Abstract: A hydrodynamic bearing device is provided for use with a spindle motor. The hydrodynamic bearing device has a sleeve made of a sintered metal that is obtained by sintering a sintering material that is iron, an iron alloy, copper, a copper alloy or a mixture thereof. This sintered metal has independent pores, which do not communicate with each other, by selecting conditions for forming a desired sintered body within a predetermined range. The conditions includes a grain size of powdered metal of a material for the sintered metal, a molding pressure when the molded body is formed, sintering temperature and sintering period in the sintering step.

Abstract: A fluid dynamic bearing unit is provided which has a high load capacity against a moment load, whose bearing sleeves can be manufactured and fixed easily, and which can provide a required fixing power. The bearing sleeve is inserted into an inner periphery of a housing, and its bottom end is fixed to the top end of a spacer part with an adhesive. Another bearing sleeve is inserted into another part of the inner periphery of the housing, and its top end is fixed to the bottom end of the spacer part with an adhesive.

Abstract: A spindle motor includes a shaft including a core spindle member with a large and a small diameter portions and an encircling annulus member attached to the small diameter portion; a rotor hub attached to the large diameter portion; a bearing member; a radial bearing portion provided with first dynamic pressure creating grooves and formed between the outer peripheral surface of the encircling annulus member and the inner peripheral surface of the bearing member; a thrust bearing portion provided with second dynamic pressure creating grooves and formed between a lower end of the encircling annulus member and the bottom of the bearing member; a first opening formed at a radially inner side of the thrust bearing portion; a second opening formed at a radially outer side of the large diameter portion; and a communication hole continuously formed from the first opening to the second opening.

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

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

Abstract: A hydrodynamic bearing device comprises a sleeve composed of a sintered member, a shaft that is inserted in a state of being capable of relative rotation into a bearing hole provided to the sleeve, and a hydrodynamic groove formed in the outer peripheral surface of the shaft and/or the inner peripheral surface of the sleeve. The sleeve has a surface porosity of 1.5% or less, and the ridge width is at least 0.10 mm.

Abstract: A housing for a hydrodynamic bearing unit of this type is formed from a resin material having high oil resistance and low outgassing property to ensure the cleanliness of the bearing unit. An ester-based lubricating oil is used as a lubricating oil filled inside the hydrodynamic bearing unit 1, and the housing 7 is formed from an LCP-based resin material.

Abstract: A fluid dynamic bearing device includes a sleeve having a bearing hole into which a shaft is inserted, the sleeve rotatably supporting the shaft to make relative rotation about a center axis and a bearing housing made of a cold-rolled steel plate or a galvanized steel plate, the sleeve being received within the bearing housing. The bearing housing is filled with lubricating oil mainly composed of ester. A radial dynamic pressure bearing portion is provided between an outer circumferential surface of the shaft and an inner circumferential surface of the sleeve, the radial dynamic pressure bearing portion having radial dynamic pressure grooves for holding the lubricating oil as working fluid and for inducing a fluid dynamic pressure in the lubricating oil during the relative rotation. At least a surface region of the bearing housing remaining in contact with the lubricating oil is coated with a layer mainly composed of nickel.

Abstract: There is provided a hydrodynamic bearing device with which the lubricant is prevented from leaking to the outside, and good seal performance can be maintained, and a spindle motor equipped with this hydrodynamic bearing device. The hydrodynamic bearing device comprises a shaft, a sleeve, a lubricant that fills a microscopic gap, a radial bearing portion, a thrust beating portion, and a bearing seal portion. The value of a function P1/V1, where V1 is a fluctuation volume of the sleeve in the axial direction and P1 is a capillary pressure index at a vapor-liquid interface located near the opened end of the bearing seal portion, is at least a specific value.

Abstract: A sleeve and a sleeve housing are bonded to each other with adhesive. A thrust dynamic pressure bearing portion is configured between a thrust plate attached to a distal end of a shaft and the lower end surface of the sleeve. An annular step portion having a smaller diameter is provided at the lower side of the sleeve housing, and the annular step portion meets the sleeve. An annular raised portion is provided between thrust dynamic pressure grooves on the lower end surface of the sleeve and the annular step portion. In this configuration, the surplus adhesive leaked from between the sleeve and the annular step portion can be blocked by the annular raised portion, thereby preventing the adhesive from flowing into the thrust dynamic pressure bearing portion.

