Abstract: A bearing structure includes a plurality of wave-shaped grooves and an inner surface. The wave-shaped grooves are formed on the inner surface for receiving a lubricating fluid. Each of the wave-shaped grooves extends along a longitudinal axis of the bearing structure. Each of the wave-shaped grooves includes a first peak section, a second peak section, two first connecting sections, two second connecting sections and a trough section. The two first connecting sections are connected to opposite sides of the first peak section, and the two second connecting sections are connected to opposite sides of the second peak section. The trough section is disposed between the first peak section and the second peak section, and the trough section is connected to one of the first connecting sections and one of the second connecting sections. The first and second peak sections and the trough section have a circular arc structure.

Abstract: A bearing assembly for a downhole drilling motor can include a housing having an inner wall, an outer bearing race within the housing, and an inner bearing race. The outer bearing race can include a reduced-diameter portion forming a gap between the outer bearing race and the inner wall of the housing to allow for radial displacement of the outer bearing race relative to the housing. The design combines the functions of a bearing and a compliant feature into a single unit.

Abstract: A spindle motor includes a shaft arranged to extend in an axial direction, and a base portion arranged to define a portion of a housing, and including a through hole in which the shaft is inserted. A fixing region is defined between an inner circumferential portion of the base portion and a lower portion of the shaft. The fixing region includes a press-fitting region and an adhesion region defined on a lower side of the press-fitting region and in which a seal gap is defined between the inner circumferential portion of the base portion and the lower portion of the shaft. The seal gap is arranged to gradually decrease in radial width with increasing height. The seal gap is arranged to include an adhesive arranged therein over an entire circumference thereof.

Abstract: There is provided a spindle motor including: a shaft connected directly or indirectly to a base member and having a depression groove formed in a central portion of an outer peripheral surface thereof; a sleeve rotatably installed on the shaft and having a communication hole formed so as to be connected to the depression groove; and a rotor hub fixedly installed on the sleeve to thereby rotate together therewith, wherein the communication hole is inclined so that lubricating fluid may be easily injected into the depression groove, and the sleeve has a fluid storage part formed on an outer peripheral surface thereof, the fluid storage part being connected to the communication hole and temporarily storing the lubricating fluid therein.

Abstract: There is provided a spindle motor including: a base part including a base member and a lower thrust member fixedly installed on the base member; a shaft having a lower end portion fixedly installed on the base part; an upper thrust member fixedly installed on an upper end portion of the shaft; a sleeve disposed between the upper and lower thrust members and rotatably installed on the shaft; and a rotor hub fixedly installed on the sleeve to thereby rotate together therewith, wherein the sleeve includes a connection hole formed therein in order to connect an inner diameter portion thereof to an outer peripheral surface thereof.

Abstract: A rotating device includes: a rotating body, a fixed body and lubricant. A surrounding member in the fixed body has a sleeve and a housing for surrounding the sleeve. A first radial dynamic pressure generating groove and a second radial dynamic pressure generating groove are formed on at least one of the inner circumferential surface of the sleeve and the outer circumferential surface of a shaft in the rotating body. The sleeve has a flange portion protruding radially outward at the end portion of the sleeve near to a hub in the rotating body. A concave portion, which is made by axially concaving at least part of the area corresponding to a wall thickness of the sleeve on the inner circumference side of the flange portion, is circumferentially provided in the flange portion.

Abstract: There are provided a spindle motor and a hard disk drive including the same. The spindle motor includes: a sleeve installed on a base member and having a circulation hole; a shaft inserted into the sleeve; a rotor hub installed on an upper end of the shaft; and a thrust member installed in an installation groove formed in an upper portion of the sleeve and forming a connection part, the connection part allowing the circulation hole to be in communication with a sealing part formed by the sleeve and the rotor hub and having a liquid-vapor interface of a lubricating fluid disposed therein, wherein the connection part is formed between the sleeve and the thrust member in a circumferential direction, and at least any one part of a radial outer portion of the connection part has an axial gap smaller than that of another part thereof in the circumferential direction.

Abstract: A motor includes a rotor having a permanent magnet; a sleeve rotatably supporting the rotor; fluid provided in a gap between the rotor and the sleeve; a stator having a electromagnet disposed opposite to the permanent magnet to rotate the rotor relative to the stator; and a boss interposed between the sleeve and the stator. In the motor, the sleeve, the stator, and the boss are provided as separate members.

Abstract: There is provided a hydrodynamic bearing apparatus, including: a shaft; and a sleeve rotatably supporting the shaft, wherein at least one of an outer surface of the shaft and an inner surface of the sleeve includes upper and lower hydrodynamic grooves generating hydrodynamic fluid pressure while the shaft rotates, and at least one of the upper and lower hydrodynamic grooves has a depth of a lower part thereof greater than that of an upper part thereof.

