Abstract: A spindle motor comprises a stationary member having a cylindrical mounting hole therein, a tubular member fitted into the mounting hole of the stationary member, a bearing means mounted to the inner side of the tubular member, a rotor supported by the bearing means for rotation in relation to the tubular member, a stator fitted onto the outer side of the tubular member, and a rotor magnet mounted to the rotor to be located radially and outwardly of the stator. The procedure of assembling the spindle motor includes mounting the rotor magnet to the rotor, joining the rotor by the bearing means to the tubular member for rotation, fitting the stator onto the tubular member, and fitting the tubular member into the mounting hole of the stationary member.

Abstract: An inducer pump located internally in an electrical submersible pump motor enhances lubricant circulation within the motor. The inducer is located at the lower end of the shaft within a shaft bore. The inducer has a rod and a helical flight rigidly mounted to the rod. The inducer rotates in unison with the motor, pumping lubricant from a lower lubricant chamber upward through the shaft bore.

Abstract: A motor and a rotatable single phase electromagnetic actuator that has a self aligning shaft that allows for misalignment of actuator parts that would lead to excessive bearing surface wearing. Additionally, the actuator has a rotor, having a first rotor surface; a stator, having a slanted bearing surface opposed the first rotor surface; and a bearing device, mounted on and between the first rotor surface and the slanted bearing surface, positioned and shaped to separate the rotor from the stator and to self align on the slanted bearing surface in a position that substantially evenly distributes bearing loading on the bearing device.

Abstract: The motor comprises a rotor (30) fixed for rotation with a shaft (36) of a member to be driven and a crown-like stator (10) obtained by blanking a lamination stack (12) provided with coil supporting teeth (11). Within the stator crown (10) there are obtained by blanking the lamination stack (12) a plurality of receptacles (13, 15, 17) for seating electric and electronic components associated with the stator. The components comprise a transformer (24), an inductance coil (25), and a plurality of MOSs (23). The stator crown (10) is co-molded with a covering of electrically insulating plastic material to cover the receptacles (13, 15, 17) and the teeth (11) and form a tank (22) for receiving a printed circuit (21). The permanent magnet rotor is fitted with stacks of small pieces (19) obtained by blanking lamination portions within the stator crown (10). The stacks of small pieces face the magnets (31) so as to close the respective magnetic circuits.

Abstract: An instrument display method and system for use in a passenger vehicle has a number of advantageous features including particularly novel, compact, inexpensive and inherently stable electric motors. A first motor includes a rotor assembly having a shaft and a cylindrical magnet which is positioned about a stator assembly to rotate thereabout. The shaft extends through a stator of the stator assembly, a vacuum fluorescent display (VFD), and an indicia bearing layer. A mask such as a needle pointer is secured to the shaft of the rotor assembly at the indicia bearing layer to convey the value of instrument data to the passenger. A light emitting panel receives light from the VFD and transmits the light to other positions along the display system where other substantially identical electric motors move their needle pointers to likewise convey additional data to the passenger. The first motor is surface mounted directly on the back of the VFD which has electrical conductors formed therein.

Abstract: A spindle motor comprises a stationary shaft, a rotor hub rotatably mounted by ball bearings to the stationary shaft, and annular sealing members disposed between the outer surface of the stationary shaft and the inner side of the rotor hub axially outwardly of the ball bearings. The sealing member is directly fitted onto the outer race of the corresponding ball bearing. The outer race of each ball bearing is high precision finished so that the sealing member is definitely coaxial with the stationary shaft regardless of the finishing accuracy on the inner side of the rotor hub. Accordingly, the radial distance between the inner side of the sealing member and the outer surface of the stationary shaft can be minimized with high precision offering an excellent labyrinth effect.

Abstract: A spindle motor comprises a rotational member supported by bearings for rotation about a rotational axis, a rotational body and a motor rotor mounted on the rotational member for rotation therewith, and a motor stator mounted around the motor rotor. The rotational body has an outer diameter determined so that a windage loss of the rotational body is proportional to the third power of a peripheral velocity of the rotational body and an air gap diameter of the bearings and the diameter of the motor stator are determined so that the air loss of each of the bearings and the motor rotor is proportional to the square of the peripheral velocity of each of the bearings and the motor rotor at a range of constant speed of rotation of the rotational member.

