Abstract: A dynamic pressure bearing device includes a dynamic pressure face of a shaft member, a dynamic pressure face of a bearing member, lubricating fluid filled in a bearing space of a dynamic pressure bearing portion including a gap between the dynamic pressure faces, a dynamic pressure generation means for pressing so that the lubricating fluid generates a dynamic pressure that supports the shaft member in a non-contact manner with the bearing member and in a rotatable manner relatively to the bearing member, and a sliding surface layer having abrasion resistance provided to at least one of the dynamic pressure face of the shaft member and the dynamic pressure face of the bearing member.

Abstract: A pair of thrust hydrodynamic bearing portions are made to communicate with each other to form fluid circulating passages for equalizing a pressure imbalance between both thrust hydrodynamic bearing portions. Even in a case where a pressure imbalance has occurred in a lubricating fluid inside the thrust hydrodynamic bearing portions due to such a cause as the deformation of a thrust plate, the lubricating fluid is allowed to move between the pair of upper and lower thrust hydrodynamic bearing portions through the fluid circulating passages so as to overcome the pressure imbalance, thereby making it possible to stably obtain the amount of floatation in the thrust hydrodynamic bearing portions.

Abstract: In the present invention, in order to provide a fluid dynamic bearing, having heat resistance, wherein the electrical charging on a rotation portion is prevented and the torque loss caused by a lubricant is made lower, an ionic liquid or the like is added to the lubricant filled in the clearance between the opposed faces of a shaft and a sleeve unit as an electrical conductivity imparting agent.

Abstract: A method of assembling a motor comprising assembling the shaft and thrust plate to be used in the fluid dynamic bearing assembly, and at least partially inserting the combined shaft and thrust plate into a sleeve which is adapted to support a hub which in turn may support one or more disks for rotation in a disc drive or similar environment. A counterplate cup of a generally U shaped or cup shaped design including a base which is substantially parallel to a top surface of the thrust plate, and sides of a diameter which is slightly greater than the diameter of the thrust plate and which are parallel to the thrust plate is provided, filled with oil, and having its open end facing the thrust plate.

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: A gas lubricated axial thrust bearing for resisting axial forces acting on a machine rotor, comprises at least one pad mounted on a stationary machine surface and axially spaced from a surface of the rotor by a lubricating gas film. The bearing further includes a temperature sensor for sensing the temperature of the pad to provide an output signal indicative of the axial load on the bearing.

Abstract: A composite fluid dynamic bearing and its manufacturing method is disclosed. By machining a plurality of bearings independently, the grooves of each bearing have uniform slopes. Then the method of the invention combines the bearings, which have different slope of the grooves, to form a bearing module having pressure-generating grooves. In this way the precision of the machining grooves of bearings can be improved.

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 density of the UV coloring agent component is about 100 PPM to about 400 PPM, and the density of the fluorine polymer is about 0.1% by weight to about 0.6% by weight.

Abstract: A bearing member and a dynamic pressure bearing device using the bearing member includes a cylindrical body constituting a bearing member that rotatably supports a shaft member. The cylindrical body is made of a copper metal, and an anti-rust film comprising cupric benzotriazole is formed on the surface of the cylindrical body.

Abstract: A fluid dynamic bearing module for cooling fans connects the fixed part and the rotating part of a cooling fan and provides lubrication and support when the rotating part rotates relative to the fixed part. In the design of the invention the fluid dynamic bearing is a module that utilizes a bearing seat, a wear-resistant element and an anti-lift element to make the bearing module leak-proof, lift-proof, wear-resistant and able to create a balance of the lubricant and air.

Abstract: A disc drive design comprising a shaft and sleeve supported for relative rotation by a journal type fluid dynamic bearing utilizing grooves on one of the shaft or sleeve surfaces. At least a part of the shaft is generally conical in cross-section, so that a downward force component is developed to balance upward pressure on end of shaft; this conical region typically includes a fluid dynamic bearing (grooves being on either the shaft or sleeve). A grooved pattern of a design similar to that usually found on a thrust plate may be defined on an axial end surface of the shaft or the counterplate facing the axial end of the shaft, so that thrust is created to maintain separation of the end of the shaft and the facing counterplate plate during relative rotation. A diamond-like coating (DLC) may be applied to the counterplate surface or to the end of the shaft; further, either the counterplate or shaft may be made out of ceramic material to enhance this performance.

