Abstract: In an electric motor which includes an electronic control device and an armature within a closed motor casing, the electronic control device is arranged within the casing, in a position offset axially from but close to the armature. The motor includes a thermal screen which is interposed axially between the armature and the control device, and the screen includes means for dissipating heat outside the casing.

Abstract: A motor rotor 10 is formed as follows: First, in a first forging step, a hum manufacturing primary block 6A is formed. Next, a second forging step B is effected to form the primary blank 6A into a secondary blank 6B. In this step, a forging die is used to secure an annular yoke 34 to the inner cylindrical surface 61a of a hub cylindrical portion 61 by punching, in such a manner that both whole edges of the annular yoke are sealingly closed thereby. In the second forging step B, by drawing the inner cylindrical surface 34a of the annular yoke, its circularity is improved. The annular yoke can be secured to the hub cylindrical portion with use of an adhesive agent. Moreover, the annular yoke can be fixed in such a manner that it is accurately coaxial with the hub cylindrical portion. In addition, the gap between the annular yoke and the hub cylindrical portion can be eliminated.

Abstract: Bearing 1 comprises a porous bearing body 1a having a bearing surface 1b disposed to oppose an outer circumferential surface of the rotating shaft 3 via a bearing clearance 4, a lubricating oil or lubricating grease impregnated in the bearing body 1a, and hydrodynamic pressure generating grooves 1c formed on the bearing surface 1b of the bearing body 1a. The rotating shaft 3 is supported, without making contact with the bearing 1, by a hydrodynamic pressure oil film formed in the bearing clearance and the oil is circulated, via openings made in the surface of the bearing body 1a, between the inside of the bearing body 1a and the bearing clearance 4.

Abstract: An anti-electrostatic property between an impeller and a lead wire is improved particularly in a case of a miniature axial flow fan motor. In an axial flow fan motor, an impeller (6) integral with a motor yoke (12) is provided on a shaft (5) rotatably supported by bearings (2,3). An end face of the motor yoke (12) confronted with a PC board (8) mounting a drive circuit and its component parts thereon is covered by resin (P). Resin covering this portion suppresses the generation of the electrostatic current at this portion.

Abstract: A dynamoelectric machine includes a stator having a stator core. A winding is provided on the stator core and the stator core has a stator bore. A rotor including a rotor core is received in the stator bore. A permanent magnet is mounted on the rotor core periphery and a rotor shaft is mounted on the rotor core. Bearing means are provided for supporting the rotor shaft for rotation relative to the stator. A first circuit board having electrical components thereon is used in operating the dynamoelectric machine, and a second circuit board having an electrical component in the form of a sensing device thereon is used in determining the position of the rotor. The first circuit board is constructed for mounting the second circuit board thereon so that the second circuit board projects axially inwardly from the first circuit board and the sensing device is disposed in an axial position overlapping the axial position of the permanent magnet.

Abstract: A miniature heat-dissipating fan includes a stator seat having a winding wound therearound and an axle tube for rotatably receiving a rotor shaft. A circuit board is mounted around the axle tube and includes a straight edge. The circuit board further includes a number of leads each having an end led to the straight edge. A Hall element has a number of pins respectively connected to the leads of the circuit board, the pins being bendable along the straight edge of the circuit board.

Abstract: A spacing member for use with an alternator of the type having an electrical generating assembly housed in a frame with an external mounting surface to which a voltage regulator is adapted to be mounted. A brush assembly is connected to the voltage regulator and has a pair of brushes adapted to engage a pair of slip rings of the electric generating assembly when the brush assembly is positioned in a slip ring engaging position, the spacing member supports the voltage regulator in a spaced apart relationship relative to the mounting surface of the frame so as to provide an air flow passage between the voltage regulator and the mounting surface for enhancing heat transfer away from the voltage regulator and the spacing member supports the voltage regulator in a spaced apart relationship relative to the brush assembly so as to support the brush assembly in the slip ring engaging position.

