Abstract: A dynamic pressure bearing is provided which has a lubricant fluid reservoir space that can easily cope with increasing and decreasing of a lubricant fluid, and that can surely prevent leakage of the lubricant fluid to the outside caused by thermal expansion due to temperature rise, from occurring, and which can be processed relatively easily.

Abstract: Spindle-motor hydrodynamic bearing configuration having conical taper seals on the thrust-bearing ends. The spindle motor shaft is supported in a bore through the rotor by neighboring radial and thrust hydrodynamic bearings constituted through radial micro-gaps cylindrically between the shaft and rotor, axial micro-gaps between thrust plates on either shaft end and recesses endwise in the rotor bore, dynamic-pressure-generating grooves in the micro-gap forming surfaces, and lubricant retained continuously in the radial and axial micro-gaps. The thrust plates are at least partially conical, tapering axially outward. A ring fitted in each rotor bore recess has a conical inner peripheral surface corresponding to the opposing conical surface of the thrust plate, forming a taper seal sloped with respect to the rotational axial center of the motor. The gap clearance dimension gradually expands heading axially outward, wherein the lubricant forms an axial-end gas-liquid interface to function as a taper seal.

Abstract: A disk drive motor having a capillary bearing seal is provided. In one embodiment, a disk drive motor includes a stationary assembly and a rotating assembly having a fluid dynamic journal bearing disposed therebetween. A capillary seal is defined proximate an upper end of the journal bearing and coupled to at least one re-circulation path. The capillary seal is configured to advantageously retain lubricating fluids within the motor when the motor is subjected to lateral shock.

Abstract: A dynamic pressure bearing device including a dynamic pressure bearing member, a thrust dynamic pressure bearing member, and a fluid sealing section for preventing lubrication fluid in the thrust dynamic pressure bearing member from leaking outside, provided adjacent to an outer side section in a radial direction of the thrust dynamic pressure bearing member and defined by an outer circumference wall surface of the dynamic pressure bearing member. The outer circumference wall surface has an inclined outer surface having diameters that decrease in the axial direction, and a ridge section located removed in the axial direction from the fluid sealing section, wherein the outer circumference wall surface is receded in the radial direction along the ridge section than the inclined outer surface of the dynamic pressure bearing member.

Abstract: A fluid dynamic bearing assembly including a shaft and a bearing sleeve. A bearing gap is formed between the shaft and the bearing sleeve and is filled with a lubricating fluid. A reservoir containing the excess of the lubricating fluid is formed at one end of the bearing sleeve. The reservoir is not located in close proximity to the shaft. A fluid trapping recess is formed in the shaft, the fluid trap being configured to prevent migration of the lubricating fluid along the shaft into the environment.

Abstract: Spindle-motor hydrodynamic bearing configuration having conical taper seals on the thrust-bearing ends. The spindle motor shaft is supported in a bore through the rotor by neighboring radial and thrust hydrodynamic bearings constituted through radial micro-gaps cylindrically between the shaft and rotor, axial micro-gaps between thrust plates on either shaft end and recesses endwise in the rotor bore, dynamic-pressure-generating grooves in the micro-gap forming surfaces, and lubricant retained continuously in the radial and axial micro-gaps. The thrust plates are at least partially conical, tapering axially outward. A ring fitted in each rotor bore recess has a conical inner peripheral surface corresponding to the opposing conical surface of the thrust plate, forming a taper seal sloped with respect to the rotational axial center of the motor. The gap clearance dimension gradually expands heading axially outward, wherein the lubricant forms an axial-end gas-liquid interface to function as a taper seal.

Abstract: A downsized spindle motor of excellent abrasion and shock resistance is provided. A shaft is fit into a sleeve. A flange is fixed to an end of the shaft. A radial bearing is formed on faces of the shaft and the sleeve, which faces are opposite and close to each other. A face of the flange closely faces a face of a thrust plate, thereby forming a thrust bearing. Another face of the thrust plate is caulked with a tip of the sleeve. The tip of the sleeve and the thrust plate are fixed to each other by an adhesive. A tapering section is provided at an upper end of the sleeve.

Abstract: The present invention relates to a hydrodynamic bearing supporting a shaft and a sleeve so as to relatively rotate with respect to a rotation axis. In accordance with one example of the present invention, there is provided a hydrodynamic bearing in which a capillary seal portion is formed continuously in a bearing portion having a lubricating oil retained in a micro gap as a working fluid. The capillary seal portion is provided with a first capillary seal portion having a first radial gap, a dimension of the first radial gap being getting at least wider in accordance with increasing a distance from the bearing portion in the rotation axis, and a second capillary seal portion adjoining the first capillary seal portion and having a second radial gap, a dimension of the second radial gap being getting at least wider in accordance with increasing a distance from the bearing portion in the rotation axis.

