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 underlying the outer face of and embedded in the carbon ring, and a housing of a plastic insulating material molded on the rear face and the inner and outer edges 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: To reduce the number of parts composing a control circuit and to reduce an area occupied by a printed circuit board on which the parts are to be mounted, in an axial flow fan motor in which a shaft is rotatably mounted by bearings and an impeller is mounted on the shaft, the control circuit is in the form of an arcuate shape having an area corresponding to 30% to 60% of an total area of the boss portion and is installed into a printed circuit board having a diameter smaller than that of the boss portion. Also, by utilizing the functions installed into the integrated circuit of the control circuit, the parts provided on the circuit board may be dispensed with. As a result, a space which corresponds to that of the printed circuit board is generated in an interior of a casing to thereby enhance the cooling performance and to reduce the number of the parts and the manufacture steps.

Abstract: An in-hub brushless permanent magnet DC motor has a radial working gap but uses coils wound in the axial direction of the motor. The coils generate 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 stator teeth are connected to the base and extend axially into a cavity within the hub. The permanent magnet is a magnetically-segmented ring magnet located on an outer rim of the hub radially outwardly from the stator teeth. 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 coil that generates an axial field. The axially-oriented part of each coil forms part of the magnetic circuit. The magnetic flux directed radially into each stator tooth is turned axially into the post and through the coil.

Abstract: A spindle motor for a disc drive, such as a CD-ROM drive, is provided. This spindle motor is a brushless motor of a single-phase axial-winding and radial-gap type including a stator, a rotor coupled to said stator, and a driving circuit for supplying a driving signal to the stator to rotate the rotor. The stator includes a pair of upper and bottom salient-pole pieces formed with a plurality of tooth-like portions serving as salient-poles. The peak surface of each tooth-like portion is formed into a symmetrical convex shape, which minimizes the cogging torque of the motor. Further, the use of a phase-adjuster in the driving circuit allows the motor to produce large output torque at high speeds. The output characteristics of this spindle motor meet the requirements of high speed CD-ROM drives.

Abstract: This invention relates to a novel design of electric motor wherein a stationary fuel cell with an electrical output is integrated with a cylindrical type monopole (homopole) electric DC motor. Power is supplied to an output shaft by the introduction of reactants to the fuel cell. The fuel cell is positioned within the hollow cylindrical stator. The stator and fuel cell are stationary. The rotor is a hollow cylinder and is positioned to rotate about the exterior of the stator. The rotor has magnets distributed around the interior of the rotor. This novel compact combination of a fuel cell and a cylindrical form of monopole (homopole) electrical DC motor enables the combination to fit within a confined space.

Abstract: A galvano mirror is held by a mirror holder. The mirror holder is rotatable about a rotation axis and supported in a stator. A center pins (made of conductive material) are provided to the stator. A pair of receive members (made of conductive material) are provided to the mirror holder. Each of the receive member receiving respective center pin. A pair of coils are provided to opposing ends of the mirror holder, the movable parts being connected to the receive members. The center pins and the receive members constitute a electrical feeding path for feeding electricity to the coils.

Abstract: A stator structure for miniaturized DC brushless motor is disclosed.

Abstract: A motor with reduced radial forces includes a first motor part made up of 2P permanent magnet poles surrounding a second motor part formed by a magnetic yoke having a number T of pole teeth and with an air gap between the first and second motor parts. The first and second motor parts are moveable relative to one another. Exciter coils are mounted on the pole teeth and the pole teeth are separated by pole gaps. For a motor with a number 2P magnet poles and a number T of pole teeth which do not have a common submultiple greater than 1, each of the pole teeth have a centrally located auxiliary slot facing the air gap thereby to reduce undesirable radial forces.

Abstract: Eddy current loss is a significant problem in high speed permanent magnet alternator/motors. Leakage flux from the rotor magnets 32, which flows through any stationary electrically conductive material such as a bearing housing 12 will result in eddy current loss. The invention uses a magnetic flux barrier means 29,36 to prevent magnetic flux leakage from the magnets 32 to the stationary electrically conductive material 12. The flux barrier means may comprise a diverter disk 29 made from a magnetically permeable material which is located on the shaft 18 next to the rotor 26 and rotates integrally with the rotor. Alternatively it may comprise a barrier ring 36 made from an electrically conductive material which is stationary on the end of the stator 27 and extends across the air gap 38 between the rotor 26 and the stator 27.

