Abstract: A disk drive device includes a rotating body, a fluid dynamic bearing unit that rotatably supports the rotating body, and a drive unit. The fluid dynamic bearing unit has: a lubricant holding portion in which lubricant is held; a first thrust dynamic pressure groove with which a first thrust dynamic pressure generating portion for generating the dynamic pressure in the pump-in direction, which is oriented toward the inside of the lubricant holding portion, is structured; and a second thrust dynamic pressure groove with which a second thrust dynamic pressure generating portion for generating at least the dynamic pressure in the pump-out direction, is structured.

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

Abstract: Downhole tool bearings are provided with diamond enhanced materials. The diamond enhanced materials comprise diamond grains in a matrix of tungsten or silicon carbide or a silicon bonded diamond material. A brazed diamond grit or diamond particles coated with a reactive braze may be utilized for bearing applications. Bearing rings for use in downhole tools may be formed at least in part with the diamond enhanced material. In one embodiment, the bearing rings may be used in a positive displacement motor. In additional embodiments, the bearing rings may be used in a submersible pump.

Abstract: A light deflection apparatus, including a stator section including a radial bearing having a first dynamic pressure generating groove, a thrust bearing having a second dynamic pressure generating groove, and a stator coil; and, a rotor section including a polygon minor, a magnet facing the stator coil, and a rotating body having a dynamic pressure surface facing the radial bearing and a dynamic pressure surface facing the thrust bearing, the rotor supporting the polygon minor and the magnet; wherein one end portion of the dynamic pressure bearing section included of the thrust bearing, the radial bearing and of the rotating body in the thrust direction is closed excluding a gap between the dynamic pressure bearing section of the radial bearing and the dynamic pressure bearing section of the rotating body.

Abstract: A fluid dynamic bearing system used particularly for a spindle motor having a shaft that is accommodated in a bearing bush and rotatably supported with respect to the bearing bush, a bearing gap filled with a bearing fluid being located between the shaft and the bearing bush. At least the outside circumference of a section of the shaft extending into the bearing bush is made of a plastic material. As an alternative, a film made of a plastic material whose thickness is less than the width of the bearing gap can be disposed in the bearing gap.

Abstract: The invention relates to a spindle motor having a fluid dynamic bearing system that comprises a base (10), a stationary shaft (14) connected to the base, a hub (16) rotatably supported with respect to the shaft and two bearing plates (24, 44) that are disposed at a mutual spacing about the shaft and connected to the hub. A bushing (22) is provided that is disposed between the bearing plates and separated from them by a gap (30, 50) at least partly filled with a bearing fluid. There are two stopper plates (26, 46) that are fixedly connected to the shaft, each abutting one side of each bearing plate and separated from the bearing plate by a bearing gap (28, 48) filled with bearing fluid. This results in two independent fluid dynamic bearing systems, each of which is disposed about a bearing plate. The motor is driven by an electromagnetic drive system.

Abstract: A hydrodynamic bearing rotary device which can reduce rotation friction, and recording and reproducing apparatus including the same is provided. In the hydrodynamic bearing rotary device, such as hard disc devices, a rotary shaft having a hub on one end is provided in a bearing of a sleeve so as to be rotatable. Thrust hydrodynamic grooves are provided on the other end surface of the rotary shaft, to form a thrust bearing with the thrust plate. A communication path is provided in the sleeve. The second gap between the hub and the sleeve end surface is used as a flow channel and is connected to the communication path. In this way, the rotation friction torque of the thrust bearing can be made sufficiently small, and internal pressure in bonded portions of the rotary shaft or the bottom plate can be suppressed. Thus, the oil can be prevented from oozing out from a small space of the bonded surfaces. Furthermore, the hydrodynamic bearing can be made thin.