Abstract: A brushless motor having a plurality of weight reducing holes is disclosed. The weight reducing holes are formed in the thick parts of the stator housing of the motor to prevent shrinkage of the thick parts of the housing when forming the housing through injection molding. The weight reducing holes are formed in the housing by appropriately positioning cores in the mold before injecting melted resin into the mold. The weight reducing holes are formed in a bearing seat mouth of the housing as well as in an outer portion of the mouth.

Abstract: A brushless electric motor having an internal stator assembly including a lamination core and a heat sink. The motor includes an external rotor assembly adapted for rotational movement relative to the stator assembly about a central shaft. The motor also includes a tubular bearing support received within an inner space of the stator assembly adjacent to the lamination core and adjacent to the heat sink to facilitate a reduced axial length of the motor, the shaft being pressed into a bearing assembly retained within the bearing support to allow rotation of the shaft and therefore of the rotor assembly with respect to the stator assembly. The rotor assembly may have a cover with a central hub and a central shaft mounted within the hub. The motor may have a bearing assembly retained within the bearing support and receiving the shaft to allow rotational movement of the rotor assembly about the stator assembly.

Abstract: A motor and fan apparatus a centrifugal fan including a generally circular impeller having a plurality of generally radial vanes. The apparatus also includes a common shaft on which the impeller and the rotor are mounted in axially spaced relation. A circular pan shaped cover encloses the impeller and has a centrally disposed inlet and a wall disposed around the periphery of the impeller in spaced relationship from the periphery of the impeller. A fluid barrier is disposed axially adjacent to the impeller. The barrier and the cover collectively direct fluid flow from the periphery of the impeller in an axial direction parallel to the shaft. The apparatus includes a housing disposed axially adjacent to the barrier. The housing has a generally toroidal shaped part and a smaller generally circular shaped part, the generally toroidal shaped part and the generally circular shaped part are disposed in generally concentric relationship.

Abstract: A spindle motor comprises a permanent magnet having an outer diameter, an outer circumference, and a number of poles. A stator core is disposed around and spaced from the outer circumference of the permanent magnet rotor. The stator core has a yoke portion, a number of lengthwise extending and circumferentially spaced slots, and a tooth portion between each adjacent two of the slots. The slots are disposed in close proximity to the outer circumference of the permanent magnet rotor, and a width of each of the slots in a radial direction of the stator core is smaller than a width of the yoke portion and equal to or greater than 1/20 of the outer diameter of the permanent magnet rotor. A coil has two or less turns and is comprised of a conductor disposed in the slots of the stator core.

Abstract: A spindle motor assembly which utilizes a ionized air bearing to provide a conductive path through the assembly. The spindle motor assembly includes a spindle shaft that is located within a housing and rotated by an internal motor. The assembly also contains an air bearing which allows relative movement between the spindle shaft and the housing. The air bearing is supplied by a source of air that is ionized by an ionizer. The ionized air provides a conductive path between the spindle and the housing. The spindle may be coupled to a clamp that holds a magnetic disk within a disk certifier. The magnetic disk is electrically grounded to the housing through the chuck, the spindle and the ionized air bearing.

Abstract: Bearings in a motor or bearing cartridge are positioned relative to the shaft and an outer sleeve, and a bearing retainer is then pressed against the outer races of one of the bearings in order to hold the bearings in position and preload the bearings in a desired orientation. The bearing retainer is chilled to a temperature significantly different than the sleeve with which it cooperates; shrinking the retainer to a size where it may be slip fit within a sleeve or other means for supporting the bearings in place. The retainer is then pressed against the outer races of the bearings, and held in place while it returns to the temperature of the sleeve within which it is fit. In this way, the preload is defined and maintained for the long term, as the retainer is pressed tightly against the outer race of the bearings; and the retainer is held within the sleeve as it returns to the same temperature being chilled is eliminated.

Abstract: A brushless motor with stator cores integrated with a holder, comprises a rotor consisting of a pulley mounted on a motor axis and a rotor case provided with a main magnet and an FG magnet on inner and outer peripheral faces of a lateral curved surface of the rotor case, and a stator wound with a driving coil and integrated with a holder for holding function, in which the stator is fixedly mounted on a PCB provided with a hole element and is structured to support the rotation of the motor axis.