Abstract: A double-sided, non-iron core, brushless, axial magnetic field permanent-magnet type DC motor includes a shaft, two electromagnet units parallelly mounted on the shaft, and a permanent magnet unit mounted on the shaft between the electromagnet units and having its direction of magnetization disposed in parallel to the shaft. The permanent magnet unit is allowed to rotate relatively around the electromagnet units by being forced by magnetic repulsion force from both sides. Electromagnetic areas at the electromagnet units are arranged in a staggered manner, enabling permanent steel magnets at the permanent magnet unit to be alternatively fully induced from its two opposite sides to provide a high torsion output. The electromagnetic areas of the two electromagnet units are caused to change the phase alternatively at a 90.degree. phase difference, so that vibration and dead section problems are eliminated during the operation of the DC motor.

Abstract: A rotating leno forming device includes a leno disk (3) that has leno thread guides (5) therein and that itself forms a part of the rotor (2) of an electromagnetic drive arrangement. In order to achieve a very compact bearing support arrangement, shield the moving parts against external contamination, and provide for the detection of the rotational position of the leno disk, the leno device further includes a roller or ball bearing (6) of which the outer bearing race (6A) is rigidly connected to the leno disk (3), and of which the inner bearing race (6B) is rigidly connected to a centering holder (9) that is rigidly connected to a housing (8) of the leno device. Permanent magnets (7) are arranged around the circumference of the rotor (2) and cooperate with an electromagnetic stator (11) secured in the housing (8). A position sensor system (10) includes at least one signal emitter (13) mounted on the rotor (2) and a plurality of signal receivers or sensors (14) mounted on the housing (8).

Abstract: A spindle motor includes a shaft 6 which is rotatably supported; a rotor casing 7 which is turned together with the shaft 6; and a turn table 9 which is fixedly mounted on one end portion of the shaft 6 and is rotated with a disk 10 mounted thereon. An eccentric member 12 is loosely fitted on the part of the shaft 12 which is located between the rotor casing 7 and the turn table 9. The eccentric member 12 is turned with the rotation of the rotor casing 7. In place of the eccentric member, a ball may be arranged which is rolled around the shaft.

Abstract: A brushless motor includes a rotor unit comprised of a spindle and a multi-polarized magnet arranged around the spindle. A bearing housed inside a bearing housing having a circular flange formed therearound, and rotatably supports the spindle so that the rotor unit can rotate. A substrate provided with a stator unit on its top surface but nothing with its bottom surface. The bearing housing is fixed to the substrate such that a top surface of the flange and the bottom surface of the substrate is in a tight contact as a reference surface for location.

Abstract: A spindle motor has a fixed member of a motor, a rotor rotatably supported with respect to the fixed member, a shaft provided on either the fixed member or the rotor, a first ball bearing fitted on a head side of the shaft and a second ball bearing fitted on a base side of the shaft and having an axial dimension larger than an axial dimension of the first ball bearing. A circumferential wall, preferably on the fixed member, has a small gap with an outer circumferential wall of an outer ring of the second ball bearing.

Abstract: A brushless motor has a housing including an upper housing and a lower housing;a P.C.B. installed in the upper housing, a stator provided at an underside of the P.C.B., the stator having a plurality of coil layers piled up with each other and insulation layers interposed between coil layers, the coil layers being electrically connected to each other by a conductance member for generating an electric field, a rotor having permanent magnets which are radially disposed on an upper surface of the rotor in such a manner that adjacent permanent magnets have different poles from each other to generate a magnetic field which makes electromagnetic-interaction with the electric field of the stator to rotate the rotor, and a rotating shaft integrally formed at a center of the rotor so as to rotate when the rotator rotates. The brushless motor is advantageous in that since the coil is uniformly patterned, the magnetic field is uniformly generated.