Abstract: A scanner motor coupled with a polygon mirror is improved for coupling the polygon mirror to a housing via a push fit while a pressive pushing force is absorbed into the housing without being imposed upon the polygon mirror, and further for decreasing the number of parts and deleting manufacturing process and man-hour to enhance productivity and economize cost.

Abstract: An electronic component cooling apparatus capable of permitting a sufficient amount of air to be fed to an electronic component to be cooled. An impeller which includes a plurality of blades for sucking air from one side in an axial direction of a revolving shaft of a motor is fixed on a rotor of the motor. A casing having a cylindrical cavity defined therein in which the motor and impeller are received is constructed of a peripheral wall arranged so as to surround the impeller and a closing wall for closing an end of the cavity on the other side in the axial direction. The peripheral wall is formed at a portion thereof in proximity to an end thereof on the one side with a lateral discharge port through which air suckedly introduced into the cavity is discharged so that a surrounding portion for surrounding a whole circumference of the impeller is left at a portion of the peripheral wall in proximity to an end on the other side.

Abstract: A contactor for a motor vehicle starter comprises a contactor coil, a movable contactor core actuated by a control rod, and a fixed contactor core. It also has an electromagnetic auxiliary control relay which includes a movable relay core carrying a movable contact ring which is arranged for cooperation with at least one pair of fixed relay contacts, carried by a fixed annular contact carrier plate. The relay coil, the contact carrier plate, and the movable contact ring are arranged in axial succession, in that order towards the front of the contactor, and are disposed between the movable contact of the contactor and the fixed core, so that the relay and the contactor are closed in the same, forward, direction.

Abstract: The asynchronous discoidal electric motor has stator (1A, 1B) windings (13) and radial rotor bars (2) embedded in notches (11, 22) opened by a very narrow slit (11, 21). These slits (11, 21) and notches (12, 22) may be machined electrochemically using a wire. Application to asynchronous discoidal electric motors with winding embedded in the stator and with a cartwheel structure on the rotor.

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 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 spindle motor assembly includes a hub, a motor, and a bearing cartridge having a plurality of bearing balls disposed between a sleeve and a shaft. The shaft includes a cylindrical hollow portion which is attached to a cylindrical protrusion portion of the hub to provide a stable attachment between the hub and shaft without increasing the height of the spindle motor assembly. Grooves are formed on the outer peripheral surface of the cylindrical protrusion portion to alleviate stress between the hub and shaft resulting from thermal expansion.

Abstract: A self-propelled wheel for wheeled vehicles includes an axle, a stator drum ixed to the axle, and a wheel hub and rim rotatably mounted on the axle. Permanent magnets are fixed on the wheel and oppose an outer lateral face of the stator drum and an outer peripheral edge of the stator drum. Excitation of the stator drum causes the permanent magnets, and thereby the wheel, to rotate on the axle.

Abstract: A technique for preventing damage to ball bearings in small form factor devices where the drive motor has at least one piezoelectric crash stop ring disposed about the shaft and inside the rotor of the motor. The crash stop ring must be dimensioned to permit only a small amount of movement of the rotor relative to the shaft. The permitted movement is less than the minimum movement which would cause damage to the elements of the ball bearing.

Abstract: The invention relates to a rotor for an electric machine, specifically a transverse flow machine, comprising at least one support disk and at least one annular pole structure arranged on an end face of the support disk, coaxial to the rotor axis, and extending in axial direction. The pole structure comprises two adjacent rows, separated by an intermediate layer of magnetically and electrically nonconducting material (spacer ring), of the peripheral direction alternately magnetized magnet arrays with interposed collector or soft-iron elements. An end ring is coordinated with each pole structure. A plurality of magnet arrays features an inner and an outer magnet. The design of the collector or soft-iron elements adjoining a magnet array in the peripheral direction is such that they form in radial direction an inner stop and an outer stop for the magnet array.The invention is characterized in that an intermediate element is coordinated with a plurality of magnet arrays.