Abstract: A disk storage drive is provided with a brushless drive motor having a stator with a winding. An external rotor housing including a permanent magnet coaxially surrounds the stator and is spaced therefrom by a substantially cylindrical air gap. A hub is provided that is concentric to the rotor housing and is connected to the rotor housing for rotation therewith. A bearing above the stator rotatably supports an upper end of the rotor housing on a stationary shaft and a bearing below the stator braces the open end of the rotor housing by a ring element having substantially the same heat expansion characteristics as the rotor housing.

Abstract: An electric drive for small vehicles, especially wheelchairs, includes a d.c. motor, which is arranged as a wheelhub motor in the running wheel of the small vehicle. Efficiency and manufacturing costs are improved, while ensuring simple assembly, wherein the possibility of automatically locking the running wheels is provided, along with a short and lightweight design. The d.c. motor is an external rotor motor, whose external rotor forms the wheelhub or the wheel rim of the running wheel. The stator of the d.c. motor is stationarily connected to the small vehicle via a brake housing (3). A central spring pressure brake is provided which can be released electromagnetically and manually and brakes the external rotor of the d.c. motor in the case of a power failure.

Abstract: In a brushless motor, its magnet unit is formed by laying on each other a first magnet made of a flexible bond magnet material which is anisotropic and a second magnet made of a flexible bond magnet material which is isotropic, and the second magnet is smaller in wall thickness than the first magnet, and is confronted with the stator and the magneto-electric conversion element.

Abstract: A rotor is formed by a rotary frame 3 composed of a nonmagnetic material, a field magnet 5, a yoke 4 and an auxiliary yoke 7. A disk 12 is mounted on the rotary frame 3. An opening 4b is formed in the yoke 4 to thereby cause attractive magnetic flux from the field magnet 5 to effectively act on a clamping yoke 13 of the disk, so that the disk 12 can be firmly clamped. The yoke 4 covers the circumferential part of the field magnet 5 on its disk 12 side to thereby cut off magnetic flux leakage toward the disk 12, so that its adverse effect on the recording surface of the disk 12 can be avoided. The auxiliary yoke 7 so arranged that a stator coil 6 is interposed between the auxiliary yoke 7 and the field magnet 5 is secured to the rotary frame 3 to thereby increase effective rotating magnetic flux so that output torque is increased.

Abstract: A flat commutator for an electric motor of a vehicle fuel pump. The commutator is made with a one-piece carbon ring having a flat outer face, a one-piece conductor ring with a base portion embedded in the carbon ring and underlying outer face, and a housing of a plastic insulating material molded on the rear face of the carbon ring and adapted to mount the commutator on a motor armature. A plurality of circumferentially spaced apart grooves extend radially and axially completely through both the carbon ring and the conductor ring to provide a plurality of individual sintered carbon segments each with a separate conductor for electrically connecting the segments with armature coils.

Abstract: An electric wheel motor mounted integrally in a wheel has at least one electric leader line extending from the inside of a motor main body of the motor to the outside thereof. A breather passage is provided in the at least one electric leader line and communicates the inside of the motor main body with the outside thereof.

Abstract: An electrical generator (1) comprising first and second relatively rotatable winding assemblies (5,8), the first winding assembly (5) having a first electrical output for connection to a first electrical load (4) and the second winding assembly (8) having a second electrical output for connection to a second electrical load (6 or 19), and a permanent magnet assembly (12) freely rotatably mounted between the winding assemblies (5,8) such that, in use, rotation of the winding assemblies (5,8) relative to the permanent magnet (12) assembly induces a current in both winding assemblies. A third winding assembly (19) may rotate with the second winding assembly (8) relative to a fourth winding assembly (20) that rotates into the first winding assembly (5). The third winding assembly 19, may comprise said second electrical load, and the fourth winding assembly (20) may be connected to a fourth electrical load (22,23). The first and fourth electrical loads (4,22,23) may be de-icing elements on a propeller.

