Abstract: A hydrodynamic bearing unit is provided, which can greatly reduce costs, while achieving high accuracy of squareness between a shaft portion and a flange portion which constituting a shaft member formed in one piece by forging. A recess portion is provided at a corner portion between the shaft portion and the flange portion, in which the recess potion is constituted with a first recess portion formed by forging at an end face of the flange portion and a second recess portion formed by rolling at an outside periphery of the shaft portion.

Abstract: A hydrodynamic bearing device of a shaft, a sleeve rotatably supporting this shaft, wherein a herringbone groove is formed at a predetermined part of an inner periphery wall face of the sleeve, and, a thrust receiver supporting a thrust side of the shaft fixed to a lower face of the sleeve, thereby sealing predetermined lubricant, wherein a spiral groove which is narrower in groove width and shallower in depth than the herringbone groove, and which is oriented to the thrust receiver in a rotation direction of the shaft, is formed on inner periphery wall face of the sleeve.

Abstract: A hydraulic dynamic pressure bearing motor has a rotational shaft mounted to undergo rotation about a rotational axis and having a shaft section and a flange section. A sleeve has a cavity for receiving the rotational shaft. A cover member is disposed over an open end of the sleeve cavity. A hydraulic dynamic pressure bearing includes minute radial and thrust clearances disposed between outer surface portions of the shaft and flange sections of the rotational shaft and inner surface portions of the sleeve and the cover member. A lubricating fluid is disposed in the minute radial and thrust clearances. The minute radial and thrust clearances are dimensioned so that during a non-rotational state of the rotational shaft, the flange section of the rotational shaft contacts preselected inner surface portions of the sleeve and the cover member while the shaft section of the rotational shaft does not contact any portion of the sleeve and an inner peripheral surface of the cover member.

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

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

Abstract: There is provided a disk drive motor including a shaft, a thrust plate, a bearing housing positioned about the shaft, and a combination of groove sets on either the shaft or the bearing housing. The asymmetrical grooves are oriented to pump fluid in a specific direction during rotation of the housing around the shaft. Vents are also positioned to allow unwanted gases to escape.

Abstract: A hydrodynamic oil-impregnated sintered bearing unit 1 are comprised a hydrodynamic oil-impregnated sintered bearing 1a, a housing 1b, and a thrust bearing portion for thrust-supporting a shaft. A sealing washer 20 made of metal or resin material is arranged on an opening-portion side of the housing 1b, and that, of a surface of the shaft 2, at least on a region including a portion opposite to the sealing washer 20 a thin layer 21 of a fluorine-containing polymer is formed.

Abstract: An air spindle is provided which allows high-speed operation without reducing the bearing stiffness in the air spindle by reducing the heat generation at bearing portions. By increasing the number of nozzles for the radial bearing or increasing the axial distance between the nozzles, the ratio of the supply air flow rate Q to the bearing stiffness H is set at 2-10 to release heat generation at the bearing portions to outside by the gas.

Abstract: A hydrodynamic type bearing unit comprises a shaft member 2, a bearing member 4 and a bearing clearance formed between the shaft member 2 and a bearing member 4 to produce a hydrodynamic pressure during the rotation of a shaft member 2. The bearing clearance is composed of a first clearance C1 on one axial side and a second clearance C2 on the other axial side and the first and second clearances C1 and C2 are mutually oppositely inclined against an axial direction.

Abstract: The invention is a hydrodynamic bearing device including a shaft member having a dynamic pressure generating surface rotatably attached to a cylindrical bearing sleeve having a dynamic pressure generating surface, with a gap between the attached dynamic pressure generating surfaces being filled with a lubricant. To prevent the lubricant from leaking, a covering member is fixed by adhesive to one of the openings of the bearing sleeve. A two-part liquid epoxy resin is applied to seal a gap in a joining portion between the bearing sleeve and the covering member. The adhesive satisfies the condition, n/2≦m≦2n, where m is the molecular-weight of a primary agent and n is the molecular-weight of a curing agent.

Abstract: To provide a hydrodynamic bearing, small in size and light in weight, and yet simple in structure and inexpensive in cost, which can exhibits a sufficient rigidity. The bearing is structured so as to comprise a radial bearing portion including a groove 26 capable of introducing fluid such as air, and a thrust bearing portion whose one end is connected with the radial bearing portion and whose other end is open to the outside, whereas the structure guides a fluid introduced at the radial bearing portion to the thrust bearing portion and utilizes a pressure at the thrust bearing portion, thereby obtaining a stable thrust force without separately disposing a thrust hydrodynamic pressure generating mechanism. The fluid introduced to the thrust bearing portion is thereafter discharged through an opening 28 linked with outside.