Abstract: A rotor for an electrical machine according to one embodiment of the present invention comprises a shaft defining an axis of rotation of the rotor, and first and second pole pieces affixed to the shaft for rotation therewith and together defining an interior cavity. The rotor additionally includes a slip ring affixed to the shaft for rotation therewith. Further, the rotor comprises a field-generating coil disposed within the interior cavity, the coil comprising a plurality of turns of electrical wire, the electrical wire further having a section extending to and electrically coupled to the slip ring. Also, the rotor has a retainer disposed exterior to the cavity and adjacent the first pole piece, the retainer comprising a radially-extending channel containing a portion of the section of electrical wire.

Abstract: An alternator, in particular for a motor vehicle, comprises half-shells to which stator windings are fixed and which rotatably receive a rotor shaft, and a rectifier circuit made up of power diodes each comprising body and a lead extending axially from said body. The bodies of some of the diodes are connected to ground while the bodies of the other diodes are connected to an output terminal of the alternator. The diode bodies are fixed on or in the back half-shell of the alternator on or in a dissipating support which is generally in the form of a plate that is insulated from the half-shell and that is outside it. According to the invention, the distance between the dissipating support and the back half-shell, and the positions of the said other diodes on the dissipating support are such that the leads of said other diodes project into openings formed in the back half-shell.

Abstract: A polygon mirror assembly includes a polygon mirror and a supporting stand for supporting the polygon mirror. The supporting stand and the polygon mirror are combined in a pressure combination manner. The polygon mirror supporting structure can be provided so that the fastening of the polygon mirror is easily carried out, no unbalance of the center of rotation occurs and any eccentricity can be made extremely small.

Abstract: The invention relates to a structure of a spindle motor. The spindle motor comprises a housing assembly; a shaft fixed to the center portion of the housing assembly, a stator secured to the housing assembly around the shaft, a spindle hub having an inner cylindrical portion and an outer cylindrical portion, a rotor magnet secured to a circumferential inner surface of the outer cylindrical portion of the spindle hub, and a pair of bearings provided around the shaft in the inner cylindrical portion; wherein the spindle hub has a flat plate portion formed in the center part thereof and the flat plate portion has an opening through which the shaft is passed, thereby the flat plate portion functions as a labyrinth seal.

Abstract: The invention is a spindle motor including a rotor hub bearing a rotational load, lubricant-containing bearing systems rotatably supported by the rotor hub, and stator windings wound on a stationary member, so as to oppose the rotor magnet. At least a portion of the rotor hub is in a clean environment, with the motor substantially sealed by a sealing unit. The spindle motor has a leakage prevention unit which prevents the lubricant trying to leak out the bearing systems and out the motor, when centrifugal forces produced by a rotor hub rotating at a high speed are exerted on the lubricant.

Abstract: A drive device with an electric motor with permanent magnets and a pole top more particularly for use with servo drives in motor vehicles. A relay is provided for switching the motor current with at least one electromagnet, which contains a relay coil and a relay armature, and with at least one relay contact. The relay is mounted in the pole top of the electric motor and the magnetic field lines of the electromagnets are closed through the permanent magnets and the pole top of the electric motor.

Abstract: A brushless motor includes a coil for energizing a motor to thereby rotate a rotor of the motor, a core having a plurality of projection poles around which the coil is wound, a terminal pin serving as a relay in feeding electric current to the coil, a lead wire extending from a terminal end of the coil, and a bracket for fixedly holding the core. The lead wire is electrically connected with the terminal pin directly or indirectly fixed to the core; and the terminal pin is extended to outside of the motor through a through-hole of the bracket so as to electrically connect with a motor driving circuit.

