Abstract: Disclosed therein is a fan motor including: a lower bracket having a lower protrusion which is located at the central portion and has a lower bearing insertion portion therein and a space which is formed around the lower protrusion; an upper bracket having an upper protrusion which is located at the central portion and has an upper bearing insertion portion therein; a rotor located between the lower protrusion and the upper protrusion and rotating together with a shaft; and a stator core surrounded by a lower insulator which is located above the lower protrusion and an upper insulator which is located below the upper protrusion.

Abstract: A motor includes a stationary portion and a rotating portion. The rotating portion includes a sleeve portion. The sleeve portion includes a communicating hole. A dynamic pressure bearing is defined in a first gap between a shaft portion and the sleeve portion. An upper seal portion and a lower seal portion are arranged radially outward of the dynamic pressure bearing. The upper seal portion and the lower seal portion are arranged in communication with each other through the communicating hole. The communicating hole and a space extending from the upper seal portion to the lower seal portion through the first gap are filled with a lubricating oil. A fixing region where an outer tubular portion and a base portion are fixed to each other is arranged to overlap with the dynamic pressure bearing in a radial direction in plan view.

Abstract: A linear actuator is provided that includes a housing having an input member supported for rotation therein. An output member travels linearly along the input member when the input member is rotated relative to the output member. A guide rail extends along an inner surface of the housing. The output member engages the guide rail to prevent rotation of the output member.

Abstract: A rotating portion of a motor includes a hub body portion and a shaft arranged to extend in an axial direction. The hub body portion includes a through hole and a recessed portion. The recessed portion extends radially outward from an outside surface of the shaft, has an annular shape and is recessed axially downward. The recessed portion includes first, second, and third ridge portions. The first ridge portion is an axially upper edge of an inside surface defining the through hole, the second ridge portion is arranged radially outward of the first ridge portion, and the third ridge portion is arranged radially outward of the second ridge portion, and is located axially above both the first ridge portion and the second ridge portion. An adhesive is arranged to cover the outside surface of the shaft and reach a portion of the second ridge portion.

Abstract: A rotary electric machine includes a stator in which windings are arranged around a plurality of main poles of a stator core, and a hybrid type rotor arranged with an air gap between the stator and the rotor has a step angle for the rotor of about 4.09° and uses metal bearings for supporting a rotor shaft of the rotor. Setting of the step angle for the rotor to be about 4.09° can make a rotation angle of the rotor caused by excitation of the windings by an input pulse signal larger as compared with a typical motor having a step angle of about 1.8°. With this unique arrangement, the rotor can be rotated at higher speeds, increasing the motor efficiency. Therefore, the motor output at approximately the same level as that of a conventional motor can be obtained without keeping the air gap high precision. Due to this, even if inexpensive slide bearings, i.e.

Abstract: The invention relates to a motor holder for receiving an electric machine, in particular for receiving the bearing of an electric machine, comprising a surrounding outer wall, an intermediate floor joined to the surrounding outer wall, a floor for receiving a bearing, which floor is moulded in the intermediate floor and is joined to the intermediate floor by a transitional region, the transitional region having an encircling first annular wall and at least one encircling second annular wall which form an annular storage space provided in the transitional region. The invention relates to an electric machine having a motor holder of this type.

Abstract: A machine comprises a rotor (101), a stator (102), main bearings (103), and safety bearings (104) for supporting the rotor in a situation where the main bearings are non-operating. When the rotor is supported by the main bearings, there are radial and axial clearances between the rotor and the safety bearings. A contact surface (107) of the rotor contacting the safety bearing in response to closure of the axial clearance is oblique with respect to a spatial plane perpendicular to a rotational axis of the rotor so that an angle (?) between the rotational axis and a normal of the contact surface at a point of contact between the rotor and the safety bearing is greater than zero and at most 10 degrees. The obliqueness of the contact surface eliminates at least partly an excitation for whirling motion when the rotor is supported by the safety bearings.

Abstract: A fan motor includes: a rotor configured to be rotated so as to generate air movement; a stator configured to rotatably support the rotor via a fluid dynamic pressure bearing; and a driving mechanism configured to rotationally drive the rotor with respect to the stator. The rotor comprises a hub fixed to an impeller. The stator includes a bottom housing which supports a sleeve. The fan motor is configured to have a thickness of 3.2 mm or less along the rotational axis R of the rotor.

