Abstract: A method for producing a housing for a hydrodynamic bearing apparatus includes forming a housing 7 which has a cylindrical shape and which includes a fixing face 7c for fixing the outer circumferential surface 8b of a bearing sleeve 8, and axial circulation grooves 7d for bringing both end faces 8c, 8d of the bearing sleeve 8 into circulation on the inner periphery. The method includes providing a groove molding portion 18a2 on the outer circumference of a rod 18 which serves as a forming mold for the inner periphery of the housing 7, and forming the circulation grooves 7d of the housing by forging with the groove molding portion 18a2 of the mold. Moreover, after a sealing face 107d and a cylindrical outer circumferential surface 107e provided on the outer periphery of the housing 107 are formed by forging, an inner circumferential surface 107c is formed by forging.

Abstract: A bearing assembly having a cylindrical outer bearing shell. The outer bearing shell including a first annular outer land, a second annular outer land, and a recess therebetween. The outer bearing shell further including a first positioning bore having a first bore diameter and a second positioning bore having a second bore diameter. The second bore diameter may be smaller than the first bore diameter. A diameter of the first annular outer land may be larger than a diameter of the second annular outer land.

Abstract: A vibration control apparatus may include a fluid bearing provided around a rotating body to form a fluid bearing gap between the fluid bearing and the rotating body; and/or a pressure regulator configured to variably control a pressure of the fluid bearing, based on imbalance information of the rotating body, to compensate for imbalance of the rotating body. A computed tomography scanner may include a gantry configured to generate a computed tomography image while rotating around a test subject; a fluid bearing provided around the gantry to form a fluid bearing gap between the fluid bearing and the gantry; and/or a pressure regulator configured to variably control a pressure of the fluid bearing, based on imbalance information of the gantry, to compensate for imbalance of the gantry.

Abstract: A self-compensating hydrostatic journal bearing is disclosed, which is substantially a base provided for a spindle to mounted thereat passing through a hole thereof, while allowing a gap to be formed between the circumference surface of the hole and the spindle for a hydraulic fluid to flow therethrough. There are at least two oil holes formed on the base, and correspondingly, there are at least two first chambers formed on the circumference surface for allowing each first chamber to be in fluid communication with one of the at least two oil holes, and for each first chamber, there is one second chamber being arranged in the vicinity thereof. When the spindle is forced to bias, the gap axially opposite to the bias is changed for causing the hydraulic fluid to flow inside the channels between the first chambers and the second chambers correspondingly and thus accomplishing a fluid self-compensating process.

Abstract: A rotating device includes a fluid dynamic bearing unit. The fluid dynamic bearing unit includes a shaft encircling member that encircles a shaft, an intermediate encircling member that encircles the shaft encircling member, a shaft holder formed with a shaft hole into which an end of the shaft is fitted to fix the shaft, a base-side encircling member fixed to the shaft holder and encircling the intermediate encircling member, and a ring member fixed to the intermediate encircling member and encircling a rod encircling member. A lubricant is present between a rotating body and a fixed body. A first air-liquid interface is present between the base-side encircling member and the intermediate encircling member, and a second air-liquid interface is present between the ring member and the rod encircling member.

Abstract: A rotating assembly adapted for use in turbines and pumps is provided. The rotating assembly includes a shroud that rotates around a central axis and a disk seated in a recess in the shroud so that the disk rotates with the shroud, the disk being oriented perpendicular to the central axis. The rotating assembly also includes a stationary element in which at least one surface of the disk contacts a fluid so that when the fluid flows under pressure, the surface of the disk resists the generation of drag between the surface and the stationary element of the rotating assembly. A shroud is provided that includes a circular recess with a cavity on an outer perimeter extending away from the fixed assembly. A method of manufacturing a rotating assembly is provided.

Abstract: There is provided a sliding member including: a substrate; and a protective film provided on the substrate, wherein the protective film is composed only of a metal base layer provided on the substrate, a low-hardness diamond-like carbon layer provided as a single layer on the metal base layer, and a high-hardness diamond-like carbon layer provided as a single layer directly on the low-hardness diamond-like carbon layer. The sliding member has the protective film which has excellent frictional wear resistance property and satisfactory adhesion property to the substrate, regardless of having a simple structure.

