Abstract: A seal member is fixed to a predetermined position on an outer peripheral surface of a shaft portion. During rotation of a shaft member, a lower end surface of the seal member is opposed to an upper end surface of a bearing sleeve through an intermediation of a thrust bearing gap to form a second thrust bearing gap. An outer peripheral surface of the seal member defines between itself and an inner peripheral surface of an upper end portion of a housing a seal space having a predetermined volume.

Abstract: To provide a fluid dynamic pressure bearing device that achieves high rigidity against moment without degradation in assembly precision and bearing performance, bearing sleeves are arranged in an axial direction and coaxiality of radial bearing surfaces formed on inner peripheral surfaces of the bearing sleeves is set to 3 ?m or less. This secures width precision between the radial bearing gaps to prevent a degradation in bearing performance and a failure such as wear etc. caused by contact between a shaft member and the bearing sleeves. Further, a first radial bearing surface and a second radial bearing surface are provided on at least one sleeve, and this allows a sleeve assembly constructed from the bearing sleeves to be supported at least three positions in the axial direction in a process of assembling the sleeve assembly.

Abstract: Provided is a fluid bearing device with a hub part having high molding precision and dimensional stability and capable of being produced at low cost. An annular gate (14) is formed at a portion of a cavity (15) corresponding to an outer peripheral edge portion of a lower end surface (10c1) of a flange part (10c), and a molten resin (P) is filled into the cavity (15) through the annular gate (14) to form a hub part (10) made of resin. The hub part (10) molded by the injection molding exhibits a radial resin orientation through an entire periphery thereof. Further, an annular gate trace (16) is formed at the outer peripheral edge portion of the lower end surface (10c1) of the flange part (10c) of the hub part (10).

Abstract: In spindle motors journaled on fluid-dynamic-pressure bearings, especially in such spindle motors employed in recording-disk drives in implementations that subject the drives to vibration and shock, sealing performance of a capillary seal formed between motor rotor-side and stator-side bearing surfaces, cohesiveness of oil-repellant on rotor-side/stator-side dry-area surfaces adjoining the capillary seal section, and motor inter-component adhesive strength are improved. The capillary-seal-constituting rotor-side/stator-side surface(s) are exposed to a plasma or to ultraviolet rays under predetermined conditions to improve the wettability of the surface(s) for the bearing fluid. The dry-area surface(s) are similarly irradiated so as to improve their wettability for the oil-repellant. Adhesively bonded component surfaces are likewise irradiated so as to improve their wettability for the adhesive, enhancing adhesive strength.

Abstract: In a disk drive device, a magnetic recording disk is mounted on a hub. A base rotatably supports the hub via a bearing unit. The base has a ring-shaped wall that surrounds the bearing unit and that protrudes towards the hub. A laminated core is fixed to the base. The laminated core has a ring portion and twelve teeth that radially outwardly extend from the ring portion. Coils are wound around the twelve teeth. The base includes an increasing-thickness portion formed so that the less the distance between a part of the increasing-thickness portion and the ring-shaped wall is, the thicker the part of the increasing-thickness portion becomes.

Abstract: A method of manufacturing a motor includes coupling a base cover to a sleeve having a penetration hole formed therein, such that one side of the penetration hole is closed; inserting a shaft in the penetration hole; coupling a plate to the shaft such that the shaft is inserted in the plate; and pressing and coupling a hub to the shaft such that the shaft is inserted in the hub while the base cover is supported in an axial direction of the shaft to the base cover by using a jig, wherein the base cover is elastically deformed to make contact with the shaft. In the method of manufacturing the motor, the jig is used to deform the base cover so as to come in contact with the shaft, thereby applying the support load in the axial direction.

Abstract: In accordance with the method, a gas bearing is energized to center the piston in the cylinder prior to rigidly attaching the planar spring or springs between the piston and the compressor frame. This automatically and very accurately centers the piston in the cylinder to provide the added stiffness of a planar spring and gas bearing in an easily manufactured configuration. Various exemplary embodiments are disclosed, including embodiments having the piston cantilevered from one end using a single or multiple springs, an embodiment having a spring on each end of the piston, a double piston embodiment and embodiments using and not using the gas bearing during operation of the compressors.

