Abstract: A fluid dynamic bearing device includes a sleeve having a bearing hole into which a shaft is inserted, the sleeve rotatably supporting the shaft to make relative rotation about a center axis and a bearing housing made of a cold-rolled steel plate or a galvanized steel plate, the sleeve being received within the bearing housing. The bearing housing is filled with lubricating oil mainly composed of ester. A radial dynamic pressure bearing portion is provided between an outer circumferential surface of the shaft and an inner circumferential surface of the sleeve, the radial dynamic pressure bearing portion having radial dynamic pressure grooves for holding the lubricating oil as working fluid and for inducing a fluid dynamic pressure in the lubricating oil during the relative rotation. At least a surface region of the bearing housing remaining in contact with the lubricating oil is coated with a layer mainly composed of nickel.

Abstract: A gas bearing spindle includes a rotation shaft, a sleeve, and a housing. The sleeve includes a bearing portion formed of a nonmetallic sintered body; and a retaining ring formed of a metal. Further, the retaining ring and the bearing portion are in contact with each other at a first fit surface that is a boundary surface between the outer circumferential surface of the bearing portion and the inner circumferential surface of the retaining ring, as well as at a second fit surface that is a boundary surface between the outer circumferential surface of the bearing portion and the inner circumferential surface of the retaining ring, is distant further away from the sleeve through hole relative to the first fit surface, and is formed adjacent to a center of the sleeve through hole in a direction in which the sleeve through hole extends, when viewed from the first fit surface.

Abstract: An apparatus and associated method characterized by an enclosure having a side member that defines a substantially orthogonally directed cavity penetrating the side member. A motor shaft in the enclosure has a distal end that is operably aligned with the cavity. A shear transfer member in the enclosure is operably affixed to the motor shaft. One of the shaft and the shear transfer member is sized for a close mating engagement with the side member in the cavity, and the shear transfer member is further sized for being simultaneously shear coupled to the side member.

Abstract: A hydrostatic arrangement for a spin welding machine includes, a spindle rotationally supported with at least one of a thrust hydrostatic bearing and a journal hydrostatic bearing, and a hydraulic unit configured to supply liquid to the at least one of a thrust hydrostatic bearing and a journal hydrostatic bearing at at least two different pressures.

Abstract: An outer peripheral surface (8d) of a bearing sleeve (8) is formed on a radially inside with respect to a first dynamic pressure generation portion (B1). In this case, it is possible to reduce a thickness of the bearing sleeve (8) while securing a first thrust dynamic pressure generating portion (B1) which has a thrust load capacity equivalent to that in a conventional case where a thrust dynamic pressure generating portion is formed in an end surface of the bearing sleeve. Accordingly, it is possible to reduce the thickness of the bearing sleeve (8) without sacrificing a bearing performance in a thrust direction. With this structure, a total amount of a lubricating oil sealed in a bearing device can be reduced, thereby reducing a capacity of a buffering function so as to downsize a sealing portion (9), and by extension, downsizing a fluid dynamic bearing device (1).

Abstract: There are provided a fluid dynamic bearing assembly and a motor having the same. The fluid dynamic bearing assembling according to the present invention may include: a sleeve formed to have a hollow into which a shaft is inserted; a sleeve housing formed to insert the sleeve therein; a bypass passage formed to axially communicate the upper portion and the lower portion of the sleeve between the sleeve and the sleeve housing dispersing pressure of a lubricating fluid in the hollow; and an oil sealing cap having an oil passage communicated with the bypass passage and taper-sealing the lubricating fluid within the oil passage.

Abstract: Disclosed are a hydrodynamic bearing assembly and a motor including the same. The hydrodynamic bearing assembly may include a sleeve supporting a shaft to allow a top portion of the shaft to be protruded upwardly in an axial direction and including a coupling part of which a bottom end is protrusively formed, a base cover coupled with a bottom of the sleeve in the axial direction while maintaining a gap therebetween, and support part formed at an outer end portion of the base cover and formed to be protruded in the axial direction such that an outer peripheral surface thereof is in contact with and coupled to an inner peripheral surface of the coupling part of the sleeve.