Abstract: A drive unit for transport devices comprises a spindle (1) with a stator (2) and, mounted on said spindle so as to be capable of rotation, a rotor (3), all these elements forming an electric motor (4) and a rim (5). The device is provided with permanent magnets (6, 7, 8, 9), cores (10) with coils (11), and sensors (12) for determining the angular position of the rotor (3). The rotor (3) is designed as concentric shells (13,14) and joined to the rim (5). The permanent magnets (6, 7, 8, 9) are mounted on the sleeves (13, 14), each magnet facing another magnet of opposite polarity; on each sleeve (13, 14) permanent magnets (6, 7, 8, 9) are mounted so that their polarity alternates. The stator (2) is located between the permanent magnets (6, 7, 8, 9) and carries the coils (11) with cores (10), the coils being connected around the periphery to the stator (2) and arranged with gaps between themselves and the permanent magnets (6, 7, 8, 9).

Abstract: A bicycle electricity generator is provided including an annular stator and an annular rotor, both of which are coaxially mounted on a bicycle wheel axle in a position between a bicycle wheel hub and a fork, wherein the stator is fixed either on the wheel axle or on the fork; the rotor is fixed in connection with the bicycle wheel hub, the rotor's rotating center being coincident with the rotating center of the bicycle wheel; a rotating force transmitting member made of a resilient material for transmitting a rotating force from the hub to the rotor is provided in a position between the rotor and the hub so as to form frictional engagement with both the rotor and the hub, wherein either an auxiliary transmitting structure is provided for auxiliarily transmitting a rotating force from the bicycle wheel hub to the rotor and wherein one portion of the auxiliary transmitting structure is fixedly secured with respect to the rotor and another portion of the auxiliary transmitting member is fixedly secured with resp

Abstract: In a bearing arrangement including a thrust bearing and a radial bearing, the thrust bearing includes a first thrust plate which is fixedly secured to a stator plate, and the radial bearing is integrally attached to the first thrust plate of the thrust bearing. Because the radial bearing is directly attached to the first thrust plate of the thrust bearing, the perpendicularity of the radial bearing with respect to the thrust support surface can be easily ensured. Also, the first thrust plate normally consists of a highly rigid member, and this also contributes in the favorable perpendicularity of the radial bearing with respect to the thrust support surface. This bearing arrangement is useful in a spindle motor for turning a floppy disk in a floppy disk drive.

Abstract: A dynamoelectric machine has a stator end cap mounted on a stator core, which attaches a control circuit board directly onto the stator. The end cap has integrally formed fingers which permit snap on connection of the circuit board. Guide pins make certain the circuit board is oriented properly upon connection to the end cap. The end cap also has wire fixtures which hold winding leads of a winding and permit insulation displacement terminals on the circuit board to plug into the winding leads and achieve electrical contact at the same time the circuit board is mounted on the end cap. Hall devices mounted onto the circuit board are guided into pockets formed on teeth of the stator end cap for precise location. The end cap is constructed to shield the winding from contact with the motor shell. In addition, backward curved fans are employed to reduce mechanical noise in the direction of high speed rotation.

Abstract: A retaining ring for use with a shaft is provided. The retaining ring is in shape of a thin plate and includes a plurality of pedal-like portions with any two adjacent pedal-like portion being connected to each other by a deformable connection portion. The plurality of pedal-like portions defines a channel at the center of the retaining ring for passage of the shaft. As the shaft enters the channel, the connection portion deforms in response.

Abstract: A brushless DC motor is disclosed. In the motor, an axial vibration limit unit is provided on a bearing and electromagnetically attracts a rotor, thus preventing the rotor from being centrifugally lifted during a high speed rotation of the rotor. In the operation of the motor, an axial displacement of the rotor is sensed by an induction coil of a sensor. The induction coil generates a variable induction current indicative of an axial displacement of the rotor, and outputs the current to a controller through an amplifier, thus controlling the vibration limit unit. The electromagnetic bearing of this invention thus supports the shaft and rotor in an axial direction and almost completely prevents any axial vibrations of the rotor, thereby reducing operational vibrations and noises and improving the axial dynamic characteristics of the brushless DC motor.

Abstract: A robot having a pair of magnetic couplings that each couple a motor in a cylindrical first chamber to an associated cylindrical ring closely spaced from the cylindrical wall of said first chamber. The robot includes a mechanism to convert rotation of each of these rings into separate motions of the robot. In the preferred embodiment, these separate motions are radial and rotational.

