Abstract: A component of a disc drive has a coating of a predetermined length on its surface, the coating having at least two separate tapered regions applied in independent steps, the at least two separate tapered regions each having a length that is less than the predetermined length of the component surface. When the component is a shaft of a spindle motor, the ends of the shaft are masked before the tapered regions of coating are applied, and the thickness of the masks covering the shaft ends is varied to control a taper of tapered regions.

Abstract: A compact surface self-compensated hydrostatic bearing includes a rotor assembly including a rotor plate having upper and lower fluid restricting faces, a rotor top and bottom, each having bearing surfaces angled with respect to an axis of rotation of the rotor assembly; a stator assembly including a stator top and a stator bottom housing the rotor assembly therebetween, the stator top and bottom having bearing surfaces facing and spaced apart from the rotor top and bottom bearing surfaces forming upper and lower bearing gaps, respectively, therebetween; the stator top and bottom including a lower and an upper fluid restricting surface, respectively, facing and spaced apart from the rotor upper and rotor lower fluid restricting faces, respectively, forming upper and lower restricting gaps, respectively, therebetween; and a fluid supply system configured to supply pressurized fluid to the bearing gaps and into the upper and lower fluid restricting gaps.

Abstract: A fluid bearing device 40 comprises a sleeve 1, a shaft 2, a thrust plate 4, a radial bearing component 21, and a thrust bearing component 22. A bearing hole 1a is formed in the sleeve 1. The shaft 2 has a shaft main component 5 that is inserted in the bearing hole 1a, and a flange 3 provided on the axial lower side of the shaft main component 5. The thrust plate 4 is fixed to the sleeve 1 and covers the shaft 2 from the axial lower side. A screw hole 5a that is coaxial with the shaft main component 5 is formed in the shaft main component 5 from the end face on the axial upper side toward the axial lower side. An annular concave component 3c that is coaxial with the shaft 2 is formed in the end face on the axial lower side of the shaft 2.

Abstract: An oil dynamic bearing, a motor and a disk drive adapted to be reduced in both size and thickness are disclosed. The oil dynamic bearing (B) includes at least two bearing portions (B1, B2), each having a bearing near end nearer to the rotational axis or the bearing center of the bearing and a bearing far end farther from the rotational axis or the bearing center of the bearing. The near and bearing far ends are each connected to a taper seal portion, which in turn communicates with the atmosphere. The taper seal portion connected to the bearing near end of the bearing portion (B1) and the taper seal portion connected to the bearing near end of the other bearing portion (B2) make up a common taper seal portion.

Abstract: A fluid dynamic bearing design featuring a shaft, a first and second conical bearing affixed, respectively, to a first and second end of the shaft, and asymmetric seals on each bearing. The asymmetric seals pump fluid into reservoirs on the first and second conical bearings.

Abstract: Thus, if a shock or other disturbance to the system occurs that tilts the bearing assembly, the resulting motion is both a tilting, and a motion which is axial. If a shock axially moves the hub assembly, only an axial motion occurs. Thus the system has a non-linear behavior. Pursuant to this invention, when a tilting disturbance occurs, and some of it is dissipated in a net axial movement at a different frequency, energy is subtracted out of the system with motion that is not linearly related to the disturbance was that created it.

Abstract: The invention provides a special type bearing device that is insusceptible to damage, is light in weight, has a long service life and excellent wear resistance, is insusceptible to the effect of change in temperature, is easy to fabricate, and has little offensiveness towards mating members. Further, the same is capable of sufficiently retaining a lubricant such as oil and grease, and retaining the lubricant for a long period of time without the need of supplying oil during operation, thereby rendering it maintenance-free. That is, the special type bearing device as described above has an axial shaft, a pair of rotating bodies fixedly attached to the shaft, and a supporting body with which the rotating bodies are in contact, wherein any one of the shift, the rotating bodies, and the supporting body is made of RB ceramic or CRB ceramic.