Abstract: A typical dynamic bearing design comprises a ring shaped or circular thrust plate mounted at or near the end of a shaft, the shaft defining together with a surrounding sleeve a journal bearing by providing grooves on only one of the two surfaces facing the gap between the shaft and sleeve. On the ring shaped thrust plate supported by the shaft, the traditional upward thrust bearing defined between the lower face of the thrust plate and the facing surface of the sleeve is maintained; but no grooves are on the surface of the thrust plate distant from the shaft and a facing counterplate surface. Further, the journal bearing is defined to have an asymmetry so that a bias force pressure along the surface of the shaft toward the thrust plate is established.

Abstract: A 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 fluid dynamic bearing is configured that a distance L1 from an annular region of a cover member along a direction of an axis of rotation to a first thrust bearing surface of a radial bearing member, and a distance L2 from a stopper surface of a stopper portion to a second thrust bearing surface of a thrust bearing member, satisfy the following relationship: L1<L2, wherein the annular region of the cover member is in contact with the stopper surface of the stopper portion, and the first thrust bearing surface of the radial bearing member is separated from the second thrust bearing surface of the thrust bearing member to form a gap being filled with a lubricant fluid when the radial bearing member is in non-rotating state with respect to a stationary shaft.

Abstract: A hydrodynamic bearing, a motor including the same, and a recording and reproducing apparatus which can improve vibration resistance property and suppress noises even in a situation where vibration is expected are provided. Radial hydrodynamic grooves formed on an inner peripheral surface of a sleeve have a shape which satisfy the relational expression L2<L1/2. L1 refers to a length of a hydrodynamic causing portion of a radial bearing portion in an axial direction; and L2 refers to a length in the axial direction from a benchmark point where an end portion of the radial bearing portion on an outward side in the axial direction and center of a predetermined radial hydrodynamic groove cross each other, to a relative rotational direction backward side end portion of a radial hydrodynamic groove adjacent to the predetermined radial hydrodynamic groove on the forward side in a relative rotational direction.

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

Abstract: A fan with an anti-leakage device for an oily bearing includes a base, an axial barrel, a fan wheel and a bearing. The axial barrel extends from the base and provides a first end, a second end, a first oil storage groove at the second end. The fan wheel extends a spindle from the inner side thereof and provides a joining part surrounding an end of the spindle and being adjacent to the inner side of the first end. The bearing is received in the axial barrel and further includes an axial through bore, which provides two inverted cone shaped ends, and at least a second oil storage groove, which is provided at a wall surface of the axial through bore for being adjacent to the spindle closely. Thus, a closed circuit is formed for the lubrication oil flowing back to the bearing without leakage.

Abstract: Assembly precision in a motor is improved and greater cost reduction is achieved. A fluid dynamic bearing apparatus includes a housing and bearing sleeve as fixed-side members, a shaft member as a rotational-side member having a portion for mounting a rotor magnet, and a disk hub. The shaft member is supported by the bearing sleeve in the radial direction in a non-contact manner by the hydrodynamic effect of a lubricating oil produced in a radial bearing gap between the inner circumferential surface of the bearing sleeve and the outer circumferential surface 9 of the shaft member while the shaft member is in rotation. The apparatus includes a disk hub which is fixed on the shaft member and has a portion for mounting the rotor magnet, and the disk hub is a molded resin article formed by insert-molding using the shaft member as an insert piece.

Abstract: The invention relates to a fluid dynamic bearing having a bearing bush having a central bearing bore in which a shaft is rotatably supported. Surfaces facing each other of the shaft and of the bearing bore are separated from one another by a bearing gap filled with a bearing fluid. A first radial bearing section and a second radial bearing section are disposed along the bearing gap between which a separator section is disposed. The width of the bearing gap varies with its axial length. The bearing gap has a first inner width ib1 and a second inner width ib2 in the region of the first and of the second radial bearing section on the sides facing the separator section and a first outer width ab1 and a second outer width ab2 on the sides remote from the separator section. According to the invention, the differences resulting from the inner widths and the outer widths ib1?ab1 and ib2?ab2 ib1, lie in an interval of a?t to a+t, where a is greater than zero and t is greater than a.