Abstract: A system for keeping the imperfectly machined surfaces of bearings apart at rest. The system includes a first bearing surface which moves facing a second bearing surface, the first surface having a distribution of discrete diamond-like carbon (DLC) pads deposited upon an adhesion layer. The DLC pads are at a height which is approximately the height of the roughness or imperfections of the surfaces. The pads are distributed over the surface at approximately three pads to forty pads or more per square inch. The pads keep the bearing surfaces from coming in contact. Also disclosed is a hydrodynamic bearing having a thrust plate having hydrodynamic grooves and DLC pads on a thrust surface, and a rotor member having an end facing the thrust plate, and a ball and socket bearing having DLC pads deposited on either the socket surface or ball surface.

Abstract: The improved sliding bearing provides fitting of a cap into a sleeve with steadily fixation of adhesive, and prevention of the remained adhesive outside of the desired area. The sliding bearing comprises a sleeve, a shaft enclosed in said sleeve, and, a cap fitted into the sleeve, the sleeve having a shouldered hole with a first shoulder on which the cap is held, wherein the internal circumferential surface of the sleeve or the external circumferential surface of the cap includes a second shoulder circumferentially formed thereon. The second shoulder of the sleeve is of an outer diameter larger than the diameter of the cap, and an inner diameter approximately same as or slightly larger than the outer diameter of the cap, while the second shoulder of the cap is of an inner diameter smaller than that of the sleeve, and an outer diameter approximately same as or slightly smaller than the inner diameter of the sleeve.

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

Abstract: A fluid bearing includes a rotary body with a rotor having a cylindrical surface to be borne and a thrust plate arranged at least at an end of the rotor, and a housing including a radial bearing section arranged vis-a-vis the surface of the rotor and a thrust bearing section arranged vis-a-vis the thrust plate. The thrust plate has a hole bored around the axis of rotation of the rotary body and the inner diameter of the hole is greater at the rotor side than at the opposite side.

Abstract: The bearing apparatus used in the motor comprises a rotary shaft, a cylindrical-shaped radial bearing, and a thrust bearing for supporting the lower end portion of the rotary shaft. The rotary shaft is composed of a pipe made of stainless steel and a resin member for closing the lower end portion of the pipe. A groove for generation of dynamic pressure is not formed in the inner peripheral surface of the radial bearing or in the inner peripheral surface of the rotary shaft either. On the upper end portion of the rotary shaft, there is mounted a fan which, due to the rotation of the rotary shaft, takes in the air into the rotary shaft and, in the peripheral surface of the rotary shaft, there are formed blow-out holes for blowing out the air taken in by the fan from the outer peripheral surface of the rotary shaft.

Abstract: A method and apparatus for rotatably interconnecting computer storage disks to a stationary base is provided. The apparatus provides a hybrid bearing assembly having an oil-filled thrust bearing and an air-filled radial bearing. In particular, the apparatus provides a hybrid bearing having an oil-filled thrust bearing that is highly resistant to leakage. In addition, the apparatus provides a hybrid bearing having a radial air bearing with a very large diameter to provide great stiffness in a radial direction using common manufacturing tolerances. The method of the present invention includes rotatably interconnecting a hub for suspending computer storage media to a base or enclosure using an oil-filled thrust bearing and an air-filled radial bearing. The method further includes balancing the pressures in both directions along the axis of the thrust bearing to prevent leakage of the oil from the bearing. The method also includes providing an air bearing having a very large diameter.

Abstract: Fluid bearing equipment which is free from lockup or seizure which may occur due to a deficiency of a lubricating fluid when the equipment is operated at a high rotation speed in a high temperature environment. The fluid bearing equipment is arranged such that maximum pressure generating portions 23 of dynamic pressure generating grooves 15, 16 provided in a thrust-side dynamic pressure generating portion are located closer to the outer circumference of a stationary thrust plate 9 than a radially middle position of the thrust-side dynamic pressure generating portion. With this arrangement, the lockup and seizure of a motor can be prevented which may otherwise occur due to a deficiency of the lubricating fluid when the equipment is operated at a high rotation speed in a high temperature environment.