Abstract: There is provided a hydrodynamic bearing device that maintains high bearing angular stiffness, and that prevents oil film separation in the bearing by smoothly discharging any bubbles present inside the bearing. With a hydrodynamic bearing device, a communicating hole and a radial hydrodynamic groove constitute a circulation path for a lubricant, and a first thrust bearing surface is provided at a location in contact with the circulation path. A first hydrodynamic groove formed in the first thrust bearing surface is a spiral groove with a pump-in pattern. Any bubbles in the bearing are smoothly discharged by the circulation of the lubricant produced by the asymmetrical radial hydrodynamic groove. The pressure generated at the thrust bearing surface during rotation of the bearing has a distribution such that there is a wide range of high pressure.

Abstract: In a hydrodynamic bearing device in which a radial bearing face having a dynamic pressure generating groove on a shaft or an inner periphery of a sleeve is provided and a clearance between the shaft and the sleeve is filled with lubricant, an annular depression is provided on one end face of the sleeve adjacent to a rotor hub and a cover plate for covering the depression is attached to the sleeve so as to define a reservoir for the lubricant or air for the purpose of preventing such a risk that absence of an oil film occurs in clearances of a bearing of the hydrodynamic bearing device due to outflow of oil upon forcing of the oil by air received into the bearing. A step portion is provided on the other end face of the sleeve such that the step portion and the reservoir are communicated with each other by a communication hole. During operation of the hydrodynamic bearing device, air in the hydrodynamic bearing device reaches the reservoir via the communication hole so as to be discharged from the reservoir.

Abstract: A shaft body 2 of a fluid dynamic bearing having a flange portion 4 at one end is supported rotatably via radial direction micro clearances by the sleeve 5 having a dynamic pressure generating groove 11 on the inner peripheral portion. A flange portion 4 is inserted between the lower end surface of the sleeve 5 and end plate 7. A dynamic pressure generating groove 12 is formed on the lower end surface of sleeve 5, and a dynamic pressure generating groove 13 is formed on the upper surface of the endplate 7. The lower end surface of the sleeve 5 and the upper surface of the flange portion 4, and the upper surface of the end plate 7 and the lower surface of the flange portion 4 are facing each other via respective thrust direction micro clearances. Sleeve 5 is inserted into the case 6 such that the upper end surface is projected from the upper end surface of the case 6.

Abstract: A thrust dynamic pressure bearing with high inclination-resistant rigidity against axis runout and additionally low bearing loss torque is implemented. Herringbone grooves (131) having intermediate bends (132) are provided on rotating-side bearing surface (11) provided on the rotating-side bearing member. When rotating-side bearing surface (11) rotates in direction A (clockwise), lubricating oil generates dynamic pressure in an area centering on intermediate bend (132) along radially outer part (133) and radially inner part (134) of herringbone groove (131). As a result that groove width (G) of a dynamic pressure generating groove and width (L) of a land adjacent to the dynamic pressure generating groove holds G>L at an arbitrary radius (2) position, a thrust dynamic pressure bearing with high inclination-resistant rigidity and additionally low bearing loss torque is provided.

Abstract: A hydraulic dynamic bearing has a rotor comprised of a flanged shaft having a thrust ring portion and a cylinder portion, a hub attached to the flanged shaft, and a rotor magnet attached to an inner peripheral face of a skirt portion of the hub. A stator rotatably supports the rotor and comprises a bearing sleeve to which are attached stator coils, and a stator base plate that supports the sleeve. A gap exists between confronting surfaces of the flanged shaft and the bearing sleeve, and lubricating oil is sealed in the gap. Thrust dynamic pressure generating grooves are formed in one or both faces of the thrust ring, and the grooves are in the form of a herringbone pattern having radial inner groove sections and outer groove sections. The depth of the inner groove sections is shallower than that of the outer groove sections, and the depths of both groove sections are constant. The optimum inner-to-outer groove depth ratio is 0.6 to 0.7.

