Abstract: A fluid dynamic pressure bearing includes a shaft arranged along a central axis, an annular member fixed to the shaft, a sleeve, a lubricant, and a lubricating film. A stepped surface is provided on the outer circumferential surface of the shaft. The annular member preferably includes a lower surface extending radially with respect to the central axis and arranged to make contact with the stepped surface in the inner edge portion of the lower surface. The sleeve preferably includes an upper surface axially opposed to the lower surface of the annular member. The lubricant is provided between the shaft and the sleeve and between the annular member and the sleeve. The lubricating film is provided on the lower surface of the annular member at least over a region lying radially outwardly of the inner edge portion of the lower surface.

Abstract: A method of making a fluid dynamic bearing (10) includes the flowing steps. At least two bearing parts (10a, 10b) are firstly provided. Each of the bearing parts has its shape corresponding to a portion of the fluid dynamic bearing to be formed. Then, the bearing parts are combined to form a profile of the fluid dynamic bearing to be formed. Finally, the combined bearing parts are sintered to form an integral body. The fluid dynamic bearing is thus obtained.

Abstract: A hydrodynamic bearing device is provided for a spindle motor used in a hard disk drive or the like with a good state of fastening and good fastening strength between a shaft and a fixed member. The hydrodynamic bearing device includes a shaft that has a cylindrical main shaft portion and a fixing portion provided at one end of the main shaft portion, a sleeve that has a bearing hole in which the main shaft portion is inserted in a rotatable state, and a fixed member that is fixed to the fixing portion of the shaft. A nitride layer is formed on the main shaft portion, and a nitride layer non-forming film is formed on the fixing portion.

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 thrust plate used in a fluid dynamic pressure bearing of the present invention includes a concave portion in which a lower end portion of a shaft is accommodated. The thrust plate is immersed in a lubricant, and is disposed between the lower end portion of the shaft and a bottom-portion upper surface of a bearing housing without being fixed to the bearing housing. Accordingly, the thrust plate radially moves in accordance with the position in which the lower end portion of the shaft is in contact with the concave portion of the thrust plate. As a result, the centers of the shaft and the thrust plate motor can be aligned satisfactorily.

Abstract: A dynamic pressure bearing manufacturing method, comprising the steps of forming a herringbone groove pattern on the outer peripheral surface of a cylindrical mask and a spiral groove pattern on the lower surface of the flange part thereof, inserting the mask in a dynamic pressure bearing and optical fibers into the mask, radiating light from an external light source to the mask through optical fibers to transfer the herringbone groove pattern onto the inner peripheral surface of the dynamic pressure bearing and, at the same time, radiating the light from the upper side of the flange part to transfer the spiral groove pattern onto the upper surface of the dynamic pressure bearing performing development, and forming a herringbone groove on the inner peripheral surface of the bearing by etching and a spiral groove on the upper surface thereof.

Abstract: Materials with different thermal expansion coefficients are selected individually for a bearing guide and a slider that constitute a fluid bearing. The guide and the slider are combined in close contact with each other (i.e., with a zero bearing clearance between the two) in a temperature environment different from a temperature at which the fluid bearing is actually used. In consequence, the bearing clearance at the operating temperature can be adjusted based on a difference from the temperature for the fluid bearing assembly.

Abstract: There are provided a thrust plate with which there is less warpage when the thrust plate has been incorporated into a hydrodynamic bearing device, which improves the reliability of the hydrodynamic bearing device, as well as a hydrodynamic bearing device, a spindle motor, and an information apparatus equipped with this thrust plate, and a method for manufacturing a thrust plate. With a thrust plate that is provided at one end of a shaft of a hydrodynamic bearing device and that closes off one end of a sleeve formed so as to surround the shaft via a lubricating fluid (oil), a laser irradiated portion is provided to the opposite side of the thrust plate from the side facing the shaft in order to reduce the warpage that is produced by the formation of a hydrodynamic groove on the side facing the shaft, and the warpage that occurs during assembly, etc.

Abstract: In a disclosed fluid dynamic bearing motor, and a disc drive employing the same, variations in motor performance due to a change in viscosity of a bearing fluid caused by a temperature change is canceled. The fluid dynamic bearing includes a sleeve with a shaft insertion hole in it. A shaft is rotatably inserted into the shaft insertion hole. A bearing fluid is disposed between an internal surface of the shaft insertion hole and the shaft. The shaft is formed of a material selected from a group consisting of steel, iron alloy material, aluminum alloy material, and copper alloy material. The sleeve is made of titanium material.

