Abstract: A bearing structure for a motor rotor includes an outer periphery with an engaging portion tightly engaged to an inner periphery of an axle tube. The bearing structure further includes an axle hole for pivotally supporting a shaft of the motor rotor. A longitudinal length of the axle hole is longer than that of the engaging portion or a longitudinal length of the axle hole is longer than that of a connecting member interconnected between inner periphery of an axle tube and outer periphery of the bearing.

Abstract: The present invention is directed to a high speed spindle motor comprising a stator assembly including a stator having multiple conductors that create a plurality of magnetic fields when electrical current is conducted by the conductors and a body of a phase change material such as a thermoplastic substantially encapsulating the stator. A rotatable hub having a magnet connected thereto is in operable proximity to the stator. The high speed motor also includes a shaft, a bearing surrounding the shaft and one of the bearing or shaft being fixed to the stator assembly and the other of the bearing or shaft being fixed to the rotatable hub. Hard disc drives using the motor, and methods of developing and constructing the motor and hard disc drives are also disclosed.

Abstract: A dynamic pressure bearing device having a structure in which forces in the radial and thrust directions can be easily balanced with each other, and lubricant hardly leaks is provided.

Abstract: A hydrodynamic bearing apparatus comprises two hydrodynamic bearing sections which have a shaft member, a bearing member fit to the shaft member with a predetermined space therein, lubricants filling the space between the shaft member and the bearing member, and which are separately placed in the axial direction of the shaft member. The lubricants of the two hydrodynamic bearing sections are separated from each other by an air layer. The lubricants are pressured by hydrodynamic generating grooves formed on the hydrodynamic bearing sections such that the shaft member and the bearing member are rotatably supported in relation to each other. The hydrodynamic generating grooves separately formed on the two hydrodynamic bearing sections are formed into an unbalanced shape such that the lubricants are moved in a predetermined direction to correct the slope of the shaft member and the bearing member when rotation is suspended.

Abstract: A fluid bearing device achieves superior in wear resistance in starting and stopping and in manufacturing ability. The fluid bearing device includes a shaft having a flange portion, a sleeve opposing to the shaft across a fluid bearing clearance of a radial fluid bearing, a counterpart member opposing to at least one of plane of the flange portion across a fluid bearing clearance of a thrust bearing. The flange portion and the sleeve portion being formed of copper alloy of mutually difference composition.

Abstract: A rotary apparatus includes: a radial fixed member; a rotary unit rotatably supported on the radial fixed member; a radial dynamic pressure bearing portion at which the radial fixed member faces the rotary unit; and dynamic pressure generating grooves formed on the radial dynamic pressure bearing portion. The dynamic pressure generating grooves are asymmetrically formed with respect to a rotary axis of the rotary unit.

Abstract: A spindle motor in which a shaft and a sleeve are supported by a radial fluid bearing and a thrust bearing in a noncontact state via a bearing clearance and are relatively driven rotatively, a lubricant reservoir having one end communicating with the bearing clearance and another end communicating with the outside is provided on an outer peripheral side of the sleeve whose inner periphery opposes the shaft, and a lubricant supplying passage, which is a clearance of the lubricant reservoir on its side which communicates with the bearing clearance, is set to a size exhibiting capillarity. Bubbles in the lubricant inside the lubricant reservoir are discharged through the clearance communicating with the outside, and the bearing clearance is automatically lubricated stably through the lubricant supplying passage by means of capillarity.

Abstract: A motor having a magnetic bearing comprises a base formed with a bearing seat; a stator fixed to the base; a rotor provided with a rotation shaft and rotatable with respect to the stator by magnetic forces generated from excitation; a bearing fixed to the bearing seat of the base for receiving the rotation shaft of the rotor; and a magnetic element pair including a first element and a second element. The first element is telescopically interference-fitted on the rotation shaft, the second element is fixed relative to the bearing seat and lets the rotation shaft insert therethrough, and a magnetic force is generated between the first element and the second element. When the rotor rotates and an external force acts on the rotor in a direction, a magnetic force between the magnetic element pair counteracts the external force to achieve an axial positioning effect and avoid the contact wear.