Abstract: A flange on a shaft of a fluid dynamic bearing unit is to be provided with a hole connecting an outer periphery of the flange and an outer periphery of the shaft. A radial groove is provided on a surface of two flange half pieces, and a vertical groove communicating with the radial groove is provided on an inner circumferential surface of the flange half pieces. Upon combining the two flange half pieces with the grooves facing each other and attaching them to the shaft, a path connecting an outer periphery of the flange and an outer periphery of the shaft is formed. The groove may be formed in a desired cross-sectional shape such as a semicircle, triangle or rectangle. The groove may be formed only on either of the flange half pieces, and the groove can be formed by a simple process such as pressing.

Abstract: A spindle motor can suppress the generation of noise during swinging and the extend service life, and also suppress the increase in current consumption. The outside diameter Do of a thrust hydrodynamic groove 3 is at least 10% of the outside diameter Dd of a disk-shaped medium 20, and the depth of the radial hydrodynamic groove is greater than the depth of the thrust hydrodynamic groove. By adjusting to specific numbers, the angular stiffness in the thrust bearing is raised, and even if a disturbance torque should be applied, wear or noise caused by metal contact inside the bearing can be suppressed.

Abstract: An active fluid bearing system is provided. In one example, the active fluid bearing system includes an interface region formed between an outer surface of an inner member and an opposing inner surface of an outer member. The inner and outer members are disposed for relative rotation of the inner and outer members, and thereby form an interface region having a hydrodynamic bearing region and an active bearing region. A liquid is disposed in the interface region at the hydrodynamic bearing region, and is further disposed in the active bearing region if the inner and outer members are not relatively rotating. The bearing system is operable for evacuating at least a portion of the liquid from the active bearing region during relative rotation of the inner and outer members. The active bearing region may be a journal bearing or a thrust bearing.

Abstract: The angular stiffness of a bearing is kept high, and at the same time air inside the bearing is discharged smoothly, without accumulating, which prevents oil film separation on the bearing. With the present invention, a communicating hole is provided, the hole and a radial hydrodynamic groove constitute a circulation path for a lubricant, there is a first thrust bearing face in contact with the circulation path, there is a first hydrodynamic groove on the face, this groove is a herringbone groove with a pump-in pattern, and no low-pressure part is generated in the thrust bearing, so even if the bearing undergoes a pressure change, there is no risk that the air accumulated in a low-pressure part will expand and cause oil film separation on the bearing face.

Abstract: A thrust bearing, in particular for a turbo charger, has an essentially disc shaped bearing body (10) with a central through opening (12) for a shaft, at least one bearing surface (14) surrounding the through opening (12) for a collar which is placed on the shaft, and at least one oil supply channel which leads from a radially outer region of the bearing body to the through opening (12). In order to realize a cost effective manufacture of the thrust bearing it is proposed according to the invention that the at least one oil supply channel is designed to be a groove (16?).

Abstract: This invention provides a hydrodynamic bearing assembly which realizes a high rotation rate in a stable manner with robust rigidity. The hydrodynamic bearing assembly has a total radial gap of 3 microns or less for preventing contact with the thrust bearing. The thrust bearing is a pump-out type, and the radial bearing has offset grooves on the surface thereof to supply fluid flow to the thrust bearing. A depth ratio of the grooves relative to the diameter of the shaft is preferably 0.005 or less to avoid reduced translational rigidity.

Abstract: An ultra-thin spindle motor having a groove formed on the outer circumferential surface of a thrust bearing is disclosed. The present invention relates to an ultra-thin spindle motor among small-sized motor using a hydro dynamic pressure generating bearing and its object is to provide a spindle motor capable of stably driving without requiring a sleeve that was required to support a shaft in a radial direction in which a thrust bearing sleeve for coupling a hub and a thrust bearing is constructed and a radial hydro dynamic pressure generating groove is formed on the outer circumferential surface to thereby allow a radial hydro dynamic pressure to be generated and support a thrust bearing sleeve coupled integrally to the hub.

Abstract: A fluid dynamic pressure bearing device includes a first capillary seal (50) formed between an outer circumferential surface of a bearing member 20 and an internal circumferential surface of a seal member (30). A second capillary seal portion (60) is formed between an outer circumferential surface of a shaft member (10) and a protrusion hole (31) of the seal member (30). A ventilation hole (32a) is formed in a substantially intermediate portion of a side wall of the seal member. A lubricant holding gap (73) is formed between an inner surface of a top wall (31) of the seal member (30) and the upper end surface of the bearing member (20). Leakage of lubricant (80) is suppressed by action of the capillary seal portions (50, 60), and the liquid surface is positioned in the first capillary seal portion (50) above the ventilation hole (32a), whereby extra lubricant (80) is filled in the first capillary seal portion (50) and the lubricant holding gap (73).