Abstract: A robust spindle motor is provided having improved shock resistance for fluid containment, as well as enhanced air purging characteristics. In an aspect, axial displacement of relatively rotating components is restricted by utilizing a limiter situated adjacent to a limiter bushing forming an axial limiter gap therebetween. A fluid channel, at least partially diverging, extends from a hydrodynamic bearing to the axial limiter gap, and continues to a region beyond the axial limiter gap. In an aspect, an axially diverging slot is situated adjacent to the axial limiter gap. Power is reduced by reducing viscous drag between relatively rotating components, hydrodynamic bearing length is increased, and higher stiffness of the hydrodynamic bearing is provided. Fluid volume may be increased, thereby offsetting fluid evaporation losses and allowing for the use of lower viscosity lubricants.

Abstract: A fluid dynamic bearing with a modified air-gap is disclosed. One embodiment provides a clamp adjacent to the fluid dynamic bearing, the clamp for clamping at least one disk with respect to the fluid dynamic bearing. In addition, a cap is also provided proximal to a shaft of the fluid dynamic bearing, the cap having an outer end proximal to the clamp such that an air-gap is provided between the outer end of the cap and the clamp.

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 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 hydrodynamic bearing is provided that includes an annular main foil having axially spaced inner and outer surfaces. Bump foils are supported circumferentially on the outer surface. Top foils are supported circumferentially on the inner surface opposite the bump foils. In one example, spacers are arranged between the top foils and the main foils. The spacers can be provided by chemically etching the main foil, in one example. The bump foils include first and second corrugated portions respectively providing first and second axially heights. The first axial height is less than the second axial height and is arranged at a leading edge of the bump foil relative to the direction of airflow across the hydrodynamic bearing.

Abstract: Method for gas bearings comprising two relatively rotating parts, one part of which consists of a spindle shaft and the other part of which is provided with a bearing surface and is made from a material through which gas can be conducted to the bearing gap, for producing holes conducting gas to the bearing surface, distinguished by the steps: (a) with the aid of a high-energy beam directed towards the bearing surface, a certain number of first holes smaller than the final number of holes calculated from experience are made in the bearing surface to make a primary airflow through this part of the bearing surface possible; (b) the preliminary airflow is measured; (c) on the basis of the measured airflow, the exact number necessary of additional second holes to be made in order to obtain the desired necessary airflow is calculated; (d) the calculated number of additional second holes are made in the bearing surface.

Abstract: A resin housing 7 is injection-molded by using a forming mold 11. Moreover, a concave shaped adhesive reservoir 10 is formed by a sink mark of the resin during injection molding on its inner circumferential surface 7e simultaneously with the injection molding of the housing 7. Accordingly, the adhesive can be prevented from overflowing and the adverse influence caused by the overflowing of the excessive adhesive can be avoided. A decrease in the molding precision of the housing can be also prevented and cost reduction by dispensing with a processing step can be enabled.

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

Abstract: 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 a method for manufacturing a bearing member which is made of a porous material and has dynamic pressure grooves formed by electrochemical machining, the bearing member is impregnated with liquid such as hydrosoluble liquid or water prior to electrochemical machining. Since the hydrosoluble liquid or water is retained due to capillary force in the bearing member for which electrochemical machining is to be performed, the hydrosoluble liquid or water is not replaced with an electrolyte used in the electrochemical machining. Thus, the step of removing the electrolyte after electrochemical machining can be omitted, increasing production efficiency. Moreover, the bearing member is free from a trouble of rust as the electrolyte does not remain in the bearing member. Since the hydrosoluble liquid or water exhibits excellent affinity for the electrolyte, it does not harm processing accuracy in electrochemical machining and can be easily removed after electrochemical machining.

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 hydrodynamic bearing has a plurality of grooves (34) defined therein. The grooves are used for generating hydrodynamic pressure. Each of the grooves includes an upper branch (344) and a lower branch (342) coupled to the upper branch. The upper branch has a larger angle (?1) of divergence from the groove than that (?2) of the lower branch.