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 fluid dynamic bearing motor and method are described, wherein motor components, including complex shaped motor components, are molded of plastic. The molding ensures form control and dimensional control thereby accomplishing design requirements, and eliminating or reducing component costs and component machining. The mold can be shaped to form various motor geometries, thereby eliminating the need for multiple component assembly and related assembly costs. In an aspect, a plastic integral motor hub is formed by injection molding. Alternatively, a plastic motor hub is affixed to a metal sleeve. In another aspect, fluid containment structures are molded into the motor component, reducing the number of components as compared with machined metal components. In a further aspect, bearing structures such as grooves are molded into the motor component, thereby eliminating processes such as electrochemical machining. In yet a further aspect, a plastic hub faces a thrustplate, reducing expensive sleeve machining.

Abstract: An apparatus for inhibiting oil leakage is disclosed by which the oil leakage can be effectively inhibited with a simple structure, where the apparatus is extensively formed along an outer periphery of a rotation shaft at a position higher than at least an upper end of a bearing and is formed with an oil barrier that restrains oil rise.

Abstract: A fluid dynamic bearing unit is provided which has a high load capacity against a moment load, whose bearing sleeves can be manufactured and fixed easily, and which can provide a required fixing power. The bearing sleeve is inserted into an inner periphery of a housing, and its bottom end is fixed to the top end of a spacer part with an adhesive. Another bearing sleeve is inserted into another part of the inner periphery of the housing, and its top end is fixed to the bottom end of the spacer part with an adhesive.

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 gas bearing (100) having pressurised axially extending chambers (110) in a housing (102) having a shaft bore (104) therein, the axially chambers (110) being in fluid communication with a bearing surface (108) that defines the bore via laser-drilled capillaries (118). The end (122) of each laser-drilled capillary at the bearing surface (108) is flared such that the narrowest portion of the capillary is set back from the bearing surface (108). This shape can ensure that the load carrying function of the bearing (100) does not fail during shaft eccentricity by ensuring that pressure restriction must happen within the capillary and not the gap being shaft and bearing surface. The bearing surface may face in an axial and/or radial direction with respect to the shaft. The axial chambers may be pressurised axially such that the outer circumference of the housing is unbroken and hence usable for other purposes.

Abstract: There is provided a hydrodynamic bearing assembly and a motor having the same. The hydrodynamic bearing assembly includes a sleeve having a shaft inserted thereinto; a hub base coupled to an upper portion of the shaft and rotating together with the shaft; a stopper plate fixedly coupled to an upper surface of the sleeve and preventing the shaft from lifting while the shaft rotates; and a thrust dynamic pressure generating groove formed on at least one of an upper surface of the stopper plate and a lower surface of the hub base corresponding thereto.

Abstract: A flatness of a part of a component formed of a resin material that faces a thrust bearing gap is easily increased. A housing (7) is injection-molded using a resin material and has a bottomed-cylindrical shape integrally including a cylindrical side portion (7a) and a flat bottom portion (7b). The resin material to be used for the injection molding of the housing (7) contains, as filler, a reinforcing fiber having a fiber diameter of 6 to 8 ?m and an aspect ratio of 10 to 40.

Abstract: A method of positioning a shaft and associated seal in turbomachinery utilizing electromagnetic bearings. The method includes applying electrical power to the electromagnetic bearings' windings, the shaft center being in a first position and the shaft being in contact with the associated seal. Power adjustment to the electromagnetic bearings moves the shaft. Shaft movements can manipulate the seal, the movements being of decreasing amplitude to a position in which the seal is out of contact with the shaft when the shaft is rotated at its centered position during normal operation. The shaft is in its centered position during normal operation when the shaft axis is substantially coaxial with an axis of the electromagnetic bearings. Movements of decreasing amplitude may include oscillations of decreasing amplitude about one or more axes, or may include a spiral rotation with a decreasing radius to move the shaft center from initial to final positions.

