Abstract: In the brushless motor, a magnetic recording disk is to be mounted on a hub. A base plate rotatably supports the hub on the upper surface. A laminated core is fixed on the upper surface of the base plate and has a ring portion and a plurality of teeth that extend radially from the ring portion. Coils are wound around the plurality of teeth. A cylindrical magnet is fixed to the hub and is magnetized for driving with a plurality of poles along the circumferential direction and is arranged to radially face the plurality of teeth of the laminated core. A wire of one end of one of the coils is drawn out to the bottom surface of the base plate through a hole arranged on the base plate. The wire is connected to a driving line for supplying a current to the coils at a position other than the position of the hole on the base plate. The hole of the base plate is plugged with a resin.
Abstract: A bearing unit for a disk drive device is formed by a sleeve concave portion and a shaft concave portion, and is provided with a capillary seal portion in which the gap between the sleeve concave portion and the shaft concave portion is increased in diameter toward the hub side of the sleeve. Assuming that: the outer circumferential diameter at the tilt starting end on the base member side of the shaft concave portion is D0; the inner circumferential diameter at the tilt starting end on the hub side of the sleeve concave portion is D1; the facing outer circumferential diameter of the shaft concave portion, which faces, in the radial direction, the inner circumference at the tilt starting end of the sleeve concave portion, is D2; and the diameter of the most concave inner circumference of the sleeve concave portion is D3, D2 is smaller than D0, D3 is larger than D1, and the difference between D3 and D0 is larger than that between D0 and D2.
Abstract: The disk drive device includes a base member, a hub, a bearing unit which is arranged on the base member and which rotatably supports the hub, and a spindle drive unit which drives the hub to rotate. The spindle drive unit includes a stator core having a salient pole, a coil wound around the salient pole and a magnet opposed to the salient pole. The hub formed of magnetic material includes an outer cylinder portion engaged with an inner circumference of a recording disk and an inner cylinder portion to which an outer circumference of the magnet is fixed. The base member having a wire hole through which a wire from the coil passes, and a concavity that is formed at a bottom surface of the base member wherein the wire passes through the wire hole along a bottom face of the base member to a wiring member at the concavity.
Abstract: A disk drive device includes a fixed body section, a rotating body section, a bearing unit and a drive unit. The bearing unit includes a shaft that is a rotation center, a sleeve that has an accommodating portion in which the shaft is accommodated and that permits relative rotation around the shaft, a radial space defined by an inner wall surface of the sleeve-accommodating portion and an outer wall surface of the shaft, first and second radial dynamic pressure grooves that generate a radial dynamic pressure in at least one of the inner wall surface of the sleeve and the outer wall surface of the shaft that define the radial space, a lubricant charged into the radial space, and a porous filter that is disposed in at least a portion of the charging space in which the lubricant is charged, for capturing foreign matter contained in the lubricant.
Abstract: A method of manufacturing a bearing device component is provided. The bearing device includes a shaft and a sleeve that surrounds the shaft, and at least either one of the shaft and the sleeve is referred to as a work. The method includes: a process of forming a coating of an anti-sticking-lube polymer on the work; a process of applying a photoluminescence material to a range overlapping a range where the coating of the anti-sticking-lube polymer is formed; and a condition detecting process of causing the photoluminescence material to emit light by causing the work to be irradiated with excitation light that excites the photoluminescence material, and detecting an applied condition of the photoluminescence material based on the light emission of the photoluminescence material, thereby detecting a condition of the coating of the anti-sticking-lube polymer.
Abstract: The disk drive device includes a base plate, a hub on which a recording disk is mounted, a shaft bearing unit that is arranged on the base plate and that rotatably supports the hub, and a spindle drive unit that drives the hub to rotate. The spindle driving unit includes a stator core having a salient pole, a coil wound around the salient pole, and a magnet opposed to the salient pole. The hub formed of a magnetic material includes an outer cylindrical portion engaged with an inner circumference of the recording disk. A shaft is inserted into a sleeve, and the sleeve, which is of an approximate cylindrical shape, is inserted into a housing as part of the shaft bearing unit. The shaft is fixed to the rotational center of the hub, rotating along the axis together with the hub.
Abstract: A method manufacturing of a fluid dynamic bearing includes: forming a substantially linear groove having a length corresponding to a circumferential direction width of the dynamic pressure groove formed on the inner circumferential surface of a shaft housing hole portion, along the circumferential direction of a surface orthogonal to a first processing direction along the central axis direction of a work, by a byte that performs a micro alternating drive in a second processing direction orthogonal to the first processing direction; and extending the dynamic pressure groove that extends in the first processing direction by continuously forming the substantially linear grooves in the first processing direction by displacing the relative positions of the work and the byte in the first processing direction.
Abstract: A first sleeve rotatably extends around a shaft. First and second flanges are fixed to the shaft. A second sleeve extending around the first sleeve is fixed thereto. A first annular member fixed to the second sleeve surrounds the first flange. A second annular member fixed to the second flange surrounds a portion of the second sleeve. A first capillary seal includes a clearance between the first flange and the first annular member. A second capillary seal includes a clearance between the second annular member and the second sleeve. Lubricant is provided in the clearances in the first and second capillary seals. The second annular member and the second sleeve are designed so that the lubricant in the clearance in the second capillary seal can be viewed from a point in a radial position which is outward of the second sleeve as seen in an axial direction.
Abstract: A disk drive device includes: a hub on which a recording disk is to be mounted; a base configured to rotatably support the hub via a bearing; a core that is fixed to the base and includes a circular portion and S salient poles (where S is a natural number greater than or equal to 3) extending from the circular portion in the diameter direction; a three-phase coil that is formed by being wound around each of the S salient poles; and a magnet that is fixed to the hub and faces the S salient poles in the diameter direction, and that is provided with P driving magnetic poles in the circumferential direction (where P is a natural number greater than or equal to 2).