Abstract: The invention provides a motor and a bearing support and motor housing assembly, wherein the bearing support is detachably mounted to the housing with a flexible fastener, such as a snap ring. A resilient member, such as a spring washer, is seated between the fastener and either the housing or the bearing support to apply a biasing force against the fastener.

Abstract: An improved, simplified spindle motor design for use in a disc drive is provided, which utilizes a two-piece shaft and provides a central connector in the bottom section of the shaft which can be easily connected through the base to a power source for the motor. The improved spindle motor has a stator and motor connector which can be easily assembled into the spindle motor before the bearings and other elements are installed so that the cleaning and soldering of the stator and motor connector can be efficiently achieved. Further, the spindle and motor connector design incorporates an effective electrical grounding path between the stator and the central shaft of the spindle motor.

Abstract: The stator disc (18) of the motor (2) of a disc motor type elevator machinery is s provided with an annular cavity (19a) in which the stator (9) is placed. The stator (9) is attached to one of the walls of the cavity. The rotor (13) is placed in a rotor disc (12). Between at least one (28a) of the walls of the cavity (19a) and the rotor disc (12) there is a sealing (26a) which seals the cavity so as to render it a closed space. The sealing blocks the entry of external particles into the rotor and stator.

Abstract: A spindle-drive motor, especially for driving a hard drive, with a stator, a rotor, an axle between them having at least one bearing, and a drive, where the rotor or stator is provided with a bushing which accommodates at least one bearing. The bushing and bearing together form a sealing gap which seals the rotor and the stator with respect to each other.

Abstract: A system and method for facilitating the reduction or elimination of end play associated with an armature in an electric motor is disclosed. The system and method utilize an end play assembly which includes a housing having an integrally molded lock for retaining a screw in an unengaged and locked position. The end play assembly also includes a coil spring which urges the screw towards an engaged and unlocked position when the end play assembly is mounted in a housing of the electric motor. The lock includes at least one wing portion which engages a notch on the housing of the electric motor such that when the end play assembly is mounted in the motor housing, the notch forces the lock into the unlocked position which releases the screw so that the spring can urge, rotate or screw the screw to cause a screw end to be forced into engagement with the end of an armature of the electric motor.

Abstract: The present invention is directed to a method of insulating the stator of an electronically commutated direct current motor, in order to also fulfill high insulation and protection requirements. This method comprises the following steps:the stator (1) is introduced into a closable form with laterally retractable jaws (21);the form is closed, wherein it encloses the outer contours of the stator (1) including the printed circuit board (11), with a spacing, at least in regions;a thermoplastic hot-melt adhesive based on polyamide is injected under pressure into the form;the form is opened and the extrusion-coated stator (1) is removed.

Abstract: A stator assembly for an axial-flow fan motor for cooling electronic components consisting of a base, a stator, and insulating pins for connecting the base to the stator. The stator consists of a core covered by an insulating coating and a winding formed thereon from magnet wire. The stator also includes mounting holes formed in the core. The winding is electrically connected to the base through free ends of the magnet wire forming the winding. Each insulating pin has a first conductive end which is mounted to the base and a second non-conductive end which is received in one of the mounting holes on the stator. In the preferred embodiment, the base consists of a printed circuit board which includes circuitry for operating the motor within which the stator assembly is mounted. The method of securing the stator to the base is also disclosed.

Abstract: An electric spindle motor has a base assembly (19) and a hollow notatable hub (16) housing a motor. The hub (16) is mounted for rotation about an axis and a stator (12) is mounted on the base assembly (19) inside the hub (16). A liquid filled journal bearing (11,21) acts between the base assembly (19) and the hub (16) to provide radial support of the hub (16). A gas filled thrust bearing (26, 27, 35) also acts between the hub (16) and base assembly (19) to provide at least axial support of the hub (16).