Abstract: A bearing arrangement 2 comprising an outer race 10, a shaft 4 arranged to rotate with respect to the outer race 10 thereby defining an axis of rotation 8 of the shaft 4. The shaft 4 and the outer race 10 are arranged to define a region of overlap between the shaft 4 and the outer race 10 along the axis of rotation. An inner race 12 is disposed between the outer race 10 and the shaft 4 in the region of overlap and coupled for rotation with the shaft 4, the inner race 12 and the shaft 4 defining an annular reservoir 40 between them for accommodating radial expansion of the shaft 4 or radial displacement of the shaft 4 with respect to the axis of rotation 8.

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: The invention includes a method for continually circulating a fluid in a system, in the absence of an external pumping mechanism, by providing a fluid, an active space capable of generating a higher pressure zone and causing a contiguous lower pressure zone, a passive space, and a porous medium disposed between the active space and the passive space, and generating a pressure differential relationship between the active space and the passive space causing the fluid to circulate freely in both directions between the active space and the passive space, across the porous medium, without the aid of an external pumping system, such that the fluid circulation defines a self-acting self-circulating fluid system, and to the system created thereby.

Abstract: The spindle motor includes a rotating shaft and a sleeve. The rotating shaft has a stepped portion in a fluid dynamic pressure shafting system. The sleeve is fitted over the circumferential outer surface of the rotating shaft. A sleeve recess is formed in the inner surface of the sleeve so that the edges of the stepped portion are spaced apart from the sleeve.

Abstract: There are provided a hydrodynamic bearing assembly and a motor including the same. The hydrodynamic bearing assembly includes: a sleeve having a shaft hole into which a shaft is rotatably inserted; and a hub fixed to an upper end of the shaft and extended in an outer radial direction, wherein an upper surface of the sleeve and a lower surface of the hub have an oil interface formed therebetween to seal oil.

Abstract: There are provided a hydrodynamic bearing assembly and a motor including the same. The hydrodynamic bearing assembly includes: a sleeve having a shaft rotatably inserted therein; a hub provided on an upper end of the shaft and having a main wall part protruding downwarly in an axial direction; and a stopper provided at an inner side of the main wall part to limit floatation of the hub and form an oil interface between an inner surface thereof in an inner radial direction and an outer surface of the sleeve, wherein the stopper has a lower porosity in a portion filled with oil than that of other portions thereof.

Abstract: The hydrodynamic bearing assembly includes: a sintered sleeve having a shaft hole formed therein such that a shaft is rotatably inserted thereinto and including at least one dynamic pressure bearing part to generate dynamic pressure in a lubricating fluid filled in a bearing clearance at the time of rotation of the shaft; and a housing provided to enclose an outer peripheral surface of the sintered sleeve, wherein a bottom surface of a dynamic pressure groove of the at least one dynamic pressure bearing part has a porosity higher than that of a protrusion surface thereof.

Abstract: There is provided a bearing assembly including: a sleeve supporting a shaft; a base cover coupled to the sleeve by press-fitting and closing a lower portion of the sleeve; and at least one deformation prevention part formed to be depressed from an outer peripheral surface of the base cover in an inner diameter direction and preventing deformation of the base cover when the base cover is press-fitted into the sleeve.

Abstract: An aspect of the present disclosure relates to a fluid bearing having an adjustable effective surface area and a method of adjusting the load carrying capacity of a fluid bearing. The fluid bearing may include a bore defining a central longitudinal axis and lubricating fluid provided within the bore. The fluid bearing may also include a bearing including a bearing surface, wherein at least a portion of the bearing is positioned within the bore. An adjustable effective bearing surface area may also be provided. The method includes adjusting effective bearing surface area of the bearing.

