surface portions of the shaft and flange sections of the rotational shaft and inner surface portions of the sleeve and the cover member. A lubricating fluid is disposed in the minute radial and thrust clearances. The minute radial and thrust clearances are dimensioned so that during a non-rotational state of the rotational shaft, the flange section of the rotational shaft contacts preselected inner surface portions of the sleeve and the cover member while the shaft section of the rotational shaft does not contact any portion of the sleeve and an inner peripheral surface of the cover member.

Abstract: In a spindle motor, a core with a specified thickness is formed by laminating thinnest possible magnetic steel sheets to allow consumed current to be reduced. For example, by providing a structure of a core of a spindle motor with seven 0.2 mm thick steel sheets being laminated, it becomes possible to make consumed current smaller than that for a core laminated with four 0.35 mm thick steel sheets. Thus, a spindle motor is provided as being suited for downsizing an HDD and possible to reduce consumed power.

Abstract: In a thin dynamic pressure hydraulic bearing motor used for a compact HDD device which motor is provided with a thin hydraulic dynamic pressure bearing comprising a flanged rotary shaft comprising a shaft and a flange, a sleeve into which the flanged rotary shaft is rotatably inserted, a ring-like lid 35, and lubricating oil filling minute clearances formed by those bearing components, the thrust clearance c is determined as being equal to or less than a value for which a product md of the maximum vertical shift m at a rim of a magnetic disk and a diameter d of the flange of the flanged rotary shaft is divided by 4r, four times a radius r of the magnetic disk. Thus, even when no bearing stiffness is provided for the hydraulic dynamic pressure bearing motor at rest, the magnetic disk is made so as not to contact with a head supporting system such as a head loading arm.

Abstract: In a hydraulic bearing motor, by means of dynamic pressure generating grooves provided on a thrust shaft with a larger diameter not only on the end face thereof but also on the shaft surface thereof, pressures generated in oil when rotating a shaft body are made to be applied not only in the axial direction but also in the radial direction with high magnitude. This can provide the hydraulic bearing motor as being capable of satisfying features of exhibiting small NRRO, and vibration and shock resistance even with a thinned hydraulic bearing motor.

Abstract: In a method for assembling a spindle motor having a liquid dynamic pressure bearing having a flanged shaft member formed by press-fitting a dynamic pressure ring member on a cylindrical member, a hub is press-fit on the flanged shaft member without causing deviation in the press-fit position of the dynamic pressure ring member. A hub press-fitting apparatus press fits a mount hole of the hub on a cylindrical end portion of the cylindrical member. The hub press-fitting apparatus comprises a hub holding member, a rotation shaft member, a coupling member, and an anti-rotation member. During assembly, a temporary coupling between the hub press-fitting apparatus and the liquid dynamic pressure bearing is made by screwing a threaded tap in a tap hole provided in an end face of the cylindrical member.

Abstract: Cleaning apparatus provide for the cleaning of a workpiece by first immersing the workpiece in a cleaning tank having a cleaning liquid therein for a predetermined period of time, removing the workpiece from the cleaning tank, moving the workpiece through air for a pre-selected period of time, and supplying the workpiece to a drying device which then dries the workpiece. As the workpiece is moved through the air, the workpiece may be vibrated, moved at an incline then a decline, and/or have air blasted at it, so that any liquid, e.g. rinsing solution, remaining thereon is caused to fall off, such occurring prior to the drying of the workpiece by the drying device.