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

Abstract: A fluid dynamic bearing motor is described. In one embodiment, the fluid dynamic bearing motor includes a stationary member and a rotating member. The motor further includes a fluid dynamic thrust bearing disposed along an axial surface of a sleeve. The thrust bearing is configured to axially support the relative rotation of the rotating member and the stationary member and to pump bearing fluid towards a corner of the sleeve. The motor also includes a fluid dynamic journal bearing disposed radially inboard of the thrust bearing along a radial surface of the sleeve, where the radial surface is adjacent to the axial surface. The journal bearing is configured to radially support the relative rotation of the rotating member and the stationary member and to pump bearing fluid to the corner of the sleeve.

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

Abstract: In an aerostatic gas bearing, slot sections can be easily processed, bearing stiffness and a load capacity can be improved, and an amount of gas flow can be greatly reduced as compared with a conventional circular slot restriction bearing. A multiplicity of radial slots are formed on both the end surfaces of a bearing member. A bearing housing is assembled by fixing slot side plates on both the side surfaces thereof and accommodated in a casing, and a shaft having an outside diameter slightly smaller than the inside diameter of the bearing housing is inserted through the bearing housing. Gas is fed from a gas feed port and flown into a multiplicity of slots through a peripheral groove and fed-gas introduction path. The gas flows into the radial bearing clearance between the shaft and the inner peripheral surface of the bearing housing, thereby the shaft is rotatably supported.

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

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. The thrust bearing 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 in the area of the thrust bearing, into which a fixing element is inserted. The fixing element is at least partially provided with a spherical surface. The element is inserted in such a way that the surface of the sphere projects slightly from the end of the shaft and rests on the counter bearing, at least when the motor is at a standstill. Therefore, when the motor is standing still or particularly during its start-up or shut-down phase, the spherical element (and not the bearing surface of the thrust plate) rests on the bearing surface of the cover plate.

Abstract: A high precision spindle suitable for hard disk drives, optical disk drives, such as DVDs, CD drives, and other applications includes a hub, a hybrid hydrodynamic an aerodynamic bearing system, a brushless motor, a starting/stopping assistant device and a base. The hybrid fluid film bearing system ensures that the spindle works at high precision, low acoustic noise and low power consumption. The starting/stopping assistant device lifts the rotating portion of the spindle and its load by means of magnetic force, hence, reduces the friction between the contacted surfaces of thrust air bearing. It reduces the starting/stopping time and lessens the wear of bearing, therefore, effectively suppresses the contamination caused by wear particles. Magnetic seals are also provide to prevent journal bearing fluid from leaking.

Abstract: A downsized spindle motor having a longer bearing service life and enhanced shock resistance includes a flange 11, which bears an axial load of a shaft 8, and which is fixed to an end of shaft 8. Laser welded section 14 is provided at the fixed section between shaft 8 and flange 11. Rotor hub 50 is fixed to another end of shaft 8, and laser welded section 54 firmly bonds the two elements.

Abstract: A hydrodynamic bearing fitted with a seal portion capable of suppressing oil leakage efficiently is offered. Also, a rotor device and a motor using this bearing are offered. The seal portion is formed using a shaft-side tapering portion formed in a shaft and a sleeve-side tapering portion formed in an insertion hole in a sleeve. If the axis of rotation tilts when the shaft is at rest or during rotation, the interval between the outer surface of the shaft and the inner surface of the insertion hole decreases in the opening portion of the insertion hole. However, the two tapering portions secure a gap sufficient to hold oil within the hydrodynamic bearing if the interval decreases. Leakage of the oil from the opening portion of the insertion hole can be suppressed efficiently.

Abstract: The squareness of the both end surfaces of the flange portion with respect to the outer circumference of the shaft portion of the shaft member is set to 0.001 mm or less respectively, and the flatness of both end surfaces of the flange portion is set to 0.001 mm or less respectively. The squareness of the end surface of the bearing member with respect to the inner circumference of the bearing member is set to 0.002 mm or less, and the flatness thereof is set to 0.0015 mm or less. The flatness of the inner surface of the bottom portion of the housing is set to 0.002 mm or less.