Abstract: A spindle motor comprises a base, a stator coil connected to the base, and a sleeve-and-bearing unit connected to a central portion of the base. The sleeve-and-bearing unit has a sleeve and a bearing section mounted in the sleeve having a linear expansion coefficient greater than that of the sleeve. The sleeve has a groove disposed in an outer peripheral surface thereof for receiving an adhesive material for connecting the base to the outer peripheral surface of the sleeve. A rotor unit is connected to the sleeve-and-bearing unit for undergoing rotation relative to the sleeve-and-bearing unit. The rotor unit has a shaft section supported by the bearing section for undergoing rotation, a hub connected to the shaft section for rotation therewith, and a rotor magnet connected to the hub and disposed opposite to and spaced apart from the stator coil.

Abstract: A motor includes a stationary shaft and a rotatable rotor hub disposed about the stationary shaft. The rotor hub is adapted to support a magnetic storage disk such a hard disk. The motor includes thrust oil dynamic pressure bearings that axial support the rotor hub on the stationary shaft. The motor also includes radial gas-lubricated dynamic bearings that radially support the rotor hub on the stationary shaft. The thrust oil dynamic pressure bearings include electrically conductive fluid lubricant that provides a ground between the rotor hub and the stationary shaft thereby preventing undesirable discharges of electrostatic charges that may build up on the magnetic storage disk.

Abstract: A thrust bearing section (14) is constituted by one bearing end face (11f1) of a hydrodynamic type oil-impregnated sintered bearing (11) and a flange portion (13a) provided on a rotating shaft (13). The squareness between the bearing end face (11f1) and the bearing inner periphery (11h) is set within 3 &mgr;m, and the squareness between the flange portion (13a) and the outer periphery of the rotating shaft (13) is set within 2 &mgr;m. The bearing bore diameter d and the bearing length L of the hydrodynamic type oil-impregnated sintered bearing are set as L≦1.2 d, and a radial bearing surface (11b) is arranged at one place on the bearing inner periphery (11h).

Abstract: A hydraulic dynamic bearing has a rotational assembly and a bearing member for rotationally supporting the rotational assembly. The bearing member has a main body having a recess portion and a cover for covering an open end of the recess portion. The rotational assembly has a shaft main body having an end portion extending into the recess of the bearing main body for undergoing rotation relative thereto and a ring member disposed in the recess of the bearing main body. The ring member is connected to the end portion of the shaft main body for rotation therewith. Axial dynamic pressure generating grooves are formed in upper and lower surface portions of the ring member for generating axial dynamic pressure during rotation of the rotational assembly. Radial dynamic pressure generating grooves are formed in an outer peripheral surface portion of the ring member for generating radial dynamic pressure during rotation of the rotational assembly.

Abstract: A motor includes a stationary shaft, a stationary thrust plate fixed to the stationary shaft and a rotor adapted to rotate about the stationary shaft and stationary thrust plate. A rotary thrust plate is fixed within an upper opening of the rotor facing an upper surface of the stationary thrust plate. Portions of a surface of each of the stationary and rotary thrust plates and lubricant therebetween define an upper thrust bearing. The rotary thrust plate is formed with a lubricant injection hole that allows for simple manufacturing steps wherein the motor is completely assembled before lubricant is injected through the lubricant injection hole into the upper thrust bearing and a lower thrust bearing defined between portions of adjacent surfaces of the stationary thrust plate and the rotor.

Abstract: A long service-life motor free from oil-spill from its bearing is achieved by a construction including (a) a frame having an opening, (b) a housing disposed on the frame and having one side thereof open, (c) a stator secured to the housing, (d) a sleeve situated in the housing and having an inner wall being machined straight in its axial direction, (e) a rotary shaft extending through the sleeve and being rotatably supported by the sleeve, (f) a groove formed on part of the inner wall of the sleeve, facing the rotary shaft and retaining oil, (g) a ventilating path formed on at least one of an inner wall of the housing or an outer wall of the sleeve, (h) an annular recess formed on the outer wall of the sleeve and communicating to the ventilating path, (i) a rotor having a magnet opposite to the stator, and (j) oil lubricated in a space between the shaft and the sleeve, the groove retaining oil, the annular recess as well as another space formed by the bottom face of the housing and the sleeve.

