Abstract: A bearing arrangement comprises first and second axially spaced oil film bearings rotatably supporting a rolling mill roll shaft. An annular pressure plate is carried by and fixed relative to the roll shaft for rotation therewith. Third and fourth oil film bearings act on opposite sides of the pressure plate to axially fix the roll shaft.

Abstract: An air bearing assembly supporting a turbine driven rotatable motor shaft is provided. The assembly includes a composite cylindrical air bearing having alternating, bonded segmented porous carbon sections and nonporous carbon sections. The composite bearing has a sleeve installed circumferentially therearound. The sleeve has openings therein, therethrough and therearound such that the openings are adjacent the porous carbon sections and are oriented so as to be in longitudinal and circumferential registry with the porous carbon sections. Air passageways deliver supplied air into and through the sleeve openings, thence into and through the porous sections, thereby providing frictionless support for the rotating shaft. The assembly includes “O”-rings installed circumferentially therearound, one at each end of the assembly. A specific embodiment, namely a rotary bell cup atomizer driven by a turbine mounted on a rotatable motor shaft supported by the air bearing assembly, is disclosed and claimed.

Abstract: A rotational gas bearing allows rotation about a single axis while supplying a pressurized gas through the bearing. The gas bearing includes a gas supply member and a gas sink member. A cylindrical depression is located in one of the gas supply member and the gas sink member. A cylindrical protrusion protrudes from the other of the gas supply member and the gas sink member and is sized to fit within a cylindrical depression with a predetermined clearance. The gas supply bearing surface is opposed to the gas sink bearing surface. An opening is located in the gas supply bearing surface. A porous coating covers a portion of the gas supply bearing surface surrounding the opening. The porous coating communicates with the pressurized gas supply via the gas supply member for maintaining a bearing pressure between the porous coating and the gas sink bearing surface, such that the bearing pressure is greater than the feed pressure.

Abstract: A disk drive device includes a chassis, a top cover fixed to a chassis, a rotating body on which a disk retained in a disk retaining space formed between the chassis and the top cover is to be mounted, and a bearing body that supports the rotating body in a freely rotatable manner relative to the chassis. The bearing body has a lubricant applied in a predetermined area, and a capturer that captures the vaporized lubricant from the gas-liquid interface is provided in a space in communication with the disk retaining space from the gas-liquid interface of the lubricant.

Abstract: Provided is a sintered metal bearing, which is formed of raw material powder containing copper-based powder and iron-based powder as main components, the sintered metal bearing including a radial bearing surface along an inner periphery thereof. The copper-based powder includes fine copper powder exhibiting a particle size distribution in which a ratio of particles with a diameter of less than 45 ?m is 80 wt % or more, the fine copper powder occupying one-third or more of a whole of the copper-based powder in terms of a weight ratio. A compressed body formed by compressing the raw material powder is sintered at 900° C. or more to 1,000° C. or less.

Abstract: An inner peripheral surface and a lower end surface of a bearing sleeve made of a sintered metal are each formed into a smooth cylindrical surface or a flat surface that does not have a dynamic pressure generating portion. Thus, a step of forming the dynamic pressure generating portion can be omitted from a manufacturing step of the bearing sleeve, and cost of dies can be markedly reduced. Further, the inner peripheral surface of the bearing sleeve is formed into the smooth cylindrical surface, and hence a radial dynamic pressure generating portion is formed on an outer peripheral surface of a shaft member. However, the outer peripheral surface of the shaft portion is accessible to tools, and hence the radial dynamic pressure generating portion can be formed easily with high accuracy. As a result, accuracy of a radial bearing gap is enhanced so that a bearing rigidity is enhanced.