Abstract: A fluid dynamic bearing motor and method are described, wherein motor components, including complex shaped motor components, are molded of plastic. The molding ensures form control and dimensional control thereby accomplishing design requirements, and eliminating or reducing component costs and component machining. The mold can be shaped to form various motor geometries, thereby eliminating the need for multiple component assembly and related assembly costs. In an aspect, a plastic integral motor hub is formed by injection molding. Alternatively, a plastic motor hub is affixed to a metal sleeve. In another aspect, fluid containment structures are molded into the motor component, reducing the number of components as compared with machined metal components. In a further aspect, bearing structures such as grooves are molded into the motor component, thereby eliminating processes such as electrochemical machining. In yet a further aspect, a plastic hub faces a thrustplate, reducing expensive sleeve machining.

Abstract: A fluid dynamic bearing is disclosed. A shaft is fit in a sleeve and rotates with respect thereto. A lubricant is filled between the shaft and the sleeve. At least one elliptical groove is formed on either the shaft or the sleeve and between the shaft and the sleeve. At least one non-elliptical groove connects to the elliptical groove. When the shaft rotates with respect to the sleeve, the lubricant is filled in the elliptical and non-elliptical grooves.

Abstract: In a disk drive device, a hub has an outer circumferential wall portion configured to hold a recording disk. A base member has a cylindrical portion, whose central axis is the rotation axis of the hub, on a surface on the side of the hub. A fluid dynamic bearing holds a lubricant and rotatably supports the hub relative to the base member. A ring-shaped attraction plate including a magnetic material is fixed to the base member and faces a magnet in the axial direction. The outer circumferential wall portion is configured such that the outer circumferential wall portion surrounds the attraction plate and that the range of the outer circumferential wall portion in the axial direction overlaps with the range of the attraction plate in the axial direction.

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: An inner periphery of a molded part having a step from an inner periphery of an electroformed part is molded to a nonconductive coating which covers the surface of a master. When the nonconductive coating is removed, a radial clearance having a diameter greater than that of a bearing clearance is created between the inner periphery of the molded part, which is exposed to the interior, and an outer periphery of a shaft member. A bearing member which forms the bearing and radial clearance with the shaft member is manufactured by performing electroforming on the master with the nonconductive coating formed on part of the surface of the master, thereby forming the electroformed part; then injection molding the bearing member with the electroformed part and the nonconductive coating on the surface of the master inserted into a cavity; and then removing the nonconductive coating from the bearing member.

Abstract: Rolling mill bearings incorporate bearing bushings with pluralities of hydrostatic pad recesses, that are preferably in conjunction hydrodynamic bearings also formed within the bushing. Each recess has an isolated lubricant passage that is adapted for coupling to a separate isolated source of pressurized lubricant. In some embodiments herein, the isolated pressurized lubricant source is supplied by a dedicated outlet of a pressure pump. In this manner each hydrostatic pad recess has a dedicated pressurized lubricant supply that is not interrupted by loss of lubricant pressure events in other bearing pads or elsewhere within the rolling mill lubrication system.

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: A method of manufacturing a bearing device component is provided. The bearing device includes a shaft and a sleeve that surrounds the shaft, and at least either one of the shaft and the sleeve is referred to as a work. The method includes: a process of forming a coating of an anti-sticking-lube polymer on the work; a process of applying a photoluminescence material to a range overlapping a range where the coating of the anti-sticking-lube polymer is formed; and a condition detecting process of causing the photoluminescence material to emit light by causing the work to be irradiated with excitation light that excites the photoluminescence material, and detecting an applied condition of the photoluminescence material based on the light emission of the photoluminescence material, thereby detecting a condition of the coating of the anti-sticking-lube polymer.

Abstract: An oil film is formed in a radial bearing clearance of a first radial bearing portion (R1) and a second radial bearing portion (R2) so as to rotatably support a shaft member (2). A bearing sleeve (8) and the shaft member (2) are accommodated in a housing (7), and the housing (7) has an inner space filled with a lubricant oil and has an opening sealed by a seal member (9). A first seal space (S1) is formed by means of an inner peripheral surface (9a2) of the seal member (9). The housing (7) and the seal member (9) are formed through injection molding of a resin.