Abstract: A bicycle generator including a coil stator and a magnetic rotor. The coil stator includes a planar support, and an induction coil portion formed by a plurality of series-connected coil units which are evenly spaced along the circumference of the planar support. The magnetic rotor is rotatable relative to and substantially parallel to the coil stator, and includes a permanent magnet having a plurality of magnetic pole pairs formed on its circumference. The number of coil units in the induction coil portion is equal to the number of magnetic pole pairs in the magnetic rotor, and the coil units is winded into trapezoid or sector shape, and the span angle of each of the magnetic pole in the magnetic rotor is substantially equal to the span angle of each of the coil units in the coil stator. Alternatively, the bicycle generator may comprises a cylindrical coil stator and a cylindrical magnetic rotor.

Abstract: A bearing system for brushless DC motors is disclosed. The bearing system has an electromagnetic force generator in a bearing so as to generate an electromagnetic force or a magnetic force. The bearing system thus magnetically attracts the shaft when eccentricity of the shaft in the bearing is reduced during a high speed operation of the shaft, thus allowing the shaft to keep desired eccentricity in the bearing and increasing dynamic pressure of oil in the bearing and preventing a formation of an oil whirl, and improving dynamic characteristics of the motor such as low operational vibrations and noises during a high speed operation of the motor.

Abstract: A motor terminal device comprises a storage case having an engaging section and installed on the motor side and a storage cover having an engaging section which can be engaged with the engaging section of the storage case. The storage case stores external connecting terminals and electrical components including capacitors and choke coils, while the storage cover has elastic projecting pressers located in a position corresponding to the electrical components to secure the electrical components by pressing. The presser for the choke coil includes a pair of plate walls which sandwiches the choke coil therebetween and presses the same toward the storage case. The presser for the capacitor includes a butyl rubber or urethane foam pasted on the inside of the storage cover.

Abstract: A motor structure having a stator core including an armature coil wound on stator plates and arranged in parallel on the surface of the motor mounting plate and a bearing mechanism for supporting a rotor rotatably provided at the center of the stator oppositely to the stator wherein the stator core is coupled by an integrally molded form with a housing for holding the bearing mechanism

Abstract: In a starter having a motor yoke, a housing and an end frame forming a cylindrical starter frame, a cylindrical thermal insulation cover is fitted around the starter frame through rubber-made elastic rings. The rings are tightly fitted in V-shaped grooves formed circumferentially on fitting faces, one being between the housing and the yoke and the other being between the yoke and the end frame. Each ring is pressed radially inward by a large diameter part of the thermal insulation cover to fill in the V-shaped groove and contact the fitting face. Further, in a motor for the starter, a resilient plate sheet is disposed between a commutator and a brush holder to return a brush passing therethrough to the original position when the brush tends to move during sliding contact with the commutator.

Abstract: An object of the present invention is to provide a low cost, high performance, thin structure rotary motor for driving medium used in magnetic disk drive unit, optical disk drive unit or the like, in order to improve the productivity of terminating processing and the reliability of the coils. Magnetic materials which are divided to a plurality of blocks or divided corresponding to respective magnetic pole teeth are connected by means of thin portions. The respective magnetic pole teeth are wound continuously with wire without cutting the wire at the positions in which the thin portions are connected. When a stator is assembled, a plurality of blocks or magnetic pole teeth are disposed on a substrate by separating or bending the thin portions.

Abstract: A motor vehicle for urban use has a chassis, a plurality of wheels mounted on the chassis, an electric motor, an electric energy source supplying current to the electric motor located inside one of the wheels, and gears including a conical gear provided on an axle of the electric motor and a circular gear provided in a casing, with a roller bearing received in a groove of the circular gear.

Abstract: A hybrid type stepping motor includes coils located on the outer or inner periphery of stator yokes provided on a fixed shaft. This structure allows the coils to be disposed more easily and thus at a lower cost. Furthermore, it is possible to achieve a great increase in the density of winding. Auxiliary magnetic plates and auxiliary magnets are disposed at both ends of a stator yoke assembly so that a magnetic circuit is formed at both ends. According to the invention, a motor having any desired number of phases may be achieved. A magnet is disposed in each space between adjacent teeth of either a rotor or a stator or otherwise of both rotor and stator. The magnetomotive force of the magnet suppresses leakage magnetic flux and concentrates the magnetic flux within the region between the rotor and stator. As a result, in operation, an abrupt change in the magnetic flux can be obtained, which leads to an increase in the torque.