Abstract: A hydrodynamic bearing assembly with improved activation features is provided. The opposing surfaces in the radial and thrust bearings have grooves 2 and 5 with depths shallower gradually towards the downstream flow of the fluid passing therethrough, for generating the uniform dynamic pressure distribution. This allows the dynamic pressure distribution to be leveled so as to increase the bearing supporting force and prevent the dew grom being generated. Any one or both of the opposing surfaces in the thrust bearing has the inclined surface from the inner portion towards the outer portion so that the gap between the opposing surfaces is extended to about 2 microns. This causes the contacting points thereof when halted to be closer to the axis so that the friction can be reduced and the driving torque can be reduced when restating the bearing assembly. This also prevent the contact in the thrust bearing due to the external oscillating motion.

Abstract: A bearing unit is provided which supports a shaft (51) rotatably. It includes the shaft (51), a radial bearing (55) to support the shaft (51) circumferentially, a thrust bearing (58) to support the shaft (51) at one of thrusting-directional ends of the latter, a housing (56) having disposed therein the radial bearing (55) and thrust bearing (58) supporting together the shaft (51) and which is filled with a viscous fluid (67), and a spacer member (65) disposed inside the housing (56) to keep a gap defined between the end face of the radial bearing (55) and one side of a radial projection (54) included in the shaft (51). On the end face of the radial breading (55) opposite to one side of the radial projection (54), there is formed a first dynamic pressure producing recess (63) which produces a dynamic pressure by the viscous fluid.

Abstract: A hydrodynamic bearing system for a spindle motor, preferably for driving magnetic disks in disk drives, having at least one journal bearing, that encompasses a rotatably borne shaft in a bore of a sleeve, and at least one thrust bearing, that encompasses a thrust plate rotatably received in a recess of the sleeve and securely joined to the shaft and a counter-bearing associated with the thrust plate that is in the form of a cover plate. The thrust plate and the cover plate are arranged in a common recess of the sleeve, wherein the cover plate is fixed in the recess in a defined position so that a bearing gap with a desired gap width remains on both sides of the thrust plate.

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

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

Abstract: A dynamic pressure bearing motor includes a rotary shaft, a rotary hub coupled to the rotary shaft, a dynamic pressure bearing sleeve that supports the rotary shaft by dynamic pressure and has a fallout stopper flange section that protrudes outward in the radial direction, a thrust dynamic pressure bearing section formed in an axial direction between the dynamic pressure bearing sleeve and the rotary hub, and a circular ring-shaped member that surrounds an outer circumference surface of the dynamic pressure bearing sleeve. The circular ring-shaped member has a hub mounting section that connects to an end surface of the rotary hub in a region radially outside the thrust dynamic pressure bearing section, and a main body section that protrudes inward from the hub mounting section.

Abstract: A hydrodynamic bearing system, particularly for the rotary bearing of spindle motors to power hard disk drives. The bearing system includes a bearing sleeve, a shaft accommodated in an opening in the bearing sleeve and at least one radial bearing section provided between the bearing sleeve and the shaft with the aid of which the shaft and the bearing sleeve are supported rotatably in relation to each other. A bearing gap is formed between the shaft and the bearing sleeve and is filled with a liquid lubricant. A lubricant reservoir and equalizing volume independent from the design of the bearing arrangement is provided in that at least one duct is formed in the bearing sleeve that extends from an outer section of the bearing sleeve to the bearing gap and that is at least partially filled with lubricant.