Abstract: A hydrodynamic bearing (300) has a bearing surface adapted for receiving a shaft to rotate thereon. The bearing surface has a plurality of grooves (34) defined therein. The grooves are used for generating hydrodynamic pressure. A depth of each of the grooves is changed in a sloping trend along the extension direction of the groove.

Abstract: A hydrodynamic bearing (300) has a bearing surface adapted for receiving a shaft to rotate thereon. The bearing surface has a plurality of grooves (34) defined therein. The grooves for generating hydrodynamic pressure each has at least one interior surface (3421). The at least one interior surface has a sloping surface along a circumferential direction of the hydrodynamic bearing.

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 method for manufacturing a hydrodynamic bearing (30) comprises the 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 pushing a feedstock of powder and molten binder into the mold to surround the substrate under pressure, whereby a desired bearing preform (20) is formed; step (203): separating the substrate (10) from the bearing preform by means of debinding; step (204): sintering the bearing preform; step (205): precision machining the bearing preform to form the desired hydrodynamic bearing.

Abstract: Working fluid can be prevented from leaking into a vacuum chamber during processes other than a process for injecting working fluid, using a simple construction, and an appropriate amount of working fluid can be injected into an object that is to receive the injection such as a bearing unit.

Abstract: Fluid-dynamic-pressure bearing manufacturing method for more efficient and fail-safe degassing of bearing oil. Method makes it possible to prevent the generation of air bubbles in the course of an oil-charging operation that amounts to a step following degassing, and to single out the causative source of air bubbles when their generation has been detected. At the same time oil that is under a reduced-pressure environment within an oil-storing vacuum chamber is vacuum-degassed, immersed within the oil a stirrer for agitating and degassing the oil is rotated by indirect drive means, and the oil after having been degassed is supplied to a vacuum chamber where a fluid-dynamic-pressure bearing unit is retained—which has been pumped down to a pressure below the pressure within the oil-storing vacuum chamber—and is charged into the bearing clearances by raising the internal pressure of the bearing-retaining vacuum chamber.

Abstract: A method of lubricating a wave bearing comprising application of an oil comprising a perfluoropolyether, derivatized perfluoropolyether, fluorosilicone, polychlorotrifluoroether, or polyphenyl ether, wherein the oil is capable of sustaining temperatures greater than 121° C., and at an operating speed of up to 1.4 million DN without decomposition.

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: Adhesive is applied to an inner surface of a sleeve housing, and a sleeve is inserted from a lower end part thereof into the sleeve housing. An outer edge of the lower end part of the sleeve is provided with an adhesive holding portion in a chamfered shape, and a part of the adhesive is held between the adhesive holding portion and the inner surface of the sleeve housing.

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

Abstract: A rolling element bearing comprises an inner ring and an outer ring which are each provided with a raceway, and a series of rolling elements which are in contact with the raceways of each ring. A lubricant film is provided in the contacts between the rolling elements and the raceways, which film forms a lubricant meniscus at the inlet side of each contact. In the bearing starved lubrication conditions prevail. The surface of each rolling element has minute recesses filled with a lubricant quantity, said recesses being flattened in the contact area defined by the contact between the rolling elements and the rings and thereby releasing lubricant at the inlet side of each contact resulting in a displacement of the meniscus further away from said contact. This meniscus displacement results in an increased lubricant film thickness in each contact area, thus improving the lubricating conditions in the bearing.

Abstract: A production method for sintered bearing member comprises: compacting a metal powder into a green compact, sintering the green compact into a sintered compact; impregnating a resin solvent into the sintered compact, and removing the resin solvent adhering to a surface of the sintered compact, thereby exposing a matrix as sintered on a surface of the sintered compact. Pores existing in portions other than the surface are sealed with the resin.

Abstract: A method for withdrawing liquid from the liquid bearings of a spindle (1) carried in liquid bearings (3, 5) distinguished in that with the help of pressurized gas, the liquid, together with the gas, is forced to exit the spindle during the operation of the spindle via at least one first channel (12), and that when the spindle is shut down, is forced to exit via at least one second channel (13) with a smaller flow-through cross-section than the first channel.