Abstract: A bearing system and a spindle motor assembly adopting the same are provided. The bearing system includes a lower base on which a fixed shaft is installed, a cylindrical body fit on the fixed shaft, first and second magnetic bodies installed on the upper and lower ends of the cylindrical body, respectively; a third magnetic body installed so as to face the second magnetic body on the lower end of the cylindrical body, a fourth magnetic body facing the first magnetic body on the upper end of the cylindrical body at a predetermined space, and an upper base to which the fourth magnetic body is fixed and which is fixed to the upper portion of the fixed shaft.

Abstract: In a motor 5 in which a thrust bearing 8 using the magnetic force acting between a stator 40 side and a rotor 20 side and a radial bearing 7 using the dynamic pressure generated between the outer peripheral surface 440 of a fixed shaft 44 and the inner peripheral surface of the center hole 21 of the rotor 20 are formed between the stator 40 and the rotor 20, along the axial direction L of the motor shaft between the outer peripheral surface 440 of the fixed shaft 44 and the inner peripheral surface of the center hole 21 of the rotor 20, an annular clearance 70 for generating dynamic pressure between the outer peripheral surface 440 of the fixed shaft 44 and the inner peripheral surface of the center hole 21 of the rotor 20, an annular air chamber 92 for an air damper which communicates with this clearance, and an annular clearance 91 for the air damper which communicates the chamber with the external portion are formed in this order.

Abstract: A storage-disk drive motor miniaturized and made thinner by eliminating the conventional thrust plate for the rotor-hub thrust dynamic pressure-generating bearing, and by employing only one rotor-hub radial dynamic pressure-generating bearing. The motor is inner-rotor type wherein the rotor magnet is radially inward of the stator. To maintain thrust bearing rigidity absent the thrust plate, the stator/bracket and the rotor magnet are configured such that magnetism between them imparts a energizing force to the rotor hub biasing it axially, and at the same time, specially striated dynamic-pressure-generating grooves in the rotor hub bearings generate thrust to balance this energizing force. Due to the special rotor-hub bearing configuration, the means for venting the lubricant retained in the bearing micro-gaps are modified accordingly.

Abstract: It is an object of the present invention to provide a hydrodynamic bearing which is highly reliable and capable of preventing a lubricant contained therein from flowing out of the bearing. In the hydrodynamic bearing, lower and upper end portions of a stationary shaft are properly spaced from a sleeve and a thrust plate, respectively, and an air channel is provided inside the stationary shaft with one end thereof opening to a space defined between an outer circumferential portion of the stationary shaft and the sleeve and with the other end thereof communicating with the outside. Thus, the hydrodynamic bearing has a highly reliable construction which can assuredly prevent the flow-out of the lubricant.

Abstract: A spindle motor has a rotor, a stator and a dynamic pressure bearing for supporting the rotor for rotation relative to the stator. The dynamic pressure bearing comprises a rotational shaft mounted for undergoing rotation and having a thrust bearing portion and a radial bearing portion. A bearing member rotatably supports the rotational shaft and has a closed end forming a small diameter cylinder portion for receiving the radial bearing portion of the rotational shaft and an open end forming a large diameter cylinder portion for receiving the thrust bearing portion of the rotational shaft such that first gaps for receiving a lubricating oil are formed between the rotational shaft and the bearing member. A thrust pressure member is connected to the bearing member to form a capillary seal between the rotational shaft and the open end of the bearing member and to form second gaps between the thrust pressure member and the rotational shaft for receiving a lubricating oil.

Abstract: A positive and negative rotation gas dynamic pressure bearing comprises a stationary bearing member, a movable bearing member mounted for rotation relative to the stationary bearing member, dynamic pressure generating grooves having first and second ends and formed in one of confronting surfaces of the stationary bearing member and the movable bearing member, a self-switch valve connected to the movable bearing member for rotation therewith, and conducting holes having first and second ends and formed in the movable bearing member. During rotation of the movable bearing member in a first direction of rotation, a high dynamic pressure is generated at central portions of the dynamic pressure generating grooves, and a valve body of the self-switch valve moves toward a lower space of a valve case of the self-switch valve to close the second ends of the conducting holes.