Abstract: For a precision spindle motor, an invention for reducing distortion resulting from interference fits of a thrust plate to spindle motor shaft and of a counter plate to a journal. A method of assembly according to the invention includes the step of balancing an interference pressure about a centerline of at least one of the thrust plate and the counter plate of the spindle motor. A precision spindle motor according to the invention comprises a journal having a bore defined therein, a shaft located in the bore, a thrust plate mounted to a top portion of the shaft by means of an interference fit, and a counter plate mounted to the journal adjacent to the thrust plate by means of an interference fit, wherein an interference pressure is balanced about a centerline of at least one of the thrust plate and the counter plate.

Abstract: To provide a bearing structure of a flat type brushless motor for floppy disk drive in which a stator is arranged in a plane shape and a disk acting as a rotor yoke rotates along the plane shape without the use of conventional ball bearings so that the bearing structure can be high in the rigidity, stable in the motion, and low in the cost. For having a maximum bearing length, the bearing structure comprises a support shaft arranged with its axis extending depthwisely of the motor and having two journal regions provided on both ends thereof and a recessed region thereof between the two journal regions; and a rotor shaft mounted in the center of the disk and having a cylindrical body thereof onto which the journal regions of the support shaft are rotatably fitted. Accordingly, the motor will minimize the frictional loss of the sleeve bearing and increase its operational life. Also, the steadiness (of deflection, inclination, and rigidity) in bearing action will be enhanced.

Abstract: The invention relates to a high precision axial and radial aerostatic and aerodynamic bearing for a motor. The bearing surfaces of the stator and the rotor are of a toroidal shape.

Abstract: A spindle motor includes a printed wiring board. A stator is fixed to the printed wiring board. A housing is fixed to the printed wiring board. A bearing is provided on the housing. A rotor shaft is rotatably supported by the bearing. A hub base is mounted on the rotor shaft. A stator winding provided on the stator is bonded to the printed wiring board. The stator may have an inner circumferential portion formed with a plurality of grooves. In this case, it is preferable that the printed wiring board has a plurality of through holes at positions corresponding to positions of the grooves in the stator.

Abstract: A motor control system with a motor having an essentially cylindrical casing and a control system having a processor and power control elements. The control system generates the driving current for the motor based on an external command signal fed to the control system, transmits the driving current to the motor via a line, and receives signals which indicate the status of the motor. The control system is mounted directly on a housing. The housing is connected to the casing by narrow webs bridging the air interspace formed between the casing of the motor and the housing of the control system, thereby mitigating mechanical and thermal influences of the casing of the motor and the housing.

Abstract: In a thin type flexible disk drive motor, in order to improve undesirable jittering of rotation, an inertia ring of larger diameter than that of the rotor frame is fixed immediately under the rotor. The inertia ring consists of a short cylinder part of the larger diameter to be fixed under the rotor frame and a flange part of the diameter not smaller than that of FG (frequency generation) magnet part. The disk drive motor also has a drive pin engaging assembly that allows a drive pin to be secured within a hub of the flexible disk while stabilizing the drive pin and after disk chucking.

Abstract: A bearing installation for a Floppy Disk Driver motor which is simple in structure and high in accuracy of a rotating action of a rotary shaft, thus hardly impairing the read and write characteristics of a Floppy Disk Driver device.

Abstract: Invention relates to an on-board electrical generator system that may be retrofitted to existing railroad vehicles, such as freight cars, box cars, and the like, where rotation of the vehicle's axle powers the system. A preferred use thereof is to charge the battery for the electrically controlled brakes on the vehicle. Such vehicles typically include a chassis, having plural axles mounted thereon, and a journal box or adaptor block having a projection generally aligned parallel with the axles. Each axle contains a pair of wheels, which are inwardly mounted from the respective axle ends and rotatable with the axle. The generator includes a rotor fixed for rotative movement relative to a stationary stator, whereby such relative movement causes electric currents to be generated in the stator containing the generator in a non-rotatable housing.

Abstract: An arrangement for providing exciter current in the rotor of an electric machine. The rotor winding is connected to the slip rings by exciter current conductors which are arranged in pairs in a central shaft bore of the rotor. The slip rings are arranged on a shaft stub which is connected to the rotor shaft with a releasable coupling. The central shaft bore includes bolt-side connection elements into which radially extending current supply bolts are releasably attached. The exciter current conductors are metallic pipes with an orbicular cross-section which are connected permanently at the other end to solid coupling-side connection elements. The ends of the connection elements penetrate a sealing plate in the coupling and are electrically insulated therefrom. Sealing rings are used to seal the sealing plate with respect to the rotor shaft and the ends of the coupling side connection elements which penetrate the sealing plate.