Abstract: Oil-retaining configuration in partially filled or fully filled dynamic-pressure bearing system for miniaturized, low-profile spindle motor. A radial bearing section and a magnetically balanced thrust bearing section compose the bearing system. An oil taper seal is configured in between the rotor and the sleeve, radially beyond the radial bearing section, and not axially beyond the thrust bearing section. The taper-seal gap slopes radially inward, flaring with further separation from the rotor undersurface, in a configuration that lengthens the tapered space functioning as, and enlarges the capacity within, the taper-seal area, and that sets up the oil boundary surface oriented sloping radially inward. Centrifugal force during rotation thus acts pressing in on the oil boundary surface, fortifying the sealing strength. The oil-retaining configuration allows for span, between twin constituents provided as the radial bearing section, sufficient for increased conical stiffness even in a reduced-profile structure.

Abstract: A fluid dynamic bearing assembly including a shaft and a bearing sleeve. A bearing gap is formed between the shaft and the bearing sleeve and is filled with a lubricating fluid. A reservoir containing the excess of the lubricating fluid is formed at one end of the bearing sleeve. The reservoir is not located in close proximity to the shaft. A fluid trapping recess is formed in the shaft, the fluid trap being configured to prevent migration of the lubricating fluid along the shaft into the environment.

Abstract: A fluid dynamic bearing assembly including a shaft and a bearing sleeve. A bearing gap is formed between the shaft and the bearing sleeve and is filled with a lubricating fluid. A capillary seal is formed at one end of the bearing sleeve, and a recess is formed in the shaft immediately above the capillary seal. The surface of the recess forms an acute angle with an axis of the shaft.

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

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: An annular groove portion is integrally formed for preventing splashing of the lubricating oil by extending from a mount base (10) of the motor rotor to the motor shaft (6) to the metal bearing (5) and the radial ball bearing (20), allowing a spacer member (15) making contact with an inner ring (20a) of the radial ball bearing (20) to be attached inside the annular groove portion.

Abstract: A highly reliable liquid bearing unit is provided, which can, by securely repelling a lubricant by an oil repelling film, prevent the lubricant from leaking and a magnetic disk device mounted therewith. In a case where the lubricant contains a constituent of at least one of a hydrocarbon-based oil and an ester-based oil and the oil repellent film is a film of at least one of a fluorine base and a silicone base, surface tension of the lubricant is made greater than the critical surface tension of the oil repellent film by 5 mN/m or more. Moreover, when the lubricant is a fluorine-based lubricant, surface tension of the lubricant is made greater than the critical surface tension of the oil repellent film by 8 mN/m or more.

Abstract: The cone which is pressed onto or otherwise affixed to the shaft to cooperate with the sleeve to form a conical hydrodynamic bearing is modified to provide a flat surface at the axially outer end of the cone most distant from the conical surface which is used to form the conical bearing in cooperation with the bearing seat of the sleeve and the intervening fluid. The sleeve surface facing the second angled surface of the bearing cone is modified to diverge more sharply away from the second surface of the cone, or to simply be spaced further away. In this way, a larger reservoir is formed, diminishing the possibility of oil evaporation and oil loss. Finally, a relatively flat shield is supported from the sleeve overlying the flat upper surface of the cone. The divergence of the upper bearing cone surface from the surrounding sleeve also allows for filling the bearing before the shield is installed.

Abstract: The present invention relates to the field of fluid dynamic bearings. Specifically, the present invention provides a secondary fluid reservoir for the fluid used in a fluid dynamic bearing in a high-speed spindle motor assembly.

Abstract: A veneer lathe that can provide a veneer produced by cutting out a log, which is substantially free from surface scratches, and thus can be used as a surface sheet for plywood. A roller bar drives a log while pushing its peripheral surface on the upstream side of a knife fixed to a knife carriage for cutting the rotating log in a log rotating direction. The roller bar 3 has a large number of grooves defined in a peripheral surface thereof. The shape of the grooves 5a in a section crossing the shaft centerline of the roller bar 3 is set so that an angle between a tangent at a corner portion 3e constituted by a line 3d of an outer periphery of the roller bar 3 and a line 3b extending outward from an upstream side face of the grooves 5a is 130 to 160 degrees.