Abstract: A shaft material integrally having a shaft portion and a flange portion is formed by a forging process. The end face of the shaft portion of the shaft material and the end face of the flange portion on the opposite side of the shaft portion are ground relative to the corrected face, and the outer circumferential surface of the shaft material is ground relative to the end faces. This renders the cylindricity of the radial bearing faces formed on the outer periphery of the shaft portion of the produced shaft member to be 3 ?m or lower. Moreover, a shaft material integrally having the shaft portion and flange portion is formed, while simultaneously thrust hydrodynamic groove regions are formed on both end faces of the flange portion. After the forging process, radial hydrodynamic groove regions are formed on the outer circumferential surface of the shaft portion.

Abstract: A method for manufacturing a hydro dynamic bearing device is provided for the finishing treatment of lubricating oil after lubricating the hydro dynamic bearing device, specifically for properly and effectively wiping off the lubricating oil adhering to the outside of the housing and adjusting the oil-level height of the lubricating oil filled in the housing.

Abstract: The invention relates to a ring (120) that is intended for being mounted tightly around a shaft of a hydraulic machine to form a portion of a hydrostatic or hydrodynamic bearing. The ring includes at least one first section (122), at least one second section (124) and means (132) for mounting the first and second sections around the shaft. Each section (122, 124) includes two edge surfaces (1223, 1243) connecting the external (1221, 1241) and internal (1222, 1242) radial surfaces thereof. The first section (122) is provided with at least one threaded hole (127) accessible via an edge surface (1223) and capable of receiving a screw (132) projecting from an edge surface (1243) of the second section (124). The screw (132) is provided, on the portion of the shank (134) thereof that projects from the second section (124), with at least one raised pattern (140) for rotatably moving the shank (134) in order to screw or unscrew the shank in the threaded hole (127).

Abstract: A method for manufacturing a hydrodynamic bearing (30) comprises steps of: step (201): providing a substrate (10) with a plurality of protrusions (14) formed on a periphery thereof; step (202): placing the substrate in a middle of a hollow mold, then injecting a feedstock of powder and molten binder into the mold to surround the substrate under pressure, thus forming a desired bearing preform (20); step (203): separating the substrate from the bearing preform by means of catalytic debinding; step (204): separating the binder from the bearing preform; step (205): sintering the bearing preform; step (206): precision machining the bearing preform to form the desired hydrodynamic bearing.

Abstract: A dynamic bearing manufacturing includes steps of: providing a bearing and a processing tool, the bearing having an axial hole, and the processing tool having at least one protruding pattern formed on an exterior wall of the processing tool; positioning the processing tool into the axial hole of the bearing; pressing the processing tool to contact with an inner wall of the bearing so as to transfer and print the protruding pattern of the processing tool onto the inner wall of the bearing; rotating the processing tool at a first rotation speed and driving the bearing to rotate at a second rotation speed; and forming at least one concave pattern on the inner wall of the bearing, and the at least one concave pattern being corresponding to the protruding pattern of the processing tool.

Abstract: A head-slider. The head-slider includes a magnetic-recording head and an air-bearing surface. The air-bearing surface includes air-bearing portions, shallow-recessed surfaces, and a deep-recessed surface. Air-bearing portions are configured to fly nearest to a magnetic-recording disk; shallow-recessed surfaces have a first depth from the air-bearing portions; the deep-recessed surface has a second depth, larger than the first depth, from the air-bearing portions. Air-bearing portions and shallow-recessed surfaces are configured to generate positive pressure; and, the deep-recessed surface is configured to generate negative pressure.

Abstract: An apparatus for manufacturing a hydro dynamic bearing device is provided for the finishing treatment of lubricating oil after lubricating the hydro dynamic bearing device. The hydro dynamic bearing is constructed of an axial member housed in a housing, a radial bearing part for supporting the axial member in a non-contact manner in a radial direction by a hydro dynamic pressure action of the lubricating oil generated in a radial bearing clearance, and a sealing part arranged in an opening part of the housing, and the apparatus has a laser for measuring an oil-level height of the lubricating oil in the housing.

Abstract: A method for manufacturing a hydrodynamic bearing with hydrodynamic pressure generating grooves comprises steps of: step 201: providing a substrate with a first annular protrusion and a plurality of projections formed on a periphery thereof, the projections being in a side of the first annular protrusion; step 202: placing the substrate in a middle of a hollow mold, then injecting a feedstock of powder and molten binder under pressure into the mold to surround the substrate, thus forming a desired bearing preform; step 203: separating the substrate from the bearing preform by means of catalytic debinding; step 204: separating the molten binder from the bearing preform; step 205: sintering the bearing preform to thereby form the hydrodynamic bearing.