Abstract: To prevent air from being trapped inside a bearing and causing the bearing to have oil film rupture and NPPR to deteriorate. A flange having a shape substantially like a disc is provided integrally with a shaft near its lower portion. A sleeve having a bearing hole is fitted to the shaft so as to be relatively rotatable. Hydrodynamic grooves are provided on at least one of an outer periphery of the shaft and an inner periphery of the sleeve. The flange forms a thrust bearing surface with a lower end surface of the sleeve. Hydrodynamic grooves are provided on at least one of the lower surface of the sleeve and an upper surface of the flange. During rotation of the bearing, the hydrodynamic grooves circulate the lubricant. Capillary pressures at respective portions in the lubricant circulation path have difference in magnitudes.

Abstract: A fluid dynamic-pressure bearing includes a thrust dynamic-pressure bearing between a bearing member and a rotor hub and a tapered sealing portion continuous with the thrust dynamic-pressure bearing and defining a radial gap whose width gradually increases in the axial direction. A neck is formed in a passageway between the thrust dynamic-pressure bearing and a lubricating fluid/air interface maintained in the tapered sealing portion for increasing flow resistance of the lubricating fluid.

Abstract: The invention relates to a spindle motor having a hydrodynamic bearing system, particularly to drive platters in a hard disk drive, the platters being disposed on a rotor, and the bearing system being formed by a bearing sleeve arranged on a baseplate and a shaft rotatably supported in an opening in the bearing sleeve and at least one thrust plate connected to the shaft. A liquid lubricant is filled into a bearing gap formed between the shaft, the thrust plate and the bearing sleeve. The invention is characterized in that the thrust plate rests directly against the rotor and is accommodated in an annular recess in the bearing sleeve facing the rotor.

Abstract: An apparatus and method for increasing the buffer volume in a fluid dynamic bearing is disclosed. One embodiment provides a thrust washer coupled with a shaft of a fluid dynamic bearing. In addition, at least one groove is provided on an outward facing side of the thrust washer. In so doing, the at least one groove increases a fluid capacity of the capillary buffer of the fluid dynamic bearing without requiring a change in the size or shape of a capillary buffer of the fluid dynamic bearing.

Abstract: A compact disk storage device having an outer-rotor dc-brushless electric motor for directly driving a disk for recording and reproducing information, having an axially deep, tank-form flange and a stationary shaft, upon which the mounting annulus of the flange and a bearing assembly of the hub are axially displaced. The bearing assembly has the stationary shaft fixedly mounted centrally in the deepened flange via a support bush. The hub includes a cap for sealing an extremity of the bearing assembly and an inverted cup shape rotor providing magnetic shielding.

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 dynamic pressure gas bearing motor in which a radial dynamic pressure gas bearing and a thrust dynamic pressure gas bearing are ensured to have sufficient length and diameter even though the clamping screw holes for introducing screws to reliably hold a disk are formed in the top wall of the motor rotation body.

Abstract: Small-size, small-height fluid dynamic-pressure bearing device that causes a low shaft loss and is less prone to troubles such as shortage and leakage of lubricating liquid. A thrust dynamic-pressure bearing is formed at an inner position and a region having a slightly-widened gap is provided outside of the thrust dynamic-pressure bearing to retain the lubricating liquid therein. Further, an oil circulating path is communicated with the region having a slightly widened gap. The gap of this region is set to be greater than the gap at the thrust dynamic-pressure bearing portion by the value of the depth of dynamic-pressure generating grooves. The region having a widened gap may be provided with rows of grooves for stirring-up lubricating oil towards the center.

Abstract: Hybrid orbital fluid dynamic bearing motors are disclosed. The motors achieve improved efficiency advantages observed in fluid dynamic bearing motors containing an orbital ring. In addition, the hybrid orbital FDB motor has serial thrust bearings and traditional style journal bearings, which provide typically higher radial and angular stiffness not observed in previous orbital fluid dynamic bearing motor designs. Designs for centering orbital rings are also disclosed.