Abstract: An improved spindle motor design of a type especially for use in a disc drive is disclosed, which provides a simplified design for installation of the stator over the shaft, and should especially locate the stack both radially and axially in a specific location relative to the shaft so that its location relative to the surrounding, rotating parts of the motor is fixed. In addition, the improved spindle motor design fixes the stack on the shaft through radial interference, eliminating the need for adhesive to fix the stator to the shaft. Also, the design minimizes the cost of assembling the stack on the shaft, isolates the stack and shaft from conveying vibration one to the other, and electrically grounds the stack to the shaft.

Abstract: An inside out electric motor includes a rotor having an interior surface defining an interior space and a magnetic element mounted on the rotor. The motor also includes a stator having a bobbin. The bobbin has a bearing positioned at a central axis of the bobbin. The bearing rotatably engages the rotor to permit the rotor to freely rotate with respect to the stator. The bobbin also has a pole member molded into the bobbin so that an end of the pole member is spaced radially inward from and at least partially aligned with the magnetic element, and a winding wound around the bobbin so that the winding passes adjacent the pole member.

Abstract: An elevator motor (2) employing permanent magnets (30) attached in a circle on the surface (36) of the rotor disc (12). The rotor disc (12) forms part of both the magnetic circuit and the supporting structure of the rotor (13). The permanent magnets (30) are placed in a separate cavity formed in the stator disc and having one side open, said cavity also housing the stator windings (17). The outer cavity wall directed towards the rotor disc (12) is provided with a sealing member to close the cavity.

Abstract: A thrust bearing for an open-end spinning rotor (1) supported by its rotor shaft (2) in the bearing slot of a support-disk bearing arrangement (4). The thrust bearing has a magnetic bearing system (10) or (25) comprising magnetic support elements (12), (13) stationarily arranged on a thrust bearing housing (11) and a rotating magnetic bearing device (14) fastened to rotor shaft (2). Bearing element (15) of magnetic bearing device (14) is releasably connected to rotor shaft (2) via an elastic connection (20), (21) positively supported in corresponding receiving grooves (22), (23) of either the rotor shaft or the magnetic bearing device (14).

Abstract: An electrical machine, such as an electric motor, generator or torquer-generator, includes a relatively rotatable cylindrical armature and magnetic pole structure separated by an annular gap into which a surrounding fluid may flow during operation of the machine. In order to prevent the build-up of deposited solid material in the gap between the components, one of the components is provided at its surface with a narrow elongate projection which extends helically along and around the surface. The height of the projection is slightly less than the gap between the components so that it remains out of contact with the surface of the other component so as not to frictionally engage it and interfere with relative rotation between the components.

Abstract: A stator of a direct drive motor is disclosed. The stator comprises a supporting member which supports a central portion of the stator, a first core including a mounting section and a magnetic pole section, a fixing member fixing the first core onto the supporting member through the mounting section of the first core, and a second core mounted on an upper surface of the first core, the second core including a magnetic pole section and a hole section disposed on the mounting section of the first core, wherein an upper end of the fixing member is lower than an upper face of the second core.

Abstract: A torque motor includes an annular, cylindrically symmetric support base, and a plurality of electromagnet coils affixed to the support base at regular intervals around a cylindrical circumference of the support base. There is additionally an annular, generally cylindrical, rotationally movable rotor ring overlying the support base and having an inner surface, and a plurality of permanent magnets affixed to the inner surface of the rotor ring at regular intervals around a cylindrical circumference of the rotor ring. The number of permanent magnets is even and equal to the number of electromagnet coils, and the permanent magnets are arranged in alternating polarities around the circumference of the rotor ring. In a preferred form, there are six of each type of magnet, spaced equidistantly around the circumference of the respective rings.

Abstract: In an electric motor with a stationary and a movable active motor part, one of the two active motor parts comprising a motor winding and the other a motor magnet, an air gap being formed between said active motor parts. The motor winding (9) is built up on a synthetic resin carrier foil and is formed through local removal of copper material with which the synthetic resin foil (23) had previously been fully coated. The synthetic resin carrier foil (23) and the planar coils (28) adhering thereto are provided with an adhesive filler material (30) such that the adhesive filler material (30) fills up the gaps (26) formed between the individual conductor tracks through the removal of the copper material. The assembly thus stabilized is wound into an evenly rounded cylinder.