Abstract: A friction wheel door drive for a sliding door for lifts consisting of at least one rectilinearly or curvilinearly moved door leaf (1), which is suspended of guide rollers (3) and is guided at a guide (2) is presented. At least one of the guide rollers (3) is formed as a motor roller (3') moving the door leaf and in the form of an outside rotor motor. The motor may be either a direct current motor with permanent magnets in the outside rotor and electronic commutation or a polyphase induction motor with a laminated outside rotor having a short-circuited winding and a laminated inner stator with a polyphase alternating current winding. Force transmission between the motor roller (3') and a running roller (3") may be provided by a transmission (18), between motor roller (3') and running roller (3") is possible.

Abstract: The present invention relates to an electric motor comprising an attached additional element, in particular an incremental shaft encoder, and a mounting base plate which has seated thereon the additional element and is connected to the electric motor such that its angular position is adjustable during assembly. The adjustability of the angular position is to be improved, whereby mounting is simplified. To this end, a profile toothing is provided on the electric motor and a counter-profile toothing on the mounting base plate, the toothings engaging each other in a substantially accurately fitting manner, thereby permitting a mounting of the base plate in different angular positions in angular steps which are predetermined by the tooth pitch.

Abstract: A spindle motor for a disc drive data storage device in which the stator is isolated from the stationary portion of the motor used to attach the spindle motor to the disc drive housing by use of resilient members interposed between the stator and the stationary portion of the motor. In a preferred embodiment, the resilient members comprise a plurality of toroidal rings, or O-rings, and, in a first aspect of the invention, these rings are interposed radially between the stator and the stationary portion of the spindle motor and are axially constrained in relationship to the motor by a corresponding number of annular grooves formed in the stationary portion of the motor. In a second aspect of the invention, metal-to-metal contact between the stator and the stationary portion of the motor in the axial direction is eliminated through the use of a non-metallic washer at one end of the stator and an axial O-ring at the other end of the stator.

Abstract: A slim-line direct current (DC) brushless motor for automotive and HVAC applications utilizes a single contact bearing assembly to rotatably couple an exterior rotor to an interior stator. The rotor includes a flat permanent magnetic and the stator assembly includes a flat coil. The flat coil is made from a stamped copper member. The rotor is staked to the bearing assembly by a hub-shaft. The lone contact bearing can be a double horizontal row contact bearing, a four point contact bearing, or a closed cylindrical roller bearing. A cooling fan is disposed on the top of the rotor to cool internal control circuitry within the motor. The motor is easily assembled and has a minimal number of moving parts.

Abstract: A motor capable of generating an electric signal having a particular and precise frequency may be used in a rotary magnetic head apparatus for a video tape recorder. A wiring pattern for generating the signal is disposed on a stator opposite a rotor. Alternating magnetic flux provided by movement of the rotor produces the signal. Gaps in the wiring pattern allow the wiring pattern and wiring for iron core assemblies also disposed on the stator to be disposed on a single circuit board. A toroidal coupling line and a loop coupling line close the loop without crossing the gaps.

Abstract: In the motor, the compound bearing assembly is assembled from stepped-diameter shaft 1, sleeve-like outer race ring 5, first balls 4, second balls 8a, and inner race ring 7 a, and has a base-end portion of large-diameter portion la of the stepped-diameter shaft 1 fixedly mounted on a base member 10 of the motor at right angles to permit the stepped-diameter shaft 1 to extend upward. After that, the compound bearing assembly is fixedly mounted in a central hub portion 12 of a rotor 11 of the motor in an insertion manner to complete the motor provided with the compound bearing assembly. Consequently, it is easy for the motor manufacturer to assemble his product or motor with the compound bearing assembly at high accuracy. (See FIG.

Abstract: The elevator machinery (26) comprises a motor (6) and its traction sheave (18). The rotor (17) is disc-shaped and air gap (ag) between it and the stator (14) can turn a plane which is substantially perpendicular to the shaft (13). The stator (14) forms a ringlike sector (28) and is placed in an outer part and the traction sheave (18) is fixed to the rotor, between the stator (14) and the shaft (13). The diameter of the traction sheave is smaller than that of the rotor. The structure of the motor allows the use of traction sheaves (18) of different diameters (2*Rv) with rotors (17) of the same diameter. The motor is very flat. In other words, its length in the axial direction is small.