Abstract: A fluid dynamic bearing device having high bearing performance at low cost is provided. A bearing member 6 includes an inner diameter part 8 having a radial bearing surface and an outer diameter part 7 having a mounting surface for a bracket 5. Both the inner diameter part 8 and the outer diameter part 7 are made of a resin. The inner diameter part 8 is preferably formed of an oil-impregnated resin, and more preferably a porous resin, and the outer diameter part 7 is formed of a nonporous resin.

Abstract: A spindle motor can suppress the generation of noise during swinging and the extend service life, and also suppress the increase in current consumption. The outside diameter of a thrust hydrodynamic groove is at least 10% of the outside diameter of a disk-shaped medium, and the depth of the radial hydrodynamic groove is greater than the depth of the thrust hydrodynamic groove. By adjusting to specific numbers, the angular stiffness in the thrust bearing is raised, and even if a disturbance torque should be applied, wear or noise caused by metal contact inside the bearing can be suppressed.

Abstract: A brushless motor is provided which has excellent anti-impact properties and is easily assembled even if the brushless motor is reduced in size. A stator (2) includes a bearing (5) for holding a rotating shaft (3), a bearing housing (6) in which the bearing (5) is placed vertically relative to the stator base (1), a thrust plate (7) for receiving one end of the rotating shaft (3) in a thrust direction, a metal thrust cover (8) for holding the thrust plate (7), a metal installation member (25) including an annular section (25a) which is superposed over a base (6b) of the bearing housing (6) and projecting pin sections (25b) which project from the annular section (25a) to the outer periphery of the thrust cover (8). The projecting pin sections (25b) of the installation member (25) have projection sections welded to the thrust cover (8).

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: A thrust bearing allows a first structure to rotate relative to a second structure about an axis of rotation while supporting an axial load between the first structure and the second structure. In an embodiment, the thrust bearing comprises a first annular bearing race slidingly disposed in a first annular recess in the first structure. In addition, the thrust bearing comprises a second annular bearing race engaging the second structure. Further, the thrust bearing comprises a plurality of circumferentially spaced roller elements axially disposed between the first bearing race and the second bearing race. The roller elements contact the first bearing race and the second bearing race. The first bearing race and the first recess define a first annular fluid cavity axially positioned between the first bearing race and the first structure. The first bearing race rides on a fluid disposed in the first fluid cavity.

Abstract: The invention relates to a helico-axial pump (1) for conveying a multiphase mixture (M), which helico-axial pump (1) includes a rotor (2) rotatably journalled about a longitudinal axis (A) in a pump housing (6) and having a first part rotor (21) and a second part rotor (22), wherein the first part rotor (21) and the second part rotor (22) include a compression stage (K, K1E, K1A, K2E K2A) having a helico-axial impeller (3) and a stator (4) for the compression of the multiphase mixture (M). In accordance with the invention, a hydrodynamic stabilization bush (70) having a stabilization surface (700) is provided and formed between the first part rotor (21) and the second part rotor (22) such that a stabilization gap (8) is formed before the stabilization surface (700) so that a hydrodynamic stabilization layer (S) is formed from a stabilization medium (M) in the stabilization gap (8) in the operating state.

Abstract: A sleeve portion is inserted into a hole portion of a base bracket on which an adhesive of heat cure type is applied while a rotor portion and a stator portion are retained by a position determining jig. Then, the sleeve portion is initially affixed to the base bracket by a high frequency induction heating of an induction coil. Then, the initial affixation is cured completely in an oven. Since the adhesive of heat cure type is used, generation of outgass will be minimized and a manufacturing cost of the motor having such components will be reduced.