Abstract: An air bearing assembly supporting a turbine driven rotatable motor shaft is provided. The assembly includes a composite cylindrical air bearing having alternating, bonded segmented porous carbon sections and nonporous carbon sections. The composite bearing has a sleeve installed circumferentially therearound. The sleeve has openings therein, therethrough and therearound such that the openings are adjacent the porous carbon sections and are oriented so as to be in longitudinal and circumferential registry with the porous carbon sections. Air passageways deliver supplied air into and through the sleeve openings, thence into and through the porous sections, thereby providing frictionless support for the rotating shaft. The assembly includes “O”-rings installed circumferentially therearound, one at each end of the assembly. A specific embodiment, namely a rotary bell cup atomizer driven by a turbine mounted on a rotatable motor shaft supported by the air bearing assembly, is disclosed and claimed.

Abstract: A sleeve housing of a bearing mechanism according to a preferred embodiment of the present invention includes a cylindrical portion arranged to cover outer circumferences of a sleeve and a plate portion, and a bottom portion arranged to close a lower portion of the cylindrical portion. The bottom portion includes a plurality of projecting portions arranged in a circumferential direction in an upper surface of the bottom portion. Each projecting portion is arranged to project upward to be in contact with a lower surface of the sleeve. Each of the projecting portions and the plate portion are arranged radially opposite each other. At least a portion of an adhesive is arranged to exist between an outer circumferential surface of the sleeve and an inner circumferential surface of the cylindrical portion.

Abstract: A gas bearing (100) having pressurized 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 pressurized axially such that the outer circumference of the housing is unbroken and hence usable for other purposes.

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 fluid dynamic bearing device which can exhibit high bearing performance is provided at low costs by forming a highly accurate bearing gap. At least a region in the outer circumferential surface of a shaft which faces the radial bearing gap is constituted of an electroformed part, and the region of the shaft excluding the electroformed part is constituted of a resin portion.

Abstract: A fluid dynamic bearing device which exhibits high bearing performance at low cost has a highly accurate bearing gap. At least a region in the outer circumferential surface of a shaft, which faces the radial bearing gap, is constituted of an electroformed part, and the region of the shaft excluding the electroformed part is constituted of a resin portion.

Abstract: A sintered metal bearing member is provided that includes radial bearing surfaces arranged at two regions spaced apart from each other in an axial direction on an inner peripheral surface. The bearing member includes radial dynamic pressure generating portions in contact with the radial bearing surfaces. The radial dynamic pressure generating portions are formed on the radial bearing surfaces. The bearing member includes a thrust bearing surface arranged on at least one of the end surfaces and a thrust dynamic pressure generating portion for generating a dynamic pressure in the lubricating oil in contact with the thrust bearing surface. The thrust dynamic pressure generating portion is formed on the thrust bearing surface. The bearing member includes a middle relief portion arranged between the radial bearing surfaces in the axial direction. The middle relief portion has a larger diameter than the radial bearing surfaces.

Abstract: A plain bearing includes a bearing body in which a body, which is to be stored, is arranged. The bearing body is surrounded by a supporting body. The bearing body has a partial joint arranged at an angle in relation to the horizontal. The plain bearing has an active cooling system and an articulated lubrication system.

Abstract: Coast-down bearing apparatus and methods are provided. The coast-down bearing includes a plurality of segments each having a radius of curvature substantially equal to an outer radius of a shaft and spaced radially therefrom to define a clearance, with the plurality of segments being configured to receive the shaft when a magnetic bearing drops the shaft. The coast-down bearing also includes a plurality of slots disposed between adjacent ones of the plurality of segments.

Abstract: An electric motor includes an armature shaft which is mounted in at least one floating bearing. The floating bearing comprises a bearing inner ring, which is positioned on the armature shaft, a bearing outer ring, which is received in a bearing seat, and a fluid pump for a vehicle fluid system having the electric motor. Lubricant disposed between the armature shaft and the bearing inner ring forms a hydrodynamic lubricant film and generates a constant relative movement between the armature shaft and the bearing inner ring.