Abstract: A compact disk storage device having outer-rotor electric motor for directly driving a disk for recording and reproducing information has an axially deep, tank-form flange and a stationary shaft, upon which the mounting annulus of the flange and the ball bearings of the hub are axially displaced. The hub includes a cover disk for sealing an extremity of the ball bearings and an inverted cup shape rotor providing magnetic shielding. The flange includes a mounting rim substantially aligned with the back surface of the cup-shape rotor. The facing cup-like and tank-form shapes readily enable labyrinth seals and substantial and abutting axial extents along the axis of the stationary shaft.

Abstract: A brushless motor assembly for a magnetic disc drive device includes a bracket for the support of a fixed shaft carrying a stator core at a lower end thereof. A generally cylindrical hollow hub encircles the fixed shaft and carries a rotor magnet at a location confronting the stator core. The bracket is of a size sufficient to protrude into the hollow of the hub and defines a labyrinth seal between an outer peripheral face thereof and an inner peripheral face of a corresponding portion of the hollow of the hub.

Abstract: Lead wires of large electric motors are routed through annular shrouds located inside of the motor housing to surround respective stator coilheads. Each of the shrouds includes at least one attachment portion defining an opening for passage of the leads. In one embodiment, a support element defining a lead channel aligns with the lead opening. The support element includes a mounting structure for attachment of a conduit box thereon. A seal arrangement having a planar seal element may be provided in the lead channel to support and separate the individual leads, while providing a seal to inhibit passage of cooling air from the housing interior into the conduit box. In another embodiment, a cover arrangement is attached directly to the attachment portion of the shroud. The cover arrangement may include a flexible gasket juxtaposed to a rigid cover plate.

Abstract: A shaft-fixed-type motor comprises a motor frame having a frame through hole formed therein, a fixed shaft having a shaft through hole at a center and fixed to the motor frame and a rotary member having a shaft hole into which the fixed shaft is inserted, and rotatably supported with respect to the fixed shaft. The motor also includes a hydrodynamic bearing mechanism arranged between an outer surface of the fixed shaft and an inner surface of the shaft hole, a rotor assembly integrally configured with the rotary member, a stator assembly installed to the motor frame and positioned opposite the rotor assembly and a joining member having a head portion and a shaft portion. The joining member is for fixing the fixed shaft to the motor frame by inserting the shaft portion into the shaft through hole of the fixed shaft and the frame through hole of the motor frame and plastically deforming an opposite end from the head portion.

Abstract: A starter has a housing formed with a fitting part and a flange on the outer periphery thereof. The fitting part is in circular shape when viewed in the axial direction and is press-fitted, in the socket-and-spigot joint manner, into a fitting hole of an engine-side body with the flange being in abutment with a fitting plane of the engine-side body. The outer diameter Ho of the fitting part is set larger than the axial length of the center of gravity of an armature of a starter motor from a fitting plane of the flange.

Abstract: The invention relates to a spindle driving motor, in particular an external rotor motor, the main components of which are accommodated in the interior of a driving hub (4) or the back iron (5). According to the invention, in order to minimize the number of joints, both ball bearings (11, 12) are arranged directly, yet correctly as far as assembly is concerned, between the fixed shaft (10) and the back iron (5), a collar (15) having a larger diameter serving in particular to this end.

Abstract: A spindle motor has a simple structure that is usable with a base having sufficient rigidity and enables heads to sandwich each recording disk outside the base. The spindle motor for rotating the disks and an actuator for driving the heads are assembled on the base into a disk drive. A rotor assembly of the spindle motor consists of a stationary shaft separable from the base, bearings attached around the stationary shaft, a hub installed around the bearings, a yoke attached to the hub, magnets attached to the yoke, and magnetic seals arranged at the top and bottom of the bearings, to seal the inside of the hub from the atmosphere in the disk drive. The stationary shaft has a skirt serving as a positioner for positioning the rotor assembly with respect to the base. The base has a hole for receiving the stationary shaft and stator coils concentrically arranged around the hole. The stationary shaft of the rotor assembly is engaged with the hole of the base, to complete the spindle motor.