Abstract: In a hydrodynamic bearing apparatus for rotatably supporting a rotor by a hydrodynamic bearing, wear of the apparatus caused by sliding contact of dynamic pressure bearing faces in starting and stopping thereof is prevented to thereby promote durability, working of a dynamic pressure generating groove is facilitated and the bearing faces are prevented from being adsorbed to each other. By providing a low friction metal layer having water repellency at dynamic pressure bearing portions of a hydrodynamic bearing apparatus, friction can be reduced, wear or dust formation can effectively be restrained and the bearing faces can be prevented from being adsorbed to each other by dew condensation.

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 compact externally pressurized gas bearing spindle assembly can increase the degree of vacuum in a vacuum chamber. In a spindle assembly wherein a rotary shaft is provided in a housing through a bearing gap, and compressed gas is introduced into the bearing gap to support the rotary shaft in a non-contact manner relative to the housing, an exhaust gas suction device for sucking gas discharged from the bearing gap is provided inside the housing or the rotary shaft. The bearing gap near the outside of the housing is smaller than the other bearing gap. Near the bearing gap near the outside of the housing, a non-contact seal gap is formed to prevent leakage of compressed gas into the vacuum chamber in a non-contact manner.

Abstract: The invention concerns an open-end spinning apparatus with a spin-rotor (1), the shaft (3) of which is supported by an aerostatic, radial bearing (5) with an air gap (9) between the bearing assembly and the shaft (3) and the invention further concerns the aerostatic bearing for this purpose. In accord with the invention, the open-end spinning apparatus is thereby improved, in that the construction material for the bearing surface of the spin-rotor (1) and/or the bearing surface of the radial bearing (5) is polyimide or Aramid. In spite of possibly occurring bearing surface contacts, the operating life of the radial bearing is substantially increased by the use of these materials.

Abstract: A receiver in a communication system is coupled to a transmission channel for receiving communication signals transmitted over a transmission channel. The receiver includes signal receiving electronics for receiving communication signals directed to the receiver. The receiver also includes a controller, responsive to the receipt of a communication signal by the signal receiving electronics, to provide an enunciator enable signal, and a clock signal generator for generating a clock signal. The receiver further includes an enunciator coupled to the clock signal generator, for producing an electronic sound signal. The enunciator includes a volume control module for receiving a first periodic signal and providing a volume control signal. The enunciator also includes a divider for receiving the clock signal and providing a corresponding output signal having a frequency corresponding to the frequency of the clock signal frequency divided by a divider value.

Abstract: A hydrodynamic type bearing unit with enhanced moment load capacity. In the bearing unit, a radial bearing clearance and thrust bearing clearances are set at such widths that a tilted spindle member comes into contact at the outer periphery of its spindle with both axial ends of a radial bearing surface opposed thereto, as well as at the rims of both end faces of its flange portion with respective thrust bearing surfaces opposed thereto, so that the moment load can by supported by both the radial bearing part and the thrust bearing part. Specifically, the radial bearing clearance &dgr;R and the thrust bearing clearances &dgr;A are set in accordance with the expression D&dgr;R/L+&egr;≧&dgr;A≧D&dgr;R/L (where D is the diameter of the flange portion, L is the axial length of the radial bearing part, and &egr; is a machining error).

Abstract: A hydrodynamic bearing according to the present invention comprises a rotary shaft having a convex portion provided at one end portion thereof, a sleeve which rotatably supports the rotary shaft, and having herringbone grooves formed in an inner wall thereof at positions, a thrust bearing which is provided in contact with an end portion of the rotary shaft on the convex portion side and restricts movement of the thrust bearing or the rotary shaft in an axial direction thereof, and a lubricant sealed in a space surrounded by the rotary shaft, the sleeve and the thrust bearing.

Abstract: The invention relates to a bearing for a shaft with a high speed characteristic, which takes up external forces acting on the shaft, wherein a one-piece hydrostatic bearing (2) is provided for taking up axial and radial forces at a high speed characteristic and a shaft (3) to be mounted is mounted by the pressure medium of water without contact, a bearing body has several channels (17,20,21), these channels end in jets (18,22,23) and between the jets (18,22, 23) and a shaft (3) to be mounted andlor other elements (4) is located a gap (19,24,25) with different heights (H,h), wherein water flows through these jets and mounts the shaft (3) to be mounted by a film of water. The total force of this bearing is taken up by a flange bolted to the machine tool.