Abstract: A spindle motor, a fluid dynamic bearing for said spindle motor, and a method of manufacturing said bearing wherein said bearing includes a non-capillary seal fluid reservoir.

Abstract: A spindle motor, a fluid dynamic bearing for the spindle motor, and a method of manufacturing the bearing wherein the bearing does not include a capillary seal fluid reservoir.

Abstract: A seal whose primary axis lies in the radial direction where the fluid bearing is primarily extending in the axial direction between the rotating shaft and surrounding sleeve. The capillary seal is positioned with an opening adjacent an end of the fluid bearing gap, and comprises two diverging walls, with the narrowest gap between the two generally radially extending walls being closely adjacent an end of the fluid gap. The walls diverge as they extend radially away from the fluid bearing. In this way, the fluid held in the radial capillary seal is maintained adjacent an end of the gap, while the size of the reservoir provided or defined by the diverging walls provides a relatively large reservoir volume.

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 fluid bearing with an oil circulating hole therein has a bearing housing fixedly assembled to a stator base having a closed bottom surface; and upper and lower bearing portions; and a thrust receiving portion to rotatably support a rotating shaft. An opening oil reservoir is in the bearing housing and a lower oil reservoir is formed at the lower portion thereof. An intermediate oil reservoir is located between the upper and lower bearing portions. The oil circulating hole is formed in parallel with the rotating shaft in order to communicate with the opening oil reservoir, the intermediate oil reservoir and the lower oil reservoir. A space is defined at an opening portion which is covered with a cap in order to prevent oil from leaking.

Abstract: A fluid dynamic bearing includes a shaft rotating within a sleeve. The shaft and sleeve are supported for relative rotation by fluid in the gap between the shaft and sleeve. To prevent fluid from leaking out of the fluid dynamic bearing into the surrounding atmosphere, one end of the fluid is defined by a capillary seal.

Abstract: A dynamic pressure bearing is provided which has a lubricant fluid reservoir space that can easily cope with increasing and decreasing of a lubricant fluid, and that can surely prevent leakage of the lubricant fluid to the outside caused by thermal expansion due to temperature rise, from occurring, and which can be processed relatively easily.

Abstract: A dynamic pressure bearing device includes a dynamic pressure bearing member that generates a dynamic pressured by pressurizing a lubrication fluid by a dynamic pressure generation device, and supports a rotary shaft by the dynamic pressure generated in the lubrication fluid, a thrust dynamic pressure bearing member formed by an end face in an axial direction of the dynamic pressure bearing member and an end face in an axial direction of a rotary member that rotates together with the rotary shaft, which are disposed opposite each other in the axial direction, and a fluid sealing section for preventing the lubrication fluid in the thrust dynamic pressure bearing member from leaking outside, provided adjacent to an outer side section in a radial direction of the thrust dynamic pressure bearing member and defined by an outer circumference wall surface of the dynamic pressure bearing member.

Abstract: An inner space of a housing sealed with a seal member as well as internal pores of a bearing member (pores in a porous structure) are filled with a lubricating oil without the presence of air, so that the oil surface of the lubricating oil is within a seal space. Under a reduced pressure of 100 Torr, no lubricating oil leaks outside of the housing even at any attitude of the fluid lubricated bearing device such as normal, inverted, or horizontal attitude.

Abstract: A dynamic pressure bearing is provided in which leakage of liquid lubricant due to precession of a housing can be prevented from occurring. In the dynamic pressure bearing, the inner diameter of a tapered inner peripheral face 20 of the housing 1 which constitutes a capillary sealing portion 23 is gradually increased as moving from an opening 17 toward the inner area in the axial direction. When the housing 1 is rotated, therefore, a centrifugal force applied on liquid lubricant existing on the tapered inner peripheral face 20 acts in the direction along which the liquid lubricant is pushed toward the inner area, as indicated by an arrow 19. Consequently, the centrifugal force which is due to precession of the housing 1, and which pushes the liquid lubricant 15 toward the outside as indicated by an arrow 29 can be cancelled by the force acting in the direction toward the inner area, with the result that leakage of the liquid lubricant due to precession of the housing 1 can be prevented from occurring.

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

Abstract: A 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.

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 spindle motor comprising: a stator portion which includes a stator board which is fixedly disposed, a plain bearing which is secured onto the stator board, and a wound coil disposed around the plain bearing; a rotor portion which includes a rotating shaft which is rotatably supported by the plain bearing, a rotor yoke which is integrally fixed to the rotating shaft, and a rotor magnet provided to the rotor yoke; and a plate which is provided on at least one end face of the plain bearing and adapted to prevent leakage of lubricating oil to the outside due to rotation of the rotor portion.

