Abstract: A hydrodynamic bearing system for use in spindle motors having a shaft and a bearing sleeve. At least one bearing member is mounted an outer surface of the shaft. A fluid trap member is further provided in the bearing system, the fluid trap member being integrated into the bearing member. A fluid trapping cavity is formed between the fluid trap member and a surface of the bearing member.

Abstract: A fluid dynamic pressure bearing apparatus includes a radial dynamic pressure bearing formed in a gap portion between a bearing member and a shaft member. The apparatus also includes a thrust dynamic pressure bearing having a first thrust bearing portion formed between a top surface of the thrust plate and a first facing member opposing thereto in the axial direction and a second thrust bearing portion formed between a bottom surface of the thrust plate and a second facing member opposing thereto in an axial direction. Dynamic pressure generating grooves are formed on the radial dynamic pressure bearing and the thrust dynamic pressure bearing.

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: 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 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: A variable-gap fluid dynamic bearing motor assembly is described. In one embodiment, the assembly includes a hub configured to rotate about a rotational axis and to support at least one disc. The assembly also includes a first member attached to the hub and configured to rotate about the rotational axis and a second member. A first fluid dynamic journal bearing having a first bearing gap and a second fluid dynamic journal bearing having a second bearing gap are disposed between the first member and the second member. The bearing gaps are configured such that the second bearing gap is larger than the first bearing gap. Bearing fluid disposed within the first fluid dynamic journal bearing and the second fluid dynamic journal bearing to support the relative rotation of the first member and the second member.

Abstract: A hydrodynamic bearing having a shaft (10) and a bearing sleeve (12), which encloses the shaft with a slight radial clearance forming a concentric bearing gap. An equalizing volume cavity (20) is formed at at least one end of the bearing. At least one micro-passage (26) connects the bearing gap via appropriate openings with the equalizing volume cavity (20). Bearing fluid completely fills the bearing gap (24) and the micro-passage (26) and at least partially fills the equalizing volume cavity (20). The bearing fluid forms a continuous fluid film between the bearing gap (24) and the equalizing volume cavity (20).

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 bearing having a shaft, which is fixedly connected at one end to a rotating component, and a bearing sleeve, which encompasses the shaft at its other free end with a slight clearance. The sleeve and the shaft form a concentric bearing gap. The shaft and/or the bearing sleeve is provided with at least one groove pattern which forms at least one radial hydrodynamic bearing. A volume equalizing cavity and at least one connecting passage connecting the bearing gap with the volume equalizing cavity extend radially outwards at an angle to the bearing gap.

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: 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: An apparatus for rotatably mounting and axially fixing a gear on a shaft comprises a bushing fixed within a bore of the gear. A sleeve is received on and fixed relative to the shaft. The sleeve is surrounded by and journalled for rotation within the bushing. A thrust ring is fixed relative to and projects radially from the shaft on one side of the gear. A retainer on the one side of the gear defines a circular channel within which the annular thrust ring is axially confined.

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 method of assembling a rotor structure for a spindle motor for use in an information recording and playback apparatus is provided in which pollution of the recording medium due to gases emitted from adhesives and the like used in the manufacturing process can be prevented. To be more specific, in an assembling process of securing a rotor yoke and a rotating magnet on a disc section, the rotor yoke, the rotating magnet, and the disc section is disposed one after another at predetermined positions of a centering jig used for centering the center of rotation of the rotating magnet and the center of rotation of the disc section. A pressing mechanism is then placed on the disc section to press the disc section, the rotor yoke, and the rotating disc so as to integrate them into one piece. At the same time, emitted gases are exhausted with an exhausting apparatus in a manner such that the direction of flow of the emitted gases is from the main surface of the disc section toward the rotor yoke.

Abstract: A gas dynamic bearing motor is provided that is capable of setting a bearing radius to a large value to obtain a sufficient radial stiffness, and preventing lock of the bearing and scattering of wear powder outside the bearing. An annular groove 11 is provided on a lower end surface 87 of a hub 3 to thereby enable a deformation of an inner circumferential surface 82 of the hub 3 when recording disks 9 are loaded on the hub 3 to be suppressed to a small value, thereby enabling partial contact in the radial bearing to be suppressed and lock of the bearing to be prevented. Further, a protrusion 12 is provided on a base 7 in a circumferential direction and fitted in the annular groove 11 to construct a labyrinth seal, thereby enabling scattering of wear powder generated on bearing surfaces outside the bearing to be prevented.