Abstract: A fluid dynamic bearing device (1), comprising a dynamic pressure generating groove region (B) being provided on an inner peripheral surface (3a) of a bearing member (3), which forms a radial bearing gap, the region (B) comprising: a first region (B1) for generating a fluid dynamic pressure when the bearing member (3) and a shaft member (2) are rotated relative to each other in a forward direction; and a second region (B2) for generating a fluid dynamic pressure when the bearing member (3) and the shaft member (2) are rotated relative to each other in a reverse direction. A portion of the region (B), corresponds to an end portion on an open-to-air side of the radial bearing gap, comprises an annular projecting portion (6) provided closer to the shaft member (2) with respect to a groove bottom of each of the plurality of dynamic pressure generating grooves (4).

Abstract: A rotating device includes a fixed body having a base and a shaft, a hub, and a rotating body having a rotating-body-side encircling member fixed to the hub and encircling the shaft. A lubricant is present between the fixed body and the rotating body. The rotating-body-side encircling member and the shaft are each formed with a radial dynamic pressure generating groove. The fixed body includes a base-side encircling member having a disk part encircling the base-side portion of the shaft and a cylinder part encircling the rotating-body-side encircling member. The base-side encircling member has the disk part fixed to the shaft by interference fitting, and has the cylinder part fixed to the base. An air-liquid interface is located in a gap in the radial direction between the inner periphery of the cylinder part and the outer periphery of the rotating-body-side encircling member.

Abstract: A plain bearing includes a bearing body in which a body, which is to be stored, is arranged. The bearing body is surrounded by a supporting body. The bearing body has a partial joint arranged at an angle in relation to the horizontal. The plain bearing has an active cooling system and an articulated lubrication system.

Abstract: A bearing system includes a sleeve bearing supported on a shaft and a gear supported on the sleeve bearing. The shaft has an outer diameter shaft surface, the sleeve bearing has an inner diameter bearing surface and an outer diameter bearing surface, and the gear has a gear bore surface. At least one of the outer diameter shaft surface, the inner diameter bearing surface, the outer diameter bearing surface, and the gear bore surface includes an isotropic surface finish and a hard thin film over the isotropic surface finish. During a break-in period of operation of the bearing system, the hard thin film over the isotropic surface finish breaks in a counter surface of the bearing system to extend a hydrodynamic lubrication period of operation of the bearing system.

Abstract: Disclosed is a bearing sleeve for supporting a shaft of an air cycle machine. The bearing sleeve includes an outer diameter and an inner diameter. The outer diameter is within a range of 3.214 and 3.216 inches. Further included is a foil retaining cavity provided in the inner diameter of the sleeve. The foil retaining cavity includes a slot and first and second openings located at opposing axial ends of the slot. Each of the first and second openings include a small portion and a large portion having different axial lengths. A ratio of the combined axial lengths of the large portions to an axial length of the foil retaining cavity is within a range of 0.19:1 and 0.22:1. Further included is a seal attachment portion provided at one axial end of the bearing sleeve configured to circumferentially support a seal.

Abstract: Disclosed is a bearing sleeve for supporting a shaft of an air cycle machine. The bearing sleeve includes an outer diameter and an inner diameter. The outer diameter is within a range of 3.222 and 3.224 inches. Further included is a foil retaining cavity provided in the inner diameter of the sleeve. The foil retaining cavity includes a slot and first and second openings located at opposing axial ends of the slot. Each of the first and second openings include a small portion and a large portion having different axial lengths. A ratio of the combined axial lengths of the large portions to an axial length of the foil retaining cavity is within a range of 0.19:1 and 0.22:1. Further included is a seal attachment portion provided at one axial end of the bearing sleeve configured to circumferentially support a seal.

Abstract: Disclosed is a bearing sleeve for supporting a shaft of an air cycle machine. The bearing sleeve includes an outer diameter and an inner diameter. The outer diameter is within a range of 3.222 and 3.224 inches. Further included is a foil retaining cavity provided in the inner diameter of the sleeve. The foil retaining cavity includes a slot and first and second openings located at opposing axial ends of the slot. Each of the first and second openings include a small portion and a large portion having different axial lengths. A ratio of the combined axial lengths of the large portions to an axial length of the foil retaining cavity is within a range of 0.19:1 and 0.22:1.