Abstract: A holder member fixing apparatus of a motor facilitates the fixing of a holder member without requiring a separate jig by fixing the holder member to the upper portion of a substrate via a printed circuit board and forming a position setting hole for previously setting the fixing position of the holder member into the printed circuit board. The apparatus includes a holder member which is inserted with a rotating shaft in the center thereof and is formed with a backing stand for placing a rotor thereon to the lower portion of the outer periphery thereof, and a substrate having a plurality of couplers to the upper portion thereof to be fixedly coupled by being inserted with a plurality of brackets radially-formed along the outer periphery of the backing stand. Also, a printed circuit board fixedly installed to the upper portion of the substrate while overlapping thereon is formed with a position setting hole for leading the holder member to place to a correct position, thereby requiring no separate jig.

Abstract: A magnetic recording data storage device includes a magnetic recording disk, a spindle motor, a head supported on an air bearing carrier and an actuator connected to the head carrier for moving the head across the rotating disk. The spindle motor has lubricant covered ball bearings where the lubricant includes an alkali hydroxystearate, an ester oil, a dialkyldiphenylamine and a dialkyldithiocarbamate.

Abstract: A motor-and-pump assembly includes armature shaft of the electric motor which is retained in the pump housing by way of a main bearing and an auxiliary bearing.The objective is to align the motor housing centrically to the axis of the armature and, in addition, to achieve a reliable attachment of the motor housing to the pump housing.Therefore, the housing of the electric motor has a bowl-shaped design, and the rim of the motor housing is inserted into a concentrically circumferential groove in a flange surface on the pump housing. The diameter of the inner wall of the groove corresponds to the inside diameter of the motor housing. Thus, the inside wall of the motor housing abuts on the inner rim of the groove. The motor housing is thereby aligned centrically.The motor housing can simply be fastened to the pump housing by a clamping ring which is also inserted into the groove.

Abstract: A spindle motor comprises a motor shaft, which is rotatably supported by a motor frame via a bearing and a hub, which is formed integral with the motor shaft for securing a data disk. The hub is made of a powder metallurgical product and is bonded with the motor shaft by sintering.

Abstract: Electromagnetic shielding apparatus is provided for a motor having a rotor and a stator wherein the shielding apparatus is characterized by the absence of an electromagnetic shield in the stator of the motor.

Abstract: A brushless DC motor for a disc drive having a base and a coil-wound stator secured to an upper portion of the base. One or more first stoppers are secured to the stator and a shaft is rotatably secured in a bearing forcibly inserted in a bore in the upper portion of the base. A hub of a rotor is secured to the shaft and a cylindrical wall extends downwardly at the rim of the hub and carries a magnet facing the stator with an air gap therebetween. A second stopper is secured to the rotor, to face the first stopper to retain the rotor in the axial direction. The second stopper has a flange over which the first stopper is placed with slight clearance. An elastomer rests on the first stopper and carries guides which extend in slots in the rotor to engage and center a hole in a disc.

Abstract: A correcting signal generator 42 stores the quantitative relation of the magnetic interference between the rotation angle .theta.3 of a resolver 23 and the detected values A3, B3 of a resolver 22, and outputs the correcting values A8, B8 for the magnetic interference according to the rotation angle .theta.3. An adder 41 calculates and outputs the corrected detection values A4, B4 by adding the correcting values A8, B8 to the detected values A3, B3 of the resolver 22 output from a latch circuit 14. A resolver rotation angle calculation circuit 47 calculates and outputs an angle .theta.2 by taking an arc tangent of the quotient A4/B4 of the corrected detection values A4, B4. In the same way, a correcting signal generator 44 calculates and outputs the angle .theta.3.