Abstract: An electric motor is provided with active hysteresis-based control of winding current. The motor has an efficient stator winding arrangement, as well as at least one adjustable air gap. Also provided is a stator, windings and air gap adjustment mechanism, as well as a method and system for controlling the torque produced by the motor using active hysteresis-based control of the motor's winding currents. The stator has its windings distributed among arc sections, the windings in each arc section being associated with only one phase of the motor. The hysteresis-based control of winding current is active in that a bandwidth or spread of the hysteresis band is adjusted depending on at least one of several selectively determined factors. The motor and its associated components are particularly well-suited for use in an electrically powered vehicle, as well as in hybrid vehicles using both electric power from a battery and electric power derived from a fuel-burning engine.

Abstract: A disk drive has a sleeve-bearing spindle motor having a rotor for rotating the disk of removable data storage cartridge. A retainer which is compliant in the direction of axial movement of the rotor stops the axial movement. The retainer is mounted on a moveable platform which mounts the disk cartridge as it is inserted into the drive. The retainer includes a cantilevered beam which is compliant in the direction of axial movement.

Abstract: In a VR-type resolver which is used in combination with a motor to detect the rotation position of the motor, the teeth number of a rotor of the resolver is reduced over the teeth number of a rotor of the motor. Also, the shape of the teeth of the resolver rotor is simplified into a curved shape such as a sine wave shape. Further, in another type of VR-type resolver, the number of the magnetic poles of the stator with respect to the number of the teeth of the rotor is set as a number being capable of satisfying not only the condition that it is a multiple of the phase number N and an even number but also the condition that it is a number which can be calculated according to one of the following expressions (1) and (2), that is,stator pole number=rotor teeth number/(M+1/N) (1)stator pole number=rotor teeth number/{M+(N-1)/N} (2),where M is an integral number of one of 1, 2, and 3.

Abstract: A brushless commutated torque motor suitable for use with a rotary low frequency sound reproducing apparatus, includes a shaft having a longitudinal axis, a position sensor, a rotor having a plurality of permanently magnetized rotor pole sectors, the rotor being mounted for rotation upon the shaft, and a stator having a plurality of stator poles and stator winding slots disposed alternately therein, the stator slots having stator windings therein driven by individual power amplifiers in response to a control signal, the stator having commutation between stator windings controlled by sensing of rotor angular position by the position sensor, with each rotor pole sector being configured and disposed such that a plurality of stator poles are axially adjacent to each rotor pole sector and each rotor pole sector is angularly separated from adjacent rotor pole sectors by a selective number of stator poles.

Abstract: In a circuit-integrated motor, it is an object of the invention to solve a problem that high power output is hampered by a heated electronic component, and to provide a compact high-power motor with a self-cooling fan which is capable of affording a significant cooling effect on the electronic component and winding wire. A self cooling fan (15) disposed close to and in an opposed relation to a top face of a rotor frame (11) has a peripheral-face opening (16), and an electronic component or a radiator attached with the electronic component is located in the course of a flow passage (17) of cooling air guidedly discharged from the peripheral-face opening (16).

Abstract: A brushless three-phase synchronous generator includes a stator having primary generating windings and stator excitation windings whose number of poles is odd-number times the number of poles of the primary generating windings. The generator further includes a cylindrical rotor on which a plurality of field windings are wound in a full-pitch concentrated winding form. The plurality of field windings are respectively short-circuited by the corresponding diodes. A plurality of field windings in which voltages of the same phase are induced based on the odd-order spatial higher harmonic magnetic fields are connected in parallel and further connected in parallel to the central field windings which effectively produce primary field magnetic fluxes. A circulating rectifier element is connected in parallel to the central field windings.