Abstract: A working fluid injection apparatus has an upper chamber that stores a working fluid and a lower chamber that removably receives a bearing unit having a housing and a shaft that is inserted in the housing to form between the shaft and the housing a gap into which the working fluid is to be injected. A partition divides the upper chamber and the lower chamber into top and bottom parts, respectively. A first exhaust system brings the inside of the upper chamber to a decompressed state. A second exhaust system brings the inside of the lower chamber to a decompressed state. A valve unit opens and closes an internal cavity of the lower chamber relative to an external environment. A tapered hole is formed in the partition and communicates the upper and lower chambers to one another. A tapered shaft is inserted into the tapered hole from the upper chamber. A shaft drive unit moves the tapered shaft in the axial direction in the tapered hole.

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: Proposed is a fluid dynamic bearing system having a bearing bush, a shaft rotatably supported in a bearing bore of the bearing bush and a hub connected to the shaft. A bearing gap filled with bearing fluid and having an axial section is defined between the shaft, the bearing bush and the hub. A first and a second fluid dynamic radial bearing are disposed along the axial section of the bearing gap, the radial bearings being marked by grooved bearing patterns on the associated bearing surfaces of the shaft and/or of the bearing bush. The two radial bearings have a mutual distance dL measured from an apex line of the first radial bearing to an apex line of the second radial bearing. A separator groove is disposed in the bearing bush or in the shaft in the axial section of the bearing gap between the two radial bearings and has an axial length lS. According to the invention, the ratio between the distance dL and the length lS is greater than 5 (five).

Abstract: A gas is fed, so as to cause a gas flow to occur from a lower opening of a bearing hole of a sleeve 6 in an outward direction of an annular portion 12a of a rotor hub 12 via a radial gap 50 and an upper opening of the bearing hole, thereby lifting a rotor section 10. In a condition where the rotor section 10 is lifted, the magnitude of run-out synchronized with the rotation of the rotor section 10 is measured by using a displacement gauge 40. Then, based on the magnitude of run-out synchronized with the rotation, the run-out of the rotor section 10 is adjusted.

Abstract: A working fluid injection apparatus for injecting a working fluid into a gap between a housing and a shaft of a bearing unit of a fluid dynamic pressure bearing. The apparatus has an adapter configured to support the bearing unit in a state in which an end portion of the shaft protrudes from an open portion of the housing. A cover member has an upper opening, a lower opening, and a tapered inner surface with a radial dimension that increases gradually from the lower opening to the upper opening. The cover member is configured to be mounted in contact with an upper surface of the housing when the bearing unit is supported by the adapter so that the lower opening of the cover member surrounds the open portion of the housing and so that the protruding end portion of the shaft and the tapered inner surface of the cover member form a reservoir portion that communicates with the open portion of the housing and that is configured to store a working fluid.

Abstract: An electrode tool for electrochemical machining includes a machining electrode surface (1a). The machining electrode surface (1a) includes a conductive pattern defined by lands (3) and grooves (3a) that are formed by groove machining the electrode surface (1a). The machining electrode surface (1a) is then molded with a hard insulating resin layer (4), and a surface of the hard insulating resin layer (4) is mechanically polished to expose the lands (3) of the conductive pattern. The lands (3) are chemically dissolved to obtain a conductive pattern (14) having a surface that is formed below a resulting insulating resin surface (2), with the height difference between the two surfaces being between 1 and 5 ?m. The electrode tool allows precise surface machining of work pieces and can withstand prolonged use.

Abstract: An air foil bearing includes a top foil, one or more orifice tubes and two or more bump foil strips disposed within a housing. The top foil is forms a substantially circular shape having one or more sets of top foil orifice holes. Each set of top foil orifice holes has at least three top foil orifice holes along a circumference of the top foil. An orifice tube is provided for each set of top foil orifice holes. The orifice tube includes a flat side having a set of tube orifice holes connected to an outer surface of the top foil. The bump foil strip is attached to the outer surface of the top foil adjacent to each side of each orifice tube. Another embodiment uses a housing with an inner surface having a curved polygonal cross-sectional shape with an odd number of curved sides.

Abstract: According to the preferred embodiment of the present invention, a production method of a fluid dynamic bearing including: a shaft arranged along a center axis; an annular portion expanding radially outwards from the shaft; a sleeve having a top surface opposed to an under surface of the annular portion, for supporting the shaft and the annular portion in a relatively rotatable manner; and a lubricating fluid interposed between the shaft and annular portion and the sleeve, includes the step of preparing the annular portion having a substantially annular edge surrounding the center axis on the under surface; the step of applying a forming liquid for forming a solid lubricating film on the radially outer side of the edge of the under surface; and the step of evaporating a solvent of the forming liquid.