Abstract: A device having a directly driven rotating body (1), its circumference (11) being radially seated on radial bearings (4, 4?) in relation to the stationary body (2), and its at least one first face side (10) being axially seated in relation to the stationary body (2), wherein aerostatic bearings (5, 5?, 5?) are provided for the axial support mounting, characterized in that the first face side (10) has an annular magnet arrangement (32), which is configured coaxially to the axis of rotation (X) of the rotating body (1), and that the stationary body (2) has at least one electric coil arrangement (30), which is located opposite the annular magnet arrangement (32) in the axial direction and which forms together with the annular magnet arrangement (32) the components of an electrical direct drive (3) for the rotating body (1).

Abstract: Embodiments of the invention provide a magnetic disk drive having improved vibration characteristics and a reduced size. In one embodiment, a magnetic disk drive comprises: a motor shaft for rotating a magnetic disk; a sleeve for rotatably supporting the motor shaft; and a motor hub into which the motor shaft is press fit. The motor hub supports the magnetic disk and includes a projection portion having an inner surface and an outer surface. The inner surface is in contact with the press-fit motor shaft in directions perpendicular to the rotational axis of the motor shaft. The outer surface faces the sleeve.

Abstract: A disk drive device includes a base member, a hub member, a shaft, a flange, a sleeve, a thrust dynamic pressure generation portion including thrust dynamic pressure grooves such that thrust dynamic pressure is generated in a thrust space, a radial dynamic pressure generation portion including radial dynamic pressure grooves such that radial dynamic pressure is generated in a radial space, a lubricant filled in the thrust space in the thrust dynamic pressure generation portion and the radial space in the radial dynamic pressure generation portion, a capillary seal portion for holding the lubricant in the thrust space and the radial space, and a circulation pathway by which the thrust dynamic pressure generation portion and the radial dynamic pressure generation portion communicate with each other in order to circulate the lubricant.

Abstract: The present invention provides a fluid dynamic bearing device having high durability and capable of being produced at low cost. In the fluid dynamic bearing device, a housing and a disc hub are resin molded parts, and a thrust bearing gap is formed between an upper end surface of the housing and a lower end surface of the disc hub. In this case, the surfaces function as sliding portions temporarily in sliding contact with each other during operation of the bearing. A diameter of PAN-based carbon fibers blended as reinforcement fibers in the resin housing is 12 ?m or less, and the blending amount is within a range of 5 to 20 vol %, thereby making it possible to prevent occurrence of flaws and wear in the sliding portions.

Abstract: In this type of fluid dynamic bearing device, a dynamic pressure generating part having high molding accuracy is formed at low cost. A rotating member 2 includes a shaft part 9, and a holding member 10 as a thrust member provided in one end of the shaft part 9. In a partial annular region of a lower end surface 10a1 of a disk part 10a making up the holding member 10, a region where a plurality of dynamic pressure grooves 10a2 and a plurality of sectioning parts 10a3 formed between the plurality of dynamic pressure grooves 10a2 to section the respective dynamic pressure grooves 10a2 are arrayed spirally is formed. The above-described dynamic-pressure-groove 10a2 arrayed region is opposed to an upper end surface 8a of a housing part 8, and forms a thrust bearing clearance of a thrust bearing part T between the dynamic-pressure-groove 10a2 and the upper end surface 8a during the rotation of the shaft part 9.

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 hub (10) is a product formed by injection molding of a resin together with a core metal (13) as an inserted component, and the core metal (13) is exposed on a surface of the hub (10). With this configuration, a cavity of a die for molding the hub (10) is not divided by the core metal (13), and hence it is possible to suppress deterioration in fluidity of a resin due to arrangement of the core metal (13) in the cavity.