Abstract: An oil repelling agent to coat a dynamic pressure device, such as a fluid dynamic pressure bearing device, includes a UV coloring agent, a fluorine-based polymer and a solvent. In an exemplary embodiment of the invention, the concentration of the UV coloring agent component is about 100 PPM to about 400 PPM, and the concentration of the fluorine polymer is about 0.1% by weight to about 0.6% by weight.

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: A fluid dynamic bearing design is provided featuring a rotating shaft with at least one conical bearing formed integrally thereon. The shaft is disposed through a stationary sleeve, and a fluid separates the shaft and sleeve surfaces.

Abstract: A hydrodynamic bearing for use in a spindle motor, having a shaft, a bearing sleeve encompassing the shaft with a small radial space, and a skewback at one end face of the bearing sleeve which is fixedly connected to the bearing sleeve. The shaft features a thrust plate or a conical or cone-like extension at its end face which faces the skewback. The diameter of the conical extension increases in the direction of the end face of the shaft. A bearing gap formed between the shaft and the bearing sleeve is filled with a bearing fluid. Dynamic pressure generating grooves are provided on one of the outer surface of the shaft and the inner surface of the bearing sleeve to generate an excess pressure in the bearing fluid.

Abstract: A fluid dynamic bearing is provided having two surfaces rotatable with respect to each other, a lubricating medium located in a gap between the two surfaces during rotation of the bearing, and an interrupted and offset groove pattern formed on one of the two surfaces to distribute the lubricating medium over the surface of the bearing. The groove design is intended to be useable in either a journal, thrust or other fluid bearing design.

Abstract: A method of manufacturing a fluid dynamic bearing in which a stopper is fixed by welding. The bearing comprises a hub, a shaft erected on the hub, a sleeve, a cylindrical wall erected on the hub, and the stopper mounted on the cylindrical wall. The method comprises a first step to hold oil in the bearing gap, and a second step to locate the stopper on the peripheral wall being apart from the interface of the oil to fix the stopper by LASER welding.

Abstract: A conical hydrodynamic bearing device comprises a shaft bush having a conical inclined dynamic pressure surface around an outer circumference thereof being relatively-rotatably inserted in a bearing sleeve having a conical inclined dynamic pressure surface around an inner circumference thereof, so that a conical inclined bearing space is created in a gap between the inclined dynamic pressure surfaces of the bearing sleeve and shaft bush. A lubricant fluid is filled inside the inclined bearing space. A proper dynamic pressure generating means is formed on at least one of the inclined dynamic pressure surfaces of the shaft bush and bearing sleeve. The lubricant fluid is pressurized by the dynamic pressure generating means to generate dynamic pressure, by which the shaft bush and the bearing sleeve are relatively elevated in the radial and thrust directions so that their rotations are supported in a non-contact manner.

Abstract: A fluid bearing design is provided which according to one aspect includes a shaft defining together with a surrounding sleeve an asymmetric journal bearing, and a thrust bearing at or near an end of the shaft towards which the asymmetric journal bearing is pumping, with that end of the shaft being closed off. The journal bearing asymmetry establishes a hydraulic pressure toward the closed end of the shaft. This pressure provides an axial thrust to set the bearing gap for the conical bearing. The conical bearing itself is a relatively balanced bearing, although it may have a bias pumping toward the shaft and the journal bearing. A pressure closed equalization path from the journal bearing through the conical bearing to the end of the shaft may be established to maintain a constant hydraulic force across the conical bearing, and which may also prevent any asymmetry in the conical bearing from affecting the net thrust force acting upon the end of the shaft where the conical bearing is located.

Abstract: Hydrodynamic bearing for use in a spindle motor includes a shaft, a bearing sleeve encompassing the shaft with a small radial clearance, a plurality of hydrodynamic pressure generating grooves formed on at least one of an outer surface of the shaft and an inner surface of the bearing sleeve, and a base-plate, flange or another frame element of the motor. The bearing sleeve is constructed as a single component with the frame element of the motor.