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

Abstract: The present invention provides a dynamic pressure bearing apparatus comprising a cylindrical bearing member, and a rotary shaft disposed within a cylindrical bore of the cylindrical bearing member, and wherein the bearing member has a thrust bearing surface provided at a bottom of the cylindrical bore, a radial bearing surface provided on an inner peripheral surface of the cylindrical bearing member, and a lubricating oil reservoir provided at an opening portion of the cylindrical bore and having a diameter greater than that of the radial bearing surface, and the rotary shaft has a radial receiving surface opposed to the radial bearing surface with the interposition of a radial bearing gap, and a thrust receiving surface opposed to the thrust bearing surface, and further wherein the bearing member is closed at the bottom thereof, a dynamic pressure generating groove is formed in at least one of the radial bearing surface and the radial receiving surface, and the dynamic pressure generating groove generates a

Abstract: Disk-drive motor having two hydrodynamnic bearing sections separated with respect to the shaft by an air intervention, each composed of a radial and a thrust dynamic-pressure bearing portion, and in each of which lubricant is retained continuously throughout the radial and thrust bearing portions At least one communicating pathway is formed in the sleeve, axially communicating the thrust faces that are constituents of, and retaining lubricant continuously with, the pair of thrust bearing portions. Via the communicating pathway, the lubricant retained in the two hydrodynamic bearing sections shifts mutually from the one section to the other, such that the radii of curvature of the meniscuses forming the respective boundaries arc equalized. The amount of lubricant held in the bearing sections is accordingly equalized and lubricant leaking out of the radial bearing portions is taken up and re-circulated.

Abstract: A hydrodynamic bearing unit is provided, which can greatly reduce costs, while achieving high accuracy of squareness between a shaft portion and a flange portion which constituting a shaft member formed in one piece by forging. A recess portion is provided at a corner portion between the shaft portion and the flange portion, in which the recess potion is constituted with a first recess portion formed by forging at an end face of the flange portion and a second recess portion formed by rolling at an outside periphery of the shaft portion.

Abstract: A dynamic pressure bearing-unit is provided, which includes a shaft member (2) with a shaft (2a) and a flange portion (2b), a radial bearing (10) for supporting the shaft member (2) in the radial direction, and a thrust bearing (11) for supporting the flange portion (2b) of the shaft member (2) in the direction of thrust. The radial bearing (10) and the thrust bearing (11) support the shaft member (2) by dynamic pressure action out of contact, respectively, and the shaft (2a) and the flange portion (2b) are constructed in one piece. In this case, dynamic pressure grooves of the thrust bearing (11) are provided on the end surface of the bearing member (7) or on the upper surface of the thrust support portion (13) opposite to the flange portion (2b).

Abstract: A hydrodynamic bearing device of the present invention has a shaft, a sleeve rotatably supporting this shaft, wherein a herringbone groove is formed at a predetermined part of an inner periphery wall face of the sleeve, and, a thrust receiver supporting a thrust side of the shaft fixed to a lower face of the sleeve, thereby sealing predetermined lubricant, wherein a spiral groove which is narrower in groove width and shallower in depth than the herringbone groove, and which is oriented to the thrust receiver in a rotation direction of the shaft, is formed on inner periphery wall face of the sleeve.

Abstract: A shaft integral with a rotary polygon mirror is fitted in a sleeve so as to be rotatable, and the bearing clearance is filled with a lubricant. The lubricant comprises a base oil comprising a mixed oil consisting of a plurality of components whose vapor pressures are equal or close to each other. Suitably combining components of different viscosities makes it possible to prepare the lubricant so as to have such a viscosity to match with the bearing characteristics. Selection of components having a little difference in vapor pressure prevents viscosity change due to volatilization of a specific component. Thus, the viscosity change of the lubricant in the bearing clearance is prevented.

Abstract: The present invention relates to an improved spindle unit. The spindle unit includes a body, an external shaft placed into the body and rotating on bearings relative to the body, and an internal shaft placed into the external shaft and coupled thereto. The spindle unit further includes front and rear static journal bearings and a thrust bearing between the external and internal shafts. Flow control valves are provided which have their outlets connected to recesses communicating with the rear and front journal bearings. Operation of the valves in response to measured parameters controls the position of the internal shaft relative to the rotation axis of the external shaft. This is accomplished by controlling the flow of fluid to recesses associated with the front and rear journal bearings. By controlling the position of the internal shaft, one can insure that a workpiece attached to the internal shaft is automatically centered.

