Abstract: A dynamic bearing apparatus which supports a shaft and a bearing so as to be capable of relative rotation by a dynamic pressure of a lubricating fluid. A bottomed screw hole (21a) is provided to at least one end of the shaft (21) to screw a headed screw (24) for attaching a thrust plate (23) a lubricating fluid (F) is filled in a gap of a screw portion between the screw (24) and the screw hole (21a) or a screw non-occupied space (17), and an interposing member (25) which reduces a void cubic content in the screw non-occupied space (17) is attached to the screw non-occupied space (17).

Abstract: A hydrodynamic bearing device includes a sleeve having a bearing bore substantially at a center portion, a shaft inserted in the bearing bore in a rotatable manner, a thrust plate for supporting an end of the shaft in the thrust direction and an upper retaining portion that has an opening portion through which the shaft passes and covers the upper surface of the sleeve. A radial hydrodynamic bearing is formed between the bearing bore of the sleeve and the shaft, while a thrust hydrodynamic bearing is formed between the thrust plate and an end of the shaft. A first space is formed between the upper surface of the sleeve and the upper retaining portion. A second space is formed between the upper retaining portion and a step portion.

Abstract: A spindle motor (80) is composed of a sleeve (5), a shaft (1) that is rotatably sustained by the sleeve (5) in a radial direction through a dynamic pressure bearing (20) containing lubricant (12), and a hub (3) that is fixed to the shaft (1). The hub (3) has a raised section (11) in a ring shape that surrounds one end portion of the sleeve (3).

Abstract: A seal assembly and cartridge for sealing a space between a rotating member and a stationary member in which a sleeve extends around the rotating member and with the inner surface of the sleeve being spaced from the outer surface of the rotating member to form a gap. Pressurized fluid is introduced to the sleeve to establish and maintain a predetermined gap between the sleeve and the rotating member, so that the pressure of the fluid can be varied to maintain the predetermined gap despite variations of the diameter of the rotating member during its rotation.

Abstract: A hydrodynamic bearing device comprises a shaft bush having a substantially conical inclined dynamic pressure surface around the outer circumference thereof which is relatively rotatably inserted in a bearing sleeve having a substantially conical inclined dynamic pressure surface around the inner circumference thereof. A substantially conical inclined bearing space is created in the gap between the inclined dynamic pressure surfaces of the bearing sleeve and shaft bush. 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 present invention provides a positioning mechanism and an exposure apparatus that can be used in a vacuum ambience and has a damping function with small degassing and small dust creation. A positioning mechanism according to the present invention, when used with first and second members, serve to position the second member with respect to the first member, wherein the positioning mechanism include a positioning portion capable of relatively positioning the second member relative to the first member, and an attenuating material provided at least at a portion of a periphery of the positioning portion.

Abstract: The invention relates to a hydrodynamic bearing system for the rotary bearing of a spindle motor particularly to drive the platter(s) in a hard disk drive having a stationary shaft, a bearing sleeve journaled to be rotatable about the axis of the shaft and a cover plate fixedly attached to the bearing sleeve to cover the bearing sleeve in the region of the free end of the shaft, the surfaces of the shaft, the bearing sleeve and the cover plate facing each other and spaced apart from each other by a bearing gap forming at least one radial bearing region and at least one axial bearing region. The invention is characterized in that the cover plate has a cylinder-shaped shoulder concentric to the axis and having a thread to receive a fastening screw which is rotatably accommodated in a recess in the end face of the shaft in such a way that the bearing gap continues between the inner surface of the recess and the outer surface of the shoulder.

Abstract: A rotational member and a stationary member included in a spindle motor provided with air bearings are electrically connected while the bearing is rotating, and abrasion of the rotational member and the stationary member at stages of starting and stopping and damaging the rotational member and the stationary member by external shocks that may be exerted thereon during transportation and handling are avoided. In one embodiment, a sleeve is formed integrally with a motor base. The sleeve has an inside surface serving as a radial-bearing surface that forms a radial bearing together with the outside surface of a rotational shaft, and a thrust-bearing surface that forms thrust bearing together with a thrust plate attached to the rotational shaft. The radial-bearing surface of the sleeve is provided with a recess (groove) for holding lubricating oil while the rotational shaft is rotating.

Abstract: A hydrodynamic bearing having an improved air discharging path for discharging air from the bearing when a shaft is inserted into the bearing, and an apparatus for driving a polygonal mirror using the hydrodynamic bearing.