Abstract: A groove configuration for angular stiffness in a fluid dynamic bearing is provided. A primary groove and a secondary groove are formed on a journal bearing or thrust bearing surface. The secondary groove apex induces a heightened pressure response at a localized area to counteract angular displacement. The primary groove extends a greater circumferential distance about the bearing surface as compared to the secondary groove. The secondary groove apex is also situated closer to an axial end of the journal bearing, or closer to an outer diameter of the thrust bearing, as compared to the primary groove apex.

Abstract: There are provided a fluid dynamic bearing assembly, a spindle motor having the same, and a method of assembling a shaft and a stopper, the fluid dynamic bearing assembly, including: a shaft, a sleeve rotatably supporting the shaft by fluid dynamic pressure, the shaft rotating relative thereto accordingly, and a stopper having a body inserted into a fixing recess provided on a lower portion of the shaft, and a flange provided to be protruded from a lower end of the body to an outer side thereof in a radial direction and caught by a lower end of the sleeve, wherein the stopper includes an air vent penetrating therethrough in an axial direction.

Abstract: A fluid flow machine includes a housing with a connecting piece for a working fluid on an intake side, and a pressure side. At least one impeller is mounted on a shaft, which is held in the housing by radial and axial bearings, and a cooling arrangement is provided for at least one bearing. A revolving part of the axial bearing is designed as a cooling fluid transportation device, wherein a suction connection leads to the intake side of the impeller.

Abstract: The spindle motor includes a rotating shaft and a sleeve. The rotating shaft has a stepped portion in a fluid dynamic pressure shafting system. The sleeve is fitted over the circumferential outer surface of the rotating shaft. A sleeve recess is formed in the inner surface of the sleeve so that the edges of the stepped portion are spaced apart from the sleeve.

Abstract: A spindle motor including: a lower thrust member fixedly coupled to a base member; a shaft fixedly coupled to at least one of the lower thrust member and the base member; a sleeve disposed on an upper portion of the lower thrust member and rotatably installed on the shaft; a rotor hub coupled to the sleeve to thereby rotate together with the sleeve; an upper thrust member fixedly coupled to an upper end portion of the shaft and forming a liquid-vapor interface together with the sleeve; and a cover member fixedly coupled to the shaft so as to be disposed on an upper portion of the upper thrust member, wherein the upper thrust member includes a stepped jaw part having a lower surface supported by an upper surface of the shaft and an upper surface pressed by the cover member, so as to increase coupling strength with the shaft.

Abstract: A bearing unit includes: a shaft; a radial bearing configured to support the shaft in a circumferential direction; a thrust bearing configured to support one end of the shaft in a thrust direction; a housing having the radial bearing and the thrust bearing disposed in the inside and having a closed structure except a shaft insertion hole into which the shaft is fitted; a coming out preventing member provided on one end side of the radial bearing at which the thrust bearing is provided configured to prevent the shaft from coming out from the radial bearing; and viscous fluid filled in the housing. The coming out preventing member is made of a resin material having a value of a Young's modulus equal to or higher than 3.4 GPa.

Abstract: A thinner fluid dynamic bearing capable of stable shaft rotation, a motor including the bearing, and a recording-medium driving apparatus including the bearing are provided. Pressure-generating grooves are provided in thrust surfaces of a thrust bearing portion 39 opposite a circular plate 35 and a stopper 33 to attract a working fluid from inner and outer edges of the thrust bearing portion 39 to a radially midway portion thereof as a shaft member 16 rotates relative to a support 22. One or more through-holes 48 are provided between inner edges of annular regions of the thrust surfaces in which the pressure-generating grooves are provided and the midway portion in the radial direction. The through-holes extend through the thrust bearing portion 39 in a central-axis direction of the shaft member.

Abstract: A sliding bearing, such as a journal bearing, includes at least two bearing elements, the bearing surfaces of which are slidably supported with respect to each other. At least one of the surfaces is provided with a first type of cavity which may comprise a lubricating substance, the first type of cavity being defined by a specific range of geometric properties. At least one surface is provided with at least a second type of cavity which may comprise a lubricating surface, the second type of cavity being defined by geometric properties which are different from the geometric properties of the first type of cavity.