Abstract: Thus, if a shock or other disturbance to a disc stack spindle bearing assembly 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: A bearing device comprises a bearing fixing base, a hub, an oil seal bush, and an oily felt. The bearing fixing base is fixedly joined with a tubular support; the hub is fixedly joined with a rotor spindle which extends into the tubular support and rotates with respect to the tubular support; the oil seal bush is disposed between the spindle and the tubular support with a receiving clearance being defined between the oil seal bush and the tubular support; the oily felt is disposed in the receiving clearance. The oily felt supplies lubrication oil to lubricate the oil seal bush for prolonging a life span of the bearing device.

Abstract: Accurately formed critical tolerance fit components are provided for fluid dynamic bearing motors, including disc drive memory systems. In an aspect, critical tolerance fit components are molded to a metal insert and include a portion of a hub, a disc seating surface, and a disc locating surface. The insert includes another portion of a hub, a sleeve, or a disc clamp retainer for a novel disc clamp. In an aspect, the plastic component is situated to cause the thermal expansion of the plastic to be restricted by the thermal expansion of a metal insert. Expensive machining of a stamped metal hub is minimized or eliminated by using the molded component portions. Strict component tolerances are provided as needed for perpendicularity relative to motor rotation for seating a disc with accurate flatness, a circumferential surface for centering the disc, and tight parallelism between a disc mounting surface and a center shaft.

Abstract: A low-cost shaft member for hydrodynamic bearing apparatuses restores the pressure balance in a thrust bearing gap formed on both axial sides of the flange portion in an early stage. A shaft material integrally having a shaft portion and a flange portion with a through-hole between both end faces of the flange portion is formed in a common forging step. As a result, the through-hole is formed to open to an inner diameter side of the bearing gaps avoiding the thrust bearing gaps formed on both end faces of the flange portion of the shaft member as a finished product.

Abstract: A hydrodynamic bearing assembly according to an aspect of the invention may include: a sleeve against which a shaft is supported so that an upper end of the shaft, being compressed and inserted into a hub base of a rotor case, protrudes upwardly in an axial direction; a first oil sealing unit having a first oil interface provided between the hub base and a counterpart component arranged downwardly in the axial direction; and a second oil sealing unit communicating with the first oil sealing unit through a communication channel and being tapered to form a second oil interface inside or outside the sleeve, wherein oil in the first oil sealing unit moves toward the second oil sealing unit along an inner diameter direction by a rotation of the rotor case.

Abstract: There are provided a hydrodynamic bearing assembly and a method of manufacturing the same. The hydrodynamic bearing assembly includes: a lubricating oil filled so as to form a liquid-vapor interface between stationary members and rotating members; and a lipophilic coating formed on the liquid-vapor interface of the lubricating oil so as to prevent lubricating oil leakage. Therefore, the lipophilic coating is formed on the interface of the lubricating oil and an oil repellent material is formed on a surface of at least one of the stationary members and the rotating members, whereby the scattering and the leakage of the lubricating oil may be effectively prevented.

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: The present invention provides a process for producing a saturated aliphatic hydrocarbon prepared using an ?-olefin as a raw material and represented by the general formula (1), including the steps of: (I) producing a vinylidene olefin by dimerizing the ?-olefin in the presence of a metallocene complex catalyst; (II) further dimerizing the vinylidene olefin in the presence of an acid catalyst; and (III) hydrogenating the obtained dimer. Further, there are provided a lubricant composition containing the saturated aliphatic hydrocarbon compound produced by the above process, a bearing oil consisting of the lubricant composition, and making use of the same, a bearing and gyral equipment. The saturated aliphatic hydrocarbon compounds produced by the process of the present invention have low-temperature fluidity, exhibiting low evaporativity, and excellent in thermal stability and oxidation stability.