Abstract: A disc drive includes a disc drive motor for rotating a storage disc. The motor includes a motor base which carries a wiring assembly having a plurality of electrical contacts. A rotor hub is rotatably coupled to the base and rotatably carries a storage disc. The rotor hub includes a permanent magnet. A stator assembly includes a plurality of stator windings adapted for operation with the permanent magnet of the rotor hub. A wire guide coupled to the stator assembly positions wires of the stator windings adjacent the electrical contacts of the wiring assembly. The wires are soldered to the contacts after which the wiring guide can be removed. The stator assembly can be "potted" in an adhesive to reduce problems associated with resonant frequency of the disc drive motor. The wire guide acts as a retainer for the adhesive preventing the adhesive from interfering with rotation of the rotatable hub.

Abstract: An air gap varying motor includes a base, a rotation body, a motor rotor, a motor stator which is fixed in the base, and has an inner surface for contacting and supporting the motor rotor to enable the motor rotor to rotate about a predetermined axis, and which is disposed to have a distance spaced from said motor rotor An engagement and adjustment member connects the rotation body and the motor rotor and to adjust a distance between the motor rotor and the motor stator.

Abstract: It is intended to provide a stepper motor having windings which are easy to wind. Increase in size of the motor itself can be circumvented.First and second coil blocks 20 and 21, respectively, are formed by first and second annular bobbins 27 and 34, respectively, and by first and second annular yokes 28, 29, 35, 36. The bobbins have winding portions 25, 32 on which first and second exciting coils 26, 33, respectively, are wound. A magnet rotor 22 having a rotating shaft 41 mounted thereto is rotatably held in a gap 43 between the coaxial laminations of the coil blocks 20, 21. Connector terminals 37 and 38 consisting of first connection portions 37a, 38a and second connection portions 37b, 38b are buried in the annular bobbins 34 of the second coil block 21. The first connection portions 37a, 38a protrude from a flange 30 in a direction substantially perpendicular to the axis of the rotating shaft 44.

Abstract: A compact electric motor construction employing fluid bearings for use in a disk drive apparatus includes a spindle having a shaft and a thrust plate and a hub assembly including a hub having an outer disk support portion with an inner thrust bearing surface located axially above the upper thrust bearing surface of the thrust plate. The hub also includes an inner sleeve which substantially surrounds the shaft and provides an air gap between its inner diameter and the outer diameter of the thrust plate. The air gap is vented to the interior of the motor cavity by vent passages. Transition grooves are provided on bearing surfaces adjacent all fluid seal zones for controlling the migration of bearing fluid in a radial direction and for providing a low fluid pressure region adjacent capillary seals at the ends of the shaft to contain the seal and prevent leakage.

Abstract: A permanent magnet electric generator has a raised output as compared with the output of a similar conventional permanent magnet generator in which the polar arcuate angle of the permanent magnets is equal to the polar arcuate angle of controlling magnetic poles. Electricity is generated in armature coils 16 by the rotation of permanent magnets 8 of a rotor 4. Controlling magnetic poles 9 formed of a magnetic material are interposed between the permanent magnets 8 of the rotor 4, and a field controlling coil 17 is provided on a stator 11. The value of the polar arcuate angle .theta. m of the permanent magnets 8 divided by the sum of the polar arcuate angle .theta. m of the permanent magnets 8 plus the polar arcuate angle .theta. p of the controlling magnetic poles 9 is set at 0.55 to 0.7.

Abstract: A system for producing electrical power on a wheeled vehicle is disclosed. The system includes a wheeled vehicle that has a chassis carried upon a plurality of wheel units where each wheel unit is rotatably coupled to the chassis. The wheel unit includes a wheel and a hub upon which the wheel rotates relative to the chassis. At least one of the wheel units is adapted to generate electricity and has at least one length of reactive wire and a magnetic field generator positioned in the wheel unit for relative motion therebetween during rotation of the wheel. The configuration induces an electrical flow in said length of reactive wire thereby producing electricity.