Abstract: A hydrodynamic bearing system for use in spindle motors having a shaft and a bearing sleeve. At least one bearing member is mounted an outer surface of the shaft. A fluid trap member is further provided in the bearing system, the fluid trap member being integrated into the bearing member. A fluid trapping cavity is formed between the fluid trap member and a surface of the bearing member.

Abstract: A fluid dynamic bearing cartridge includes a shaft or sleeve adapted to be fixed in place has at least one fluid dynamic bearing supporting the shaft and one or more seals at either end of the shaft. The seal arrangements may include a pair of centrifugal capillary seals at either end of the shaft. Alternatively, a grooved pumping seal or centrifugal capillary seal at one end may be used in combination with a static capillary seal, especially where a journal bearing defined along the shaft near the capillary seal has an imbalanced groove section.

Abstract: A method and apparatus is provided for allowing a molecularly thin film to be established on a surface of the gas fluid dynamic bearing. The film can be controllably replenished so that the problem of liquid lubricant starvation is overcome. A suitable non-sludging lubricant of low surface tension is held in a porous reservoir within the stationary portion of the bearing. This fluid migrates out of the reservoir to coat the contiguous bearing surfaces. Alternatively, the lubricant may be held in a porous reservoir within the rotating portion of the bearing; due to centrifugal force, as the rotating portion spins, the fluid is spun out and coats the opposite non-rotating surface. The reservoir may be replaced by a singular reservoir such as a simple hole, depression, cavity or groove filled with lubricant.

Abstract: A bearing having a conical hydrodynamic bearing section and a pivot bearing section. The bearing can be used with a spindle motor. The conical hydrodynamic bearing section is formed by the conical portion of the shaft and a correspondingly shaped cavity of the bearing sleeve. The pivot bearing section is located adjacently to the conical bearing section and is formed by the curved end face of the shaft and an endplate inserted into the cavity of the bearing sleeve.

Abstract: A bearing system in which an axially stiff narrow gap fluid dynamic gas bearing is preloaded by an axially less stiff larger gap fluid dynamic bearing. As an example two fluid dynamic bearings are provided spaced apart along a shaft, radially aligned with an air/gas filled spherical or conical or similar type bearing. A shaft end thrust bearing is also defined for axial support.

Abstract: The invention is a fluid dynamic bearing motor featuring a stationary assembly supported from a base, a rotating assembly supported on the stationary assembly, a fluid dynamic bearing in a gap between the stationary and rotating assemblies, a radial capillary seal is defined proximate a first end of the gap, and at least one re-circulation hole extending from the radial capillary seal to a second end of the gap.

Abstract: A bearing system in which an axially stiff narrow gap fluid dynamic gas bearing. As an example two fluid dynamic bearings are provided spaced apart along a shaft, one of the bearings comprising a fluid dynamic bearing, the other comprising an air bearing. The fluid dynamic bearing has a larger gap, while the air bearing has a relatively small gap. The overall working surface area of the air bearing may be twice as much or more than the working surface area of the fluid bearing.

Abstract: A fluid dynamic bearing assembly including a shaft and a bearing sleeve. A bearing gap is formed between the shaft and the bearing sleeve and is filled with a lubricating fluid. A reservoir containing the excess of the lubricating fluid is formed at one end of the bearing sleeve. The reservoir is not located in close proximity to the shaft. A fluid trapping recess is formed in the shaft, the fluid trap being configured to prevent migration of the lubricating fluid along the shaft into the environment.

Abstract: In a plain bearing for the transmission of high axial forces and great flexural moments with slight relative movements the one co-operating bearing component has an annular rib which engages into an annular groove provided on the other co-operating bearing component. The annular rib which can be of an outwardly convergent trapezoidal cross-section is provided with anti-friction linings on its free side faces and possibly peripheral faces. The anti-friction linings, like the co-operating bearing component in question, in particular an outer ring carrying the annular rib, can be subdivided segment-like. The segments can then be released individually from their composite assembly and maintained, in particular provided with new anti-friction linings. A preferred use of this plain bearing is the arrangement thereof between a pylon-supported machine head and the pylon head of a wind power installation.