Abstract: A spindle motor comprises a hollow shaft 13 having one end formed with a thrust plate 15, and a sleeve 12 provided to face the shaft 13 through a radial fluid bearing clearance R therebetween, wherein a thrust fluid bearing S is formed between the opposite flat surfaces 15s of the thrust plate 15 and the sleeve 12 facing the flat surfaces 15s. In addition, the hollow shaft 13 has a connection portion 30 at the lower end formed in a concave shape, such that the thrust plate 15 is guided by the inner peripheral surface of the connection portion 30 such that it is coaxial with the shaft 15, and fixed to the shaft 13 by fitting the cylindrical portion 20b of a set screw 20 to the through hole 15b of the thrust plate 15 and the connection portion 30.

Abstract: A bearing unit is provided which includes a shaft (51) to support rotatably, radial bearing (55) to support the shaft (51) circumferentially, a thrust bearing (66) to support the shaft (51) in the direction of thrusting, and a housing (56) having the radial bearing (55) and thrust bearing (66) disposed therein and in which a viscous fluid (57) is filled. The housing (56) has a sealed structure except for a shaft insertion hole (65) formed therein and through which the shaft 51 is introduced. Between the outer surface of the shaft (51) and the inner surface of the shaft insertion hole (65), there is defined a gap (69) having a sufficient width to prevent the viscous fluid (57) filled in the housing (56) from leaking out of the latter. The housing (56) is formed as a one-piece structure by molding a synthetic resin.

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

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

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

Abstract: A motor with fluid dynamic pressure bearing is disclosed. The motor includes a dynamic pressure bearing member having a concave section that is concave in an axial direction, a rotary shaft that is rotatively supported by the dynamic pressure bearing, and a rotary member that is joined to the rotary shaft in one piece along a joint section between the rotary member and the rotary shaft, and rotatively driven by electromagnetic drive force, an expanded diameter section that is provided on the dynamic pressure bearing member. A fallout preventing member is provided on the rotary member, which overlaps the expanded diameter section of the dynamic pressure bearing member in the axial distraction to prevent the rotary shaft from filing out of the dynamic pressure bearing member.

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

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

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

Abstract: A dynamic pressure bearing device includes a rotary shaft, a dynamic pressure bearing member for supporting the rotary shaft, two radial dynamic pressure bearing parts and a thrust dynamic pressure bearing part formed between the dynamic pressure bearing member and the rotary shaft, and a lubricating fluid continuously filled in the two radial bearing parts and the thrust bearing part. A bypass passage for pressure release is provided for communicating across the two radial dynamic pressure bearing parts to flow the lubricating fluid corresponding to the amount of the unbalance caused by the unbalance of the pumping effect forces from a high-pressure side to a low-pressure side through the bypass passage to reduce the unbalance.

Abstract: A railway car door (10) includes a substantially planar door (14) and a pair of elongated support members (18) which are rotatably mounted to the door. A drive mechanism (50) is operatively associated with the railcar door for imparting rotational forces on the support members. A pair of greaseless crank (22b) and roller hanger assemblies (26) movably support the door member on a track (24). Each crank assembly includes a crank pin (96) having a shaft portion 100 with a peripheral recess (114) closely embraced by a self-lubricating sleeve (116). Each roller hanger assembly includes a housing (102) having a well or channel (106) with at least one self-lubricating annular member or washer (120) disposed at the bottom wall (122) thereof. The peripheral recess (114) of the crank pin shaft portion with sleeve (116) are closely rotatably received in bore or channel (106) with the outer terminal end face (124) of the crank pin shaft portion placed in engagement with the at least one annular member or washer (120).

Abstract: A spindle motor, a fluid dynamic bearing for said spindle motor, and a method of manufacturing said bearing wherein said bearing includes a non-capillary seal fluid reservoir.

Abstract: A spindle motor, a fluid dynamic bearing for the spindle motor, and a method of manufacturing the bearing wherein the bearing does not include a capillary seal fluid reservoir.

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

Abstract: 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 hydrodynamic bearing device which supports a relative-rotation shaft or bearing by the hydrodynamic pressure of lubricating fluid which develops in a clearance between the bearing and the shaft, wherein leakage of the lubricating fluid to the outside of the bearing is satisfactorily prevented by a simple arrangement.