Abstract: Air flows are produced in a sliding bearing between the bearing surfaces (L) sliding relative to one another of a movable body (1, 3) and a stationary body (2). Compressed air is expanded through nozzles (4) between the bearing surfaces (L) to atmospheric pressure. As a result of these air flows, the static pressure between the bearing surfaces (L) is reduced so that compressive forces acting between the moving and the stationary body are produced. The bearing surfaces (L) and air flows are so matched to one another that the movable body (1, 3) is in a force-free state of equilibrium on assuming a position in which the bearing surfaces (L) of the movable body (1, 3) are not in contact with the bearing surfaces (L) of the stationary body (2). In order to ensure a clearly defined equilibrium position, the clearance between the movable body (1, 3) and the stationary body (2) is chosen so that any possible change of the spacings between the bearing surfaces brings about an opposing change of the pressure ratios.

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: In a hydrodynamic pressure bearing according to the present invention, the lubricating fluid held in the radial bearing portion is pumped toward the thrust bearing portion by grooves formed in the radial bearing portion. And the hydrodynamic pressure bearing is provided with a circumferential groove formed in the vicinity of the boundary region between the radial and thrust bearing portions so as to control the flow of lubricating fluid between the bearing portions depending on the amount of lubricating fluid held therein. The circumferential groove is formed on the sleeve member near the inner opening of a communicating hole which in turn axially passes through the thrust plate and communicates the gap defined by the shaft and the sleeve member therebetween with the external atmosphere. While a predetermined amount of lubricating fluid is retained in the gap, some extra lubricating fluid is also retained in the vicinity of the inner opening of the communicating hole.

Abstract: A long service-life motor free from oil-spill from its bearing is achieved by a construction including the following elements: a frame having an opening, a housing disposed on the frame and having one side thereof open, a stator secured to the housing, a sleeve situated in the housing and having an inner wall extending straight in its axial direction, a rotary shaft extending through the sleeve and being rotatably supported by the sleeve, an annular recess formed on part of the shaft and facing the inner wall of the sleeve, a tapered section of the shaft end facing a bottom face of the housing, a rotor having a magnet opposite to the stator, and oil lubricated in a space between the shaft and the sleeve, and pooled in the groove as well as in another space formed by the tapered section, the bottom face of the housing and the sleeve. This construction allows the bearing to be downsized and also processed with ease.

Abstract: A hydrodynamic bearing system where the bearing includes a shaft and two independent bearings, comprising a top cone or bi-sphere and a bottom cone or bi-sphere separated by a segment of the shaft. The bearing includes a hub supported bearing element rotating around the shaft and the shaft supported top cone and bottom cone; complementary surfaces of said bearing element and said cone define a narrow gap between the bearing support element for the bearing fluid. Sealing plates or seal elements define a fluid gap with a radially extending face of the cone; a gap also exists between an interior surface portion of each cone and the shaft. These gaps are connected so that separate flow paths are established, one around the top cone or bi-sphere and one around the bottom cone or bi-sphere. By providing two independent bearings, the stator can be mounted to the shaft, facing magnets supported on the hub to form an in-hub motor.

Abstract: A novel hydro-dynamic fluid bearing device is herein disclosed which comprises a cylindrical shaft, a substantially cylindrical bearing member for axially supporting the shaft rotatably in a cylindrical hole having a bottom surface, a supporting member fixed on one side of the shaft and the bearing member, and a rotation member fixed on the other side of the shaft and the bearing member and rotatably supported on the supporting member, grooves for generating hydro-dynamic fluid being formed on at least one of the outer peripheral surface of the shaft and the inner peripheral surface of the cylindrical hole of the bearing member, wherein the bearing member is made of a resin material, and the outer peripheral surface of the substantially cylindrical portion is fixed to an annular reinforcing member having a higher rigidity than the bearing member.

Abstract: The present disclosure relates to a spindle motor including a shaft having an outer circumferential surface. The spindle motor also includes a thrust plate fixedly connected to the shaft. The thrust plate projects radially outward from the outer circumferential surface of the shaft and includes top and bottom surfaces. The spindle motor also includes a hub assembly mounted on the shaft. The hub assembly is adapted for mounting a storage disk. The spindle motor further includes a liquid hydrodynamic bearing and an aerodynamic bearing. The liquid hydrodynamic bearing is formed along the top and bottom surfaces of the thrust plate and is adapted for transferring loads in an axial direction relative to the shaft. The aerodynamic bearing is formed along a portion of the hub assembly and is adapted for transferring loads in a radial direction relative to the shaft.