Abstract: The invention relates to a fluid dynamic bearing system that comprises at least one stationary part that has a shaft and two bearing plates disposed on the shaft at a mutual spacing, and at least one rotating part that is supported so as to rotate about a rotational axis with respect to the stationary part, and comprises a bearing bush and a sleeve enclosing the bearing bush. A bearing gap filled with bearing fluid is provided between the parts and at least one sealing gap for sealing the bearing gap that extends concentric to the rotational axis. The bearing comprises at least one fluid dynamic radial bearing and two fluid dynamic axial bearings and at least one recirculation channel that connects the two axial bearing regions to each other.

Abstract: A groove configuration that improves angular stiffness in a fluid dynamic bearing is provided. A primary groove and a secondary groove are formed on a journal bearing or thrust bearing surface. The secondary groove apex induces a heightened pressure response at a localized area to counteract angular displacement. The primary groove extends a greater circumferential distance about the bearing surface as compared to the secondary groove. The secondary groove apex is also situated closer to an axial end of the journal bearing, or closer to an outer diameter of the thrust bearing, as compared to the primary groove apex. Bearing wear is prevented or minimized under gyroscopic loading. The improved angular stiffness may result in the heads of a storage device being accurately aligned with disc storage tracks. Discs may thus be designed with increased track densities, allowing for smaller discs and increased storage capacity of discs.

Abstract: A fluid dynamic bearing includes a shaft member engaged with a circular plate extending radially outward therefrom; a support including a cylinder rotatably accommodating the shaft member, an outer surface of the support having a tapered portion toward an axial upper surface thereof opposing the circular plate; a stopper, an inner surface of the stopper having a constant diameter in an axial direction in a portion opposite to the tapered portion of the support so as to form a tapered gap with respect to an outer surface of the support located under the axial upper surface of the support; and a working fluid placed between the inner surface of the stopper and the outer surface of the support.

Abstract: A hydrodynamic bearing device comprises a sleeve, a shaft, and a flange cover. The sleeve has a bearing hole and a communicating hole which communicates between both end faces. The shaft is disposed in a state of being capable of relative rotation in the bearing hole of the sleeve, and has a main portion, a flange that is larger in diameter than the main portion, and a communicating hole that communicates with both end faces of the flange. The flange cover is disposed opposing to the lower face of the flange. The pressure loss at the communicating hole is smaller than the pressure loss at the communicating hole.

Abstract: A bearing is mounted in an axle tube of a motor and includes an axial hole for rotatably receiving a shaft of the motor. At least one guiding groove is defined in a peripheral wall defining the axial hole. The guiding groove extends axially from an end face toward but spaced from the other end face. The guiding groove includes a deposit space formed at a bottom thereof for receiving carbide and impurities to enhance the lubricating effect and to prolong the life of the motor.

Abstract: A fluid dynamic bearing has pressure-generating grooves provided in opposed thrust surfaces of a thrust bearing portion opposite a circular plate and a stopper to direct a working fluid from inner and outer peripheral edges of the thrust bearing portion toward a radially intermediate portion thereof as a shaft member rotates relative to a support. One or more through-holes are provided between inner edges of annular regions of the thrust surfaces in which the pressure-generating grooves are provided and the intermediate portion in the radial direction. The through-holes extend through the thrust bearing portion and interconnect pressure-generating grooves in the opposed thrust surfaces so that bubbles in the working fluid can be sucked smoothly into the through-holes through the pressure-generating grooves.

Abstract: A bearing unit includes: a shaft; a radial bearing configured to support the shaft in a circumferential direction; a thrust bearing configured to support one end of the shaft in a thrust direction; a housing having the radial bearing and the thrust bearing disposed in the inside and having a closed structure except a shaft insertion hole into which the shaft is fitted; a coming out preventing member provided on one end side of the radial bearing at which the thrust bearing is provided configured to prevent the shaft from coming out from the radial bearing; and viscous fluid filled in the housing. The coming out preventing member is made of a resin material having a value of a Young's modulus equal to or higher than 3.4 GPa.

Abstract: A fluid bearing device 40 comprises a sleeve 1, a shaft 2, a thrust plate 4, a radial bearing component 21, and a thrust bearing component 22. A bearing hole 1a is formed in the sleeve 1. The shaft 2 has a shaft main component 5 that is inserted in the bearing hole 1a, and a flange 3 provided on the axial lower side of the shaft main component 5. The thrust plate 4 is fixed to the sleeve 1 and covers the shaft 2 from the axial lower side. A screw hole 5a that is coaxial with the shaft main component 5 is formed in the shaft main component 5 from the end face on the axial upper side toward the axial lower side. An annular concave component 3c that is coaxial with the shaft 2 is formed in the end face on the axial lower side of the shaft 2.