Abstract: A sliding bearing includes a metal part formed by electroforming on an inner periphery of the sliding bearing and an oil feeding mechanism for supplying oil to the bearing gap. As a result, oil retained by the oil feeding mechanism is supplied to the bearing gap, so the lubricity between the bearing and the shaft member is improved by an oil film formed in the bearing gap. This makes it possible to avoid the generation of noise due to defective lubrication and wear of members due to the contact sliding between the bearing and the shaft member.

Abstract: A bearing positioning structure for a motor includes an axial tube and a positioning member. The positioning member includes a pressing portion and a coupling portion. The coupling portion of the positioning member is engaged with a coupling section of the axial tube for securely mounting the positioning member to the axial tube, with the pressing portion of the positioning member pressing against a bearing to position the bearing in the axial tube. In another example, the coupling portion of the positioning member engages with a coupling section on a stator.

Abstract: A method of manufacturing a motor includes coupling a base cover to a sleeve having a penetration hole formed therein, such that one side of the penetration hole is closed; inserting a shaft in the penetration hole; coupling a plate to the shaft such that the shaft is inserted in the plate; and pressing and coupling a hub to the shaft such that the shaft is inserted in the hub while the base cover is supported in an axial direction of the shaft to the base cover by using a jig, wherein the base cover is elastically deformed to make contact with the shaft. In the method of manufacturing the motor, the jig is used to deform the base cover so as to come in contact with the shaft, thereby applying the support load in the axial direction.

Abstract: There is provided a hydrodynamic bearing assembly that includes: a sleeve with an axial hole into which a shaft is inserted; a radial dynamic pressure unit formed on at least one of an outer diameter of the shaft and an inner diameter of the sleeve; and a sub-radial dynamic pressure unit formed on at least one of the outer diameter of the shaft and the inner diameter of the sleeve in an upper part in an axial direction of the radial dynamic pressure unit, wherein an oil interface formed in an axial hole between the radial dynamic pressure unit and the sub-radial dynamic pressure unit moves up toward the sub-radial dynamic pressure unit as the temperature of a motor rises due to driving of the motor.

Abstract: A fluid dynamic bearing motor and method are described, wherein motor components, including complex shaped motor components, are molded of plastic. The molding ensures form control and dimensional control thereby accomplishing design requirements, and eliminating or reducing component costs and component machining. The mold can be shaped to form various motor geometries, thereby eliminating the need for multiple component assembly and related assembly costs. In an aspect, a plastic integral motor hub is formed by injection molding. Alternatively, a plastic motor hub is affixed to a metal sleeve. In another aspect, fluid containment structures are molded into the motor component, reducing the number of components as compared with machined metal components. In a further aspect, bearing structures such as grooves are molded into the motor component, thereby eliminating processes such as electrochemical machining. In yet a further aspect, a plastic hub faces a thrustplate, reducing expensive sleeve machining.

Abstract: In a hydrodynamic bearing device with which the lubricant is prevented from leaking to the outside, and good seal performance can be maintained, and in a spindle motor equipped with this hydrodynamic bearing device, the hydrodynamic bearing device includes a shaft, a sleeve, a lubricant that fills a microscopic gap, a radial bearing portion, a thrust bearing portion, and a bearing seal portion. The value of a function P1/V1, where V1 is a fluctuation volume of the sleeve in the axial direction and P1 is a capillary pressure index at a vapor-liquid interface located near the opened end of the bearing seal portion, is at least a specific value.

Abstract: The fluid dynamic bearing device includes a housing, two bearing sleeves fixed to the housing at positions axially spaced apart from each other, and a shaft member inserted along inner peripheries of the bearing sleeves. The housing includes a spacer portion protruding further radially inwardly than inner peripheral surfaces to which the bearing sleeves are fixed. An axial fluid path is formed in the spacer portion, and the axial fluid path communicates to flow paths formed by axial grooves of the bearing sleeves.