Abstract: The thrust member is inserted into the inner circumferential surface of the housing, to make the end face of the thrust member contact with the lower side end face of the flange portion, and at the same time, to make the upper side end face of the flange portion contact with the lower side end face of the bearing sleeve. This stated is that the thrust bearing gap is zero. Then, the thrust member is made to relatively move with respect to the housing and the bearing sleeve in the axial direction together with the axis member, with a dimension ?(?=?1+?2) that is equivalent to the sum of the thrust bearing gap (size is ?1) of the first thrust bearing portion and the thrust bearing gap (size is ?2) of the second thrust bearing portion. Then, as the thrust member is fixed to the housing at that position, the predetermined thrust bearing gap ?(?=?1+?2) is formed.

Abstract: A bearing assembly and method in which a bearing cage is disposed around a rotating member and a housing is disposed around the cage. A first portion of the radial outer surface of the cage extends in a slightly spaced relation to the corresponding portion of the inner surface of the housing, and a second portion of the radial outer surface of the cage projects from the first portion in a radial direction and engages the corresponding portion of the inner surface of the housing.

Abstract: In order to improve a method to determine the lubricant filling degree of a fluid bearing in which the bearing gap of the fluid bearing is illuminated and the luminous reflectance is analyzed so that the filling degree can be determined in a simple and reproducible manner, it is provided that a spatial intensity profile of the reflected light is recorded.

Abstract: The invention relates to an extra-roll slide bearing system (20) for a paper/board machine or a finishing machine, surrounding a shaft (2) in a roll (1). The bearing system comprises a body section (5), which is formed with a bearing housing (7) provided with hydrostatic bearing elements (3, 3A) disposed around the shaft (2). The bearing elements are fitted with slide elements (4, 4A), having a sliding surface (16) directed towards the shaft (2). Between the slide elements (4) and the shaft (2) is a bushing (6), which is mounted on the shaft (2) for rotation therewith, said slide elements (4, 4A) being adapted to position themselves around the bushing (6) with the sliding surfaces (16) against the external surface of the bushing directed away from the shaft for supporting said shaft (2), and hence the roll (1), rotatably relative to the body section (5). The bearing housing (7) has its axial ends provided with end caps (8, 9), along with packing elements (12, 14) therefor, for sealing the bearing housing.

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

Abstract: The porous oil-impregnated bearing 1 comprises a bearing body 1a made of a porous material, and oil retained in the pores of the bearing body 1a by impregnation with lubricating oil or lubricating grease. The inner peripheral surface of the bearing body 1a is formed with a bearing surface 1b opposed to an outer peripheral surface of a shaft to be supported, with a bearing clearance defined therebetween. The bearing surface 1b has a first region m1 in which a plurality of hydrodynamic pressure generating grooves 1c inclined in one direction with respect to the axial direction are circumferentially disposed, a second region m2 which is axially spaced from said first region m1 and in which a plurality of hydrodynamic pressure generating grooves 1c inclined in the other direction with respect to the axial direction are circumferentially disposed, and an annular smooth region n disposed between the first and second regions m1 and m2.

Abstract: Manufacturing method enabling optimal volume oil-fill even where differing from bearing to bearing due to machining fluctuations in volume-production dynamic pressure bearings. In a first charging method, injection of oil is divided into two cycles. The first is carried out under reduced pressure, following which the pressure is raised a predetermined amount to force the oil into the bearing gap. The oil-fill status is thereupon checked, the shortage is reckoned, and in the second cycle the shortage is injected. In a second charging method, in a first cycle a surplus volume is injected under reduced pressure and the pressure is raised a predetermined amount to force the oil into the bearing gap. Following that, what is in excess of the appropriate amount is removed from the bearing. The first cycle of injection and the pressure elevation may be implemented multiple times, in between which repeat pressure-reduction can be carried out.

Abstract: A method and 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, 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: Fluid-dynamic-pressure bearing furnished with a shaft, a top plate fixed to an upper portion of the shaft, a thrust plate fixed to a lower portion of the shaft, a sleeve, and a cuplike bearing housing that along its inner periphery retains the sleeve. A lubricating-fluid-filled continuous micro-gap is formed in between the shaft and the sleeve and the top plate and the sleeve. Radial bearing sections are formed in between the shaft cylindrical outer surface and the sleeve cylindrical inner surface. An upper thrust bearing section is formed in between the undersurface of the top plate and the top-edge face of the bearing housing. A lower thrust bearing section formed in between the bottom margin of the sleeve and the top margin of the thrust plate. The bearing sections are each provided with dynamic-pressure-generating grooves for inducing dynamic pressure in the lubricating fluid when the shaft or sleeve spins.