Abstract: A hydrodynamic bearing device includes a sleeve having a bearing bore substantially at a center portion, a shaft inserted in the bearing bore in a rotatable manner, a thrust plate for supporting an end of the shaft in the thrust direction and an upper retaining portion that has an opening portion through which the shaft passes and covers the upper surface of the sleeve. A radial hydrodynamic bearing is formed between the bearing bore of the sleeve and the shaft, while a thrust hydrodynamic bearing is formed between the thrust plate and an end of the shaft. A first space is formed between the upper surface of the sleeve and the upper retaining portion. A second space is formed between the upper retaining portion and a step portion.

Abstract: A fluid dynamic bearing device including a shaft having an interior pressure regulating hole by which a center portion of a thrust surface confronting a thrust plate and a lubricant pool portion of an inner circumferential surface of a sleeve are communicated with each other. Thus, the device is capable of obtaining stable thrust floating characteristics and preventing leaks of the lubricant as well as exhaustion of the lubricant.

Abstract: A method and apparatus is provided for allowing a molecularly thin film to be established on a surface of the gas fluid dynamic bearing. The film can be controllably replenished so that the problem of liquid lubricant starvation is overcome. A suitable non-sludging lubricant of low surface tension is held in a porous reservoir within the stationary portion of the bearing. This fluid migrates out of the reservoir to coat the contiguous bearing surfaces. Alternatively, the lubricant may be held in a porous reservoir within the rotating portion of the bearing; due to centrifugal force, as the rotating portion spins, the fluid is spun out and coats the opposite non-rotating surface. The reservoir may be replaced by a singular reservoir such as a simple hole, depression, cavity or groove filled with lubricant.

Abstract: Disclosed is a rotor/stator type homogenizer which allows the gap between the rotor and the stator to be set to a very small dimension and which does not involve generation of abrasion particles or the like even if the rotor is rotated at high speed, making it possible to efficiently homogenize a plurality of liquids having no mutual compatibility. The inner peripheral surface of the stator and the outer peripheral surface of the rotor are opposed to each other through a predetermined gap and a portion of the solutions is introduced into the gap to form a hydrodynamic bearing, thereby supporting rotation of the rotor with respect to the stator.

Abstract: Disclosed is a spindle device endowed with a sufficient load capacity for bending moment and capable of reducing power loss and heat generation of the main shaft attributable to the radial dynamic pressure bearing. In this spindle device, the rotation of the spindle rotor is supported by a pair of radial dynamic pressure bearing portions, between which there is provided a first cooling chamber so as to circumferentially surround the spindle rotor, atmosphere outside the housing being introduced into the first cooling chamber.

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

Abstract: A hydro dynamic gas bearing having a sleeve with one end closed and connected to a front end of a shaft supported at its proximal end relative to a base on a fixed side, a plurality of hydro dynamic pressure generating grooves on at least one of an outer peripheral surface of the shaft and an inner peripheral surface of the sleeve opposite the outer peripheral surface, and a through hole communicating with the outside of the base extending from the front end to the proximal end of the shaft, the through hole having an air vent for adjusting pressure between the shaft and the sleeve for adjustment of discharge air so that the sleeve rotates in a contactless fashion relative to the shaft.

Abstract: A method and apparatus for replenishing oil in a fluid dynamic bearing using a sleeve groove. The replenishing groove is formed in the sleeve surrounding the shaft so that centrifugal force drives the oil to move toward the radial bearings.

Abstract: A drive axle assembly includes a stationary member and a rotating member spaced apart from said stationary member to form a gap. A fluid bearing is formed between the stationary and rotating members by filling the gap with a fluid. The fluid creates a bearing surface between the stationary and rotating members. The fluid is pressurized to provide radial and thrust load support for the rotating member as it rotates with respect to the stationary member.

Abstract: A double sleeve type dynamic bearing comprises a fixed shaft having at least one end fixedly mountable to an apparatus in which the bearing is utilized, a rotary sleeve arranged coaxially with the fixed shaft so that a first fine gap is formed therebetween, a fixed sleeve arranged coaxially with the rotary sleeve so that a second fine gap is formed therebetween, and a lubrication oil filled in the fine gaps. The first fine gap and the second fine gap each have an open end exposed to air outside the bearing and an opposite end that is not exposed to the air, the opposite ends being in communication with each other. A holding member holds the fixed shaft and the fixed sleeve and is disposed adjacent to a lower end surface of the rotary sleeve to form a third fine gap between the holding member and the lower end surface of the rotary sleeve. The third fine gap is formed with a thrust dynamic pressure producing groove, and opposite ends of the first and second fine gaps meet each other through the third fine gap.

