Abstract: An inboard thrust surface is provided for a spindle motor that maintains fluid flow through a journal bearing and generates an added offset pressure to avoid any subambient pressure within a journal. In an aspect, journal bearing asymmetry is minimized or eliminated and axial span is increased between journal bearings, reducing wobble or run-out between relatively rotating components. In another aspect, journal axial length is decreased for low profile disc drive memory systems and other spindle motors. In an aspect, two separate thrust surfaces provide an axial force in the same direction, opposing an axial bias force created by interaction of a stator and a magnet, and minimizing power consumption.

Abstract: To simplify fabrication of an integral hub piece, the opening between the upper and lower female cones in this hub has sufficient width or radial dimension to allow access to both cones from one side of the hub with the cutting tool. A cutting tool is used which has a width smaller than the opening between the cones. Preferably, the tool has a width which is about equal to or smaller than an angular dimension through this opening which is defined by extending surfaces of the upper and lower female cones. If this limitation is satisfied, both cones can be created with a single machine set up operating from one side of the integrated hub.

Abstract: A spindle motor comprises a fixed shaft capable of being fastened at either end to the base and cover of the disc drive. The hub which rotates around the disc drive is supported for rotation by a journal bearing and thrust bearing, with the thrust bearing grooved surfaces being defined in gaps immediately adjacent the ends of the journal bearing. A fluid recirculation path is provided through the rotating sleeve connecting the surfaces adjacent the thrust bearings, with the asymmetry which provides the fluid circulation either being inherently present due to tolerances in the bearing and groove design, or specifically provided by asymmetry in the bearing groove pattern.

Abstract: To simplify fabrication of an integral hub piece, the opening between the upper and lower female cones in this hub has sufficient width or radial dimension to allow access to both cones from one side of the hub with the cutting tool. A cutting tool is used which has a width smaller than the opening between the cones. Preferably, the tool has a width which is about equal to or smaller than an angular dimension through this opening which is defined by extending surfaces of the upper and lower female cones. If this limitation is satisfied, both cones can be created with a single machine set up operating from one side of the integrated hub. Preferably the tool should only move orthogonal or parallel to the cutting tools rotational center axis.

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: The smallest shaft diameter while retaining rigidity is achieved using either ceramic or tungsten carbide. However, to maintain the stiffness of the shaft of the surrounding sleeve and supported therefrom by a hydrodynamic bearing, the gap must also be adjusted and diminished. According to this method, the shaft thickness and bearing gaps are optimized by first setting a ceramic shaft thickness, then modifying the gaps in relation to that thickness.

Abstract: A disc drive system includes a disc drive chassis, a magnetic storage disc, a read/write transducer adjacent to the disc for reading and writing information on the disc, and a hydrodynamic bearing assembly. The hydrodynamic bearing assembly rotatably couples the magnetic storage disc to the disc drive chassis. The hydrodynamic bearing assembly includes a fluid path therethrough for circulating a fluid. A labyrinth seal and magnet shield is provided proximate the hydrodynamic bearing assembly.

Abstract: A bearing assembly including a bearing cone (50) having a crowned bearing surface (56) with V-shaped grooves (60) that are shallow at their apex (62) and deepest at the outer edges (52, 54). When mated with a female bearing seat, lubricating fluid builds up along the midline of the bearing surface as the bearing seat rotates about the bearing cone.

Abstract: A bimetallic part is formed from metals or comprises metals with different thermal expansion coefficients. A first element defines the part and defines one surface of the bearing gap and has a first coefficient of expansion and a second element is wholly or partially inserted into and constrained within the first element and having a different coefficient of thermal expansion so that as the temperature changes, the stress created by the differential expansion of the two elements will cause the overall part to deform elastically as a function of temperature. This deformation will cause the gap, the elements being properly selected, to narrow as temperature rises (and viscosity falls) and to widen as temperature falls (and viscosity rises).

Abstract: A disc drive system includes a disc drive chassis, a magnetic storage disc, a read/write transducer adjacent to the disc for reading and writing information on the disc, and a hydrodynamic bearing assembly. The hydrodynamic bearing assembly rotatably couples the magnetic storage disc to the disc drive chassis. The hydrodynamic bearing assembly includes a fluid path therethrough for circulating a fluid. A labyrinth seal and magnet shield is provided proximate the hydrodynamic bearing assembly.

Abstract: A bearing assembly including a bering cone (50) having a crowned bearing surface (56) with V-shaped grooves (60) that are shallow at their apex (62) and deepest at the outer edges (52, 54). When mated with a female bearing seat, lubricating fluid builds up along the midline of the bearing surface as the bearing seat rotates about the bearing cone.

Abstract: A disc drive system includes a hydrodynamic bearing. The disc drive system includes a disc drive chassis, a storage disc, and a read/write transducer adjacent to the disc for reading and writing information on the disc. The hydrodynamic bearing assembly rotatably couples the storage disc to the disc drive chassis. The hydrodynamic bearing assembly includes a fluid path therethrough for circulating a fluid. A permanent magnet is placed in the fluid path and used for attracting magnetic particles carried in the fluid.

Abstract: A disc drive data storage system according to the present invention includes a stationary member, a rotatable member and a hydro bearing which interconnects the stationary member and the rotatable member. At least one data storage disc is attached to and is coaxial with the rotatable member. The hydro bearing includes an electrically non-conductive lubricant and an electrically conductive, non-metallic additive.

Abstract: A spindle motor includes a rotating hub for supporting one or more discs in a disc drive, and a hydrodynamic bearing system for supporting a hub for rotation, the bearing system includes a sleeve and a shaft fitted into an axial bore of the sleeve. The shaft and the sleeve rotate freely relative to one another, and together, define a journal bearing. The shaft supports an annular thrust plate. The thrust plate extends into a recess formed by an axial face stepped into the sleeve and a counterplate parallel to the axial face and the thrust plate and attached to the sleeve. A first surface of the thrust plate faces the axial face of the sleeve which has a groove pattern formed on it. A surface of the counterplate faces an opposed, second surface of the thrust plate which has a groove pattern formed on it, to form an effective fluid pumping system in the hydrodynamic bearing.

Abstract: A method is provided eliminating the need for capping the motor after filling, i.e. sealing an end of the motor after the fluid has been added.A septum or rubber plug is inserted in the bottom of the motor shaft in a counter bore which leads to a fluid reservoir for the bearing. The air-tight seal is also achieved by a temporary O-ring around the sides of the shoulder at the end of the shaft closing off the end of the bearing normally open to the surrounding environment.A needle is then inserted into the shaft via the septum, and the other end of the needle is placed in the oil that will be drawn into the motor. The motor, needle and container for the oil are placed in a vacuum chamber which is evacuated; the resulting pressure differential causes the air within the motor to exit through the needle and up through the oil.

Abstract: A hydrodynamic bearing assembly including a shaft and surrounding bushing which define a journal, the shaft and bushing defining at the end thereof which is open to the ambient atmosphere a shelf-like surface. An absorbent washer, preferably formed of a very clean, particle free absorbent paper is placed on this surface, and preferably held in place by a plastic or metal retainer. Typically, the retainer is pressed in place and held in place by spring force or the like, so that the washer is held tightly against the surface.

Abstract: A spindle motor for use in a disc drive comprises a shaft, bearings located on either end of said shaft, said bearings having inner and outer races, a hub supported on the outer race of said bearings, for rotation therewith, said inner race of said bearings being welded to said shaft, said outer race of said bearings being laser welded to said hub whereby the components of said motor are permanently fixed relative to one another.