Abstract: The cross sectional shape of an axial direction communicating path when viewed in the axial direction is flat in the circumferential direction, and the cross sectional area of the communicating path gradually decreases moving from the center of the cross section toward the both ends in the circumferential direction. When a sleeve and a cover member are bonded with an adhesive, the adhesive is actively made to flow into an adhesive inflow portion.

Abstract: A magnetic fluid is held by a magnetic field in a stationary state and by a centrifugal force during rotation, leaking and splashing of the magnetic fluid caused by the instability of the pumping of a dynamic pressure bearing are prevented without using a magnetic fluid with a high saturation magnetization value, and the service life of the dynamic pressure bearing is extended. For this purpose, a sleeve 3 having a protruding tubular section is fitted and fixed to the outer periphery of the shaft 1 having a thrust plate 2 formed in an axial vicinity so as to be rotatable relatively to the shaft, an annular cover 4 is formed outwardly from the thrust plate 2 in an axial direction, the radially inward end of the annular cover 4 serves as an opening, at least two clearance sections serve as a reservoir 10 for reserving the magnetic fluid, and a magnetomotive force member 15 is provided for concentrating the magnetic flux lines on the radially outer side of the end portion 13 of the magnetic fluid 12.

Abstract: A fluid dynamic bearing system that has a first bearing part and a second bearing part that is rotatable with respect to the first bearing part, both of which form a bearing gap filled with a bearing fluid between opposing bearing surfaces.

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 rotary device according to an aspect of the invention includes: a sleeve having an inner cylindrical surface, a first end portion and a second end portion at respective ends of the inner cylindrical surface; a shaft that is accommodated in the inner cylindrical surface in a manner rotatable relative to the inner cylindrical surface; a fluid present in a space between the shaft and the sleeve; a first pump portion formed in a middle portion of the inner cylindrical surface and configured to cause the fluid to flow toward the first end portion by the relative rotation of the shaft and the sleeve; a first radial narrow gap formed at a region of the inner cylindrical surface on a side of the first end portion with respect to the first pump portion; and a first circulation path communicated with the first pump portion.

Abstract: A bearing sleeve 8 is press-fitted into a housing 7, and an axial portion 2a of an axial member 2 is inserted into the inner peripheral surface 8a of the bearing sleeve 8, and then a thrust member 10 is attached to the lower end of the inner peripheral surface 7c of the housing 7 and positioned in a predetermined position to fix it by ultrasonic welding. The lower end of the housing 7 is pressed against the outer peripheral surface of the thrust member 10 with applying ultrasonic vibration, to fix the melting junction surface of the housing 7 on the thrust member 10.

Abstract: An apparatus and method are described for a fluid dynamic bearing motor as may be utilized in a disc drive memory system. A fluid seal is situated at a first axial end of a bearing, and a grooved pumping seal is situated at a second axial end of the bearing. In an aspect, a fluid recirculation passageway is defined through a shaft and a thrustplate, to recirculate fluid from axially above the grooved pumping seal at the second axial end of the bearing to the first axial end of the bearing. Any air ingested at the grooved pumping seal, or which came out of solution from the fluid, is purged into a fluid reservoir and out the fluid seal. In an aspect, fluid is recirculated from the center of the journal bearing and the bearing pressure grooves to the fluid recirculation passageway and toward an air purging fluid seal.

Abstract: A system and method for improving lubrication in a fluid dynamic bearing are disclosed. A fluid dynamic bearing is formed. The fluid dynamic bearing comprises a shaft having an axis of rotation and a surface comprising a first groove at a first depth and a second groove at a second depth, wherein the first and second grooves are for supporting a film of lubricating fluid. The fluid dynamic bearing further includes a hub having an axis coincident to the axis of rotation and a complimentary surface juxtaposed to the shaft which is conducive to supporting the lubricating fluid such that the shaft is rotatably retained.