Abstract: A method to create an improved hydrodynamic bearing which is relatively insensitive to changes in load and rotational speed is provided, wherein the hydrodynamic bearing is useful in a spindle motor for a disc drive or the like which is stiffer than known standard spindle motors so that the stability of the system and specifically of the actuator arm and transducer relative to the rotating disc is optimized. The hydrodynamic bearing can also be used as a bearing cartridge or as the cartridge that may be incorporated into a spindle motor or the like, where the bearing includes a shaft and at least two independent bearings each comprising a thrust plate supported on the shaft and a counter plate incorporated in a sleeve which is capable of relative rotation around the shaft.

Abstract: A spindle motor includes a stationary shaft and a rotor. A thrust bearing, a first radial bearing and a second radial bearing are defined between the shaft and rotor. A first annular air gap is established between the thrust bearing and the first radial bearing. A second annular air gap is established between the first radial bearing and the second radial bearing. The first annular air gap is able to vent to outside of the spindle motor via a breathing bore formed in a thrust plate of a stationary shaft. The second annular air gap is able to vent to outside the spindle motor only while the rotor is rotating about the shaft.

Abstract: A dynamic pressure bearing having a reduced manufacturing time and cost is produced using a single dynamic pressure generating groove. A motor having a dynamic pressure bearing according to one embodiment of the present invention includes a supporting body, a stator coil mounted to the supporting body, a rotor having opposing upper and lower surfaces, a rotor magnet for generating a rotational force in cooperation with the stator coil, the rotor magnet being attached to one of the upper and lower surfaces of the rotor so as to oppose the stator, a fixed shaft forming a dynamic pressure bearing mounted to the supporting body, and a disc-shaped lower thrust cap member attached to the supporting body proximate the lower surface of the rotor. The rotor has an inner peripheral surface defining a hole through which the fixed shaft passes.

Abstract: A spindle motor having a simplified construction with reduced axial and radial deflection while avoiding the half whirl phenomenon includes a motor frame, a rotating shaft supporting a rotor, a stator and stator coil, a permanent magnet opposing the stator, and a liquid dynamic pressure bearing. Magnetic centers of the permanent magnet and stator coil, in the axial direction of the rotating shaft, are substantially matched. The liquid dynamic pressure bearing comprises opposing surfaces of the rotating shaft and the housing. The rotating shaft has a disk-shaped thrust bearing portion disposed in a first portion of a cylindrical hole of the housing, and a radial bearing portion disposed in a second portion of the cylindrical hole. Lubricating oil fills a space between the cylindrical hole and the thrust bearing portion and radial bearing portion, and a presser ring is pressed and fixed into a third portion of the cylindrical hole to seal the bearing.

Abstract: An externally pressurized gas bearing assembly including a bearing sleeve fixed in contact with an inner peripheral surface of a housing provided with a gas supply passage communicated with fine feed ports of thrust bearings and opening at an outer peripheral surface of the bearing sleeve through an interior of the bearing sleeve. The bearing sleeve supports a main shaft in an axial direction through an externally pressurized gas by a thrust bearing surface having a plurality of fine feed ports of the thrust bearing.

Abstract: An electric spindle motor has a base assembly (19) and a hollow notatable hub (16) housing a motor. The hub (16) is mounted for rotation about an axis and a stator (12) is mounted on the base assembly (19) inside the hub (16). A liquid filled journal bearing (11, 21) acts between the base assembly (19) and the hub (16) to provide radial support of the hub (16). A gas filled thrust bearing (26, 27, 35) also acts between the hub (16) and base assembly (19) to provide at least axial support of the hub (16).

Abstract: A fluid dynamic bearing cartridge including a sleeve and a counterplate captured within a shoulder on the sleeve and including a threaded mounting extension for mounting the assembly from a base or the like. A rotating shaft is incorporated within the sleeve; the shaft includes a thrust plate which rotates in a recess defined between the counterplate and the sleeve. To incorporate this assembly into a disc drive or the like, the threaded mounting extension only needs to be mounted within a base, with a nut screwed over the threaded mounting. The base typically includes a raised portion; the sleeve is cantilevered from this base for further stability and eliminate the possibility of vibration of the shaft and sleeve with rotation of the shaft. The end of the shaft distal from the threaded mounting supports a hub which in turn supports a backiron and magnet. The base supports a stator aligned with the magnet; energization of the stator will cause rotation of the hub and the shaft.