Abstract: This invention is to provide a hydrodynamic bearing assembly, which realizes the high rotation rate in a stable manner and the robust rigidity. The hydrodynamic bearing assembly has a total radial gap of 3 microns or less for preventing the contact in the thrust bearing. The thrust bearing is a pomp-out type one, and the radial bearing has offset grooves on the surface thereof to supply the fluid flow sufficiently to the thrust bearing. The grooves also eliminate a half-whirl. A depth ratio relative to the diameter of bearing is preferably 0.005 or less to avoid the reduced translation rigidity. The radial gap is smoothly enlarged from the center to both ends along the axis, and the shaft is biased to incline the shaft relative to the sleeve, so that the shaft can be rotated with the robust rigidity. Also, a pair of the thrust bearings is provided on both ends of the radial bearing so as to realize the robust rigidity.

Abstract: A reliable hydrodynamic bearing having high rotational accuracy is offered. The hydrodynamic bearing for a small-sized motor is made of a special nonmagnetic steel material that is excellent in terms of machinability, wear resistance, and corrosion resistance. This special steel material contains 14.00% Cr, 8.00% Mn, 0.20% C, 2.00% Ni, 0.35% Si, and less than 0.05% P. This special steel material has high machinability and so machining accuracies such as surface roughness and squareness can be enhanced. Consequently, the rotational accuracy of the hydrodynamic bearing can be enhanced. This special steel material also has such a property that when pressure is applied to plastically deform it, the pressed surface hardens. Using this nature, the surfaces at which rotating and stationary parts of the bearing contact with each other are pressed. Thus, the surfaces are hardened. Hence, the wear resistance is improved.

Abstract: To provide a manufacturing method of a dynamic pressure bearing device and a dynamic pressure bearing device to inject a proper amount of lubricating oil to a bearing unit by using a simple process without leaving air bubbles in the bearing unit. The bearing unit is exposed in an atmosphere of reduced pressure such as in a vacuum chamber or the like to evacuate air in a gap between a shaft body and a bearing. The proper amount of lubricating oil is dropped to an open end of the gap of the bearing unit by using a dispenser. The bearing unit is released to an atmospheric air to fill the lubricating oil into a gap of the bearing unit.

Abstract: A hydrodynamic thrust bearing, particularly forming a part of a bearing system for a rotary bearing of spindle motors utilized to power hard disk drives. The thrust bearing includes at least one annular thrust plate and a counter bearing corresponding to the thrust plate, wherein the thrust plate is firmly connected to a shaft rotatably supported by means of a radial bearing system. The thrust plate is arranged on the shaft which has an axial bore in the area where the thrust plate is to be positioned. A fixing element affixing the thrust plate to the shaft is pressed into the axial bore of the shaft. The outer diameter of the fixing element is greater than the inner diameter of the axial bore. This type of press connection between the thrust plate and the shaft allows thinner thrust plates to be utilized with the performance of the thrust bearing remaining the same or improving.

Abstract: A bearing apparatus includes a rotating member, a fixed member opposing the rotating member and an ink-like resin material. Opposing surfaces of the rotating member and the fixed member form a bearing part and the ink-like resin material is applied to at least one of the opposing surfaces by transfer printing.

Abstract: A fluid dynamic bearing has a shaft (11) fitted in a sleeve (12) for rotation, with a fluid filled therebetween. The shaft (11) and/or sleeve (12) is formed with a pattern consisting of grooves (111g) and lands for generating a pressure distribution in the fluid and then covered with a diamond-like carbon film (11c) over the surface of the grooves and the surface of the lands.