Abstract: A hydrodynamic bearing device includes a sleeve having a bearing hole, a shaft, and a flange cover. The shaft is disposed in the bearing hole of the sleeve in a state of being capable of relative rotation, and has a large diameter flange portion. The flange cover is disposed opposite the bottom surface of the flange portion. A bubble suppression portion, which is formed as a recess on the bottom surface of the shaft, communicates with the upper surface of the flange portion through a communicating hole in the flange portion. This provides a hydrodynamic bearing device with which negative pressure is prevented from being generated in the bearing even when it is subjected to impact or vibration, and durability and reliability can be enhanced, as well as a spindle motor and a recording and reproducing apparatus equipped with this hydrodynamic bearing device.

Abstract: A hydrodynamic bearing type rotary device includes radial hydrodynamic grooves and thrust hydrodynamic grooves forming communicating channels, communicating holes designed to communicate the groove end of the radial hydrodynamic groove on the side opposite the thrust hydrodynamic grooves with the groove end of the thrust hydrodynamic groove on the side opposite the radial hydrodynamic grooves, and a circulation route composed by the communicating hole, the radial hydrodynamic groove, and the thrust hydrodynamic groove. Lubricating oil is circulated by means of a pump force of the hydrodynamic groove. The hydrodynamic bearing device prevents the formation of low-pressure parts from the bearing portion, preventing the accumulation of air bubbles, and thereby preventing the occurrence of oil film breakage at the radial hydrodynamic groove and the thrust hydrodynamic groove.

Abstract: A dynamic pressure bearing has a reduced axial dimension and is constructed to ensure smooth feeding of a lubricating oil. The dynamic pressure bearing includes a communicating hole and at least one tapered seal, and is constructed such that an opening angle of one of the at least one tapered seal through which oil feeding is possible is in a range of about 30 degrees inclusive to about 180 degrees exclusive, a tapered seal wall surface depth W1 of the tapered seal is about 0.3 mm or more, and a sum of distances over which the lubricating oil travels from both sides of an end portion of the communicating hole in a cross-section beyond a wall surface of the communicating hole along a wall surface opposite the end portion of the communicating hole exceeds an inside diameter of the communicating hole.

Abstract: A bearing mechanism includes a shaft, a bearing portion, and a cover closing a bottom end of the bearing portion. The bearing portion and the cover are preferably connected to one another by laser welding. A surface of a welded portion formed by the laser welding includes an inclined surface which is inclined such that the further from a central axis a portion thereof is, the axially higher the portion is. With this unique structure, contamination of lubricant used inside the bearing mechanism by fumes generated due to the laser welding is minimized, and therefore a reliable and durable bearing mechanism is provided.

Abstract: A hydrodynamic bearing device being low in torque, low in power consumption, high in reliability and best suited for miniaturization and a spindle motor using the same. The hydrodynamic bearing device in accordance with the present invention, dynamic pressure generation grooves being provided on at least one of a shaft or a sleeve, and a lubricant being present in a clearance where the above-mentioned shaft and the above-mentioned sleeve are opposed to each other, is characterized in that the above-mentioned lubricant contains diesters obtained from a divalent alcohol having 4 to 8 carbon atoms and having no alkyl side chain at the ? position and one or more kinds of saturated monovalent fatty acids having 9 to 13 carbon atoms.

Abstract: A bearing unit is provided which includes a shaft (51) to support rotatably, radial bearing (55) to support the shaft (51) circumferentially, a thrust bearing (66) to support the shaft (51) in the direction of thrusting, and a housing (56) having the radial bearing (55) and thrust bearing (66) disposed therein and in which a viscous fluid (57) is filled. The housing (56) has a sealed structure except for a shaft insertion hole (65) formed therein and through which the shaft 51 is introduced. Between the outer surface of the shaft (51) and the inner surface of the shaft insertion hole (65), there is defined a gap (69) having a sufficient width to prevent the viscous fluid (57) filled in the housing (56) from leaking out of the latter.