Abstract: An oil film bearing for supporting a roll neck in a rolling mill, suitable in particular for transmitting high bearing forces when the bearing partners are slightly and slowly moved with respect to each other, has a bearing surface into which are incorporated rods made of a friction-reducing material (e.g., low friction compounds), which extend in a substantially perpendicular direction to the bearing surface. The rods are deformed during heat processing to define a bearing surface. The bearing partner, such as a roll sleeve, rests on the free face of the deformed rods.

Abstract: An oil-free chain is constructed by alternately connecting a pair of outer link plates connected using pins and a pair of inner link plates connected using oil-impregnated bushings into which the adjacent pins of the outer link plates adjacent to the inner link plates are fitted. The oil-impregnated bushings are impregnated with a lubricant having a kinematic viscosity in the range of ISO-VG grade 46 to 460, the weight % of an ingredient having the highest content among the elution ingredients obtained by the GPC method is 95 wt % or more, Mn is 800 or more and 2300 or less, and the ratio of Mw to Mn is 1.0 or more and 1.3 or less. Oil film breakage at the sliding portions of the bushings is suppressed from occurring and the oil film strength is high such that an oil-free chain has a sufficiently long abrasion elongation-resistant life.

Abstract: A component for use in a bearing device according to one embodiment of the present invention includes a lubricant layer on a surface of the component. Here, the lubricant layer contains a rod-like ionic liquid crystal compound having a cation group and an anion group.

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 spindle motor including: a fluid dynamic pressure bearing assembly; a base member coupled to the fluid dynamic pressure bearing assembly; and a core fixedly coupled to the base member and having a coil wound therearound, wherein the base member has a disk portion and a coupling portion extending from an inner edge of the disk portion upwardly in an axial direction, one surface of the core is in contact with an outer circumferential surface of the overall coupling portion, and an upper end of the coupling portion is protruded upwardly, relative to an upper surface of the core.

Abstract: In a disk drive device according to an embodiment, radial dynamic pressure corresponding portions are structured such that the diameters thereof expand toward the axial outside of the sleeve, and that the shaft is in surface-contact with each of the radial dynamic pressure corresponding portions when the rotational drive of the disk drive device is stopped. Further, a herringbone-shaped radial dynamic pressure groove is formed in each of the radial dynamic pressure corresponding portions. The radial dynamic pressure groove in each radial dynamic pressure corresponding portion is formed such that the axial outside length from the turned-back portion of the herringbone-shape is longer than the axial inside length therefrom.

Abstract: There are provided a hydrodynamic bearing assembly and a motor including the same. The hydrodynamic bearing assembly includes a sleeve rotatably supporting a shaft and including a first circulation hole formed therein, the first circulation hole penetrating between an inner peripheral surface thereof and an outer peripheral surface thereof; a sleeve housing into which the sleeve is inserted; and a second circulation hole formed between the outer peripheral surface of the sleeve and an inner peripheral surface of the sleeve housing to be in communication with the first circulation hole, wherein an upper portion of the second circulation hole has a larger diameter than a lower portion thereof in an axial direction.

Abstract: Provided is a bearing capable of satisfying demands for cost reduction and further quietness, and stably maintaining high support accuracy. A sliding bearing (4) includes an inner member (5) having a mounting surface (9) with respect to a rotary shaft (2), and an outer member (6) being arranged on a radially outer side of the inner member (5). A radial bearing gap is formed between an outer peripheral surface (5a1) of the inner member (5) and an inner peripheral surface (7a1) of the outer member (6), and a lubricating oil is interposed in the radial bearing gap. Further, between the inner member (5) and the outer member (6), sealing gaps (S, S) for maintaining an oil level of the lubricating oil on both axial sides of the radial bearing gap are formed. At least a part of the mounting surface (9) of the inner member (5) is made of a metal.

