Abstract: A fluid dynamic bearing having a hub, a sleeve, and a sealing arrangement comprising a first capillary seal substantially retaining a first fluid and a second capillary seal comprising a second fluid. The second capillary seal is located between the first capillary seal and an opening between the hub and the sleeve.

Abstract: An electrode containing a dielectric layer on a surface of the electrode and an active zone containing a metal embedded below the surface of the electrode, wherein the electrode is configured to form a groove pattern on a workpiece by an electrochemical machining process is disclosed. The electrode is capable of manufacturing a workpiece such as a counter plate, a sleeve journal or a conical bearing containing a groove pattern for fluid dynamics bearing, the groove pattern having a pitch of less than 80 microns. The electrode could be made by a method including depositing a dielectric layer on a surface of a metal, depositing a photoresist layer on the dielectric layer, printing a groove pattern on the photoresist layer, etching or physico-chemically removing portions of the dielectric photoresist layers to form grooves in the dielectric layer; removing the photoresist layer; and filling the grooves with a metal to produce the electrode.

Abstract: A fluid dynamic bearing having a hub, a sleeve, and a sealing arrangement comprising a first capillary seal substantially retaining a first fluid and a second capillary seal comprising a second fluid. The second capillary seal is located between the first capillary seal and an opening between the hub and the sleeve.

Abstract: A circular magnetizer is disclosed comprising circular insulating inset holding pans of axially disposed wires, each pair carrying a current oppositely directed from the adjacent pair, the insert being disposed within and facing a back iron across a circular gap of sufficient width to allow a circular magnet to be disposed therein and spaced by a gap from the insert and/or back iron. The pan's of wires are arranged to create flux lines which will establish alternating magnetic poles separated by null zones in the magnet.

Abstract: A motor or bearing which incorporates the use of a capillary seal adjacent a bearing race between the shaft and surrounding hub or housing. The seal may take a plurality of forms, including a straight capillary seal; a seal formed between the housing and a seal ball having different radius of curvatures (preferably with the housing internal surface having a larger radius); or a centrifugal capillary seal comprising a male cone supported on a fixed or rotating shaft, and a female cone supported on a housing. The use of a capillary seal rather than ferrofluid seal should also provide a reduction in resistance across the seal gap compared to a ferrofluid seal.

Abstract: A connector assembly comprising a base portion which plugs into the base of the motor shaft and a connector body having electrical interface rods along an axial face thereof. A flexible printed circuit having one end connected to the stator has dedicated connector pads on a surface thereof which line up with and are intended to be pressed against the molded body connector rods. To maintain the pads and rods in tight electrical contact, a connector snap spring assembly is snapped in place over the connector body.

Abstract: This invention deals with compensating for thermal changes such that the spindle motor bearing preload remains as constant as possible throughout the disc drive operational temperature range. This is achieved by selecting a combination of materials with a composite thermal expansion that offsets the differential expansion of the steel bearing supports and the ceramic balls. The change in materials and configuration can be either that of the shaft, the hub, the support members, or any combination thereof.

Abstract: A connector assembly comprising a base portion which plugs into the base of the motor shaft and a connector body having electrical interface rods along an axial face thereof. A flexible printed circuit having one end connected to the stator has dedicated connector pads on a surface thereof which line up with and are intended to be pressed against the molded body connector rods. To maintain the pads and rods in tight electrical contact, a connector snap spring assembly is snapped in place over the connector body.

Abstract: A high pressure boundary seal adjacent at least one of the bearings of the spindle motor. The motor itself includes a shaft, typically a fixed shaft and a rotor supported by bearings and rotating outside the shaft. The high-pressure boundary seal comprises a ring which surrounds the shaft across a small gap and is supported from and rotates with the rotor or hub. In a first embodiment, a herringbone pattern is defined on the inner surface of the ring or the outer surface of the shaft. The upper and lower sections of the herringbone pattern are substantially equal so that a zone of high pressure is established at about the center of the pattern. This high pressure boundary zone prevents the flow of any contaminants from the interior of the motor or the bearing between the shaft and the sealing ring out into the interior section of the disc drive housing where they could potentially contaminate the disc.

Abstract: A connector assembly comprising a base portion which plugs into the base of the motor shaft and a connector body having electrical interface rods along an axial face thereof. A flexible printed circuit having one end connected to the stator has dedicated connector pads on a surface thereof which line up with and are intended to be pressed against the molded body connector rods. To maintain the pads and rods in tight electrical contact, a connector snap spring assembly is snapped in place over the connector body.