Abstract: The dynamic bearing device of the invention comprises a housing, a bearing sleeve provided inside the housing, a rotating member rotating relative to the bearing sleeve, and a dynamic bearing portion supporting the rotating member in a non-contact manner by dynamic pressure action of a lubricating fluid generated in a bearing gap between the bearing sleeve and the rotating member. The bearing sleeve has a parent body formed of a sintered metal and a bearing surface facing the bearing gap and formed by a resin layer. The dynamic pressure generating grooves are formed in the resin layer.

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: The invention relates to an exhaust gas turbocharger (1) having a housing and having a shaft (2) which is arranged so as to be capable of rotating about its longitudinal axis in the housing and on which a turbine wheel (4) and a compressor wheel (3) are seated and which is guided in radial bearings (5, 6) which are embodied as magnetic bearings and in at least one axial bearing (9), the bearings (5, 6, 9) each having a bearing plate (12, 14, 16) which is seated on the shaft (2) and at least one stator (19, 20, 21, 22, 49, 50) which lies axially opposite said axial bearing (9) on at least one side, forming a gap. In order to cool the bearings, it is proposed according to the invention that at least one flow duct (62, 65), via which at least one bearing gap can have an air stream applied to it, is formed in the housing.

Abstract: An improved rotational motor, such as a spindle motor for a disc drive, is provided. The motor first comprises a hub having a shaft portion and a horizontal body portion. The motor also comprises a sleeve surrounding the shaft portion of the hub. A fine vertical gap is retained between the shaft and the inner diameter of the surrounding sleeve. In addition, a fine horizontal gap is provided between the upper hub portion and the top of the sleeve. The vertical gap is filled with a lubricating liquid, such as a clean oil. A capillary seal is provided in the vertical fluid gap at one end. Preferably, the capillary seal is disposed at an upper end of the shaft proximal to the horizontal gap. Novel air pumping grooves are machined along the horizontal fluid gap. When the hub is rotated, the air pumping grooves create a high pressure region in the vicinity of the capillary seal.

Abstract: A dynamic pressure bearing device and a spindle motor used for a magnetic disk drive device capable of increasing an impact resistance, reducing A-PRO (oscillating motion of shaft), reducing a variation in rigidity of bearings against a variation in temperature, suppressing a current loss, and reducing a size and a thickness.

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: An inboard thrust surface is provided for a spindle motor that maintains fluid flow through a journal bearing and generates an added offset pressure to avoid any subambient pressure within a journal. In an aspect, journal bearing asymmetry is minimized or eliminated and axial span is increased between journal bearings, reducing wobble or run-out between relatively rotating components. In another aspect, journal axial length is decreased for low profile disc drive memory systems and other spindle motors. In an aspect, two separate thrust surfaces provide an axial force in the same direction, opposing an axial bias force created by interaction of a stator and a magnet, and minimizing power consumption.

Abstract: According to the invention, a shaft as a component of a shaft member of a hydrodynamic bearing and a disc member such as a thrust plate are joined to each other by welding by a simple method with high precision. A shaft having a cylindrical outer circumferential surface, in joint surfaces which are joined to each other of the shaft and a disc member having a flat surface facing an end surface of the shaft, a circumferential projection having a diameter smaller than the outside diameter of the shaft and projected in the axial direction and a recess at least of which outer periphery has a diameter smaller than the outside diameter of the shaft and larger than the diameter of the projection and has a circular shape are provided.

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 fluid dynamic bearings system of the invention provides a device located in a non-grooved low pressure region located at some point in the overall fluid circulation path of the fluid dynamic bearing to collect and trap any air bubbles which may be found in the fluid of the hydrodynamic bearing. More specifically, the air extraction device of the invention comprises a shallow angle V-shaped region which is located in fluid communication with but not in a grooved region of the hydrodynamic bearing. In summary, according to the present invention the hydrodynamic bearing comprises a shaft with a thrust plate at or near at least one end thereof. The thrust bearings are formed on the upper and lower surfaces of the thrust plate (301) and journal bearing (320) on the shaft or facing sleeve surface. Lubricant lies between each of these surfaces and facing surface of a sleeve (312) or counter-plate (308) which overlies the thrust bearing, and fluid lies in all these regions.