Abstract: Vane pump mechanical losses are reduced by removing vane friction losses and replacing them with lower magnitude journal bearing fluid film viscous drag losses. A freely rotating cam ring is supported by a journal bearing. A relatively low sliding velocity is imposed between the cam ring and the vanes. This permits the use of less expensive and less brittle materials in the pump by allowing the pump to operate at much higher speeds without concern for exceeding vane tip velocity limits.

Abstract: A rotating device includes a shaft body that has a shaft, a first flange extending outwardly from the outer periphery of the shaft, and a second flange, a bearing body that has a shaft encircling member encircling the shaft between the first flange and the second flange, a first thrust opposing part formed between the shaft encircling member and the first flange, a second thrust opposing part formed between the shaft encircling member and the second flange, an intermediate space provided in a gap between the shaft and the shaft encircling member, a radial dynamic pressure bearing, a first communication channel that allows the first thrust opposing part to be in communication with the intermediate space, and a second communication channel that allows the second thrust opposing part to be in communication with the intermediate space.

Abstract: The invention relates to a bearing arrangement for a shaft (3) of a turbine wheel (2) or of a turbine wheel (2) and of a compressor wheel (4), wherein—the turbine wheel (2) is driven by the exhaust gas of a vehicle drive unit, said bearing arrangement comprising—a static housing (9), which—together with a bearing bushing (10) arranged in a rotationally movable manner relative to the housing (9)—encloses a first bearing gap (11), wherein—the bearing bushing (10) accommodates the shaft (3) in a rotationally movable manner and encloses a second bearing gap (12) together with the shaft. The invention is characterized in that a ratio (R1/R2) of radii (R1, R2) of the first bearing gap (11) and of the second bearing gap (12) with respect to a rotational axis (14) of the shaft (3) changes at least once over the maximum axial extent (x) of the bearing bushing (10).

Abstract: A fluid dynamic bearing device includes a resin member capable of suppressing the intrusion of a lubricating oil as much as possible even when carbon fibers are compounded. A housing part as the resin member can be obtained by injection-molding a resin composition in which PPS is a base resin, and carbon fibers are compounded. The housing part is in contact with an ester-based lubricating oil filled in the inside of the bearing. The plurality of carbon fibers bound with a binder material not containing an urethane resin are cut and the carbon fibers minced by cutting are compounded into PPS to thereby obtain the above-described resin composition.

Abstract: A shaft side sealing surface (2a2) provided to an outer peripheral surface of a shaft member (2a) and a bearing side sealing surface (9a) provided to an inner peripheral surface of a bearing member (11) (sealing portion (9)) each has a tapered surface that radially shrinks toward an open-to-air side. In addition, the bearing side sealing surface (9a) has a minimum diameter (r4) set to be larger than a maximum diameter (r5) of the shaft side sealing surface (2a2).

Abstract: A slide bearing including a rotating friction partner, a counterpart and a lubrication film between the friction partner and the counterpart, wherein the friction partner or the counterpart is coated with a hard material.

Abstract: There are provided a hydrodynamic bearing assembly and a spindle motor including the same. The hydrodynamic bearing assembly includes: a sleeve including a shaft hole to have a shaft rotatably installed therein; and a cover member covering the shaft hole at a lower portion of the shaft hole in an axial direction, wherein an inner surface of the sleeve is provided with depression parts depressed in an outer diameter direction between upper and lower portions of the sleeve and portions in which radial bearings are formed, such that the portions in which the radial bearings are formed are provided with bearing closure adhesion parts allowing the portions in which the radial bearings are formed to be closer to the shaft than portions other than the portions in which the radial bearings are formed.

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 includes at least one fluid dynamic radial bearing and at least one fluid dynamic axial bearing that are disposed along sections of the bearing gap. In one aspect of the invention, an annular sealing gap for sealing open ends of the bearing gap 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: A bearing assembly includes a bearing formed to at least radially guide a shaft, a seat for the bearing, an annular gap around the bearing between the bearing and the seat that allows the bearing to undergo a movement perpendicular to an axis of the bearing, a magnetorheological fluid in the gap and a magnetic field source configured to subject the magnetorheological fluid to a magnetic field. Also, a method of controlling a strength of the magnetic field generated by the magnetic field source to control a viscosity of the magnetorheological fluid and affect an operating condition of the bearing assembly.