Abstract: A disc drive spindle motor includes a central axis, a stationary member, a rotatable member which is rotatable with respect to the stationary member and a bearing interconnecting the rotatable member with the stationary member. A data storage disc is attached to the rotatable member. A stator is supported by the stationary member at an interface for rotating the rotatable member about the central axis with a driving force frequency. The stator has a resonant vibrational frequency. The interface has a plurality of recesses which are spaced axially from one another with respect to the central axis. An adhesive is applied within a selected set of the plurality of recesses and forms a bond between the stator and the stationary member. The set of recesses is selected such that the resonant vibrational frequency is different than the driving force frequency.

Abstract: A disc drive for storing and retrieving data from at least one memory storage disc includes a drive base and a spindle motor. The spindle motor includes a rotor hub, a shaft, a bearing unit. The bearing unit rotatably supports the rotor hub about an axis. A controlled resistance electrical pathway is established from the rotor hub to ground to control disc potential and to prevent excess static charge buildup. In one embodiment, the spindle motor includes structural elements made of a conducting plastic having a controlled resistance to establish a controlled resistance electrical pathway from the rotor hub to ground. In a second embodiment, the shaft of the spindle motor includes a conductive contact button electrically connected to the shaft and operatively coupled with a contact shield electrically grounded by an electrical conductor having a controlled resistance.

Abstract: A disc drive for storing and retrieving data from at least one memory storage disc includes a drive base and a spindle motor. The spindle motor includes a rotor hub, a shaft, a bearing unit. The bearing unit rotatably supports the rotor hub about an axis. A controlled resistance electrical pathway is established from the rotor hub to ground to control disc potential and to prevent excess static charge buildup. In one embodiment, the spindle motor includes structural elements made of a conducting plastic having a controlled resistance to establish a controlled resistance electrical pathway from the rotor hub to ground. In a second embodiment, the shaft of the spindle motor includes a conductive contact button electrically connected to the shaft and operatively coupled with a contact shield electrically grounded by an electrical conductor having a controlled resistance.

Abstract: Spindle motor electrical- and motor-to-base interfaces. A compliant connector along with a circuit on a support flange is provided below a stator assembly for providing: An insertable spindle motor to drive base with less specific orientation. The support flange may comprise a small printed circuit cable or a printed circuit board. Additionally, non-specific orientation of a spindle motor to drive base assembly is described using circular traces oriented about a support flange. A circular connector is also described, as well as a biased support flange.

Abstract: A disc drive for storing and retrieving data from at least one memory storage disc includes a drive base and a spindle motor. The spindle motor includes a rotor hub, a shaft, a bearing sleeve, and a bearing unit. The bearing unit is operably coupled to the rotor hub and includes an inner race secured to the shaft, an outer race secured to the bearing sleeve, and bearing balls fitted between the inner race and the outer race. The bearing balls rotatably support the rotor hub about an axis. At least one structural element of the spindle motor has a high resistivity so as to electrically isolate the hub from the base. In another embodiment, the drive base has an interface surface for coupling with the spindle motor. The interface surface includes a layer of high resistivity material. In another embodiment, the bearing ball is made of ceramic or ruby material to improve performance characteristics.

Abstract: A disc drive includes a disc drive motor for rotating a storage disc. The motor includes a motor base having a fixed member. A rotor is rotatably coupled to the fixed member and carries the storage disc. First and second bearings are positioned between the rotor and the fixed member allowing rotation of the rotor about the fixed member. A permanent magnet is positioned between the first and second bearings. A conductive fluid between the rotor and the fixed member is maintained in operable contact with the rotor and the fixed member by the permanent magnet. The ferrofluid provides a low resistance electrical path between the rotor and the fixed member thereby electrically grounding the rotor to the motor base.

Abstract: Method and apparatus for providing a controlled resistance electrical path from one moving element of an electrical device to second or subsequent element. An electrically conductive media is introduced between the rotating and static element of an electrical device. The media, e.g. conductive grease, may be introduced into the bearings of the device. Alternatively, a housing may be disposed upon one of the elements. Into this housing is introduced a quantity of electrically conductive media and a contact element. The contact element is integral with, or is preloaded against, one end of the shaft of the second element, thereby forming an electrical path from the shaft, through the media to the housing and thence to the first element of the device. The contact element may be seen therefore to be floating in contact with the conductive media, thereby forming a controlled-resistance rotary electrical connector.