Abstract: A sleeve 1 is fixed on a base. Radial dynamic-pressure generating grooves 1A and 1B are provided on an inner surface of the sleeve 1. A thrust plate 4 hermetically seals a lower opening end of the sleeve 1. A shaft 2 is inserted inside the sleeve 1, being allowed to revolve. A flange 3 is fixed at the bottom end of the shaft 2, and its lower surface is placed close to an upper surface of the thrust plate 4. Thrust dynamic-pressure generating grooves 3A and 3B are provided on the surfaces of the flange 3. Gaps A–H among the sleeve 1, the shaft 2, the flange 3, and the thrust plate 4 are filled with a lubricant 5. Hollows 1C–1F are provided on the inner surface of the sleeve 1. The gaps A and C over the thrust dynamic-pressure generating grooves 3A and 3B and their vicinities are narrower than the surrounding gaps B and D (A<B, A<D, C<B, and C<D), and the surrounding gaps B and D are narrower than the gap H in the upper opening end of the sleeve 1 and its vicinity (B<H and D<H).

Abstract: A dynamic bearing apparatus which supports a shaft and a bearing so as to be capable of relative rotation by a dynamic pressure of a lubricating fluid. A bottomed screw hole (21a) is provided to at least one end of the shaft (21) to screw a headed screw (24) for attaching a thrust plate (23) a lubricating fluid (F) is filled in a gap of a screw portion between the screw (24) and the screw hole (21a) or a screw non-occupied space (17), and an interposing member (25) which reduces a void cubic content in the screw non-occupied space (17) is attached to the screw non-occupied space (17).

Abstract: A method of manufacturing a fluid dynamic bearing in which a stopper is fixed by welding. The bearing comprises a hub, a shaft erected on the hub, a sleeve, a cylindrical wall erected on the hub, and the stopper mounted on the cylindrical wall. The method comprises a first step to hold oil in the bearing gap, and a second step to locate the stopper on the peripheral wall being apart from the interface of the oil to fix the stopper by LASER welding.

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 fluid dynamic bearing assembly is described. In one embodiment, the assembly includes an inner member. The assembly further includes an outer member configured to rotate about a rotational axis at a first angular velocity. The assembly also includes an orbital ring disposed between the inner member and the outer member. The orbital ring is configured to rotate about the rotational axis at a second angular velocity, which is less than the first angular velocity.

Abstract: A fluid dynamic bearing motor is provided that comprises a stationary member, a rotating member that is configured to rotate about a rotational axis, a fluid dynamic bearing that is configured to support relative rotation between the stationary member and the rotating member, and a dynamic radial capillary seal defined at least in part by the rotating member.

Abstract: An externally pressurized gas bearing comprising a main shaft, and journal bearing sections having a plurality of axial gas feed rows each having a plurality of circumferentially equispaced gas feed holes, the gas feed holes in the gas feed rows being adapted to spout compressed gas to thereby rotatably radially support the main shaft in a non-contact state, the externally pressurized gas bearing being arranged so that the gas feed holes in the gas feed row are disposed so as to be positioned circumferentially intermediate between gas feed holes in the adjoining gas feed row.

Abstract: A disk drive motor is provided comprising a stationary assembly supported from a base, a rotating assembly supported by the stationary assembly, a fluid dynamic bearing positioned in a gap between the rotating assembly and the stationary assembly, a seal reservoir defined between the stationary assembly and the rotating assembly, at least one fluid re-circulation path extending through the stationary assembly and ending in the seal reservoir, and a pressure-regulating obstruction located in the re-circulation path.

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 direction to prevent the rotary shaft from falling out of the dynamic pressure bearing member.

Abstract: A through hub fill hole and air vent having an enlarged fluid diffusion path is provided for spindle motors. Oil leakage and evaporation from a motor is reduced. In an aspect, oil is retained under conditions of at least a 1000 G shock event. In an aspect, the hub fill hole has a varying diameter and geometry, and is angled, further reducing oil leakage. In an aspect, an additional cavity is employed within the hub, for maintaining rotor rotational balance. The process of filling oil into a spindle motor is made easier from a motor set up and tooling perspective. Removal of the hub and other motor components is not necessary for filling a motor. Large diameter oil fill dispenser heads, subambient and ambient fill processes, and micro dispenser fill processes may be utilized. A measured and controlled amount of oil can be dispensed, reducing variability in the motor filling process.

Abstract: An oil-retaining structure for fan comprises an oily bearing with a central axis hole for pivoting a fan shaft. An oil-collecting recess trench is formed on an inside wall of the central axis hole. There is an acute angle oil-guiding ring edge correspondingly formed at one side of the oil-collecting recess trench. When the fan rotates, lubricant inside the oily bearing is upwardly sucked and blocked by the acute angle oil-guiding ring edge, and returns to the oil-collecting recess trench so as to construct an internal-recycle oil-retaining system.