Abstract: A spindle motor includes a stationary portion and a rotating portion. The stationary portion preferably includes a shaft portion, a lower plate portion, and an outer tubular portion. The rotating portion preferably includes an inner tubular portion and a flange portion including a communicating hole. An upper seal portion is arranged radially outward of a first gap, and a lower seal portion is arranged radially outward of a second gap. The upper and lower seal portions are arranged in communication with each other through the communicating hole. The communicating hole and a space extending from the upper seal portion to the lower seal portion through the first gap, the second gap, and a third gap are filled with a lubricating oil. The third gap includes a dynamic pressure generation portion arranged to produce a radially inward pressure acting on the lubricating oil.

Abstract: There is provided a hydrodynamic bearing assembly including: a sleeve having a shaft inserted thereinto and supported thereby; a thrust plate coupled to one end of the shaft; an extension part formed at the thrust plate to be extended in an axial direction so as to be coupled to the shaft; and a coupling part formed at the shaft to contact an inner surface of the extension part so as to be coupled to the extension part.

Abstract: A dynamic pressure bearing is defined in a first gap between a shaft portion and a sleeve portion. An upper seal portion extending upward and a lower seal portion extending downward are arranged radially outward of the dynamic pressure bearing. Each of the upper seal portion and the lower seal portion includes a surface including a lubricating oil located therein. The upper seal portion and the lower seal portion are arranged in communication with each other through a communicating hole defined in the sleeve portion. The communicating hole and a space ranging from the upper seal portion to the lower seal portion through the first gap are filled with the lubricating oil. The axial distance between the surfaces of the lubricating oil in the upper seal portion and the lower seal portion is arranged to be shorter than the axial distance between an upper end and a lower end of the dynamic pressure bearing.

Abstract: A rotating device includes a rotor including a hub to receive a recording disk, and a fixed body including a base that fixedly supports a bearing unit to rotatably support the rotor. The fixed body includes a core having a cylindrical part and salient poles extending in a radial direction, a ring-shaped member having a core holding part that has the core fixed to an outer peripheral surface thereof, a sloping part extending in a direction inclined with respect to a rotational axis of the rotor from a side of the core holding part farther away from the hub, and a support part extending from a side of the sloping part farther away from the hub.

Abstract: A molded motor includes a stator, a resin casing, a rotor, a pair of bearings, a pair of bearing retainers, a resin bracket cover, and a control board. The rotor includes a shaft. The bearings are arranged to rotatably support the shaft. The bearing retainers are made of an elastic electrically insulating body. The bearing retainers are arranged to cover the bearings at radial outer sides of the bearings and to hold the bearings in place. The bracket cover is arranged to cover the open side of the casing. One of the bearings is attached to the bracket cover through one of the bearing retainers. The other bearing is attached to a bottom wall portion of the casing through the other bearing retainer.

Abstract: There is provided a spindle motor including: a sleeve supporting a shaft; and a rotor hub coupled to an upper portion of the shaft to thereby form a bearing clearance with the sleeve, wherein the sleeve and the rotor hub are provided with a plurality of sealing parts for preventing a leakage of a lubricating fluid.

Abstract: There is provided a spindle motor including a sleeve rotatably supporting a shaft, a rotor coupled to an upper end of the shaft and rotating together with the shaft, a stopper part coupled to a main wall part protruding from one surface of the rotor and facing an outer peripheral surface of the sleeve, a cover plate coupled to the sleeve while maintaining a clearance between the cover plate and lower portions of the shaft and the sleeve, a base member coupled to the cover plate, and a stator holder fixedly disposed on the base member.