Abstract: The hydrodynamic bearing gap from one end to the other of the shaft and sleeve combination is effectively separated into sections, with the fluid in each bearing section being contained within that section. The viscosity of the fluid in each bearing section can then be selected to optimize the characteristics of the entire hydrodynamic bearing. Typically, the sections of the bearing adjacent each open end of the bearing would be filled with a fluid with relatively high viscosity. The remaining sections, toward the center of bearing, would typically be filled with a lower viscosity fluid, liquid or gas so that the power consumption within the motor itself would be minimized.

Abstract: A closed type thrust dynamic pressure bearing is capable of generating enough dynamic pressure for axially bearing a rotating member at the time of start-up without damage to an end face of a flange of the rotating member. The flange of the rotating member is housed in a housing in a closed state. V-shaped dynamic pressure generating grooves are provided at upper and lower end faces of the flange, while a plurality of holes axially passing through the flange are provided radially inside an annular region where the dynamic pressure generating grooves are provided. The total sum of cross-sectional areas of the holes is at least 1/30 of the area of the annular region. Oil sumps are provided at a receiving surface of the housing opposite to the lower end face of the flange.

Abstract: A journal bearing apparatus capable of varying the clearance between a bush which protrudes from the inner surface of a sleeve in which a rotation shaft is inserted and the outer surface of the rotation shaft, in the longitudinal direction of a first dynamic pressure generating groove. Moreover, a journal bearing apparatus is capable of varying the clearance between one end of the rotation shaft and the surface of a thrust bearing, in the diametral direction of a second dynamic pressure generating groove. The clearance becomes wider towards the central part from the ends of the bush, or towards the central part from the edge parts of the surface of the thrust bearing. The shape of the end of the bush or the thrust bearing is preferably a circular arc. Thereby, the fluid pressure on the rotation shaft which faces the first and second dynamic pressure generating grooves is uniform.

Abstract: A recording disk apparatus comprises a clearance between a shaft and a thrust bearing portion tapered in a circumferential direction, a lubricant communication groove of a bearing covered by the shaft so that a lubricant on a radial bearing portion communicates with the lubricant on the thrust bearing portion through the lubricant communication groove, a lubricant circulating path which extends axially from the thrust bearing portion to the radial bearing portion to prevent the lubricant flowing out of the thrust bearing portion from returning directly to the thrust bearing portion without passing the radial bearing portion, and/or a clearance between a slide bearing and a magnetic fluid seal device substantially filled with a magnetic fluid lubricant.

Abstract: A magnetic disc drive system includes a hydrodynamic bearing. The magnetic disc drive system includes a disc drive chassis, a magnetic storage disc, and a read/write transducer adjacent to the disc for reading and writing information on the disc. The hydrodynamic bearing assembly rotatably couples the magnetic storage disc to the disc drive chassis. The hydrodynamic bearing assembly includes a fluid path therethrough for circulating a fluid. A permanent magnet is placed in the fluid path and used for attracting magnetic particles carried in the fluid.

Abstract: A motor includes a rotor bushing having first and second hemispherical grooves formed on top and bottom surfaces thereof, first and second hemispherical bearings inserted into the first and second hemispherical grooves, respectively, and a supporting shaft extending through the rotor bushing and fixed to the first and second hemispherical bearings. Respective heights of the first and second hemispherical grooves measured in the axial direction of the shaft are different from (i.e., are either greater than or less than) the axial depths of the first and second hemispherical grooves, respectively.

Abstract: A fluid bearing in which a thrust bearing is mounted at both ends of a rotary shaft to minimize movement and oscillation of the rotary shaft regardless of a thrust load. The fluid bearing apparatus includes a pair of sleeves respectively mounted into one end of a pair of bearing brackets, a rotary shaft inserted into through holes of the respective sleeves, having a second kinetic pressure generating groove on a circumferential side opposite to the inside of the respective through holes, a pair of thrust bearings mounted into the other end of the bearing brackets, and a first kinetic pressure generating groove formed between any one of the thrust bearings and a section of the rotary shaft.

Abstract: A hydrodynamic thrust bearing assembly for supporting a reduced diameter end portion of a rotating shaft includes a thrust button or plate having one end thereof abutting an end of the reduced diameter end portion to absorb axial forces exerted by the rotating shaft, and a hollow cylindrical bearing sleeve disposed around the reduced diameter end portion, and wherein the thrust button has a central aperture for introduction of a process fluid and a plurality of slots in the one end of the thrust button and communicating with the central aperture in the thrust button and with a helical groove formed in an interior surface of the sleeve.