Abstract: A spindle motor using an hemispherical-type air bearing, wherein air circulation means is formed on the shaft inserted and fixed in the air bearing, so that air inflow to the air bearing and air circulation within the bearing are highly facilitated, whereby friction and wear phenomena between the hemispherical balls and the ball casing is reduced and noises are inhibited, and whereby the life span of the air bearing can be extended and the performance of the spindle motor itself can be enhanced.

Abstract: A brushless motor includes features that prevent jolting or shaking of a rotating shaft by urging the rotating shaft in one direction and have a simple construction and can heighten the mechanical strength of a portion holding the rotating shaft in order to lower noise. The brushless motor having a rotor having magnets and a rotating shaft, a stator for generating a rotating magnetic field with respect to the rotor, an exciting coil wound on the stator for receiving electrical power and for generating the magnetic field, and a holding plate including a magnetic member mounted in a position facing permanent magnets of the rotor. Accordingly, jolting or shaking of the rotating shaft can be prevented by urging the rotor and the rotating shaft toward the holding plate in order to attract the holding plate by the magnetic power of the magnets due to mounting the holding plate in a position facing the magnets of the rotor.

Abstract: A motor comprising a rotor unit and a stator unit. The rotor unit includes a multipolar rotor magnet; a gear, disposed away from the center of rotation of the rotor unit with respect to the rotor magnet, for transmitting torque of the rotor unit to the outside; and a rotary shaft disposed at the center of rotation. The stator unit includes a substrate; and a plurality of coils disposed facing the rotor magnet on the substrate, the substrate having a cut-out section between at least two of the plurality of coils, with the cut-out section causing the outer peripheral section of the gear to be exposed.

Abstract: A brushless permanent magnet DC motor for use as a disk drive spindle motor has a radial working gap but uses flat coils that generate magnetic fields that interact with the permanent magnet fields across the radial gap. The stator includes a plurality of angularly spaced stator teeth that have faces radially spaced across the gap from the permanent magnet. The magnetic flux from the permanent magnet is directed radially across the gap and into the stator teeth. Each stator tooth has an axially oriented post around which is wound a flat coil that generates an axial field. The central axis of the coil forms part of the magnetic circuit. The magnetic flux directed radially into each stator tooth is turned axially into the post. The axially directed magnetic flux through the coil and post on each tooth is redirected from the axial direction to the circumferential direction by a ring magnetic flux guide. The ring flux guide interconnects the stator teeth and forms part of the magnetic circuit.

Abstract: A rigid disk drive spindle motor includes a bobbin carried by the motor hub which has a permanent magnet attached to the inner cylindrical surface and a laminated back iron mounted at the outer cylindrical surface. The laminated back iron may be in the form of concentric cylinders or a spiral wound strip with adjoining cylinders or convolutions secured to and electrically separated from one another by an adhesive material. In another form, the back iron may be formed as a series of washer like rings mounted on the bobbin which is a configuration similar to the laminations used in the motor stator and would permit fabrication using the same manufacturing techniques. The back iron is formed of high resistance silicon steel so that both the back iron material and the laminated structure discourage Eddy current formation. The spiral wound embodiment may also be modified by having the spiral strip periodically, axially interrupted to further reduce undesired induced currents.

Abstract: An electromagnetic drive apparatus comprises a stator yoke excited with supply of power to a coil, a rotor arranged as capable of being driven by excitation of the stator yoke so as to move a driven member, and a fixed member for positioning and supporting the rotor and the stator yoke. The stator yoke has a projecting portion or a recessed portion and the stator yoke is positioned and supported relative to the fixed member by the projecting portion or the recessed portion to provide a compact motor without causing a drop of efficiency in the power of the motor.

Abstract: A vehicle axle driven electrical generator assembly for supplying electrical power to electrically operable vehicle brakes, the generator having a magnetic field producing rotor and a stator with conductors in the magnetic field. The rotor has its axis of rotation coaxial with the axis of rotation of the axle and is rotated by a drive shaft which is either secured to the end of the axle or is loosely coupled to the end of the axle. The rotor and the stator are encircled by a housing to which the stator is secured and the housing is restrained with respect to rotation by either a link acting between the housing and a fixed portion of the vehicle or by securing the housing to the fixed portion.