Abstract: A turbocompressor assembly is provided, which is divided along a rotor axis into at least three sections. The three sections include a bearing section having an active magnetic bearing, a motor section including a motor having a stator arranged along the rotor axis, the stator enclosing a circumferential motor gap formed between the stator and the rotor, and a compressor section having a compressor for compressing a cooling fluid. A gas-tight housing encloses the rotor, the bearing section, the motor section and the compressor section. A cooling system is provided having an inlet for supplying the pressurized cooling fluid to the bearing section and the motor section through a fluid channel positioned between the bearing section and the motor section. The cooling system includes a throttling device positioned adjacent to the motor gap for limiting the flow of cooling fluid from the fluid channel to the motor gap.

Abstract: Engaging protrusions of a lower end housing are axially snap-fitted into through holes, respectively, of a yoke housing to couple therebetween. Each of spacers is circumferentially placed between and is press-fitted between corresponding adjacent two of permanent magnets fixed to an inner peripheral surface of the yoke housing. Each spacer axially contacts a corresponding contact part of the end housing. A lower ball bearing and an upper ball bearing are supported by the lower end housing and an upper end housing, respectively, to rotatably support a shaft. A wave washer is axially positioned between the lower ball bearing and the lower end housing to exert an urging force between the lower end housing and the upper end housing through the shaft.

Abstract: There is provided a spindle motor including: a rotating member including a protrusion portion protruded so as to form a clearance narrower than a bearing clearance; and a fixed member having a protrusion corresponding portion protruded so as to be disposed to face the protrusion portion and rotatably supporting the rotating member, wherein the protrusion portion includes a thrust dynamic pressure groove formed therein in order to generate thrust fluid dynamic pressure and has a radial length smaller than that of the protrusion corresponding portion disposed to face the thrust dynamic pressure groove and having a flat surface.

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: A lubricating oil is arranged between stationary and rotating portions of a spindle motor. When the motor is stationary, upper and lower surfaces of the lubricating oil are respectively located in upper and lower capillary seal portions. A first angle defined between an outer circumferential surface of the plate portion and an inner circumferential surface of a cylindrical portion at the upper capillary seal portion, and a second angle defined between an outer circumferential surface of a sleeve and an inner circumferential surface of the wall portion at the lower capillary seal portion, in a section taken along a plane including a central axis is respectively in the range of about 1 degree to about 8 degrees and in the range of about 1 degree to about 10 degrees, respectively. The upper capillary seal portion has maximum radial and axial dimensions smaller than those of the lower capillary seal portion.

Abstract: The present invention relates to an electrical device including a stator and a rotor, wherein the electrical device is preferably a generator, a motor or similar, in particular a centrifuge motor, wherein the rotor, in particular a motor shaft is rotatably supported through at least one bearing relative to the stator, wherein at least one damping device is provided between the stator and the rotor, wherein the damping device includes at least one damping element. Thus, the device provides a high level of integrated vibration damping and internal damping of the device can be adapted to particular properties and applications.

Abstract: An electric motor including a housing; an output shaft stuck out from an end face of the housing; an air purge device having an inner circumferential surface and a mounting surface, the inner circumferential surface surrounding an outer circumferential surface of the output shaft, the mounting surface is mounted on the end face of the housing, the air purge device being configured to supply air to a clearance between the inner circumferential surface and the outer circumferential surface of the output shaft; and a fastening part fastening the air purge device to the end face of the housing in a detachable manner. The housing and the air purge device respectively having fitting parts at which the housing and the air purge device are fitted to each other when mounting the air purge device to the end face of the housing.

Abstract: A disk drive device includes a rotating body that rotates and drives a disk, a stationary body which includes a chassis with a protrusive part and a stator core fastened with the chassis, and a fluid bearing unit. The chassis has a recess with a bottom provided in the protrusive part, and the fluid bearing unit includes an insertion part inserted in the recess with the bottom, and a core encircled part. A gas passage is provided which causes a clearance space between the insertion part and the recess with the bottom to be in communication with a disk retaining space.

Abstract: A rotor-stator structure including plural bumper elements that may employ synthetic sliding bearing surfaces, mounted to the stator, and designed to contact a machined surface on the rotor if generator structural deflection occurs during operation. During normal operation, the bearing surface is not in contact with the machine rotor. If extreme loads are imposed on the rotor or stator structures, or other issue like bearing failure, causes the air gap to close, the bumper elements will “touch down” on a machined surface on the rotor to maintain a minimum air gap.