Abstract: A potential-difference alleviating member for alleviating and lowering the potential difference, which is an energy difference between a rotating or fixed bearing member and a rotary hub or a fixing frame which are formed of metals of different types, is interposed between the two members so as to prevent the occurrence or advance of potential difference corrosion. Relief portions are respectively provided at a joining interface between a rotary shaft and a thrust plate and a joining interface between a bearing member and the counter plate, and the respective members are welded in the relief portions so as to be integrated.

Abstract: A method for lubricating a part without leaving air bubbles includes the steps of assembling components so that an open end is formed for application of lubricating fluid and a fluid path is provided through which the lubricating fluid is to be circulated, introducing the lubricating fluid into the open end and applying a centrifugal force to the component by moving the component about a circular path so that the centrifugal force causes the lubricating fluid to be urged throughout the fluid path. The method is used in an embodiment to lubricate a dynamic pressure bearing having a gap between relatively moving parts. The gap has an open end into which the lubrication fluid is dripped and a closed end. During movement of the bearing about a circular path, the fluid is urged from the open end to the closed end.

Abstract: A bearing comprises a rotating shaft, a sleeve which surrounds the outer wall of the rotating shaft and supports the rotating shaft in such a manner that the rotating shaft is rotatable, and a thrust bearing plate which is fixed to the sleeve and supports one end of the rotating shaft. A first herringbone pattern and a second herringbone pattern are formed either on the rotating shaft or on the sleeve, wherein the first herringbone pattern is located at a first side and the second herringbone pattern is located at a second side, wherein the first side is the side where the thrust bearing plate is located, and the second side is the side opposite the first side. The relation between width-A and width-B in the first herringbone pattern is expressed by 0<(A−B)<0.

Abstract: To provide a dynamic pressure bearing apparatus having high performance and excellent stability without hindering operations of appliances due to a leaked oil, the dynamic pressure bearing apparatus of the present invention comprises; a rotating shaft inclined in a predetermined direction from a vertical direction; a sleeve rotatably supporting the rotating shaft; an operating fluid for generating a dynamic pressure, the operating fluid being filled in a gap formed between the sleeve and the rotating shaft; and capturing means for capturing the operating fluid leaked from the gap, the capturing means being disposed on an outside surface of the sleeve in the predetermined direction.

Abstract: A dynamic pressure bearing which can eliminate an unbalanced existence of a lubricant fluid without increasing the diameter of a flange is compact in size and requires a lower rotation torque. The dynamic pressure bearing, axial through holes 21 and 22 of a flange 2 are formed so as to be adjacent to a smaller diameter portion 1B of a shaft 1, and to be opposed to an end face 1A-1 of a larger diameter portion 1A. Thus, the axial through holes 21 and 22 do not reduce the area for forming a bearing surface of the flange 2, so that the unbalanced existence of a lubricant fluid can be eliminated by the axial through holes 21 and 22 without degrading the thrust supporting ability. The diameter of the flange can be reduced, and a stable supporting ability can be attained, and a compact size and a low rotation torque can be realized.

Abstract: Spindle motor hydrodynamic pressure bearing device having upper and lower radial bearing portions axially separated by an air space, established in the micro-gap between the outer circumferential surface of the motor shaft and the inner circumferential surface of the motor sleeve element, and upper and lower thrust bearing portions established on either side of a thrust plate flange at the lower end of the shaft. A micro-gap established between the thrust plate and an opposing base surface of a recess in the sleeve element accommodating the thrust plate is continuous with the lower radial bearing micro-gap. Lubricating oil in the micro-gaps is therein retained continuously between the lower radial bearing and the upper thrust bearing. The lower radial bearing generates hydrodynamic pressure acting axially outward (toward the upper thrust bearing), and the upper thrust bearing generates hydrodynamic pressure acting radially inward (toward the lower radial bearing).

Abstract: A hydrodynamic bearing which prevents a lubricating fluid from scattering out of the dynamic pressure generating portion. The bearing includes radial spacing d of a gap at an open end of the thrust-side dynamic pressure generating portion, whose value is greater than a spacing of the thrust-side dynamic pressure generating portion, as measured relative to the thrust direction. Scattering of lubricating fluid from the open end of the thrust-side dynamic pressure generating portion is therefore prevented even when the bearing rotates at a high speed in a high temperature envivronent.