Abstract: There is provided a spindle motor including: a shaft fixedly coupled to a base member; a stationary unit coupled to the shaft so as to be disposed over the base member; and a sleeve member forming a bearing clearance with the stationary unit to be filled with lubricating fluid, wherein the stationary unit includes a plurality of stationary members and the plurality of stationary members are disposed to be opposed to each other while being spaced apart from each other by a predetermined interval so as to have the lubricating fluid interposed therebetween, the stationary members including a liquid-vapor interface formed therebetween.

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 bearing unit includes: a shaft; a radial bearing configured to support the shaft in a circumferential direction; a thrust bearing configured to support one end of the shaft in a thrust direction; a housing having the radial bearing and the thrust bearing disposed in the inside and having a closed structure except a shaft insertion hole into which the shaft is fitted; a coming out preventing member provided on one end side of the radial bearing at which the thrust bearing is provided configured to prevent the shaft from coming out from the radial bearing; and viscous fluid filled in the housing. The coming out preventing member is made of a resin material having a value of a Young's modulus equal to or higher than 3.4 GPa.

Abstract: An aspect of the present disclosure relates to a fluid bearing and a method of adjusting the load carrying capacity of a fluid bearing. The fluid bearing may include a bore defined in the fluid bearing and a rotatable bearing including a rotatable bearing surface. Lubricating fluid in the bore may be contacted with at least a portion of the rotatable bearing surface, wherein an effective bearing surface area is provided where the lubricating fluid contacts the rotatable bearing surface. The effective bearing surface area may be altered by either increasing or reducing the area of the rotatable bearing surface which is contacted by the lubricating fluid.

Abstract: A device for providing an air-gap associated with a portion of a fluid dynamic bearing, a sleeve is provided and surrounds a portion of a shaft. The sleeve and the shaft are configured for establishing the air-gap proximal to a portion of the fluid dynamic bearing. In addition, a cap is also provided and coupled to the sleeve. The cap has an outer end proximal to a portion of the fluid dynamic bearing such that the air-gap is provided between the outer end of the cap and the portion of the fluid dynamic bearing, wherein the air-gap forms a labyrinth seal.

Abstract: A bearing oil contains a first monoester which is an ester of a branched chain fatty acid containing 18 carbon atoms or a monounsaturated fatty acid containing 18 carbon atoms and ethylhexyl alcohol.

Abstract: A bearing apparatus includes a shaft, a thrust cup including an annular potion and a cylindrical portion, a rotating member including a through hole defined therein, and a lubricating oil. A second gap defined between a lower surface of the rotating member and an upper surface of the annular portion of the thrust cup includes a first region in communication with a capillary seal portion, and a second region positioned radially inward of the first region and having an axial dimension smaller than that of the first region. A lower end portion of the through hole is open at a location radially outwardly away from a boundary between the first and second regions, so that a local circulation of the lubricating oil arises within the first region during rotation of the rotating member.

Abstract: There are provided a hydrodynamic bearing assembly and a method of manufacturing the same. The hydrodynamic bearing assembly includes: an oil sealing part formed between a fixed member and a rotating member; and an oil barrier film disposed so as to prevent leakage of oil from the oil sealing part and including a self-assembled monolayer formed on a surface of at least one of the fixed member and the rotating member. The oil barrier film may be easily formed at room temperature and be continuously used for a long period of time without being damaged due to external impacts.

Abstract: A fluid dynamic bearing having at least one first bearing part as well as a second bearing part that are rotatably supported with respect to one another about a rotational axis and separated from one another by a bearing gap filled with bearing fluid. Associated bearing surfaces of the bearing parts form a first and a second radial bearing that are marked by grooved bearing patterns disposed on at least one bearing surface. Between the radial bearings, there is a separator gap having an enlarged gap distance compared to the bearing gap. The ends of the grooved bearing patterns of the radial bearings adjoining the separator gap penetrate into the separator gap. This measure prevents the creation of negative pressure at the ends of the grooved bearing patterns, as a result of which the formation of air bubbles is also reduced.