Abstract: A disk drive device includes a hub, a base plate, and a bearing unit. The bearing unit includes a shaft housing member, joined to the hub, having a through-hole in the center, a shaft having a smaller diameter section and a larger diameter section, a radial dynamic pressure grooves, and a lubricant agent. The opening shape of bearing hole of the base plate is so formed as to be larger than the outer shape of the larger diameter section. In the bearing unit, the larger diameter section of the bearing unit is fixed by a hardening resin present between the bearing unit and the bearing hole.

Abstract: The fluid dynamic bearing assembly of including: 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 and dispersing pressure of a lubricating fluid in the hollow; an oil sealing cap having an oil passage communicated with the bypass passage and taper-sealing the lubricating fluid within the oil passage; and a thrust plate formed to have a hole corresponding to a shape of the outer peripheral surface of the shaft and axially disposed under the sleeve.

Abstract: Multi-recess hydrostatic journal bearings support a rotating shaft and have inclined surfaces, each inclined surface forming a variable radial gap with the surface of the shaft, the variable gaps converging in the direction of rotation of the shaft to increase hydrodynamic forces, reduce a turbulent component of shear friction, and improve the thermal stability of the journal bearing. The inclined surfaces can be formed in one or more of portions of recess bottoms in recesses, portions of gap lands surrounding recesses, and portions of an inner surface of a bushing.

Abstract: A rotating device includes a sleeve which encircles a shaft, a housing which supports the shaft and which forms an annular supporting recess where the lower end of the sleeve enters together with the shaft, a ring member which is provided above the sleeve and which is fixed to the shaft in a manner encircling the shaft. A first gap between the sleeve and the shaft includes first and second radial dynamic pressure generating portions. An annular sleeve recess is formed in upper face of the sleeve. The ring member includes a ring entering portion that enters the sleeve recess in a non-contact manner. An outward gap in the radial direction where the ring entering portion and the sleeve recess face with each other in the radial direction includes a second air-liquid interface of a lubricant.

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 hydrostatic bearing is provided that includes a plurality of bearing pads that form loading carrying areas.

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: A hydrodynamic journal pad bearing is provided having several pads circumferentially distributed around the rotor of a large steam turbine with each pad mounted onto a platform separating the pad from a cylindrical cage in turn connected to the floor of a hall housing the turbine and having an interface between at least one of the several pads and the platform on which the at least one of the several pads is mounted is formed such as to include at least two areas with different curvatures to increase the stiffness of the interface in the event of a relative movement between the pad and the platform.

Abstract: A disk drive device includes a hub, a base plate, and a bearing unit. The bearing unit includes a shaft housing member, joined to the hub, having a through-hole in the center, a shaft having a smaller diameter section and a larger diameter section, a radial dynamic pressure grooves, and a lubricant agent. The opening shape of bearing hole of the base plate is so formed as to be larger than the outer shape of the larger diameter section. In the bearing unit, the larger diameter section of the bearing unit is fixed by a hardening resin present between the bearing unit and the bearing hole.

Abstract: There are provided a hydrodynamic bearing assembly and a spindle motor including the same. The hydrodynamic bearing assembly includes: a sleeve including a shaft hole to have a shaft rotatably installed therein; and a cover member covering the shaft hole at a lower portion of the shaft hole in an axial direction, wherein an inner surface of the sleeve is provided with depression parts depressed in an outer diameter direction between upper and lower portions of the sleeve and portions in which radial bearings are formed, such that the portions in which the radial bearings are formed are provided with bearing closure adhesion parts allowing the portions in which the radial bearings are formed to be closer to the shaft than portions other than the portions in which the radial bearings are formed.