Abstract: A bearing material includes: a backing metal made of stainless steel; and a porous sintered metal layer integrated with at least one surface of the backing metal by means of a bonding layer, particles of an inorganic substance being contained in a dispersed manner at grain boundaries of the porous sintered metal layer, wherein the porous sintered metal layer containing the particles of the inorganic substance are composed of 4 to 10% by weight of tin, 10 to 40% by weight of nickel, not less than 0.1 and less than 0.5% by weight of phosphorus, and the balance consisting of copper.

Abstract: A fluid bearing device achieves superior in wear start-stop resistance and in manufacturing ability. The fluid bearing device includes a shaft having a flange portion, a sleeve opposing to the shaft across a fluid bearing clearance of a radial fluid bearing, a counterpart member opposing to at least one of plane of the flange portion across a fluid bearing clearance of a thrust bearing. The flange portion and the sleeve portion being formed of copper alloy of mutually difference composition.

Abstract: A washer in accordance with the present invention mainly comprises an axial hole and a plurality of oil-bearing holes. The oil-bearing holes are connected an outer surface of the washer to an inner surface, and surround the axial hole.

Abstract: The fixed shaft type spindle motor of the invention has a fixed shaft vertically installed on a base and a rotor hub supported to freely rotate by the fixed shaft through a bearing. The bearing is composed of a compound ball bearing, and a larger diameter portion of a stepped top-form connection member having the larger diameter portion and a smaller diameter portion is fixedly engaged with the upper end of the outer ring of the compound ball bearing. And, the smaller diameter portion of the connection member is fastened to the rotor hub. The rotary shaft type spindle motor has a rotary shaft vertically installed on the rotor hub, in which the rotary shaft is supported to freely rotate on the base through the bearing. The bearing is composed of a compound ball bearing, and the larger diameter portion of the stepped top-form connection member having the larger diameter portion and the smaller diameter portion is fixedly engaged with the lower end of the outer ring of the compound ball bearing.

Abstract: A ceramic dynamic-pressure bearing having dynamic-pressure grooves. At least a portion including a surface (dynamic-pressure gap definition surface) facing a dynamic-pressure gap is formed of ceramic, and dynamic-pressure grooves GV are formed, by electrolytic etching, on the ceramic dynamic-pressure gap definition surface such that, on a cross section of the groove GV taken perpendicular to the longitudinal direction of the groove GV, a curvature portion R having a radius of 3-7 &mgr;m is formed at a meeting position where a groove sidewall surface SG and a groove bottom surface BG meet. In a preferred embodiment, a large number of pores K are formed on one or more of the rotary surfaces M of the dynamic-pressure bearing formed of ceramic such that the surface porosity falls in the range of 10 to 60%.

Abstract: The present invention relates to a dynamic pressure-type liquid bearing unit which can prevent lubricating oil from flowing outside by discharging air that is trapped in the bearing. A sleeve and a thrust plate that is attached to one end side of the sleeve sandwich a thrust bearing leaving a gap around the thrust bearing. Unsymmetrical herringbone-shaped dynamic pressure-generating grooves are formed on at least one of the outer circumferential surface of the stationary shaft and the inner circumferential surface of the sleeve. A first capillary sealing portion is formed between one end of the stationary shaft and the sleeve, and a second capillary sealing portion is formed between the other end of the stationary shaft and the thrust plate. Groove portions for removing air are formed between the first capillary sealing portion and the second capillary sealing portion.

Abstract: The invention concerns an open-end spinning apparatus with a spin-rotor, the shaft of which is supported by an aerostatic, radial bearing with an air gap between the bearing assembly and the shaft. The construction material for the bearing surface of the spin-rotor and/or the bearing surface of the radial bearing is polyimide or aramid.

Abstract: Disclosed is a sealing structure for a motor using a kinetic pressure bearing, capable of improving productivity by reducing assembling time through modification in the sealing structure of the bearing, and of extending life of a motor, improving performance of a motor by more effectively preventing leakage of an oil in the interior of the bearing, to the outside.