Abstract: The invention relates to a safety bearing for retaining a rotor shaft (4) of a machine (1), wherein the safety bearing (2) comprises a first carrier body (7) rotating about a virtual geometric center line (M) and roller bodies (5), wherein each roller body comprises a region (19) that is located between the center line (M) and the first carrier body (7), wherein the roller bodies (5) are each connected in a rotatable manner to the first carrier body (7) via a shaft (6). The invention creates a safety bearing (2) with which the likelihood of an occurrence of a backward-whirl is considerably reduced as compared to the safety bearings known from the prior art.

Abstract: A rotor shaft is supported in a rotatable manner at both ends by bearings respectively disposed to a housing forming a part of a stator and provided with a positioning portion of the bearing in at least one shaft end. The positioning portion is formed of an annular step-like rise portion that abuts on a circular arc surface provided to an inner ring corner of the bearing. A rotor shaft capable of holding the bearing in a stable manner over a long period is thus obtained without increasing the number of components and the numbers of working processes and assembly man-hours for the shaft. It thus becomes possible to solve problems, such as an increase in cost due to a large amount of working margin and increases of the direct material cost and in weight due to a larger finishing diameter of the shaft.

Abstract: According to one embodiment, an electric motor includes a stator, a rotor, bearings and a rotor shaft, in a frame, supporting surfaces on the rotor, and a plurality of threaded holes in the frame, which are configured to receive bolts for pressing the support surfaces from outside.

Abstract: Systems and methods for rotor bearings that enable improved oil circulation, wherein axial grooves are formed in the outer periphery of each bearing to form channels that allow axial flow of oil through the channels. Each bearing includes a collar, a sleeve and an interference ring. The collar has a bore through its center in which a rotatable sleeve is positioned. The outer periphery of the collar has a circumferential groove and at least one axial groove that extends from one face of the collar to the other. An axially permeable interference ring positioned within the circumferential groove extends radially outward from the groove beyond the outer periphery of the collar. The interference ring (e.g., a looped coil spring) allows fluid in the axial groove to flow through the interference ring. The axial groove may have a different depth than the circumferential groove.

Abstract: A bearing apparatus according to a preferred embodiment of the present invention includes a bearing portion having a bottom and being substantially cylindrical; a shaft inserted in the bearing portion, and arranged to rotate about a central axis relative to the bearing portion; a bearing opposing portion defined in one piece, arranged above the bearing portion, and arranged to hold an upper end portion of the shaft while covering an outer circumferential surface upper portion and an upper end surface of the shaft; and a cylindrical seal portion arranged to extend downward from the bearing opposing portion. An inner circumferential surface of the cylindrical seal portion and an outer circumferential surface of the bearing portion are arranged to together define a seal gap therebetween, the seal gap including a seal portion having a surface of a lubricating oil defined therein.

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: A motor includes a shaft component, an upper plate portion, a lower plate portion, and a sleeve portion. The shaft component includes an inner shaft portion and an outer shaft portion. The sleeve portion is disposed between the upper plate portion and the lower plate portion. A radial gap is defined between the sleeve portion and the outer shaft portion. A fixing range in which the outer shaft portion and the inner shaft portion radially overlap is provided. At least a portion in an axial direction of the fixing range radially overlaps with an existing range in the axial direction of the radial gap.

Abstract: The invention relates to an electric tool, in particular a hand-held electric tool, having a housing, which has a rear housing part and at least one front housing part arranged in front of the rear housing part in the longitudinal direction of the electric tool, and an electric drive motor having an armature shaft that extends in the longitudinal direction of the electric tool. The armature shaft is rotatably mounted together with a rear bearing arranged at the rear housing part. According to the invention, the rear bearing is designed as a fixed bearing.

Abstract: A lubricating oil is arranged between stationary and rotating portions of a spindle motor. When the motor is stationary, upper and lower surfaces of the lubricating oil are respectively located in upper and lower capillary seal portions. A first angle defined between an outer circumferential surface of the plate portion and an inner circumferential surface of a cylindrical portion at the upper capillary seal portion, and a second angle defined between an outer circumferential surface of a sleeve and an inner circumferential surface of the wall portion at the lower capillary seal portion, in a section taken along a plane including a central axis is respectively in the range of about 1 degree to about 8 degrees and in the range of about 1 degree to about 10 degrees, respectively. The upper capillary seal portion has maximum radial and axial dimensions smaller than those of the lower capillary seal portion.