Abstract: An axial gap type electric motor includes a stator assembly having a plurality of stator coils fixed to a circuit board and a rotor assembly having a rotor magnet supported via a dynamic pressure gas bearing on the stator assembly. The stator coils are enclosed by a molding material into a single block. An upper face of the block opposed to the rotor magnet is rendered flat. Since the block of the stator coils has no irregularities that cause turbulent flows of air, flows of air flowing through a gap between the rotor magnet and the stator coils are rendered laminar. Consequently, windage loss can be reduced.

Abstract: The invention relates to a structure of a spindle motor. The spindle motor comprises a housing assembly arranged downward of a cover and having an inner cylindrical portion; a stator secured to circumferential outer surface of the inner cylindrical portion of the housing assembly; a spindle hub provided above the housing assembly and having an outer cylindrical portion; a rotor magnet secured to circumferential inner surface of the outer cylindrical portion of the spindle hub; a hydrodynamic bearing formed in the inner cylindrical portion of the housing assembly; a rotating shaft having one end secured to the spindle hub to integrally rotate with the spindle hub and the other end positioned in the hydrodynamic bearing; and restrainer disposed between the cover and the one end of the rotating shaft to restrain axial movement of the rotating shaft to a predetermined extent.

Abstract: A motor includes a stator core having a plurality of projected poles, a stator coil wound around an insulating portion of the stator core, a printed circuit board for supplying electricity to the stator coil, and a holder having a hollow projection and fixed to the stator core. The projection of the holder is inserted and fixed in a hole formed in the printed circuit board and is used for positioning and fixing the stator core. A portion of the projection of the holder has a hole. A terminal pin is fixed in the hole of the projection of the holder and has a step portion around which the stator coil is. The step portion is fixed to a solder land of the printed circuit board to be wired to the stator coil so as to make the terminal pin and the land electrically conductive.

Abstract: A spindle motor has a tapped hole formed in the end surface of a rotor hub at the center of rotation of the rotor hub. A clamping member presses a disk against a disk holding surface of the rotor hub by a clamp screw threaded in the tapped hole. Since the disk is clamped through a clamping member by threading and tightening one clamp screw, the clamping operation is efficiently carried out and disk imbalance due to the clamping clamp screw is decreased.

Abstract: A capstan motor assembly and an assembling method thereof are provided. In the capstan motor assembly, a stator coil is mounted directly on a printed circuit board (PCB) substrate, on which a capstan motor shaft and a rotor are assembled. Accordingly, separate assembly of the capstan motor is not required, to thereby enhance productivity. Also, after assembling a body of the capstan motor, the position of the magnetic resistance device is accurately controlled, to thereby produce a capstan motor assembly of good quality.

Abstract: A drive magnet unit is fixedly mounted on the inner cylindrical surface of the cylindrical portion of a rotor yoke which is fixedly mounted on a hub, in such a manner that the drive magnet unit confronts a stator core. The rotor yoke has an annular portion along its open end. The rotor yoke has a curved portion along the open end which forms a gap with the outer cylindrical surface of the drive magnet unit. The annular portion is sheared along its base, thus forming a shear plane. The inner surface of the bottom of the rotor yoke, and the inner cylindrical surface of the cylindrical portion of the rotor yoke form a right-angled portion with which the right-angled outer edge portion of the drive magnet unit is engaged. The peripheral surface of the right-angled portion defines a through-hole in the bottom which is engaged with the hub. The gap is filled with adhesive, to fixedly secure the drive magnet unit to the rotor yoke.

Abstract: A brushless permanent magnet DC motor for use as a disk drive spindle motor has a radial working gap but uses flat coils that generate magnetic fields that interact with the permanent magnet fields across the radial gap. The stator includes a plurality of angularly spaced stator teeth that have faces radially spaced across the gap from the permanent magnet. The magnetic flux from the permanent magnet is directed radially across the gap and into the stator teeth. Each stator tooth has an axially oriented post around which is wound a flat coil that generates an axial field. The central axis of the coil forms part of the magnetic circuit. The magnetic flux directed radially into each stator tooth is turned axially into the post. The axially directed magnetic flux through the coil and post on each tooth is redirected from the axial direction to the circumferential direction by a ring magnetic flux guide. The ring flux guide interconnects the stator teeth and forms part of the magnetic circuit.