Abstract: An annular groove portion is integrally formed for preventing splashing of the lubricating oil by extending from a mount base (10) of the motor rotor to the motor shaft (6) to the metal bearing (5) and the radial ball bearing (20), allowing a spacer member (15) making contact with an inner ring (20a) of the radial ball bearing (20) to be attached inside the annular groove portion.

Abstract: A highly reliable liquid bearing unit is provided, which can, by securely repelling a lubricant by an oil repelling film, prevent the lubricant from leaking and a magnetic disk device mounted therewith. In a case where the lubricant contains a constituent of at least one of a hydrocarbon-based oil and an ester-based oil and the oil repellent film is a film of at least one of a fluorine base and a silicone base, surface tension of the lubricant is made greater than the critical surface tension of the oil repellent film by 5 mN/m or more. Moreover, when the lubricant is a fluorine-based lubricant, surface tension of the lubricant is made greater than the critical surface tension of the oil repellent film by 8 mN/m or more.

Abstract: The housing made of a resin composition is formed by injection molding with a sintered metal bearing sleeve as an insert piece. The housing includes a cylindrical body part, a sealing portion extending from the top of the body part radially inwards, and a bottom part closing the lower end of the body part. Of these, the body part and bottom part are integrally formed, to which the sealing portion is welded.

Abstract: The present invention has its object to provide a hydrostatic gas bearing excellent in a vibration-damping characteristic. The hydrostatic gas bearing is provided with a gas ejecting equipments composed of a cylindrical fine hole having a diameter of not less than 0.04 mm and not more than 0.4 mm,wherein a helium gas is ejected through the cylindrical fine hole. The cylindrical hole has a diameter D and a length L, and in the case where a relationship of D4/L is not more than 2×10−4 mm3 is established, the hydrostatic gas bearing excellent in the vibration-damping characteristic is specifically realized.

Abstract: A hydrodynamic bearing device with reduced costs is provided. A housing with a bearing sleeve housed therein is formed by drawing. A cup shaped thrust member is positioned in a bottom part of the housing, and by bringing this thrust member into contact with a lower end surface of the bearing sleeve, the widths of thrust bearing gaps within first and second thrust bearing parts are set to prescribed values.

Abstract: A production method for a sintered bearing, comprises compacting a raw metallic material powder into a bearing green compact; sintering the green compact into a sintered compact; and forming a resin coating over the entire surface of the sintered compact by electrodeposition.

Abstract: Disclosed is a spindle device endowed with a sufficient load capacity for bending moment and capable of reducing power loss and heat generation of the main shaft attributable to the radial dynamic pressure bearing. In this spindle device, the rotation of the spindle rotor is supported by a pair of radial dynamic pressure bearing portions, between which there is provided a first cooling chamber so as to circumferentially surround the spindle rotor, atmosphere outside the housing being introduced into the first cooling chamber.

Abstract: A hydrodynamic bearing having a shaft, which is fixedly connected at one end to a rotating component, and a bearing sleeve, which encompasses the shaft at its other free end with a slight clearance. The sleeve and the shaft form a concentric bearing gap. The shaft and/or the bearing sleeve is provided with at least one groove pattern which forms at least one radial hydrodynamic bearing. A volume equalizing cavity and at least one connecting passage connecting the bearing gap with the volume equalizing cavity extend radially outwards at an angle to the bearing gap.

Abstract: A hydrodynamic bearing having a shaft (10) and a bearing sleeve (12), which encloses the shaft with a slight radial clearance forming a concentric bearing gap. An equalizing volume cavity (20) is formed at at least one end of the bearing. At least one micro-passage (26) connects the bearing gap via appropriate openings with the equalizing volume cavity (20). Bearing fluid completely fills the bearing gap (24) and the micro-passage (26) and at least partially fills the equalizing volume cavity (20). The bearing fluid forms a continuous fluid film between the bearing gap (24) and the equalizing volume cavity (20).