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

Abstract: A brushless motor includes a highly reliable thrust-receiving member that simplifies the machining and assembling of parts and prevents deformation of the bearing and leakage of lubricating oil. A stator base has a cylindrical portion serving as a base portion of a bearing housing of the motor. The cylindrical portion is integral with the stator base. A sleeve bearing is pressed in and mounted in a fixed condition on the inner side of the cylindrical portion. A stator core consisting of a conductive wire is mounted in a fixed condition on the outer side of the cylindrical portion, thereby forming a stator. A thrust-receiving portion for the rotary shaft is molded integrally with the stator base at the opening of the cylindrical portion by outsert and resin integral molding, this thrust-receiving portion serving to receive the end of the rotary shaft opposite to the output end thereof.

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

Abstract: A 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 fluid dynamic bearing device including a shaft having an interior pressure regulating hole by which a center portion of a thrust surface confronting a thrust plate and a lubricant pool portion of an inner circumferential surface of a sleeve are communicated with each other. Thus, the device is capable of obtaining stable thrust floating characteristics and preventing leaks of the lubricant as well as exhaustion of the lubricant.

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

Abstract: A 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: Radial loads and vibrations and axial loads on a rotor are balanced by a fluid bearing controlled by a self-regulating system that supplies fluid flow or pressure to the gap between the rotor and stator in response to signals of imbalance generated in the machinery itself. The resulting balancing force is thus created by fluidics, and in certain embodiments the sensing circuit is fluidics-based as well. This system provides enhanced flexibility and response time relative to conventional fluid bearings.

Abstract: The present invention relates to the field of fluid dynamic bearings. Specifically, the present invention provides an apparatus and method useful for maintaining axial movement of a rotor in a high speed spindle motor assembly.

Abstract: An improved rotational motor, such as a spindle motor for a disc drive, is provided. The motor first comprises a hub having a shaft portion and a horizontal body portion. The motor also comprises a sleeve surrounding the shaft portion of the hub. A fine vertical gap is retained between the shaft and the inner diameter of the surrounding sleeve. In addition, a fine horizontal gap is provided between the upper hub portion and the top of the sleeve. The vertical gap is filled with a lubricating liquid, such as a clean oil. A capillary seal is provided in the vertical fluid gap at one end. Preferably, the capillary seal is disposed at an upper end of the shaft proximal to the horizontal gap. Novel air pumping grooves are machined along the horizontal fluid gap. When the hub is rotated, the air pumping grooves create a high pressure region in the vicinity of the capillary seal.

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 fluid dynamic bearing motor is described. In one embodiment, the fluid dynamic bearing motor includes a stationary shaft having a first end coupled to a first plate and a second end coupled to a second plate. The motor also includes a hub that is configured to rotate relative to the shaft. A fluid dynamic journal bearing, disposed between the shaft and the hub, radially supports the relative rotation of the shaft. The motor further includes a first seal, which is defined in part by the first plate and is disposed radially outboard of the journal bearing, and a second seal, which is defined in part by the second plate and is disposed radially outboard of the journal bearing.

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: 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 spindle motor for a hard disc drive. The spindle motor includes an oil outflow prevention part mounted at an inner side of an oil inlet, preventing oil from flowing out through the oil inlet, but allowing an outflow of air bubbles that are generated due to gasification of the oil. Accordingly, the contamination of the spindle motor due to oil that has flowed out is decreased.

Abstract: It is the object of this invention to provide a gas dynamic pressure bearing system with high rigidity and reliability. The unit is configured such that a thrust bearing sends lubricating gas under pressure in a radial direction, and a radial bearing sends the gas toward the thrust bearing, thereby increasing the bearing rigidity. In addition, one or more dynamic pressure generating grooves which constitute the thrust bearing are extended and connected to a particle catching holes formed in a shaft. With those configurations, the dust particles are trapped in the catching hole and are kept away from the bearing gaps.

Abstract: It is an object of the present invention to provide a miniaturized, high-precision, easy, and low-cost dynamic pressure bearing device and a manufacturing method thereof. In manufacturing a dynamic pressure bearing device, a first and a second ring-shaped member are fixedly fitted to an outer peripheral surface of a rotating shaft member to constitute a rotating portion, an intermediate member is disposed between these members to constitute a fixed portion, a thrust bearing portion is formed in gaps between the first and second ring-shaped members and the intermediate member, and a journal bearing portion is formed in a gap between the rotating shaft member of the rotating portion and the intermediate member, the first and second ring-shaped members being fixed only with an adhesive applied on surfaces thereof which is to be fitted to the rotating shaft member.