Abstract: An electrostatic driving apparatus for a microactuator is provided, in which a parasitic capacitance is offset to improve the performance thereof. According to the complementary electrostatic driving apparatus for the microactuator, in order to prevent an excitation signal from being mixed with a sensing signal via the parasitic path formed of parasitic capacitance according to the structure of the microactuator and vibration characteristics thereof, which cause noise, signals having opposite polarities are applied to activating vibration plates using an inverter such that the activating vibration signals of each plate, which cause noise, are offset, thereby markedly improving the signal-to-noise ratio. Also, the vibration displacement can be easily detected by a circuit which is not integrated with an actuator. In addition, a sensing unit is simplified, reducing the initial costs.

Abstract: An electric machine comprising a ferromagnetic first part (11) having a plurality of teeth (11C) arranged in a row, a ferromagnetic second part (12) having a plurality of poles (16, 17) arranged in a pole row confronting the row of teeth (11C) of the first part (11) and spaced from the row of teeth by an air gap (18), bearing means supporting the first and second parts (11, 12) for relative movement along the air gap (18), and winding means (15) associated with the first part (11) for producing a multipolar magnetic field continuously travelling along the air gap and linking the first and second parts (11, 12) across the air gap (18). The travelling magnetic field has an even number of poles and a pole pitch corresponding to the pole pitch of the second part (12).

Abstract: In a method to manufacture a stator by coupling a plurality of core segments as so to compose a serial body of core segments and rounding the serial body into an annular body, a stator which method can secure an optimum length of a connected wire by preventing the connecting wire from being too long or too short between the core segments at a stage to round the serial body of core segments into the annular body and method of manufacturing thereof are provided. A member to form a motor stator is composed of a plurality of core segments which are movably coupled, a plurality of insulators which cover the core segments and have head portions having spaces allowing a connecting wire to pass therethrough, and the coil wire which is wound around the core segments to form a coil and serves as a connecting wire passing through the head portions, the member being capable of securing an optimum length of the connecting wire.

Abstract: An alternator for vehicle includes a stator and a rotor. The stator is composed of a stator core which is a lamination of steel-sheets and stator winding. The rotor is composed of a pole core, a pair of cooling-fans disposed on opposite axial ends of the pole core and a field coil. The pole core is composed of a cylindrical center core, a pair of disk yokes extending from the center core and claw-pole-pieces extending from the disk yokes to longitudinally cover the field coil. In such a generator, a ratio Y/X of a circumferential distance Y between the adjacent claw-pole-pieces to a circumferential width X of the tooth edges and a ratio r1/R1 of the inside diameter r1 of a cylindrical space where the claw-pole-pieces are disposed to the outside diameter R1 of the same are in specific ranges.

Abstract: A connector assembly comprising a base portion which plugs into the base of the motor shaft and a connector body having electrical interface rods along an axial face thereof. A flexible printed circuit having one end connected to the stator has dedicated connector pads on a surface thereof which line up with and are intended to be pressed against the molded body connector rods. To maintain the pads and rods in tight electrical contact, a connector snap spring assembly is snapped in place over the connector body.

Abstract: A motor for providing reciprocating motion comprises a stator defining an arcuate pole face and a flat pole face and an armature defining a complimentary arcuate pole face and flat pole face, where the armature rotates about a pivot internal to the structure of the armature in order to maintain a fixed air gap between the arcuate pole faces of the stator and the armature and a variable air gap between the flat pole faces of the stator and the armature.

Abstract: Device for magnetic suspension of a rotor (10, 20, 30) in relative rotational movement along a predetermined rotation symmetric path with respect to a stator (14, 24, 26, 34, 36). Rotor (10, 20, 30) comprises a rotational body (11, 21, 31) which essentially consists of an electrically conductive unmagnetic material. Fitted at the stator (14, 24, 26, 34, 36) is at least one magnetic member (12, 22, 25, 32, 35), which comprises at least one rotation symmetric magnet (12, 22, 25, 32, 35) concentric with the rotational axis. The magnetic member is disposed to give rise to a rotation symmetric magnetic field concentric with the rotational axis. When and only when the rotational body (11, 21, 31) tends to leave the predetermined path and rotate eccentric, the magnetic field generates induced eddy currents in the rotational body (11, 21, 31), the eddy currents gives rise to restoring stabilising forces.