Abstract: Although a rotor shaft of a spindle motor for driving an optical disc is constituted by stainless steel not to cause damage or friction when the disc is mounted or removed, it is intended to provide a spindle motor which does not require to use a material with bad workability such as stainless steel. A rotor shaft or a rotor cap mounted on the rotor shaft is made from a resin material or an alloy material with good workability such as brass, and a hard coating is provided on its surface to provide hardness necessary for components made of a material with good workability.

Abstract: A hybrid stepping motor according to the present invention has coils wound on stator yokes arranged on a fixed shaft or coils arranged on the inner peripheral surface of stator yokes. For this reason, the coils can be easily formed, a coil mounting density higher than that by a conventional technique can be obtained, and cost reduction can be obtained. An auxiliary magnetic plate and an auxiliary magnet are arranged on both the sides of a stator yoke member to form magnetic circuits at both the ends of the stator yoke member. Therefore, motors having various numbers of phases can be obtained, and a core are partially or entirely constituted by a non-layered structure, thereby improving torque/current characteristics.

Abstract: Proportional control of the output of an alternator achieved mechanically to change the reluctance of the magnetic path between the stator and the rotor and thereby change the electrical output of the alternator.

Abstract: In a compact drive for a float-mounted cylinder of a rotary printing machine, the spindle carrying the cylinder is housed together with a motor in a carrier tube mounted in the side wall.

Abstract: This invention provides a two-phase motor which is applicable to a field where high rotation precision is required as in an FDD spindle motor, which requires a low cost, and which can maintain stable characteristics free from magnetic balance fluctuation between the two phases due to assembly. This motor has a ferromagnetic stator having N stator salient poles and a rotor magnet having M poles. N and M are selected to be both even numbers so a relation N:M=2:2n-1 (n is a natural number) holds. The N stator salient poles are divided into first and second salient pole groups of N/2 stator salient poles on which windings are concentratedly wound. The stator salient poles belonging to the first and second salient pole groups are alternately arranged in the circumferential direction of the stator. The phases of the windings of the stator salient poles belonging to the first and second salient pole groups are sequentially opposite to each other in the circumferential direction in units of groups.

Abstract: An inner rotor type scanner motor rotating a rotary polygon mirror for deflection scanning is composed of two units, a rotary unit and a stationary unit. Then balancing can readily be achieved on two planes of the rotary polygon mirror and a drive magnet of the motor. The rotary unit is arranged in such a manner that a motor housing holds a bearing of a rotary member to which the rotary polygon mirror and drive magnet are fixed, and the stationary unit is arranged in such a manner that a stator coil and a magnetic member are mounted on a base.

Abstract: A spindle motor having a shaft member secured to a fitting member, a rotary member which is rotatable relatively to the shaft member, a rotor magnet fitted to the rotary member in such a manner that the rotor magnet confronts the rotor magnet and a stator, wherein a pair of inner annular grooves are formed in the shaft member, a pair of outer annular grooves are formed in the rotary member and a plurality of ball members are accommodated in ball-accommodating space defined by these annular grooves.

Abstract: A brushless DC drive motor with an external rotor has three pole shoes on a substantially ring-shaped stator for each two poles on the rotor. The stator winding is commutated by a three-phase commutation network in such a fashion that first, second and third networks in the stator winding are cyclically connected to an external DC source in accordance with rotor position. Each of the networks comprises at least one stator coil wrapped around a neck of a single corresponding one of the pole shoes.

Abstract: A disk spindle motor having a permanent magnet central shaft. A pair of annular, non-magnetic combination thrust and journal bearings having truncated-conical outer surfaces are spaced apart on the shaft. The bearing coact with complementary surfaces of the hub of a motor rotor. Shaft end caps connect the shaft to base means and have radially extending shoulders which define annular gaps with the rotor and function as ferrofluidic seals.