Abstract: The invention relates to a gas bearing of a rapidly rotating shaft, whose end supports a tool, in particular to a gas bearing of a rapidly rotating shaft, whose end supports a polygon mirror (27) for a spindle of an optical application. To provide radial support along the shaft (3), gas bearings are arranged in a housing (5), whereby a first gas bearing (9) and a third gas bearing (8) are positioned concentrically in relation to one another and a second gas bearing (2), which is located midway between the first gas bearing (9) and the third gas bearing (8), is mounted in an eccentrically offset manner to the first gas bearing (9) and the third gas bearing (8). The invention is also provided with an adjusting device (1) for increasing the eccentric offset of the second gas bearing (2) as the rotational speed of the shaft (3) increases.

Abstract: Fluid bearings, vacuum chucks and methods for producing these devices. One example of a method for forming a fluid bearing includes forming a plate having a face surface and a bonding surface, coupling a first side of a body to the bonding surface, placing the face surface of the plate against a predetermined surface, and generating a pressure difference to conform the face surface to the predetermined surface. One example of a fluid bearing of the invention includes a plate support and a flexible bearing plate having a bonding surface which is attached to the plate support with an adhesive which is flexible before hardening. The flexible bearing plate conforms to a predetermined surface during a portion of the time that the adhesive hardens. Examples of vacuum chucks, and methods for forming vacuum chucks, and other aspects of the invention are described.

Abstract: A fluid dynamic bearing including a shaft rotating within a sleeve and a thrust plate or the like supported at an end of the shaft rotating in a recess defined with the sleeve. The thrust plate faces a counterplate supported from the sleeve over the recess, and the sleeve and shaft are supported for rotation by fluid in the gap or gaps between the shaft and sleeve, thrust plate and sleeve, and thrust plate and counterplate. To prevent fluid from leaking out of the fluid dynamic bearing into the surrounding atmosphere by seeping between the counterplate and sleeve face it rests on, a seal recess is defined in the sleeve, a crush ring seal is placed in the recess. The counterplate is then pressed into the recess, crushing the crush seal ring and blocking any passage of the fluid from the gap region surrounding the thrust plate through the gap between counterplate and sleeve.

Abstract: A hydrodynamic thrust bearing, forming a part of a bearing system for a rotary bearing of spindle motors utilized to power hard disk drives, which includes at least one annular thrust plate and a counter bearing corresponding to the thrust plate. The thrust plate is firmly connected to a shaft rotatably supported by a radial bearing system. The shaft features an axial bore extends from one shaft end located outside the bearing system until the area where the thrust plate is to be positioned. A fixing element is inserted into the axial bore, an outer diameter of the fixing element being greater than the smallest inner diameter of the bore. This enables the thrust plate to be easily mounted in a press fit even in the area around the middle of the shaft.

Abstract: This specification discloses an etching method for making fluid bearings. The invention uses an ejection axis as the mask of the bearing cast. A protection material is inserted into the inner diameter of the fluid bearing, producing a protection pattern. After pulling out the ejection axis, the bearing cast is etched to form a desired oil groove in the inner diameter. Afterwards, the etching solution is washed away and the protection pattern is removed. The invention can be easily integrated with existing manufacturing procedures, achieving the goal of mass production and lowering costs. In addition, the invention can avoid such problems as rough edges as in the prior art. At the same time, the disclosed method makes the radial and stop parts of the fluid bearing, simplifying the manufacturing procedure.

Abstract: In a dynamic pressure bearing, when a step portion (1a) is formed on the inner peripheral surface (1b) of a sleeve (1) and radial dynamic pressure grooves (3) are formed on the inner peripheral surface of the step portion, the width (L) in the axial direction of the dynamic pressure grooves is set to be slightly smaller than the width (D) in the axial direction of the step portion. The dynamic pressure grooves of the sleeve are formed by electrolytic etching.

Abstract: A method and apparatus for assembling a hydrodynamic bearing in a motor is provided. The method comprises affixing a first bearing upon a shaft, applying an axial tension force to the shaft, and affixing a second bearing upon the shaft in a spaced apart relation to the first bearing, as the axial force is applied to the shaft.