Abstract: In a guiding device for mechanical members, which consists of two parts intended to engage by sliding friction, one of the two parts, called the smooth part, has a smooth, functional, i.e. friction, surface and the other part, called the pierced part, has at least one functional, i.e. friction, surface, including emergent cavities intended to accommodate a grease of the lubricating-paste type and especially an EP grease (extreme-pressure grease) comprising a soap-type constituent, an oil-type constituent and an extreme-pressure additive. The contact angle &thgr; between the functional surface of the smooth part and the grease is in the range from 20 degrees to 40 degrees and the material of the pierced part is such that the contact angle between the functional surface of the pierced part and the grease is in the range from 45 degrees to 75 degrees. The device may be of the slideway/runner type, shaft/bearing type, ball/socket joint type, etc.

Abstract: In a bearing arrangement, a rotary shaft has an annular groove opposite a bearing portion so that a part of the annular groove extends outward from the bearing portion, and lubrication oil is disposed between the rotary shaft and the bearing portion.

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: The invention relates to a fluid-conveying machine, in particular, a pump having a component rotating in a stationary housing part inside an annular gap. The stationary housing part separates an interior having a higher product pressure from an exterior having a lower pressure. A rotating component is mounted in an external bearing which is sealed with respect to the interior via a sealing system. In order to improve the sealing, the invention provides that the annular gap is formed between two sliding bearing shells which comprise extremely hard, wear-resistant materials and, in accordance with the operating principle of a radial sliding bearing, form a first pressure-reducing stage. A feedback device, which feeds back the leakage from this first sealing stage into the conveying process of the machine, is connected downstream of the first pressure-reducing stage. A second sealing stage is arranged axially downstream of the feedback device.

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 hydrodynamic bearing having a liquid accommodating portion in which, even when a liquid in the bearing expands as a result of a temperature rise, it is possible to prevent the liquid from leaking to the outside. In order to attain the object, in a hydrodynamic bearing including: a shaft and a sleeve which relatively rotate; a dynamic pressure bearing portion which is formed between the shaft and the sleeve; and an accommodation portion which accommodates a liquid in the bearing, and which is disposed in a space between the shaft and the sleeve and in the vicinity of an atmosphere side, the accommodation portion is an opposition space portion in which a conical face formed on the shaft and having a diameter that is gradually reduced as moving toward an end portion of the shaft is opposed to a conical face which is formed on an inner side face of the sleeve and which covers the conical face of the shaft.

Abstract: A method for designing bearings, of improved performance, the load-bearing surfaces of which feature micropores about 2 to 10 microns deep and, preferably, aspect ratios on the order of 7 to 20. The hydrodynamic pressure distribution of a suite of bearing surfaces with different micropore geometries and densities is modeled numerically. The load-bearing surfaces of the bearings are fabricated with micropores having the optimal density and geometry determined by the numerical modeling. Conical micropores may be created by single laser pulses, with the pore size and shape controlled by controlling the laser beam profile, the laser beam power, and the optical parameters of the focusing system.

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 method for designing bearings, of improved performance, the load-bearing surfaces of which feature micropores about 2 to 10 microns deep and, preferably, aspect ratios on the order of 7 to 20. The hydrodynamic pressure distribution of a suite of bearing surfaces with different micropore geometries and densities is modeled numerically. The load-bearing surfaces of the bearings are fabricated with micropores having the optimal density and geometry determined by the numerical modeling. Conical micropores may be created by single laser pulses, with the pore size and shape controlled by controlling the laser beam profile, the laser beam power, and the optical parameters of the focusing system.

Abstract: The invention relates to an electromotor comprising a stator part and a rotor part, which parts form an oil-containing spiral groove bearing system. Surface areas of said parts are provided with a so-called oil barrier in order to prevent the oil from creeping from the bearing system to the environment. According to the present invention, said oil barrier comprises a monolayer of perfluorocarboxylic acid anions, especially those having a chain length of 10-20 C-atoms and/or perfluoroalkylthiol anions. Oil barriers of this type can be easily provided on the rotor part and stator part by means of dipping. These oil barriers have a very small thickness and can very suitably be used to prevent oil creepage.