Abstract: In order to alleviate mutual interference between axial dynamic pressure portions and a radial dynamic pressure portion in a ring-like hydraulic dynamic pressure bearing, in the case of a ring-like hydraulic dynamic pressure bearing 1 constituted by supporting a shaft portion 4 constituted by fixing a ring 3 to an end portion 2A of a shaft main body 2 by a bearing portion 5, ring-like spaces 8 and 9 for storing lubricant for generating dynamic pressure are provided along contiguous portions of the radial dynamic pressure bearing portion and the axial dynamic pressure bearing portions formed between the ring 3 and the bearing portion 5, and the ring-like spaces 8 and 9 are maintained at atmospheric pressure via paths formed at the bearing portion 5 to thereby prevent negative pressure from generating at boundary regions of the two dynamic pressure bearing portions.

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

Abstract: A potential-difference alleviating member for alleviating and lowering the potential difference, which is an energy difference between a rotating or fixed bearing member and a rotary hub or a fixing frame which are formed of metals of different types, is interposed between the two members so as to prevent the occurrence or advance of potential difference corrosion. Relief portions are respectively provided at a joining interface between a rotary shaft and a thrust plate and a joining interface between a bearing member and the counter plate, and the respective members are welded in the relief portions so as to be integrated.

Abstract: A scanner motor of a laser beam printer capable of removing a bearing friction during a high-speed rotation thereof, thereby minimizing generation of noise and vibrations, while achieving an enhancement in durability and keeping a stable drivability of a mirror.

Abstract: An oil-impregnated bearing and rotor shaft combination includes an oil-impregnated bearing with a central hole for pivotally holding a rotor shaft. The oil-impregnated bearing is mounted in a hole of an axle tube in a slip-fit manner. Each of two ends of the hole of the axle tube is sealed by a cap by means of tight engagement to thereby restrain the oil-impregnated bearing in the hole of the axle tube and between the caps. The rotor shaft is extended through an opening in the upper one of the caps and through the central hole of the oil-impregnated bearing with a lower end of the rotor shaft pivotally supported by an inner side of the lower one of the caps.

Abstract: An air bearing (1) for a shaft (2), adapted to rotate at high peripheral speed, of a motor spindle for driving a machining tool includes a shaft (2) having bearing surfaces (3, 5, 6) and mating bearing surfaces (9, 11) of bearing elements (8, 10) which are equipped with several bearing pockets (13). The bearing pockets (13) communicate, via bores (14, 15) in the bearing elements (8, 10), with a source of compressed air. The bearing elements (8, 10) are made of graphite whereby the air bearing's (1) function is not adversely affected by temporary overloading.

Abstract: An object of the present invention is to provide a hydrodynamic bearing device which has an improved construction to prevent a lubricating fluid from scattering out of a dynamic pressure generating portion. The hydrodynamic bearing device of the present invention is characterized in that a radial spacing &Dgr;d of a gap at an open end of a thrust-side dynamic pressure generating portion is set greater than a spacing 26 of the thrust-side dynamic pressure generating portion as measured with respect to the thrust direction. With this arrangement, the scattering of the lubricating fluid from the open end of the thrust-side dynamic pressure generating portion is prevented even when the hydrodynamic bearing device is operated at a high rotation speed in a high temperature environment.

Abstract: A spindle motor is disclosed which allows more excellent abrasion resistance and productivity exhibited by making the thrust to be integrally formed at driving shaft and by making each of kinetic pressure-generating grooves that generate fluid kinetic pressure in axial direction to be formed at different formation position from each other that may be less influenced than ever by force of friction with fluid material.

Abstract: A hydrostatic bearing assembly, with an integral rotating-shaft hydrodynamic pump, adapted for use as a stiff zero static-friction actuator pivot bearing for the head-stack assembly of a disk drive data storage apparatus. The zero static-friction pivot bearing avoids all “limit cycling” and “sticking” problems arising from static bearing friction during micro-tracking operations. The motor-driven hydrodynamic pumping element is disposed coaxially to the zero static-friction hydrostatic bearing element in a single assembly adapted for use as an actuator pivot bearing. The hydrodynamic pumping element and the hydrostatic bearing element both use a plurality of spaced-apart radial journal-bearing layers and a plurality of axial thrust-bearing layers to provide stiffness in all directions at any rotational velocity.