Abstract: In a rotating device which comprises a rotor; a radial bearing; a lower thrust bearing; a dynamic pressure generating means, a radial bearing area (mm.sup.2) which is the area of the rotor facing the radial bearing, a thrust bearing area (mm.sup.2) which is the area of the rotor facing the lower thrust bearing, and the rotor weight (g) are determined so as to satisfy the following formula:(a radial bearing area)/(thrust bearing area).times.(rotor weight)<300.

Abstract: A fluid bearing apparatus includes a thrust load supporting portion formed between an external side surface of a fixing shaft and an internal side wall of an opening in a bushing; the surface and wall facing each other. The thrust load supporting portion includes a ball inserting groove formed on the external side surface of the fixing shaft and/or the internal side wall of the bushing and a ball inserted into the ball inserting groove. The upper end portion of the shaft is lower than the upper end portion of the bushing. Since the thrust load is supported by the balls instead of by the upper end portion of the fixing shaft, it is possible to prevent movement of the fixing shaft when the fluid bearing apparatus starts to rotate. The frictional resistance of the upper end portion of the fixing shaft can be reduced when the fluid bearing apparatus starts to rotate and stops its rotation.

Abstract: In a dynamic pressure bearing apparatus having a fixed shaft, dynamic pressure generating grooves formed at least on one side of circularly facing surfaces of a rotor and of the fixed shaft which is rotatably meshed with the rotor, a radial bearing formed in an axial direction and a thrust bearing is formed by one end of the fixed shaft and axially facing surfaces of the rotor, the rotor is rotatably supported against the fixed shaft by air dynamic pressure which is generated in the radial bearing and the thrust bearing. The radial dynamic pressure bearing generating grooves are formed on the radial bearing in a dynamic pressure groove shape which pumps air pressure toward the thrust bearing side. An air guide hole is formed in the fixed shaft from the one end to another end of the fixed shaft.

Abstract: A bearing having two surfaces (60, 72) rotatable with respect to each other, a lubrication medium located in a gap between the tow surfaces during rotation of the bearing and a sinusoidal groove pattern (20) formed on one of the tow surfaces to distribute the lubrication medium over the surface of the bearing and create a pressure distribution in the bearing to create a stiff hydrodynamic bearing.

Abstract: An improved rotary valve having a gas bearing which prevents contact between the rotating piston and the cylindrical housing. The same working gas which the rotary valve controls is accumulated in an accumulation chamber. Fluid flow passageways, having a fixed flow resistance along their length, connect the accumulator chamber with a plurality of cavities formed on the cylinder wall of the housing. Pressurized gas is thereby pumped into the clearance gap between the piston wall and the cylinder wall, increasing in pressure where the piston wall comes closer to the cylinder wall, and decreasing in pressure where the clearance gap increases. The net effect is a centering force applied to the piston whenever it varies from an equilibrium position.

Abstract: In a deflecting/scanning apparatus, a rotating polygon mirror is rotatably supported by an air bearing constituted by a stationary shaft and a rotating sleeve which are made of a ceramic material. An upper portion of an end face of the rotating sleeve is covered with a lid as a separate member. A vent hole formed in the lid is sealed with an adhesive to form an air damper chamber.

Abstract: The invention is a spindle motor including a rotor hub bearing a rotational load, lubricant-containing bearing systems rotatably supported by the rotor hub, and stator windings wound on a stationary member, so as to oppose the rotor magnet. At least a portion of the rotor hub is in a clean environment, with the motor substantially sealed by a sealing unit. The spindle motor has a leakage prevention unit which prevents the lubricant trying to leak out the bearing systems and out the motor, when centrifugal forces produced by a rotor hub rotating at a high speed are exerted on the lubricant.

Abstract: A hydrodynamic bearing according to this invention and an electric motor with this hydrodynamic bearing include a shaft having a lubricating-fluid filling hole, one end of which is open toward the outside of the motor and the other end of which leads to the gap between the shaft and a sleeve in which lubricating fluid is filled. At least part of the filling hole except for the opening facing the outside of the motor has a smaller diameter than that of the outer opening. An elastic member formed of elastic material is inserted into the lubricating fluid fillng hole.