Abstract: A veneer lathe comprising a knife (2) for peeling a log (1), which is secured rotatably to a knife stock, and a roller bar (3) disposed to press a circumferential surface of the log (1) at an upstream side, in relative to said knife (2), of a rotational direction of the log (1). The roller bar (3) has a diameter of not more than 30 mm, and is provided on the circumferential surface thereof with a large number of projections (5) whose height is not higher than the circumferential surface of the roller bar (3). The roller bar (3) is sustained in a sliding bearing (9) and adapted to receive a rotational force from a driving source. The roller bar (3) functions not only as a pressure bar but also as a power transmitting media to rotate the log (1), thereby preventing the generation of lathe check of veneer to be produced.

Abstract: A method for designing bearings, of improved performance, the load-bearing surfaces of which feature micropores about 2 to 10 microns deep and, preferably, aspect ratios on the order of 7 to 20. The hydrodynamic pressure distribution of a suite of bearing surfaces with different micropore geometries and densities is modeled numerically. The load-bearing surfaces of the bearings are fabricated with micropores having the optimal density and geometry determined by the numerical modeling. Conical micropores may be created by single laser pulses, with the pore size and shape controlled by controlling the laser beam profile, the laser beam power, and the optical parameters of the focusing system.

Abstract: Particle traps in a hydrodynamic bearing unit prevent particles, generated by repeated motor start and stop operations or lubricant cavitation caused by shock loads or introduced by ambient sources, from circulating with the bearing lubricant, thereby preventing accelerated wear of bearing grooves. Each trap is defined by an annular bevel shaped channel defined along the inner radial wall of a shaft sleeve. Each trap is located in close proximity to hydrodynamic bearings so that existing particles and any wear particles generated by the bearings may be pumped into the traps by centrifugal force created by rotation of the bearing unit and imparted to the lubricant. The centrifuge-like effect forces the particles against the back wall of each channel while the bevel shaped configuration of the channels prevents particles from migrating out of the channels after the motor stops.

Abstract: A method for designing bearings, of improved performance, the load-bearing surfaces of which feature micropores about 2 to 10 microns deep and, preferably, aspect ratios on the order of 7 to 20. The hydrodynamic pressure distribution of a suite of bearing surfaces with different micropore geometries and densities is modeled numerically. The load-bearing surfaces of the bearings are fabricated with micropores having the optimal density and geometry determined by the numerical modeling. Conical micropores may be created by single laser pulses, with the pore size and shape controlled by controlling the laser beam profile, the laser beam power, and the optical parameters of the focusing system.

Abstract: A hydrodynamic bearing apparatus which includes at least two hydrodynamic bearing sections for rotatably supporting a shaft member and a cylindrical member, where the bearing sections constitute a continuous bearing clearance. A hydrodynamic pressure generating portion is provided for generating a hydrodynamic pressure in a lubricant which is filled in the bearing clearance. One hydrodynamic generating portion is shaped asymmetrically to move the lubricant in one direction. Two capillary sealing sections are also provided. One capillary sealing section is positioned downstream in a moving direction of the lubricant and is configured such that the lubricant moves by a predetermined amount to cancel a differential pressure which is generated at the hydrodynamic bearing sections.

Abstract: A compact electric motor construction employing fluid bearings for use in a disk drive apparatus includes a spindle having a shaft and a thrust plate and a hub assembly including a hub having an outer disk support portion with an inner thrust bearing surface located axially above the upper thrust bearing surface of the thrust plate. The hub also includes an inner sleeve which substantially surrounds the shaft and provides an air gap between its inner diameter and the outer diameter of the thrust plate. The air gap is vented to the interior of the motor cavity by vent passages. Transition grooves are provided on bearing surfaces adjacent all fluid seal zones for controlling the migration of bearing fluid in a radial direction and for providing a low fluid pressure region adjacent capillary seals at the ends of the shaft to contain the seal and prevent leakage.

Abstract: A dynamic groove bearing (9,89,111) with an inner bearing part (15) and an outer bearing part (17) which is rotatable about the inner bearing part (15). The bearing parts (15,17) are provided with cooperating bearing surfaces (23,35) between which a bearing gap (45) filled with liquid lubricant (75,105) is present. The bearing surface (35) of at least one of the bearing parts (17) is provided with a pattern of grooves (51,53). The bearing surface (35) of the outer bearing part (17) is provided with an annular recess (67, 91,113) which bounds the bearing gap (45). The annular recess (67, 91, 113) is asymmetrical, having at a side thereof facing the bearing gap (45) a first lateral surface (69) adjoining the bearing surface (35) of the outer bearing part (17) and enclosing an obtuse angle .beta..sub.1 with the bearing surface (35) of the outer bearing part (17).