Abstract: A bearing system in which an axially stiff narrow gap fluid dynamic gas bearing is preloaded by an axially less stiff larger gap fluid dynamic bearing. As an example two fluid dynamic bearings are provided spaced apart along a shaft, one of the bearings comprising a fluid dynamic bearing, the other comprising an air bearing. The fluid dynamic bearing has a larger gap, while the air bearing has a relatively small gap. The overall working surface area of the air bearing may be twice as much or more than the working surface area of the fluid bearing.

Abstract: Spindle-motor hydrodynamic bearing configuration having conical taper seals on the thrust-bearing ends. The spindle motor shaft is supported in a bore through the rotor by neighboring radial and thrust hydrodynamic bearings constituted through radial micro-gaps cylindrically between the shaft and rotor, axial micro-gaps between thrust plates on either shaft end and recesses endwise in the rotor bore, dynamic-pressure-generating grooves in the micro-gap forming surfaces, and lubricant retained continuously in the radial and axial micro-gaps. The thrust plates are at least partially conical, tapering axially outward. A ring fitted in each rotor bore recess has a conical inner peripheral surface corresponding to the opposing conical surface of the thrust plate, forming a taper seal sloped with respect to the rotational axial center of the motor. The gap clearance dimension gradually expands heading axially outward, wherein the lubricant forms an axial-end gas-liquid interface to function as a taper seal.

Abstract: A very thin lubricant coating is applied to one or both of the facing surfaces defining the gap of a hydrodynamic bearing to prevent wear of these surfaces. The lubricant film is necessarily very thin, in the range of about 10 Å to 1000 Å, so that the film is thin enough that it does not materially affect the performance of the hydrodynamic bearing gap which is about typically 1-10 &mgr;m. The thin lubricant film could be a perfluoropolyether (PFPE) or a mixture of PFPE or a phosphazine derivative. To improve the adhesion and lubricating performance, functional PFPE can be used. For pure metallic surface like steel, phosphate esters can also be used because of its affinity with the metallic surface, e.g., ferrous. For example, the film could be PFPE, or a mixture of PFPE and a phosphazine derivative. The lubricant should be chosen to be thermally stable, and non-reactive with the typical ambient environment.

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: 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 method and apparatus is provided for allowing a molecularly thin film to be established on a surface of the gas fluid dynamic bearing. The film can be controllably replenished so that the problem of liquid lubricant starvation is overcome. A suitable non-sludging lubricant of low surface tension is held in a porous reservoir within the stationary portion of the bearing. This fluid migrates out of the reservoir to coat the contiguous bearing surfaces. Alternatively, the lubricant may be held in a porous reservoir within the rotating portion of the bearing; due to centrifugal force, as the rotating portion spins, the fluid is spun out and coats the opposite non-rotating surface. The reservoir may be replaced by a singular reservoir such as a simple hole, depression, cavity or groove filled with lubricant.

Abstract: A hub and shaft are provided which are mounted for relative rotation by providing two conical bearings spaced apart along the shaft, and a bearing seat facing each conical bearing. Fluid is maintained in the gap between each cone and the facing bearing seat, supporting the cone and seat for relative rotation. The outer surface of the bearing seat is insulated from the remainder of the motor by a thermal insulator which extends at least part way along the outer surface of the seats. This insulator is effective at keeping the bearings warm even in a relatively low temperature environment in which the motor may be used. The insulator may comprise a cylindrical ceramic or similar low thermal conductivity material extending at least part way along the axial distance outside of the bearing cones. Alternatively, an air space may be defined in the outer surface of the bearing seat, extending at least part way between the bearing cones.