Abstract: A smooth surface of a shaft member is divided from an outer circumferential surface by a step so that its axial length dimension becomes shorter than the axial length dimension of a hydrodynamic groove region formed on the inner circumferential surface of a bearing sleeve, whereby the hydrodynamic groove regions excluding lower portions of a land between hydrodynamic grooves oppose the smooth surface.

Abstract: A bearing unit (90) for rotatably supporting a shaft (100) comprises a seamless holding member (120) with a gap allowing a shaft to run through and extend to the outside, a bearing (130) arranged in the inside of the holding member to rotatably support the shaft so as to make it radially revolvable, an anti-shaft-release member (115) fitted to the shaft so as to abut the bearing in order to prevent the shaft from slipping away in the thrusting direction and a space-forming member (113) arranged in the inside of the holding member so as to secure a space around the anti-shaft-release member. A bearing unit may further comprise an lubricating oil seal member and the space-forming member may be used to form a passage way for lubricating oil to prevent lubricating oil from leaking.

Abstract: The invention provides a hydrodynamic bearing device including at least one of a shaft structure and a sleeve having a dynamic pressure-generating mechanism, and a lubricant present in a gap between the shaft structure and the sleeve. The lubricant contains a diester with a total carbon number of 20-28 obtainable by a divalent alcohol that has at least one ether bond, and one or more types of C6 to C10 saturated monovalent fatty acid.

Abstract: To manufacture a shaft member, which is excellent in both accuracy and strength at low cost, a shaft member (2) includes a shaft portion (21) and a flange portion (22) provided to one end of the shaft portion (21). The flange portion (22) has an annular shape, and the shaft portion (21) and the flange portion (22) are fixed by a welded portion (23), which is formed by applying a laser beam (35) to an upper end of an inner periphery thereof.

Abstract: The invention concerns a rotary nozzle combination (P) for coating product comprising an atomizing bowl (3) and a rotor (11) adapted to rotate the bowl about a geometrical axis (X-X?), and means (4, 5, 6, 7) for controlling the presence and/or proper mounting of the bowl (3) on the rotor (11). The rotor (11) is spaced apart from a non-rotating part (P1) and the control means comprise first means (4, 5) enabling a force (F3) to be applied on the bowl (3) tending to vary the thickness of an air-film of the pneumatic thrust bearing (P1), as well as second means (7, 8) for determining the air pressure in the bearing (P1). The pressure of air in the thrust bearing (P1) can be determined when the latter is normally supplied and compared with at least one reference value.

Abstract: A bearing mechanism includes a shaft, a sleeve portion, a thrust portion, and a cover portion. Lubricating oil is arranged in a communicating channel in the sleeve portion, a thrust gap between the sleeve portion and the thrust portion, and a tapered gap between an outside surface of the thrust portion and the cover portion. A lower end opening of the communicating channel is defined in an outer circumferential portion of a lower surface of the sleeve portion radially outward of the thrust gap. A radially outermost portion of the thrust portion is arranged either tangent to a wall surface of the communicating channel or closer to a central axis than the wall surface. The tapered gap is arranged closer to the central axis than a radially outermost point of the wall surface. The outer circumferential portion and the cover portion define a guide gap therebetween.

Abstract: Assembly precision in a motor is improved and greater cost reduction is achieved. A fluid dynamic bearing apparatus 1 comprising a housing 7 and bearing sleeve 8 as fixed-side members 2, a shaft member 9 as a rotational-side member 3 having a portion 3c for mounting a rotor magnet 5, and a disk hub 10, the shaft member 9 being supported by the bearing sleeve 8 in the radial direction in a non-contact manner by the hydrodynamic effect of a lubricating oil produced in a radial bearing gap between the inner circumferential surface 8a of the bearing sleeve 8 and the outer circumferential surface 9a of the shaft member while the shaft member 9 is in rotation, the apparatus 1 comprising a disk hub 10 which is fixed on the shaft member 9 and has a portion 3c for mounting the rotor magnet 5, and the disk hub 10 being a molded resin article formed by insert-molding using the shaft member 9 as an insert piece.