Abstract: An electric rotating machine as disclosed herein includes an armature core having an outer peripheral portion with slots, a rotatable shaft having an outer periphery and rotatably supporting the armature core, a plurality of lower layer coils each having at opposite ends thereof respective lower layer coil protrusion portions, and a plurality of upper layer coils disposed radially outside of the lower layer coils and each having at opposite ends thereof respective upper layer coil protrusion portions. According to the novel method of this invention, the lower layer coil protrusion portions are bonded to the upper layer coil protrusion portions with a welding torch of an arc welding machine by radially moving at least one of the welding torch and boundary portions, at which the corresponding protrusion portions abut one another, relative to each other.

Abstract: An electromagnetic machine, for using electrical energy to generate a propulsive force, includes an inertia ring disposed within an outer casing. The inertia ring can rotate freely relative to the outer casing. The outer casing supports a pair of primary coils. The inertia ring carries a plurality of secondary magnetic coils thereon. There is a pair of brushes that energizes the secondary magnetic coils on either side of each of the primary coils, as the secondary coils move past the pairs of brushes. The primary coils are energized to attract the secondary coils on one side thereof while repelling the secondary coils on the other side thereof to thereby impart rotational movement to the inertia ring relative to the outer casing.

Abstract: An x-ray generating device having an improved high efficiency motor is disclosed. The x-ray generating device comprises a cathode assembly and an anode assembly arranged opposite each other in a vacuum vessel. According to the invention, the anode assembly is coupled and rotated by the rotor of a high efficiency motor which has near traditional gaps by positioning the motor stator assembly in close proximity to the rotor of the motor and applying a same potential to both the stator core and the rotor. The stator assembly further includes poly-phase stator winding coils arranged on the stator core. The coils are electrically insulated from the stator core, and they are supplied with poly-phase AC signals from a motor controller to induce magnetic interactions and rotate the rotor and the anode assembly.

Abstract: A positioning device for a miniature fan includes a coil seat having an axle tube, an upper polar plate assembly, a lower polar plate assembly, and a winding mounted between the upper polar plate assembly and the lower polar plate assembly. A circuit board is mounted to the axle tube and includes a sensor element for activating rotor. The sensor element is located on a line extending from an end edge of the upper polar plate assembly along a direction parallel to a longitudinal axis of the axle tube.

Abstract: A resilient restricting member of a rotation restricting member which restricts a pinion moving body from rotating is accommodated in a frame of a restricting member holder under a flexed and loaded state so that the rotation restricting member has a sufficient rotation-restricting function as long as the rotary force of the pinion moving body does not exceed the load acting thereon at the time of engagement and restriction of rotation. When a pinion gear abuts the end face of a ring gear and the pinion moving body is restricted from moving forward, the entire rotary force of an output shaft acts on the pinion moving body. The resilient restricting member flexes further in the restricting member holder to allow rotation of the pinion moving body, thus enabling the pinion gear to mesh the ring gear. Thus, the rotary force of the output shaft is converted to the advancing force of the pinion moving body surely even when the spiraling of the helical spline is not so large.

Abstract: A rectifier accommodating portion, a condenser accommodating portion, a regulator accommodating portion and a connector accommodating portion are recessed on the inner surface of a rear bracket, and baniers which constitute a cooling air passageway are integrally made to protrude axially from the surface of the inner wall of the rear bracket so as to separate between each accommodating portion. Further, intake openings and a connector receiving hole are provided through the rear bracket so as to communicate the rectifier accommodating portion, the regulator accommodating portion and the connector accommodating portion from the exterior while a plurality of exhaust openings are provided through the outer circumference in the circumferential direction.

Abstract: An electric motor comprising a stator having sixteen or thirty two slots and three windings asymmetrically arranged in the slots to achieve a substantially balanced three-phase operation.