Abstract: A rotary table device includes a hollow motor drive source, a table rotated thereby, and a rotary bearing supporting the table. The rotary bearing is provided an outer race having an inner surface to which a rolling surface is formed, an inner race having an outer peripheral surface to which a rolling surface opposing to the rolling surface of the outer race is formed, and a plurality of rolling members disposed in a rolling passage formed by the rolling surface of the outer race and the rolling surface of the inner race, and a cooling medium passage (?, ?) is formed so as to be adjacent to either one of the inner race and outer race constituting a rotational driving side. According to the structure mentioned above, a rotary bearing and a rotary table device capable of achieving suitable cooling effect can be provided.

Abstract: A groove is provided in the periphery of a pressure receiving area of a pressure receiving surface opposing to the load of axis weight within a bearing surface supporting an axis, and a liquid supply route communicating with the groove is provided so that liquid is supplied to the groove through the liquid supply route. In such a configuration, a bearing having a simple structure and a high compact load capacity and a liquid cooling type screw compressor using the above bearing are provided.

Abstract: To manufacture a shaft member, which is excellent in both accuracy and strength at low cost, a shaft member (2) includes a shaft portion (21) and a flange portion (22) provided to one end of the shaft portion (21). The flange portion (22) has an annular shape, and the shaft portion (21) and the flange portion (22) are fixed by a welded portion (23), which is formed by applying a laser beam (35) to an upper end of an inner periphery thereof.

Abstract: In a bearing apparatus, a first cup portion defining a portion of a stationary portion of a bearing apparatus includes a circular plate portion and a cylindrical portion projecting downward from an outer edge portion of the circular plate portion. A rotating portion of the bearing apparatus includes an annular recessed portion arranged to accommodate at least a lower end portion of the cylindrical portion. Accordingly, it is possible to limit the axial dimension of the bearing apparatus while also enabling both a radial dynamic pressure groove array and a pumping groove array to have a sufficient axial dimension. Additionally, one end of a through hole defined in the rotating portion is arranged to open into the annular recessed portion, so that any air bubbles introduced into a lubricating oil by the pumping groove array can be efficiently caused to flow downward through the through hole and out of the bearing apparatus.

Abstract: A protrusion (7b3) directed axially downwards is provided at a bottom portion (7b) of a housing (7), and an outer peripheral surface (7b31) of the protrusion (7b3) is fixed to an inner peripheral surface (6a) of a bracket (6). When a thrust load is applied to the bottom portion (7b) of the housing (7), a part of the load is supported by the bracket (6) via the protrusion (7b3). Thus, a strength of a boundary portion (P) between a side portion (7a) and the bottom portion (7b) of the housing (7) increases, making it possible to prevent rupture of the boundary portion (P) due to an excessive thrust load. On the other hand, a wall thickness of the bottom portion (7b) can be made invariable, so it is possible to suppress deformation through molding shrinkage of a thrust bearing surface formed on an inner end surface (7b1) of the bottom portion (7b).

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: A fluid dynamic bearing includes a body; an inner surface of the body being formed with a plurality of sawteeth trenches; each bending angle of each tooth of the sawteeth trench being selected from one of two difference values. Each sawteeth trench has eight teeth, four at the right side and four at the left side. Eight bending angles of eight teeth of one trench are selected from two kinds of different angles which are alternatively arranged. The bearing is suitable for spindles of various rotation speeds so as to generate fluid dynamic pressure and the bearing is also suitable for various rotation speeds of spindles.

Abstract: A housing for a fluid lubrication bearing apparatus is formed of a resin composition containing polyphenylene sulfide (PPS) as a base resin. The ratio of the base resin to the resin composition is not lower than 40 vol % but not higher than 70 vol %. Moreover, in the composition, an epoxy compound having two or more epoxy groups per molecule of the compound and epoxy value of 0.5 meq/g or more to the resin composition may be added so that the amount of epoxy groups in the resin composition is 8 meq/100 g or more. A carbon fiber may also be added to the resin composition in an amount of not less than 10 vol % but not more than 35 vol %. An inorganic compound may be further added to the resin composition to be the remainder of the resin composition.