Abstract: A molding pin (23) is formed in a sectional shape of being held in contact at two points (contact points are denoted by P?) with an imaginary cylindrical surface (C?). As a result, an undercut of a fixation hole (21b1) is reduced or eliminated, and hence it becomes easier to process a die. Moreover, a corner portion (21d) between a cylindrical surface (21c) and the fixation hole (21b1) becomes obtuse, and hence the die becomes less liable to deform and break. Therefore, manufacturing cost of the die can be reduced, and hence cost reduction of the bearing device can be achieved.

Abstract: A method for manufacturing a hydrodynamic bearing (30) includes the following steps. First, a substrate having a surface with multiple protrusions thereon is formed. The protrusions are adapted for forming grooves in a preform. The preform, when finally processed, becomes a shaft of the hydrodynamic bearing or a bearing of the hydrodynamic bearing. Second, a feedstock of binder and powder is pushed to the surface of the substrate to form the perform on the surface of the substrate. Third, the substrate is removed from the preform. Fourth, the preform is sintered. Fifth, the preform is precision machined to obtain the shaft or the bearing, as the case may be. In the shaft or bearing, the grooves are for generating hydrodynamic pressure.

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 method of controlling the instability in fluid film bearings by using a magnetic bearing in combination with a fluid film bearing (whether it is a cylindrical journal bearing, an elliptic bearing, an offset-half bearing, a multi-lobe bearing, foil bearing or a tilting-pad bearing, does not really matter), wherein the fluid film bearing serves as the primary load carrying bearing and the magnetic bearing controls the instability of the fluid film bearing. This efficient combination results in bearings that can be used at high speeds without having neither stability nor reliability problems. An alternative method of controlling the instability in fluid film bearings is to disturb the flow in the axial direction, for example, a sleeve journal) bearing can be manufactured such that the bearing axis is skewed with the shaft axis or a variable geometry bearing can be manufactured to allow for bearing angular misalignment.

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: Methods of machining a single piece hub with integral upper and lower female cones includes providing a single piece hub with upper and lower conical voids having respective narrow ends proximal each other and respective wide ends distal each other. Surfaces of the voids are machined using a tool provided from a single side of the hub that is dimensioned to fit through an opening defined by the interface between the narrow ends of the conical void. The tool can be moved parallel to a rotational axis for accessing conical surfaces of both voids and perpendicular to the rotational axis while contacting the surfaces so as to produce a final machined surface.

Abstract: In a method of manufacturing a dynamic bearing assembly having a shaft and a sleeve whose inner circumferential surface faces an outer circumferential surface of the shaft, the shaft is inserted into a bearing hole from an upper end opening toward a bottom end opening of the bearing hole. Upon inserting the shaft into the bearing hole, fluid is fed from the bottom end opening toward the upper end opening of the bearing hole with a fluid feed apparatus.

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 system is provided that increases the spindle stiffness of a disk drive while optimizing power consumption. A multipurpose bearing provides axial stiffness and enhanced stiffness against radial and pitch loads applied to the spindle. When used in combination with a journal bearing, conventional thrust bearings may be eliminated without sacrificing overall stiffness. As a result, the height of the disk drive may be reduced, thereby making the system desirable to be used in smaller electronic devices.

Abstract: A fluid dynamic bearing includes a shaft to which a resin flange is fixed by insert molding. The process where the flange is fixed to the shaft by insert molding includes a flange forming process in which the flange, fixed to the shaft, is formed by injecting the resin into a filled portion in the lower mold through an upper mold, while cooling at least part of the shaft, arranged in a shaft arrangement portion in a lower mold, with cooling water circulating through a cooling pipe.

Abstract: To provide a fluid dynamic pressure bearing device that achieves high rigidity against moment without degradation in assembly precision and bearing performance, bearing sleeves are arranged in an axial direction and coaxiality of radial bearing surfaces formed on inner peripheral surfaces of the bearing sleeves is set to 3 ?m or less. This secures width precision between the radial bearing gaps to prevent a degradation in bearing performance and a failure such as wear etc. caused by contact between a shaft member and the bearing sleeves. Further, a first radial bearing surface and a second radial bearing surface are provided on at least one sleeve, and this allows a sleeve assembly constructed from the bearing sleeves to be supported at least three positions in the axial direction in a process of assembling the sleeve assembly.