Abstract: An example rotating device is a disk drive device that includes a base, a hub on which a recording disk is to be mounted and which rotates relative to the base, and a fluid dynamic bearing unit that allows the hub to rotate relative to the base. The fluid dynamic bearing unit includes a shaft that performs relative rotation and a cylindrical member that encircles the shaft, the cylindrical member includes a thrust dynamic pressure generating groove which is provided in one end face of the cylindrical member and which generates thrust dynamic pressure, and the thrust dynamic pressure generating groove includes a cut-and-machined face.

Abstract: There is provided a spindle motor including: a sleeve rotatably supporting a shaft; a rotor coupled to an upper end of the shaft and rotating in conjunction with the shaft; a stopper portion coupled to a main wall portion protruded from one surface of the rotor and facing an outer circumferential surface of the sleeve; a stator holder having a fixed portion coupled to an outer circumferential surface of the sleeve, an installation portion to which a core having a coil wound therearound is fixed, and a connection portion connecting an upper end of the fixed portion and an upper end of the installation portion; and a base member fixedly coupled to the stator holder.

Abstract: There is provided a spindle motor including a shaft including a body part and an extension part extended from an upper portion of the body part in an outer diameter direction, a sleeve rotatably supporting the shaft, and a rotor rotating together with the shaft and including a stopper part facing an outer peripheral surface of the sleeve, wherein the extension part and the rotor are coupled to each other outwardly of the outer peripheral surface of the sleeve in the outer diameter direction.

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: A planetary push-pull electric motor comprising a ring stator fixedly mounted on the central axis of the planetary push-pull electric motor; a planetary rotor arranged to be magnetically movable around an inner circumference of the ring stator, the planetary rotor rotatably mounted on an eccentric rotor axis in respect to the central axis of the ring stator; a series of electromagnets radially mounted about the ring stator for generating magnetic fields; and a means for transferring rotation of the eccentric planetary rotor axis to directly power an output shaft, wherein when the series of electromagnets are activated, the planetary rotor is magnetically impelled to pivot and roll from one temporary, moving contact line to an adjacent one, creating a rotary moment upon each of the temporary, moving contact lines, providing a power output.

Abstract: There is provided a spindle motor including: a rotating member including a shaft having a fixation groove provided in a lower portion thereof, a hub base extended from an upper end of the shaft in an outer radial direction, and a magnet support part extended downwardly from an outer edge of the hub base in an axial direction; a sleeve rotatably supporting the rotating member and including a reception groove depressed downwardly from an upper surface thereof in the axial direction; and a stopper member including a fixation part inserted into the fixation groove and a flange part extended from the fixation part in the outer radial direction, wherein the hub base includes a protrusion part protruding from one surface of the hub base and received in the reception groove.

Abstract: Systems and methods for rotational alignment of a device under test are disclosed herein. These systems include a chuck that includes a rotational positioning assembly that includes a lower section and an upper section that is configured to selectively rotate relative to the lower section about a rotational axis. The rotational positioning assembly further includes a first bearing that is configured to support a radial load between the upper section and the lower section and a second bearing that is configured to support a thrust load between the upper section and the lower section. The methods include providing a fluid stream to the second bearing to permit rotation of the upper section relative to the lower section, rotating the upper section relative to the lower section, and ceasing the providing the fluid stream to the second bearing to restrict rotation of the upper section relative to the lower section.

Abstract: An electric motor includes a rotor having a rotary shaft, a pair of ball bearings for supporting the rotary shaft, and two brackets having bearing housings for holding the ball bearings. The motor further includes a washer between one of the ball bearings and an end wall of one of the bearing housings. The washer includes a plurality of claws. The washer is configured including a ring-shaped yoke and the claws the center parts of which are fastened to the yoke. These claws are configured to be bent in a U-shape, and the center part of the U-shape is fastened to the yoke.