Abstract: There is provided a hydrodynamic bearing assembly including: a sleeve against which a shaft is supported so that an upper end of the shaft, being compressed and inserted into a hub base of a rotor case, protrudes upwardly in an axial direction; a first thrust dynamic pressure generating part formed in at least one of a protrusion and the hub base corresponding to the protrusion, the protrusion being formed at an end of the sleeve along an inner diameter direction; and a second thrust dynamic pressure generating part formed around a protruding end portion of the sleeve, the protruding end portion facing an upper portion of a stopper part in the axial direction and the stopper part rotating together with the rotor case. Also, an oil sealing part has an oil interface between an outer circumferential surface of the sleeve along an outer diameter direction and an inner surface of the stopper part.

Abstract: A retaining structure for motor elements includes an axial tube and a cap. The cap includes a stop and a coupling portion. At lease one motor element is received in the axial tube. The coupling portion of the cap is engaged with a coupling section of the axial tube for securely mounting the cap to the axial tube, with the stop of the cap covering an end of the axial tube to prevent the motor element from disengaging from the axial tube. In another example, the coupling portion of the cap engages with a coupling section on a stator.

Abstract: In a hydrodynamic bearing type rotary device, relationships between the number of times of intermittence life, a bearing load, lubricating fluid viscosity, a bearing size, and the like are considered in order to provide a hydrodynamic bearing type rotary device which can secure appropriate intermittence life. In a hydrodynamic bearing type rotary device, a shaft is inserted into a bearing hole of a sleeve so as to be relatively rotatable. A value of a function (Nd) is set to be 100,000 or higher: wherein Nd=?/(S·Ff·P·D).

Abstract: A fluid bearing device (50B, 50AB) is composed of a shaft (1, 51); a sleeve (9, 59) into which the shaft (1, 51) is inserted; and lubrication fluid (20) intervening in a gap between the shaft (1, 51) and the sleeve (9, 59), the fluid bearing device (50B, 50AB) supporting the shaft (1, 51) so as to be relatively rotatable freely with respect to the sleeve (9, 59), wherein an end portion of the sleeve (9, 59) is provided with a taper ring (4, 54) in annular shape, wherein at least either one of an inner circumferential surface (4a, 54a) of the taper ring (4, 54) and an outer circumferential surface (1a, 91b) of the shaft (1, 51) facing towards the inner circumferential surface (4a, 54a) of the taper ring (4, 54) is formed into a tapered surface (4a, 54a), which inclines in a direction as a gap between the inner circumferential surface (4a, 54a) of the taper ring (4, 54) and the outer circumferential surface (1a, 91b) of the shaft (1, 51) widens in accordance with leaving from the sleeve (9, 59) and forms a tape

Abstract: A bearing system for a rotor in rotating machines, such as compressors, pumps, turbines, expanders, has points of bearing and sealing for the rotor each being in the form of a combined bearing and sealing formed by a stator situated within a rotating machine house and surrounding the rotor. The stator is formed with a bore, whereby an annular clearance is created between stator and rotor, and the bore is having sectional area gradually increasing in the direction of larger pressure within the rotating machine.

Abstract: A hydrodynamic liquid metal bearing capable of use in a high temperature environment. The hydrodynamic bearing includes a rotating shaft with a raised portion extending into an annular groove formed within a stationary sleeve, the space formed between the two forming the liquid bearing surface. The raised portion in the shaft includes an axial passage and a radial passage to pump the liquid into a high pressure cavity formed in the annular groove. A low pressure cavity forms a recirculating passage with the high pressure cavity and the axial and radial passages such that the liquid metal recirculates with the rotation of the shaft. A collecting space formed between a labyrinth seal and a wind back seal collects any fluid that leaks into the space from the bearing. The leaked fluid is collected in a reservoir, and a pump delivers makeup liquid from the reservoir into the low pressure reservoir of the bearing. The bearing is a radial bearing, and in another embodiment is both a radial and a thrust bearing.