Abstract: A method and apparatus for a conical bearing is provided having a seal shield having an angle supported from the hub or sleeve which surrounds the shaft, and extending at an angle toward the outer surface of the shaft and spaced slightly away from the upper angular surface of the cone. As the cone and seal shield rotate relative to one another, fluid is drawn toward the lower inner region of the reservoir. However, due to shock or the like, some fluid may reach the radial gap between the end of the shield and the outer surface of the shaft, therefore, a ring is either incorporated into the upper end of the cone or pressed against the axial outer end of the cone, defining an axial gap which is smaller than the radial gap. In a preferred form of the invention, the ratio is about 1:3.

Abstract: A seal and bearing apparatus for a rotating shaft including a pair of sleeves with two spiral grooves (14) on an inclined surface (16).

Abstract: A disc drive storage system includes a housing having a central axis, a stationary member that is fixed with respect to the housing and coaxial with the central axis, and a rotatable member that is rotatable about the central axis with respect to the stationary member. A hydro bearing interconnects the stationary member and the rotatable member and includes a lubricating fluid having a base fluid and an additive for reducing the tendency of bubble formation in the lubricating fluid.

Abstract: A fluid dynamic bearing design featuring a shaft, a first and second conical bearing affixed, respectively, to a first and second end of the shaft, and asymmetric seals on each bearing. The asymmetric seals pump fluid into reservoirs on the first and second conical bearings.

Abstract: The cone which is pressed onto or otherwise affixed to the shaft to cooperate with the sleeve to form a conical hydrodynamic bearing is modified to provide a flat surface at the axially outer end of the cone most distant from the conical surface which is used to form the conical bearing in cooperation with the bearing seat of the sleeve and the intervening fluid. The sleeve surface facing the second angled surface of the bearing cone is modified to diverge more sharply away from the second surface of the cone, or to simply be spaced further away. In this way, a larger reservoir is formed, diminishing the possibility of oil evaporation and oil loss. Finally, a relatively flat shield is supported from the sleeve overlying the flat upper surface of the cone. The divergence of the upper bearing cone surface from the surrounding sleeve also allows for filling the bearing before the shield is installed.

Abstract: The present invention relates to the field of fluid dynamic bearings. Specifically, the present invention provides a secondary fluid reservoir for the fluid used in a fluid dynamic bearing in a high-speed spindle motor assembly.

Abstract: The present invention relates to the field of fluid dynamic bearings. Specifically, the present invention provides a secondary fluid reservoir for the fluid used in a fluid dynamic bearing in a high-speed spindle motor assembly.

Abstract: A single cone fluid dynamic bearing motor, including a shaft having a diminishing conical taper surface, a sleeve having a concavity opposite the shaft, lubricant filled in a clearance between the shaft and the sleeve, and magnetic members to generate magnetic attraction between one end of the shaft and a cone apex of the sleeve. Grooves are formed on the conical taper surface of the shaft or the sleeve so as to create load capacity when the motor rotates, whereby rotating parts of the motor are supported by the axial components of the load capacity balanced with the magnetic attraction. The motor thereby achieves reduction in thickness, current, and cost, and inhibits non-repeatable runout.

Abstract: A fluid dynamic bearing design is provided featuring a rotating shaft with at least one conical bearing formed integrally thereon. The shaft is disposed through a stationary sleeve, and a fluid separates the shaft and sleeve surfaces.

Abstract: A fluid dynamic bearing cartridge includes a shaft or sleeve adapted to be fixed in place has at least one fluid dynamic bearing supporting the shaft and one or more seals at either end of the shaft. The seal arrangements may include a pair of centrifugal capillary seals at either end of the shaft. Alternatively, a grooved pumping seal or centrifugal capillary seal at one end may be used in combination with a static capillary seal, especially where a journal bearing defined along the shaft near the capillary seal has an imbalanced groove section.