Abstract: A dynamic pressure bearing apparatus provides a configuration in which the label on which desired data is visibly printed is arranged in a manner that the label does not overlap with a cover plate at least in the area where the label faces the rotary shaft in the shaft direction where the cover plate covers the opening of the bearing sleeve. Deformation of the cover plate that may occur during attachment of the label onto the cover plate is thus prevented. The position of the cover plate is leveled with the position of the label, which makes height reduction of the bearing apparatus possible. Subsequently, even when a relatively thick label is attached onto the frame, the dynamic pressure bearing apparatus can still be made thinner without adversely affecting performance or life thereof.

Abstract: A sintered bearing is produced by a production method comprising: compacting a metallic raw material powder into a bearing green compact; sintering the green compact into a sintered compact; forming a resin coating 20 over the entire surface of the sintered compact; removing the resin coating 20 on a bearing surface 14a of the sintered compact; and impregnating a lubricating fluid L through the bearing surface 14a from which the resin coating 20 is removed.

Abstract: The fixed shaft type spindle motor of the invention has a fixed shaft extending from a base and a rotor hub rotatably supported thereon through a bearing. Where the bearing is a compound ball bearing, a larger diameter portion of a stepped connection member is fixed within the upper end of the outer ring of the compound ball bearing and a smaller diameter portion of the connection member is fixed to the rotor hub. The rotary shaft type spindle motor has a rotary shaft extending within the rotor hub, and the rotary shaft is rotatably supported through the bearing, with the larger diameter portion of the connection member fixed within the lower end of the outer ring of the compound ball bearing and the smaller diameter portion of the connection member fixed to the base.

Abstract: An oil dynamic pressure bearing device comprises a bearing, a shaft freely rotatably supported by the bearing in a non-contact manner, and a dynamic pressure bearing section defined by at least one dynamic pressure groove on at least one side of the shaft and the bearing for generating dynamic pressure by a lubricant fluid filled in a minute gap between the shaft and the bearing. Grinding scratches are formed on the dynamic pressure bearing section in a circumferential direction of the dynamic pressure bearing section. The dynamic pressure groove may be formed only on one side of either the shaft or the bearing at the dynamic pressure bearing section and the grinding scratches are formed only on the other side.

Abstract: A motor and a method of manufacturing the motor are provided for preventing undesirable deformation of the sleeve hole caused by a press fitting force during press fitting process, thus facilitating the assembly process and improving the productivity. A recess is formed on an inner peripheral wall of a center cylindrical portion at the center of a flange body. When press fitting a sleeve body into a hole (sleeve fitting hole) of a flange assembly unit for integrating both members, the annular recess of the flange assembly unit serves to reduce the contact area between the sleeve body and the flange body. The press fitting force exerted to the contact area is reduced. Therefore the deformation of the inner diameter of the sleeve body that has been press fitted is minimized, thus suppressing deformation of the inner diameter portion of the sleeve body and the flange body.

Abstract: A bearing unit comprises a bearing 60 formed of a sintered metal in which a magnetized magnetic powder is dispersed in its matrix and at least pores exposed on a bearing surface thereof are sealed by impregnation with a resin; a non-magnetic housing 90 accommodating the bearing 60; and a lubricating fluid M made of a magnetic fluid.

Abstract: A hydrostatic bearing device for two machine areas moving relative to each other and having faces parallel to each other with a fluid space delimited by parts of the two different machine areas and forming a gap. The fluid is under pressure in the fluid space. The gap between the two machine areas is blocked by means of a seal having a tapered end against one machine area and wherein the pressure reservoir maintains the fluid under pressure in the fluid space.

Abstract: In a cylindrical sliding bearing, a radial rigidity of an inner circumferential surface of a sliding layer against a radial compression force applied to the inner circumferential surface by a shaft varies in a circumferential direction so that the inner circumferential surface includes a relatively-high radial rigidity bearing area and a relatively-low radial rigidity bearing area.