Abstract: A fluid dynamic bearing motor is provided having an annular sleeve, a shaft disposed through the sleeve, a hub supported on a first end of the shaft, a journal between the sleeve and the shaft, and a fluid dynamic bearing in the journal, wherein the fluid dynamic bearing comprises an axial bearing and a radial bearing, the axial and radial bearings being formed on respectively angles surfaces to form one corner bearing.

Abstract: A bearing has a thrust plate integrated with its shaft and a bearing member surrounds both. A radial pressure bearing portion and separate thrust portion generate pressure on a lubricating fluid in a gap between the shaft and bearing member. One end of the gap is closed while the other is open and has a capillary seal formed with an angle that is large at a boundary but smaller at increasing distance therefrom. The fluids fills the gap so that gas-fluid interface is where the angle is small and causes the thrust plate to float. A pressure mechanism forces the fluid from the open to the closed end and the quantity of fluid is set to fill the mechanism even if the gas-fluid interface moves.

Abstract: Low-profile spindle motor whose entire shaft length is utilized to configure, along an encompassing sleeve, a radial dynamic-pressure bearing section. One end of the shaft is unitary with the rotor, and a cover member closes the other end. Between the sleeve upper-end face and the rotor undersurface a thrust bearing section is configured. Micro-gaps are formed continuing between the sleeve upper-end face and the rotor undersurface; the sleeve inner-circumferential surface and the shaft outer-circumferential surface; and the cover member inner face and the shaft end face, where an axial support section is established. Oil continuously fills the micro-gaps, configuring a full-fill hydrodynamic bearing structure. Hydrodynamic pressure-generating grooves in the radial bearing section are configured either so that no axial flow, or so that a unidirectional flow that recirculates from one to the other axial end of the radial bearing section through a communicating pathway is induced in the oil.

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, wherein the thrust plate is firmly connected to a shaft rotatably supported by means of a radial bearing system. The thrust plate is arranged on the shaft which has an axial bore in the area where the thrust plate is to be positioned. A fixing element affixing the thrust plate to the shaft is pressed into the axial bore of the shaft. The 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 thinner thrust plates to be utilized with the performance of the thrust bearing remaining the same or improving.

Abstract: A hydrodynamic bearing unit is provided, by which the touch between oil and a sealing member in a housing is prevented to prevent oil leakage. A bearing member made of a sintered lubricant-containing metal is disposed along the inner periphery of the housing and a spindle is supported in a non-contact manner by the hydrodynamic oil pressure that is generated in a bearing gap by the rotation of the spindle. The opening of the housing is sealed by the sealing member. A ventilation path is formed so as to communicate a sealed space enclosed by the distal end of the spindle at the bottom of the housing, the bearing member and the housing with open air. An oil reservoir is formed between the inner periphery of the housing and the outer periphery of the bearing member at the end portion of the opening side of the housing. The oil reservoir is made so as to communicate with the ventilation path.

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: 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: The present invention provides a spindle motor and a method of manufacturing a spindle motor wherein a bearing unit is manufactured as a discrete modular component. A spindle motor that meets a set of specific technical requirements can be easily manufactured by combining such a bearing unit with other spindle moor components.

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: The invention is a bearing unit and bearing system for supporting a large rotatable element, such as a mooring turret. The bearing unit includes a hydrostatic suspension system which enables the bearing unit to accommodate fabrication tolerances and also enables the bearing unit to conform to relative movements between the ship and the turret, thereby providing a compliant bearing system. The system includes multiple bearing units of the invention which serve as thrust and/or radial bearings for supporting the turret. By manifolding a plurality of bearing units together in a fluidly-isolated group, the pressure applied to the bearing units in that group is self-equalizing so that all the bearing units act in unison to equally support the load, while also allowing some degree of self-alignment and tilting of the load. As a result, the bearing system emulates a self-aligning bearing system and is able to compensate for axial and angular misalignment.

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.

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 first 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. A third gap is preferably provided between the hub and an outer diameter of the sleeve. The first vertical gap is filled with a lubricating liquid, such as a clean oil. A capillary seal is provided in the third gap. In one embodiment, the lubricating liquid extends into the horizontal gap. Oil pumping grooves are machined along the horizontal fluid gap. When the hub is rotated, the oil pumping grooves impel oil towards the shaft. This prevents any portion of the first vertical gap from becoming un-lubricated during rotation of the shaft.