Abstract: An apparatus for and a method of construction of a spindle motor having a bearing unit, a rotary shaft, a rotary hub member and an electro-magnetic motor is presented. The rotary shaft has a flange attached at a mid-section in an axial direction, between large and small diameter sections of the rotary shaft. Grooves between the bearing unit, rotary shaft and flange create radial dynamic pressure generating areas, each with as long as possible a span, and thrust dynamic pressure generating areas to both sides of the flange.

Abstract: A spindle motor for use in a disk drive, the spindle motor including a shaft having a larger diameter section and a smaller diameter section with a step formed therebetween. The spindle motor also includes a bearing sleeve having a central cylindrical opening, the shaft is inserted into the central cylindrical opening. A bearing gap is formed between the shaft and the bearing sleeve, the bearing gap being filled with lubricating fluid. A thrust plate is fixedly mounted on the shaft in the area of the step such that an upper side of the thrust plate is placed adjacently to the larger diameter section and a lower side of the thrust plate is placed adjacently to the smaller diameter section of the shaft.

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

Abstract: A gas dynamic pressure bearing is disclosed in which dynamic pressure generating grooves in a radial bearing pump out gas toward a thrust bearing, and dynamic pressure generating grooves in the thrust bearing pump in gas toward the radial bearings. This structure generates high pressure in the lubrication gas in the connecting portions of the radial bearings and thrust bearings. In order to compensate for the movement of gas by means of this pump-out and pump-in operation, a structure is provided that links the two portions of the radial and thrust bearings where the gas pressure is reduced, or connects these two portions with the space surrounding the bearing.

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

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 &dgr;(&dgr;=&dgr;1+&dgr;2) that is equivalent to the sum of the thrust bearing gap (size is &dgr;1) of the first thrust bearing portion and the thrust bearing gap (size is &dgr;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 &dgr;(&dgr;=&dgr;1+&dgr;2) is formed.

Abstract: A fluid bearing with an oil circulating hole therein has a bearing housing fixedly assembled to a stator base having a closed bottom surface; and upper and lower bearing portions; and a thrust receiving portion to rotatably support a rotating shaft. An opening oil reservoir is in the bearing housing and a lower oil reservoir is formed at the lower portion thereof. An intermediate oil reservoir is located between the upper and lower bearing portions. The oil circulating hole is formed in parallel with the rotating shaft in order to communicate with the opening oil reservoir, the intermediate oil reservoir and the lower oil reservoir. A space is defined at an opening portion which is covered with a cap in order to prevent oil from leaking.

Abstract: There is provided a means for preventing wear caused by the contacting/sliding of a thrust hydrodynamic gas bearing surface when a spindle motor is started. A cylinder 4 of a radial hydrodynamic gas bearing that has radial hydrodynamic grooves in an outer circumferential surface thereof and a disk 3 of a thrust hydrodynamic gas bearing that has thrust hydrodynamic grooves in an upper face thereof are disposed on an upper end of an axial center of a stator core 2 having a stator 2a around which a motor coil 7 is wound, a hollow cylinder 6 whose inner surface facing the cylinder 4 of the radial hydrodynamic gas bearing is smooth and a rotor magnet 8 facing the motor coil 7 are disposed on a hub 5 acting as a rotational member, a load in a radial direction is supported by the radial hydrodynamic gas bearing, and a load in a thrust direction is supported by using the thrust hydrodynamic gas bearing together with a magnetic bearing consisting of the stator 2a and the rotor magnet 8.

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

Abstract: A hydrodynamic bearing unit and a manufacturing method therefor that reduce manufacturing costs and prevent leakage of lubricating oil are provided. The bearing unit includes a shaft, a sleeve which is rotatably mounted to the shaft and which forms a radial bearing in cooperation with the shaft, and a pair of seal members which are fixed to the shaft, which form respective thrust bearing parts in cooperation with the sleeve, and which seal lubricating oil circulating in the bearing unit. The shaft has a large-diameter part functioning as one of the seal members. The other seal member is fixed to the shaft by press-fitting.