Abstract: A typical dynamic bearing design comprises a ring shaped or circular thrust plate mounted at or near the end of a shaft, the shaft defining together with a surrounding sleeve a journal bearing by providing grooves on only one of the two surfaces facing the gap between the shaft and sleeve. On the ring shaped thrust plate supported by the shaft, the traditional upward thrust bearing defined between the lower face of the thrust plate and the facing surface of the sleeve is maintained; but no grooves are on the surface of the thrust plate distant from the shaft and a facing counterplate surface. Further, the journal bearing is defined to have an asymmetry so that a bias force pressure along the surface of the shaft toward the thrust plate is established.

Abstract: A ceramic dynamic-pressure bearing which is not prone to wear or a like problem associated with starting, stopping, or a like operation mode and which can realize smooth rotation. A dynamic-pressure gap 17 is formed between a first member 14 and a second member 15, which undergo relative rotation about a predetermined axis of rotation. The relative rotation of the first member 14 and the second member 15 generate fluid dynamic-pressure in the dynamic-pressure gap 17. At least a portion of one or both of the first member 14 and the second member 15 includes a polished surface (a dynamic-pressure gap definition surface) formed of alumina ceramic facing the dynamic-pressure gap 17, and the alumina ceramic, which forms the dynamic-pressure gap definition surface finished by polishing, is adjusted to have an apparent density of 3.5-3.9 g/cm3. Also disclosed is a motor, hard disk drive and polygon scanner containing the bearing.

Abstract: A ceramic dynamic pressure bearing comprising a first member and a second member, wherein the first member and the second member define a dynamic pressure gap therebetween, the first member and the second member relatively rotate around an axis of rotation, the relative rotation generates a fluid dynamic pressure in the dynamic pressure gap, the first member has a first surface directing to the dynamic pressure gap and the second member has a second surface directing to the dynamic pressure gap, and at least one of the first and second surfaces comprises ceramic, the ceramic comprises: a ceramic matrix that is selected from alumina ceramic, zirconia ceramic and silicon nitride ceramic; and 15 vol % to 70 vol % of an electrically-conductive inorganic compound phase based on the total amount of the ceramic, the phase is dispersed in the ceramic matrix, the phase comprises at least one compound selected from tungsten carbide, silicon carbide, conductive oxide, metallic nitride, metallic carbide, metallic boride,

Abstract: According to the present invention, a cylindrical side wall is provided in a housing so as to surround an outer periphery of a stopper member. Further, an end surface of the side wall is higher than a top surface of outermost periphery of the stopper member. Oil otherwise scattered is received by the side wall for collection. Oil is thus prevented from scattering even if during manufacturing, the amount of oil dripped between the shaft and the oil-impregnated bearing is not strictly controlled, so that a slightly excessive amount of oil is dripped. Therefore, the present motor device enables manufacturing operations to be favorably performed, and is reliable having a long lifetime.

Abstract: A hydrodynamic bearing according to the present invention comprises a rotary shaft having a convex portion provided at one end portion thereof, a sleeve which rotatably supports the rotary shaft, and having herringbone grooves formed in an inner wall thereof at positions, a thrust bearing which is provided in contact with an end portion of the rotary shaft on the convex portion side and restricts movement of the thrust bearing or the rotary shaft in an axial direction thereof, and a lubricant sealed in a space surrounded by the rotary shaft, the sleeve and the thrust bearing.

Abstract: A dynamic pressure bearing device, comprising:

Abstract: A hydro dynamic gas bearing having a sleeve with one end closed and connected to a front end of a shaft supported at its proximal end relative to a base on a fixed side, a plurality of hydro dynamic pressure generating grooves on at least one of an outer peripheral surface of the shaft and an inner peripheral surface of the sleeve opposite the outer peripheral surface, and a through hole communicating with the outside of the base extending from the front end to the proximal end of the shaft, the through hole having an air vent for adjusting pressure between the shaft and the sleeve for adjustment of discharge air so that the sleeve rotates in a contactless fashion relative to the shaft.

Abstract: A very thin lubricating coating on one or both of the facing surfaces defining the gap of the hydrodynamic bearing. The lubricant film would need to be 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 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.