Abstract: The present invention provides a bearing comprised of a conical hydrodynamic bearing and a pivot bearing, which can be used with a spindle motor. It also provides a spindle motor utilizing a conical hydrodynamic bearing and a pivot bearing.

Abstract: The shaft may be supported for rotation by a conical bearing rotating within a sleeve. To prevent misalignment of the rotor and stator as the motor heats up and fluid viscosity changes, a magnetic preload is established; in a preferred embodiment, the magnetic preload is achieved using a magnetic back iron aligned with the stator magnet, the magnetic back iron being supported from the base. The shaft may further include a lower journal bearing for maintaining radial alignment and/or stiffness.

Abstract: A bearing system in which an axially stiff narrow gap fluid dynamic gas bearing. As an example two fluid dynamic bearings are provided spaced apart along a shaft, one of the bearings comprising a fluid dynamic bearing, the other comprising an air bearing. The fluid dynamic bearing has a larger gap, while the air bearing has a relatively small gap. The overall working surface area of the air bearing may be twice as much or more than the working surface area of the fluid bearing.

Abstract: A bearing system in which an axially stiff narrow gap fluid dynamic gas bearing is preloaded by an axially less stiff larger gap fluid dynamic bearing. As an example two fluid dynamic bearings are provided spaced apart along a shaft, one of the bearings comprising a fluid dynamic bearing, the other comprising an air bearing. The fluid dynamic bearing has a larger gap, while the air bearing has a relatively small gap. The overall working surface area of the air bearing may be twice as much or more than the working surface area of the fluid bearing.

Abstract: A hydrodynamic bearing is provided comprising a shaft having a pair of spaced apart conical bearings supporting a surrounding sleeve for rotations. The sleeve comprises a single piece rather than the two-piece design separated by a rubber expansion joint of the prior art. Instead upper and lower slots are cut into the sleeve, and the rings are pressed or otherwise tightly fitted into each slot. The single piece sleeve which also incorporates the bearing seats for the conical bearings on the shaft, is made of aluminum, while each ring is made of steel (as is the shaft and bearing cones). As the temperature rises at which the hydrodynamic bearing is operated, the sleeve expands axially putting the bearing seat closer to the cone, effectively compensating for the thinning of the fluid which supports the bearing seat and sleeve for rotation relative to the cone. Meanwhile, the steel ring, being of the same material as the shaft, prevents the aluminum sleeve from expanding radially away from the cone.

Abstract: A protective coating is applied to an inner or an outer member of a rotary fluid bearing by sputtering to minimize scuffing, wear and premature failure of the members during starts and stops of the bearing. The coating may include titanium, tungsten, chromium, amorphous carbon with or without metallic impurities, and hydrogenated amorphous carbon with or without metallic impurities. One of the members is formed in two sections to accommodate assembly of the bearing and these sections abut at end faces. Features on each end face are imparted to the other end face in a compression coining process to facilitate rapid and repeatable alignment of the two sections when separated and rejoined during subsequent manufacturing steps.

Abstract: A hydrodynamic type bearing unit comprises a shaft member 2, a bearing member 4 and a bearing clearance formed between the shaft member 2 and a bearing member 4 to produce a hydrodynamic pressure during the rotation of a shaft member 2. The bearing clearance is composed of a first clearance C1 on one axial side and a second clearance C2 on the other axial side and the first and second clearances C1 and C2 are mutually oppositely inclined against an axial direction.

Abstract: A protective coating is applied to an inner or an outer member of a rotary fluid bearing by sputtering to minimize scuffing, wear and premature failure of the members during starts and stops of the bearing. The coating may include titanium, tungsten, chromium, amorphous carbon with or without metallic impurities, and hydrogenated amorphous carbon with or without metallic impurities. One of the members is formed in two sections to accommodate assembly of the bearing and these sections abut at end faces. Features on each end face are imparted to the other end face in a compression coining process to facilitate rapid and repeatable alignment of the two sections when separated and rejoined during subsequent manufacturing steps.