Abstract: A first axial gap (L1) is formed between a seal portion (9) and a sleeve portion (8). With this, it is possible to set a moving amount of a shaft member (2) in an axial direction with high accuracy irrespective of accuracy of members such as the sleeve portion (8).

Abstract: A shaft, a circular plate portion and a cylindrical portion are integrally formed with one another through cutting operations to provide a rotor hub of a motor. An inner region on the lower surface of the circular plate portion is formed continuously with the outer peripheral surface of the shaft, and a hub thrust portion is provided in the inner portion so as to axially face a sleeve thrust portion on a sleeve main body. A stepped portion on the lower surface of the circular plate portion is disposed on the outer side of thrust dynamic pressure grooves on the sleeve thrust portion. In this manner, the stepped portion is disposed in a region where a thrust bearing portion is not provided, so that the hub thrust portion can be formed at a low cost in manufacturing the rotor hub by cutting.

Abstract: A two-stage pump having an internal fluid pathway or cycle for providing cooling to various parts in the pump, such as, an electric motor in the pump, and also for lubricating at least one or a plurality of bearings in the pump. The pump utilized hydrodynamic bearings that are adapted or configured to provide various passageways, channels and the like for using the fluid that is being pumped by the pump as lubrication for at least one or a plurality of bearings in the pump.

Abstract: A robust spindle motor is provided having improved shock resistance for fluid containment, as well as enhanced air purging characteristics. In an aspect, axial displacement of relatively rotating components is restricted by utilizing a limiter situated adjacent to a limiter bushing forming an axial limiter gap therebetween. A fluid channel, at least partially diverging, extends from a hydrodynamic bearing to the axial limiter gap, and continues to a region beyond the axial limiter gap. In an aspect, an axially diverging slot is situated adjacent to the axial limiter gap. Power is reduced by reducing viscous drag between relatively rotating components, hydrodynamic bearing length is increased, and higher stiffness of the hydrodynamic bearing is provided. Fluid volume may be increased, thereby offsetting fluid evaporation losses and allowing for the use of lower viscosity lubricants.

Abstract: A bearing unit includes: a radial bearing for bearing in a circumferential direction of a shaft; a thrust bearing for bearing one end in a thrust direction of the shaft; a housing provided on the outside of the radial bearing and the thrust bearing and filled with a viscous fluid; a seal member united with the housing so as to contain the radial bearing and the thrust bearing in a sealed state, the seal member having a shaft passing hole through which the shaft is passed; and a passage for discharging air present inside the housing, the passage formed between the housing and the radial bearing, and the passage providing communication between the one end side and the other end side in the thrust direction of the shaft projecting from the radial bearing, wherein the cross-sectional shape of the passage is a shape including at least one acute angle.

Abstract: A protrusion (7b3) directed axially downwards is provided at a bottom portion (7b) of a housing (7), and an outer peripheral surface (7b31) of the protrusion (7b3) is fixed to an inner peripheral surface (6a) of a bracket (6). When a thrust load is applied to the bottom portion (7b) of the housing (7), a part of the load is supported by the bracket (6) via the protrusion (7b3). Thus, a strength of a boundary portion (P) between a side portion (7a) and the bottom portion (7b) of the housing (7) increases, making it possible to prevent rupture of the boundary portion (P) due to an excessive thrust load. On the other hand, a wall thickness of the bottom portion (7b) can be made invariable, so it is possible to suppress deformation through molding shrinkage of a thrust bearing surface formed on an inner end surface (7b1) of the bottom portion (7b).