Abstract: A fluid bearing structure with uniform depths of bearing concaves and a method of forming the bearing concaves in the fluid bearing structure. Pipe parts are inserted into through holes formed in the bearing base to form fluid spout holes for spouting fluid between confronting bearing surfaces. Bearing concaves are formed around the fluid spout holes. The bearing base and the pipe parts are made of different materials. A coating layer is formed on the bearing base and the pipe parts by an anodic oxidation process. Thickness of the coating layer on the bearing base is different from thickness of the coating layer on the pipe parts since the base member and the pipe members are made of different materials. The material on which a coating layer grows quickly is selected for the bearing base and the material on which a coating layer grows slowly is selected for the pipe parts.

Abstract: In the method for manufacturing a fluid dynamic bearing, the fluid dynamic bearing that lubricant is not injected into is prepared in a predetermined work space. The pressure in the work space is reduced. A delivery nozzle that delivers the lubricant is inserted into the storage region. The lubricant is delivered in the storage region so that the lubricant does not spill over from the storage region. The pressure in the work space is restored. Another way is that a lubricant is ejected after an oil repellent region for preventing the lubricant from leaking out is covered.

Abstract: A first axial gap (L1) is formed between a seal portion (9) and a sleeve portion (8). With this, it is possible to set a moving amount of a shaft member (2) in an axial direction with high accuracy irrespective of accuracy of members such as the sleeve portion (8).

Abstract: A fluid dynamic bearing having a shaft (12) and a bearing sleeve (11) rotatably supported relative to each other. At least one of the shaft and the bearing sleeve is made of steel or stainless steel made of by weight C: 0.6˜1.20%; Si: 1.0% or less; Mn: 1.0% or less; Cr: 10.5˜18.0%; Mo: 1.0% or less; S.: 0.03% or less; and Fe. The dynamic pressure bearing surface (20) is formed by ridges (22) remaining in between multiple dynamic pressure grooves (21) formed by electrochemical machining.

Abstract: Provided is a fluid dynamic bearing device in which an assembly of a bearing sleeve to a housing is facilitated and which has excellent moment rigidity. A fluid dynamic bearing device (1) includes radial bearing parts (R1 and R2) and thrust bearing parts (T1 and T2). Thrust bearing surfaces (C and D) are respectively provided to first and second step surfaces (2d and 2e) of a housing (2), and the thrust bearing parts (T1 and T2) are respectively formed between the thrust bearing surfaces (C and D) and end surfaces (6b and 7b) of seal members (6 and 7) provided while protruding to an outer diameter side of a shaft member (5).

Abstract: Easy and precise setting of a predetermined thrust bearing gap is made possible. An axial gap 13 having a dimension that is equal to the sum of two thrust bearing gaps is first provided between the flange part 2b of the shaft member 2 and the bearing member or bearing sleeve 8. The shaft member 2 and the bearing sleeve 8 are accommodated inside the housing 7 with this gap dimension 8 being kept, and the bearing sleeve 8 is secured to the housing 7.

Abstract: A gas-pressure bearing including a mounted body, a cavity accommodating the mounted body, and a bearing bush surrounding the cavity. The bearing bush includes a wall, a plurality of supply passages formed in the wall and configured such that compressed gas can be externally applied. The bearing bush includes a plurality of elements joined together, and at least some of the plurality of supply passages are formed by grooves in at least one surface of mutually facing surfaces of adjacent elements of the plurality of elements.

Abstract: Oil which will serve as a lubricating fluid of a fluid dynamic pressure bearing is degassed in a first environment under a first pressure which is lower than atmospheric pressure. First and second members of the bearing are place in a second environment under a pressure lower than atmospheric pressure and higher than the pressure in the first environment. The degassed oil is supplied to the gap between bearing surfaces of the first and second members while the first and second members are in the second environment under pressure lower than atmospheric pressure and higher than the pressure in the first environment. Subsequently the pressure in the second environment is increased to force the oil into the gap between the bearing surfaces of the first and second members of the hydrodynamic fluid.