Abstract: A spindle design for a hard disk drive assembly constructed in accordance with the present invention includes a significantly large gap between the rotating, ferromagnetic hub with its permanent magnet rotor and the rotating sleeve of the fluid bearing journal member. The large gap may be filled with a medium, such as air, or a non-permeable material. The large gap is preferably on the order of several hundred microns. Because of the large gap, the magnetic flux leakage from the rotating hub members and sleeve into the stationary shaft at the center of the spindle is negligible. Consequently, iron loss in the shaft caused by magnetic flux leakage into the shaft is reduced to acceptable noise levels.

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: 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. By applying a predetermined voltage across the shaft and the disc member in a state where the joint surface of the shaft and the joint surface of the disc member are in contact with each other, the projection is melted. The melted matter is housed in the recess.

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: 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 variable-gap fluid dynamic bearing motor assembly is described. In one embodiment, the assembly includes a hub configured to rotate about a rotational axis and to support at least one disc. The assembly also includes a first member attached to the hub and configured to rotate about the rotational axis and a second member. A first fluid dynamic journal bearing having a first bearing gap and a second fluid dynamic journal bearing having a second bearing gap are disposed between the first member and the second member. The bearing gaps are configured such that the second bearing gap is larger than the first bearing gap. Bearing fluid disposed within the first fluid dynamic journal bearing and the second fluid dynamic journal bearing to support the relative rotation of the first member and the second member.

Abstract: According to the present invention, a cylindrical side wall is provided in a housing so as to surround an outer periphery of a stopper member. Further, an end surface of the side wall is higher than a top surface of outermost periphery of the stopper member. Oil otherwise scattered is received by the side wall for collection. Oil is thus prevented from scattering even if during manufacturing, the amount of oil dripped between the shaft and the oil-impregnated bearing is not strictly controlled, so that a slightly excessive amount of oil is dripped. Therefore, the present motor device enables manufacturing operations to be favorably performed, and is reliable having a long lifetime.

Abstract: The stop ring having a surface nearly vertical to the rotational center axis, which is projected at the inner periphery of the hollow cylinder of the rotor section, and the stepped surface of the fixed shaft secured on the chassis are opposed to each other with a predetermined slight clearance provided therebetween. The clearance is filled with magnetic fluid, and further, a permanent magnet is disposed on the chassis, opposing to the other surface of the stop ring.

Abstract: In order to provide a high-accuracy long-life hydrodynamic bearing not causing oil film breakage in bearing clearances and a disc rotation apparatus using the bearing, when the outside diameter of the herringbone pattern of dynamic pressure generation grooves provided on at least one of the opposed faces of a flange and a thrust plate is designated as dlo, the inside diameter thereof is designated as dli and the diameter of the turn-back part thereof is designated as dlm, the diameter dlm of the turn-back part is set so as to satisfy the relationships represented by the following equations:

Abstract: A system, method and means is provided for withstanding mechanical shock for use with fluid dynamic bearings. A sealing system is provided that withstands 1000 G shock events. In an aspect, a grooved pumping seal employed between a thrust plate and a shield, a thrust plate having spiral grooves, a fluid recirculation passageway, and a reservoir creates an asymmetric pressure gradient. In an aspect, fluid is retained and air is purged utilizing an enlarged fluid reservoir, axial channels and an angled fill hole. In an aspect, a shaft is attached to a top cover supplying radial stiffness, and an enlarged single-sided thrust plate improves dynamic parallelism.

Abstract: A pair of thrust hydrodynamic bearing portions are made to communicate with each other to form fluid circulating passages for equalizing a pressure imbalance between both thrust hydrodynamic bearing portions. Even in a case where a pressure imbalance has occurred in a lubricating fluid inside the thrust hydrodynamic bearing portions due to such a cause as the deformation of a thrust plate, the lubricating fluid is allowed to move between the pair of upper and lower thrust hydrodynamic bearing portions through the fluid circulating passages so as to overcome the pressure imbalance, thereby making it possible to stably obtain the amount of floatation in the thrust hydrodynamic bearing portions.