Abstract: Provided is a shaft member for a fluid dynamic bearing device, which is excellent in wear resistance and which can exert a high dynamic pressure effect. A shaft material (11) is rolled to form a recess (7) for causing a dynamic pressure effect of a lubricating oil in a radial bearing clearance (6). In this case, in a surface layer portion (14) of the recess (7) to be formed in an outer peripheral surface (11a) of the shaft material (11), a first hardened layer (14a) is formed by rolling. At the same time, also in a surface layer portion (15) of a surrounding region (8) of the recess (7), a first hardened layer (15a) is formed by rolling at a partial region thereof. After the recess (7) is formed by the rolling, barreling is applied to the shaft material (11). As a result, an outermost surface layer portion of the surface layer portion (15) is formed with a second hardened layer (15b) by the barreling.

Abstract: A dynamic bearing device is provided, which can prevent abrasion powder generated when a sealing member is pushed into an inner circumference of a housing from entering the housing. A sealing member is inserted into an inner circumference of an opening of a housing with an adhesive interposed therebetween The adhesive moving forward in a pushing direction of the sealing member is retained by a capillary action in a lower tapered space between an outer circumference of the sealing member and the inner circumference of the housing. Abrasion powder is captured by the adhesive in the tapered space so as to be confined in the adhesive as a result of the setting of the adhesive.

Abstract: Provided is a fluid dynamic bearing device in which an assembly of a bearing sleeve to a housing is facilitated and which has excellent moment rigidity. A fluid dynamic bearing device (1) includes radial bearing parts (R1 and R2) and thrust bearing parts (T1 and T2). Thrust bearing surfaces (C and D) are respectively provided to first and second step surfaces (2d and 2e) of a housing (2), and the thrust bearing parts (T1 and T2) are respectively formed between the thrust bearing surfaces (C and D) and end surfaces (6b and 7b) of seal members (6 and 7) provided while protruding to an outer diameter side of a shaft member (5).

Abstract: To prevent air from being trapped inside a bearing and causing the bearing to have oil film rupture and NRRO to deteriorate. In a hydrodynamic bearing, a first lubricant reservoir is provided in a gap between a lower surface of a hub and a sleeve, and a second lubricant reservoir is provided in a gap between an outer peripheral surface of the sleeve and an inner peripheral surface of the hub or an inner peripheral surface of a stopper member fixed to the hub. If air enters inside such a hydrodynamic bearing, the air has to be discharged. For this purpose, the relationship in widths of the radial bearing gap, the maximum gap of the first lubricant reservoir under the lower surface of the hub and the maximum gap of the second lubricant reservoir on the sleeve outer peripheral surface, or the relationship in magnitudes of capillary forces thereof is adjusted.

Abstract: The present invention provides a spindle motor which has superior operating characteristics. The spindle motor includes a stationary support shaft which is fastened to a base plate, a thrust plate which is fitted over the stationary support shaft, a sleeve which is rotatably provided around the stationary support shaft and is coupled to a rotor casing, and an annular stopper which is fastened to the sleeve or the rotor casing to support the lower surface of the thrust plate and prevent the sleeve from being removed. A first fluid sealing part is formed between the stopper and the thrust plate. The spindle motor further includes an annular sealing cap which is coupled to the sleeve or the rotor casing to store fluid between the sealing cap and an upper surface of the sleeve. A second fluid sealing part is formed between the sealing cap and the stationary support shaft.

Abstract: The fluid dynamic bearing system according to the invention for the rotatable support of an electric motor comprises a substantially cylindrical bearing bush having a bearing bore, a shaft rotatably supported about a rotational axis accommodated in the bearing bore, a bearing gap formed between mutually adjacent surfaces of the bearing bush and the shaft that is filled with a bearing fluid and extends in an axial direction parallel to the rotational axis, at least one radial bearing that is disposed along the bearing gap and formed by bearing surfaces of the bearing bush and the shaft, and at least one axial bearing that is formed as a magnetic bearing.