Abstract: In turbocharger, particularly an exhaust gas turbocharger for an internal combustion engine with a turbine wheel and an impeller disposed on a common shaft which is rotatably supported by friction bearings to which lubricating oil is supplied by an oil supply, a turbine speed detection device is provided comprising a pressure modulating structure disposed on the shaft for modulating the oil pressure in the oil supply in accordance with the speed of the shaft and an oil pressure sensor is arranged in the oil supply for sensing the oil pressure modulations for determining the speed of the turbocharger

Abstract: An exhaust-gas turbocharger for an internal combustion engine has an exhaust-gas turbine in the exhaust tract and a compressor in the intake tract, the exhaust-gas turbine and the compressor being connected via a shaft which is supported in a casing of the exhaust-gas turbocharger via at least one bearing. In order to improve the efficiency of the turbocharger, the bearing has a non-contact design, in that, when the exhaust-gas turbocharger is in operation, the shaft is held at a distance from, and so as to be virtually free of friction with, a bearing receptacle fixed to the casing.

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 chopper for chopping fibers or fiber strands having a back up roll and a blade roll containing blades that work against a peripheral surface of the back up roll and a method of using is disclosed. The chopper has a number of improved features for reducing the frequency of long fibers or long fiber strands and fuzz from getting into the chopped product. The chopper can have one or any combination of the improvements. The improvements include a strand guide located at least two feet up stream of the chopper, a first starting roll for starting a new strand that runs on a fluid bearing that can be adjusted to control the RPM of the first starting roll, a mount for a roll that runs against the peripheral surface of said back up roll, a strand guide insert for reducing fuzz generation and for preventing fuzz from getting into the product, and a deflector plate for catching and deflecting chopped strands thrown off the back up roll into a chopped strand product chute.

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: A shaft having a thrust plate at or near one end, and a sleeve cooperating with the shaft to define one or more journal bearings and a counterplate (which may be supported by the sleeve or defined by the sleeve) defining at least one counter thrust surface in cooperation with the thrust plate. In order to maintain an enhanced fluid distribution across the journal bearing and maintain pressure distribution boundary conditions as desired, one or more grooves are defined along the shaft extending behind or between the thrust plate and the shaft. The grooves typically extend from one radial side of the thrustplate behind the thrustplate and up to a point on the shaft adjacent or nearly adjacent to one of the journal bearings. Alternatively, the slot or slots may extend to a point between two journal bearings.

Abstract: A gas dynamic pressure bearing apparatus comprises a fixed shaft, a bearing member which is positioned opposite from the fixed shaft and at least a radial gas dynamic pressure bearing portion and a thrust gas dynamic pressure bearing portion which are positioned in a space between the fixed shaft and the bearing member. Dynamic pressure generating means are included for pressurizing gas in the radial gas dynamic pressure bearing portion and the thrust gas dynamic pressure bearing portion such that dynamic pressure action is generated. The bearing member is rotatably supported in relation to the fixed shaft by means of the pressurizing action such that rotational driving is performed by a predetermined motor. The radial gas dynamic pressure bearing portion and the thrust gas dynamic pressure bearing portion are structured such that gas is sealed from the space around the motor by a space sealing means and that gas flows from one side to other.

Abstract: A disk driving apparatus using a dynamic pressure-type bearing device of an oil lubrication type, wherein the bearing device includes a housing main body, a sleeve part fixed to the housing main body, a rotor part relatively rotatable to the housing main body, a shaft having a spherical front end clamped to the rotor part, a bottom plate at an end face of the shaft and a thrust member interposed between the shaft and the bottom plate has a dynamic pressure radial bearing constructed by the shaft and the sleeve part and having herringbone grooves formed at either of the shaft and sleeve part, the thrust member being formed of a high polymer, and a thrust pivot bearing constructed by the thrust member set at the bottom plate secured to one side of the sleeve part and one end of the shaft.

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: 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: 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: A hydrodynamic bearing design is disclosed incorporating a flexible membrane at one end of the fluid gap in the hydrodynamic bearing. If voids exist in the fluid, and if changes in the size of these voids or bubbles occur with changes in temperature or pressure in which the disc drive is being used, then the volume of the fluid will change, and increase relative to the change in size of the volume of the surrounding physical part. The flexible membrane will yield to the increased pressure of the increasing volume of the fluid. The membrane essentially acts as a spring whose spring force is overcome by the pressure created by or accompanying a increase in volume in which the lubricating fluid is contained, and preventing its escape or being forced out of the inner region of the bearing.

Abstract: A disc drive system includes a hydrodynamic bearing. The disc drive system includes a disc drive chassis, a 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 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 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.