Abstract: A motor is disclosed comprising a rotating shaft where the shaft comprises both an axial shaft and at least one thrust plate, both the shaft and thrust plate being supported for rotation by fluid dynamic bearings. A secondary fluid dynamic bearing is provided, coupled to the main support fluid dynamic bearing, and is oriented to provide additional axial and/or radial stiffness. Preferably, the secondary fluid dynamic bearing is defined between the sleeve which establishes the bore wherein the shaft rotates, the sleeve having an outer surface which is cylindrical and defines and includes one surface of the secondary fluid dynamic bearing, the other surface being defined by the inner surface of a hub which is coupled mechanically to the rotating shaft and thrust plate and is rotating over and around the sleeve.

Abstract: A dynamic pressure bearing device includes a dynamic pressure bearing member that generates a dynamic pressured by pressurizing a lubrication fluid by a dynamic pressure generation device, and supports a rotary shaft by the dynamic pressure generated in the lubrication fluid, a thrust dynamic pressure bearing member formed by an end face in an axial direction of the dynamic pressure bearing member and an end face in an axial direction of a rotary member that rotates together with the rotary shaft, which are disposed opposite each other in the axial direction, and a fluid sealing section for preventing the lubrication fluid in the thrust dynamic pressure bearing member from leaking outside, provided adjacent to an outer side section in a radial direction of the thrust dynamic pressure bearing member and defined by an outer circumference wall surface of the dynamic pressure bearing member.

Abstract: In a hydraulic bearing motor, by means of dynamic pressure generating grooves provided on a thrust shaft with a larger diameter not only on the end face thereof but also on the shaft surface thereof, pressures generated in oil when rotating a shaft body are made to be applied not only in the axial direction but also in the radial direction with high magnitude. This can provide the hydraulic bearing motor as being capable of satisfying features of exhibiting small NRRO, and vibration and shock resistance even with a thinned hydraulic bearing motor.

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 dynamic pressure bearing device includes a dynamic pressure bearing member, a rotary member that is rotatable with respect to the dynamic pressure bearing member, a thrust dynamic pressure bearing section provided in a thrust opposing region that is between an end surface in an axial direction of the dynamic pressure bearing member and an end surface in the axial direction of the rotary member, and a pumping device provided in the thrust opposing region. The thrust dynamic pressure bearing section rotatably supports the rotary member in the axial direction of the rotary member, and the pumping device provided in the thrust opposing region pressurizes a lubricating fluid inside the thrust opposing region inwardly in a radial direction, wherein the pumping device generates an inward pressurizing force larger than a rotational centrifugal force applied to the lubricating fluid within the thrust opposing region during rotation.

Abstract: In order to manufacture a dynamic pressure bearing device, there are provided a shaft member, and a thrust plate formed with a press-fitting portion into which the shaft member is press-fitted. At least two relief portions are formed in at least one of the press-fitting portion of the thrust plate and a part of the shaft member which corresponds to the press-fitting portion. The shaft member is press-fitted with the press-fitting portion such that the thrust plate extends perpendicular to an axial direction of the shaft member, while making the relief portions absorb press-fitting stress.

Abstract: A dynamic pressure bearing device having a structure in which forces in the radial and thrust directions can be easily balanced with each other, and lubricant hardly leaks is provided. The device has: a housing having an opening in each of both end portions, and an internal space; a shaft passing through the openings; and a flange disposed on the shaft, and in which radial dynamic pressure generating grooves and thrust dynamic pressure generating grooves are formed, radial dynamic pressure bearings are respectively formed in vicinities of the end openings of the housing, and thrust dynamic pressure bearings for supporting both faces are formed between the radial dynamic pressure bearings. The radial dynamic pressure bearings between which the thrust dynamic pressure bearings are interposed are formed symmetrically with respect to the thrust dynamic pressure bearings.