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 medical bag formed of a flexible material includes a front bag part and a rear bag part joined together to form a bag body. A closable liquid inlet port is provided in an upper part of the bag body. The medical bag further includes a deformable elongated member provided in the vicinity of the liquid inlet port on at least one of the front and rear bag parts. The elongated member is deformable so as to retain the liquid inlet port in an open configuration when the elongated member is in a deformed state.

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

Abstract: A hydrostatic bearing pad type rotating device includes: a stationary body; an axial pad and a radial pad each attached to the stationary body; a rotating body supported by the axial pad and the radial pad at least in the radial direction toward an axis thereof so as to be rotatable about the axis; and a motor for providing a driving force to rotate the rotating body. The motor includes a stator attached to the stationary body, and a rotor attached to the rotating body to be opposite to the stator with a gap interposed therebetween. At least one of the stator and the rotor is attached such that its location is adjustable in the radial direction toward the axis and the axial direction along the axis. In this way, a hydrostatic bearing pad type rotating device having highly precise rotation performance can be provided.

Abstract: The fluid dynamic bearing system has at least one stationary part, and at least one rotating part that is supported rotatable about a rotational axis with respect to the stationary part. A bearing gap filled with bearing fluid is formed between mutually opposing surfaces of the stationary and of the rotating part. The bearing system comprises at least one fluid dynamic radial bearing and at least one fluid dynamic axial bearing that are disposed along sections of the bearing gap. Moreover, sealing means for sealing the open ends of the bearing gap are provided. According to the invention, one of the sealing means comprises an annular sealing gap that has one end connected to the bearing gap and one end connected to an annular reservoir, the outside radius of the reservoir measured from the rotational axis being larger than the outside radius of the sealing gap.

Abstract: Disclosed is a fluid dynamic bearing device in which it is possible to prevent detachment of the shaft member reliably and at low cost without involving any increase in the device size. In a thrust bearing portion T, the lower end surface of the shaft member is held in contact with a thrust plate, and the shaft member is rotatably supported in the thrust direction. Protrusions extending radially inwards are provided on a sealing portion attached to an opening of the housing, and these protrusions are engaged with a small diameter portion formed on the outer peripheral surface of the shaft member, thereby preventing the shaft member from coming off.

Abstract: A dynamic bearing device is provided, which can prevent abrasion powder generated when a sealing member is pushed into an inner circumference of a housing from entering the housing. A sealing member is inserted into an inner circumference of an opening of a housing with an adhesive interposed therebetween The adhesive moving forward in a pushing direction of the sealing member is retained by a capillary action in a lower tapered space between an outer circumference of the sealing member and the inner circumference of the housing. Abrasion powder is captured by the adhesive in the tapered space so as to be confined in the adhesive as a result of the setting of the adhesive.

Abstract: An object is to reduce manufacturing cost of a housing, and enable to disuse an adhesive in fixation portions between a housing and a bearing sleeve and the like. A housing 7 is made of resin material, which comprises a liquid crystal polymer (LCP) as crystalline resin blended with carbon nanotubes in a blending ratio of 2 to 35 vol % as a conductive filler, by injection molding. A bearing sleeve 8, which is inserted into the inner peripheral surface 7c of the housing 7, is secured to the housing 7 by ultrasonic welding.

Abstract: Disclosed is an inexpensive fluid dynamic bearing device exhibiting high bearing performance and long life. A fluid dynamic bearing device (1) is mainly composed of a shaft member (2), and a bearing member (7) equipped with a cylindrical radial bearing surface (A) opposed to an outer peripheral surface (2a) of the shaft member (2). The bearing member (7) is formed by injection molding with an electroformed portion (10) inserted, and the radial bearing surface (A) is formed on the electroformed portion (10). Further, a thrust bearing surface (B) is formed on an upper end surface (7b) of the bearing member (7), and the shaft member (2) is supported in a thrust direction by a dynamic pressure action of a lubricating fluid generated in a thrust bearing gap opposed to the thrust bearing surface (B).