Abstract: In an apparatus for manufacturing a fluid dynamic bearing, a housing portion defines a first work area. A vacuum pump discharges air in the first work area. A lubricant discharge device is arranged in the first work area, and discharges a lubricant into an inlet of a reservoir for storing the lubricant of the fluid dynamic bearing. At least one aperture is provided in the housing portion. A first door closes the aperture and a second door closes the aperture. Between the first door and the second door, when both have closed the aperture, a second work area is formed where the fluid dynamic bearing is placed.
Abstract: A rotating device comprises a hub on which a magnetic recording disk is to be mounted and a base rotatably supporting the hub. At least one of the base and the hub is an item of manufacture. A method for manufacturing the rotating device comprises the steps of forming the item of manufacture, immersing the formed item of manufacture in an aqueous solution, the solute of which being a surfactant and the temperature of which being higher than the melting point of heptacosane, taking out the item of manufacture from the aqueous solution and immersing the item of manufacture in a liquid that can be regarded as pure water, taking out the item of manufacture from the liquid and drying the item of manufacture, and assembling the rotating device using the dried item of manufacture.
Abstract: A disk drive device comprises: a hub; a base rotatably supporting the hub via a bearing; a core fixed to the base; a cylindrical magnet fixed to the hub; and a suction plate fixed to the base, the suction plate being arranged to face the cylindrical magnet in a direction along the rotational axis and made of magnetic material. The suction plate is arranged so that the minimum distance between the suction plate and the rotational axis is greater than the minimum distance between the cylindrical magnet and the rotational axis. A projection area created by projecting the cylindrical magnet onto a plane that is perpendicular to the rotational axis partially overlaps a projection area created by projecting the suction plate onto the plane.
Abstract: A disk drive device is provided with a recording disk, a base member, a bearing unit, and a hub member. In a marking step, unbalance information indicating the displacement of the center of gravity of the hub member with respect to the rotation center of the hub member is acquired, and an information mark containing the unbalance information is applied to at least the hub member or the base member. In an installing and adjustment step, the unbalance information is read form the information mark, and the position for installing the recording disk in an outer cylinder part is determined in accordance with the unbalance information so as to install the recording disk on the hub member.
Abstract: A method of manufacturing a disk drive device including: assembling a subassembly by fixing at least a bearing unit, a drive unit and a hub to a base member in a first clean room; cleaning the subassembly in a second clean room; and sealing the subassembly by a sealing member. The first clean room and the second clean room are communicated with each other by a communicating opening for transferring the subassembly, and an atmospheric pressure in the second clean room is equal to or higher than that in the first clean room.
Abstract: A disk drive device has a hub so configured as to place and hold recording disks. Where the non-rotating eigenfrequency of resonance in a secondary rocking mode with the recording disks placed on the hub is defined to be F0 (Hz) and the rotational frequency of the hub is defined to be N (Hz), an extending part of the hub and a second cylinder part of the hub are formed such that the radial dimension of the extending part is smaller than the axial dimension of the second external cylinder part to satisfy to a relation F0>N·(3·P+2).
Abstract: A method for manufacturing a disk drive device includes (a) assembling a sub assembly by assembling a bearing unit and a rotating body to a fixed body in a clean room, the rotating body being supported by the bearing unit in a freely rotatable manner to the fixed body, (b) cleaning the sub assembly by spraying a mixture of a cleaning liquid and a first gas to at least either one of the fixed body and the rotating body; and (c) enclosing the sub assembly using an enclosing member.
Abstract: A method of manufacturing a disk drive device including: assembling a subassembly by fixing at least a bearing unit, a drive unit and a hub to a base member in a first clean room; cleaning the subassembly in a second clean room; and sealing the subassembly by a sealing member. The first clean room and the second clean room are communicated with each other by a communicating opening for transferring the subassembly, and an atmospheric pressure in the second clean room is equal to or higher than that in the first clean room.
Abstract: A disk drive device includes a bearing unit and a drive unit. The bearing unit includes: a shaft; a sleeve configured to allow relative rotation, with the shaft as the axis; a flange projected in the radial direction of the shaft and configured to rotate integrally with the shaft; a flange housing space portion provided continuously from the sleeve and configured to rotatably house the flange; a counter plate structured with both a first surface, which faces the end surface in the axial direction of the flange and seals the flange housing space portion, and a second surface that is opposite to the first surface. The projected dimension of the flange is designed to be larger than the wall thickness of the flange surrounding wall portion in the radial direction of the flange, the flange surrounding wall portion defining the flange housing space portion.
Abstract: A rotating device suitable for weight saving or thinning while maintaining a shock resistance is provided. The rotating device includes a rotating body having a hub on which a recording disk is to be mounted, and a shaft, and a fixing body including a sleeve, a housing, and a base. A lubricant is present between the rotating body and the fixing body. The sleeve is formed of a sintered metal. The housing has an encircling wall, the flange and the bottom which are integrally formed together by pressing.
Abstract: A bearing unit includes a shaft and a hub as a conductive rotating body that supports a recording disk. Also, the bearing unit includes a conductive resin housing configured to surround at least part of the shaft to support the shaft and to be able to conduct electricity to the recording disk via the shaft. The conductive resin housing includes a conductive adhesive to be applied to secure conduction with the base housing. The conductive resin housing has an exposed portion where the inner layer of the conductive resin housing is exposed, at a position to which the conductive adhesive is applied.