Abstract: There is provided a spindle motor, including: a shaft having a fixing groove formed in a lower portion thereof; a lower thrust member including a fixing part inserted into the fixing groove, a disk part extending from the fixing part in an outer radial direction, and an extension part extending from the disk part in an axial direction; a base member coupled to the extension part; a rotating member forming a bearing clearance with the shaft and rotatably provided with respect to the shaft; a first sealing part provided between an upper surface of the extension part and the rotating member; and a second sealing part provided between an inner circumferential surface of the base member and an outer circumferential surface of the rotating member.

Abstract: There are provided a fluid dynamic pressure bearing assembly, a spindle motor including the same, an electronic blower including the same, and a vacuum cleaner including the same. The fluid dynamic pressure assembly includes: a shaft fixedly installed on a base member; and a sleeve having an axial hole fixed to an outer circumferential surface of the shaft and rotatably supported by fluid dynamic pressure, wherein when the sleeve is inclined, based on an axial direction while being rotated, the sleeve comes into line-contact or surface-contact with the shaft in the axial direction.

Abstract: A BLDC motor for driving a cross flow fan in an air-conditioning application has an external rotor and an internal stator. The stator is a salient pole stator with insulated pole teeth and conductor coils. The inner diameter of the stator supports a single bearing. An electronic PCBA for control of the BLDC motor is optionally attached to the stator, all of which is encapsulated in a thermoset resin. The rotor comprises permanent magnet component(s) and a rotor frame. The rotor frame includes a stub axle that engages with the bearing element and features to provide torsional or rotational compliance between the rotor magnets and the fan. A level of compliance is provided between the bearing element and the stator to allow for angular misalignment between the rotational axis of the fan and the stator.

Abstract: There is provided a spindle motor including a sleeve rotatably supporting a shaft, a rotor coupled to an upper end of the shaft and rotating together with the shaft, a stopper part coupled to a main wall part protruding from one surface of the rotor and facing an outer peripheral surface of the sleeve, a cover plate coupled to the sleeve while maintaining a clearance between the cover plate and lower portions of the shaft and the sleeve, a base member coupled to the cover plate, and a stator holder fixedly disposed on the base member.

Abstract: There is provided a hydrodynamic bearing assembly including a sleeve; and a shaft rotatably inserted into a shaft hole and constituting a bearing clearance, wherein at least one of an inner circumferential surface of the sleeve and an outer circumferential surface of the shaft includes upper and lower radial dynamic pressure grooves having a herringbone pattern, and conditional expressions a+b>c+d and b?a>c?d>0 are satisfied.

Abstract: There are provided a rotating member assembly and a spindle motor including the same. The rotating member assembly includes: a shaft including an outer surface step part provided in an outer surface thereof; and a rotor hub including an insertion hole into which the shaft is inserted, the insertion hole including an inner surface step part provided in an inner surface thereof and corresponding to the outer surface step part, such that the inner surface step part and the outer surface step part are fittingly-coupled to each other.

Abstract: A rotary unit of a motor includes a tubular hub portion. A bearing mechanism of the motor includes a bearing portion positioned radially inward of the hub portion. A stationary unit of the motor includes a stator fixing portion positioned inward of the hub portion and higher than a lower end of the hub portion. A cylinder gap is defined between the hub portion and an upper section of the bearing portion. A first communication gap is defined between a lower section of the hub portion and an upper section of the stator fixing portion. A second communication gap is defined between the lower end of the hub portion and a radial inner section of the stator core.

Abstract: There is provided a spindle motor including: a shaft including a body portion and an extending portion extending from an upper portion of the body portion in an outer radial direction; a sleeve rotatably supporting the shaft; a rotor rotating in conjunction with the shaft and having a stopper portion facing an outer circumferential surface of the sleeve; and a cover plate coupled to the sleeve, while maintaining a gap with lower portions of the shaft and the sleeve, wherein the cover plate includes an airtight portion disposed below the shaft and the sleeve, an inner wall portion extending from the airtight portion in an axial direction and coupled to an outer circumferential surface of the sleeve, an outer wall portion coupled to a base member, and an upper wall portion connecting an upper end of the inner wall portion and an upper end of the outer wall portion.

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.