Abstract: In bearing mechanism for a motor spinning a storage disk about a center axis, an interference-fit portion of a shaft is interference-fitted into a through hole of a bushing from an axial lower side thereof such that the shaft is fixed to a rotor hub. The interference-fit portion of the shaft is defined with an upper section, a lower section, and a concave portion. When the shaft is interference-fitted into the bushing, the upper and lower sections engage with the bushing, and the concave portion radially faces an inner surface of the bushing with a gap defined therebetween.

Abstract: The invention relates to a spindle motor having a fluid dynamic bearing system, used particularly for driving the storage disks of hard disk drives, having a baseplate, a stationary bearing bush disposed in an opening in the baseplate, a shaft rotatably supported in an axial bore in the bearing bush by means of the fluid dynamic bearing system, a hub connected to the shaft, and an electromagnetic drive system. The invention is characterized in that the shaft has a flange that is fixed in an opening in the hub and whose outside diameter is significantly larger than the smallest outside diameter of the shaft.

Abstract: The preset invention aims to improve the assembly accuracy and rotation accuracy of a fluid bearing device, and to further reduce the cost thereof. A bearing sleeve is fixed on the inner periphery of a housing. An axial member is supported in a non-contact manner in a radial direction by an oil film formed in a radial bearing gap. The housing made of resin is injection molded with the use of a substrate as an insert part. On the substrate, a control circuit for controlling a polygon scanner motor is mounted.

Abstract: A motor is composed of a rotor and a stator. The rotor includes a shaft, a hub having a cylindrical wall and a thrust ring. The stator includes a motor base, an inner seal and a sleeve having a flange section. The rotor is supported in a thrust direction by a first thrust dynamic pressure fluid bearing constituted by a top surface of the thrust ring, a surface of the flange section with having a first gap between them, and lubrication fluid filled in the first gap and a second thrust dynamic pressure fluid bearing constituted by a bottom surface of the thrust ring, an end surface of the inner seal with having a second gap between them, and the lubrication fluid filled in the second gap, and supported in a radial direction by a radial dynamic pressure fluid bearing constituted by an inner circumferential surface of the sleeve, an outer circumferential surface of the shaft with having a third gap between them, and the lubrication fluid filled in the third gap.

Abstract: An oil dynamic bearing, a motor and a disk drive adapted to be reduced in both size and thickness are disclosed. The oil dynamic bearing (B) includes at least two bearing portions (B1, B2), each having a bearing near end nearer to the rotational axis or the bearing center of the bearing and a bearing far end farther from the rotational axis or the bearing center of the bearing. The near and bearing far ends are each connected to a taper seal portion, which in turn communicates with the atmosphere. The taper seal portion connected to the bearing near end of the bearing portion (B1) and the taper seal portion connected to the bearing near end of the other bearing portion (B2) make up a common taper seal portion.

Abstract: System for providing sealing between a rotor and a turbine casing in a hydraulic turbomachine includes a sealing ring arranged in a peripheral region of the rotor. The sealing ring forms at least one hydrostatic bearing with respect to at least one of the rotor and the turbine casing. The at least one hydrostatic bearing includes at least two bearing surfaces which face one another. At least one of the at least two bearing surfaces is arranged on the sealing ring. At least another of the at least two bearing surfaces is arranged on at least one of the rotor and the turbine casing. At least one groove is formed on at least one of the at least two bearing surfaces. At least one pressure-liquid line is coupled to each of the at least one groove and a pressure-liquid supply. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

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 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: 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: 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 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: 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: 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: 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: 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: A motor (100) having a dynamic pressure fluid bearing is composed of a hub (2), a rotor (4) provided with a shaft (7) of which one end portion is securely fastened by the hub (2) and another end portion is formed with a flange (8), and a stator (3) composed of a sleeve section (9) for axially sustaining the shaft (7) so as to be rotatable freely and a thrust plate (10) secured on the sleeve section (9) so as to confront with the flange (8), wherein the dynamic pressure fluid bearing is composed of a thrust dynamic pressure fluid bearing constituted by the flange (8) and the thrust plate (10), and wherein the shaft (7) is provided with a through hole (17) bored through the shaft (7) from the one end surface to the other end surface, and wherein the through hole (17) is formed in a shape having an opening to the other end surface of the shaft (7) by way of a funnel shaped section (17c) of which diameter gradually increases toward the other end surface of the shaft (7).