Abstract: In spindle motors journaled on fluid-dynamic-pressure bearings, especially in such spindle motors employed in recording-disk drives in implementations that subject the drives to vibration and shock, sealing performance of a capillary seal formed between motor rotor-side and stator-side bearing surfaces, cohesiveness of oil-repellant on rotor-side/stator-side dry-area surfaces adjoining the capillary seal section, and motor inter-component adhesive strength are improved. The capillary-seal-constituting rotor-side/stator-side surface(s) are exposed to a plasma or to ultraviolet rays under predetermined conditions to improve the wettability of the surface(s) for the bearing fluid. The dry-area surface(s) are similarly irradiated so as to improve their wettability for the oil-repellant. Adhesively bonded component surfaces are likewise irradiated so as to improve their wettability for the adhesive, enhancing adhesive strength.

Abstract: Disclosed herein is a method of manufacturing a hydrodynamic bearing in which a metal bearing made of sintered metal powder is internally subjected to chemical etching, to form hydrodynamic pressure grooves thereon, thus assuring a high-precision and reliable hydrodynamic bearing. The method includes: compressing metal powder that is a raw material of the bearing in a press unit, and sintering the compressed metal powder at a predetermined temperature, thus preparing a sintered bearing; removing foreign substances adhering to the sintered bearing through a deburring process, and pressing the sintered bearing into a desired shape; forming a hydrodynamic groove, configured to generate hydrodynamic pressure, on an internal surface of the shaped bearing using chemical etching; and conducting a post treatment of cleaning the bearing including the hydrodynamic grooves thereon and drying the bearing.

Abstract: Fixation strength of a bearing sleeve with respect to a housing is increased so that stable bearing performance can be achieved. A fluid dynamic bearing device (1) includes a housing (7) and a bearing sleeve (8) fixed to an inner periphery of the housing (7). The housing (7) and the bearing sleeve (8) have therebetween a press-fitting part (10) at which the housing (7) and the bearing sleeve (8) are fixed by press-fitting, and an adhesive-filled part (11) formed on an opening side with respect to the press-fitting part (10).

Abstract: In a rotor hub manufacturing method, a workpiece is chucked and a hole centering on the workpiece center axis is formed in the workpiece. A sealing member is press-fit into the hole, forming an internal space. A shaft feature is thereafter shaped in the workpiece by cutting work done on the periphery of the workpiece around the hole. The workpiece part including the shaft feature is then cut away from the workpiece to form a rotor hub as a shaft unit.

Abstract: A rotary gas bearing is described that comprises a first part rotatable relative to a second part. The first part comprises a support member and a first portion and a second portion attached to the support member. The first portion comprises a first bearing surface and the second portion comprising a second bearing surface. Both the first portion and the second portion are attached to the support member by screw thread connections. The second part may comprise complimentary bearing surfaces. Epoxy may be used to fix the first and/or second portions to the support member. A method of determining the bearing working gap by measuring gas flow through the bearing is also described.

Abstract: The present invention aims to improve the efficiency of a clamping step for combining a flange with a shaft and to improve productivity. The shaft and the flange are tentatively combined in the tentative clamping step. In the tentative clamping step, a concave part at the end of the shaft is pressurized by a metal mold such as a ball to be enlarged in an outer circumferential direction, thereby pressurizing this concave part against the inner circumference of the flange so as to fix the concave part. The combined body made by tentatively combining the shaft and the flange is strongly combined in a proper clamping step. In order to correct a distortion such as a warpage of the flange that has been solidly combined by the proper clamping step, sandwiching the flange by the upper and lower metals, the flange is pressurized and a flash molding is carried out.

Abstract: A method for manufacturing a hydro dynamic bearing device is provided for the finishing treatment of lubricating oil after lubricating the hydro dynamic bearing device. The hydro dynamic bearing is constructed of an axial member housed in a housing, a radial bearing part for supporting the axial member in a non-contact manner in a radial direction by a hydro dynamic pressure action of the lubricating oil generated in a radial bearing clearance, and a sealing part arranged in an opening part of the housing, and the method has the step of measuring the oil-level height of the lubricating oil in the housing by a laser detector.

Abstract: In this type of fluid dynamic bearing device, there is formed a resin member capable of suppressing the intrusion of a lubricating oil as much as possible even when carbon fibers are compounded. A housing part 7 as the resin member can be obtained by injection-molding a resin composition in which PPS is a base resin, and carbon fibers are compounded. The housing part 7 is in contact with an ester-based lubricating oil filled in the inside of the bearing. In this case, the plurality of carbon fibers bound with a binder material not containing an urethane resin are cut and the carbon fibers minced by cutting are compounded into PPS to thereby obtain the above-described resin composition.