Abstract: A 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 is provided inside the shaft in a fluid dynamic bearing device. 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: A very thin lubricant coating is applied to one or both of the facing surfaces defining the gap of a hydrodynamic bearing to prevent wear of these surfaces. The lubricant film is necessarily very thin, in the range of about 10 Å to 1000 Å, so that the film is thin enough that it does not materially affect the performance of the hydrodynamic bearing gap which is about typically 1-10 &mgr;m. The thin lubricant film could be a perfluoropolyether (PFPE) or a mixture of PFPE or a phosphazine derivative. To improve the adhesion and lubricating performance, functional PFPE can be used. For pure metallic surface like steel, phosphate esters can also be used because of its affinity with the metallic surface, e.g., ferrous. For example, the film could be PFPE, or a mixture of PFPE and a phosphazine derivative. The lubricant should be chosen to be thermally stable, and non-reactive with the typical ambient environment.

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: Spindle motor utilizing a dynamic-pressure bearing device having a full-fill structure and capable of discharging air bubbles from the lubricating oil after it is charged into the bearing device, as well as air bubbles appearing in the oil due to cavitation in handling. Thrust and radial bearing sections are configured within bearing clearances in between the rotor, the shaft, and a shaft-encompassing hollow bearing member. A communicating passage enabling the oil to redistribute itself within the bearing clearances is formed in the bearing member. At least one ray-like groove that reaches from the radially inward edge of dynamic-pressure-generating grooves in the thrust bearing section to the rim of the shaft-encompassing hollow is furnished in the bearing member. When the motor rotates the air bubbles are stirred and minced by the ray-like groove, and migrate toward release at the single oil-air interface.

Abstract: A fluid dynamic bearing is provided having two surfaces rotatable with respect to each other, a lubricating medium located in a gap between the two surfaces during rotation of the bearing, and an interrupted and offset groove pattern formed on one of the two surfaces to distribute the lubricating medium over the surface of the bearing. The groove design is intended to be useable in either a journal, thrust or other fluid bearing design.

Abstract: In order to provide a high-accuracy long-life hydrodynamic bearing not causing oil film breakage in bearing clearances and a disc rotation apparatus using the bearing, when the outside diameter of the herringbone pattern of dynamic pressure generation grooves provided on at least one of the opposed faces of a flange and a thrust plate is designated as d1o, the inside diameter thereof is designated as d1i and the diameter of the turn-back part thereof is designated as d1m, the diameter d1m is selected so that the difference between the diameters dsy and d1m becomes 0.05 mm or more and 0.

Abstract: The slide bearing is constructed of, on one hand, a hydrodyamic radial slide bearing (2) which surrounds, with a play, an axle (1) to be beared, such that between the axle (1) and the radial slide bearing (2), a first gap (9) is formed which is in connection with a source of liquid under pressure and, on the other hand, at least one hydrostatic axial slide bearing (3) which is situated with a play opposite to a radially extending surface portion (6) of the axle (1), such that also between this portion (6) of the axle (1) and a radially directed portion (12) of the axial slide bearing (3), a second gap (13) is formed which is in connection with the first gap (9).

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: Spindle motor utilizing a dynamic-pressure bearing device having a full-fill structure and capable of discharging air bubbles from the lubricating oil after it is charged into the bearing device, as well as air bubbles appearing in the oil due to cavitation in handling. Thrust and radial bearing sections are configured within bearing clearances in between the rotor, the shaft, and a shaft-encompassing hollow bearing member. A communicating passage enabling the oil to redistribute itself within the bearing clearances is formed in the bearing member. At least one ray-like groove that reaches from the radially inward edge of dynamic-pressure-generating grooves in the thrust bearing section to the rim of the shaft-encompassing hollow is furnished in the bearing member. When the motor rotates the air bubbles are stirred and minced by the ray-like groove, and migrate toward release at the single oil-air interface.

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 fluid dynamic bearing includes a shaft and a sleeve which are supported for relative rotation by fluid in the gap therebetween. A capillary seal at one end of the bearing prevents fluid from leaking out. The seal is defined between the hub and the sleeve, which are in relative rotation, and diverge from one another in the region where the capillary seal is established. The gap which is incorporated in the capillary seal is in airway communication with the gap between the shaft and the sleeve; but the capillary seal is defined by an outer surface of the sleeve and is substantially parallel to the gap between the shaft and the sleeve. The capillary seal is radially spaced from the region where one of two journal bearing groove sets is defined. The grooves sets may be located so that they are balanced about the center of gravity of the system.