Abstract: An actuator in which, when the reduction ratio of a reduction gear unit is 1/N, the number of pulses of a second encoder is set to be equal to N times (the number of pulses of a first encoder), whereby a pulse processing circuit for detecting a torsion angle is made remarkably simple.

Abstract: An electric power steering control system includes an electric motor for producing an assisting torque for the vehicle steering system through a reduction gear, a steering torque sensor fitted on the steering shaft, a controller for controlling the input to the motor in accordance with the torque sensor output, a battery for supplying power to the controller, and a voltage step-up circuit connected to the battery for driving the motor at a voltage higher than the battery voltage. The controller drives the motor at a high voltage.

Abstract: A device for detecting a load torque using angle detectors fitted with a certain spacing on a shaft which is rotated by a drive source and on the basis of a relative angular difference of angles detected by the angle detectors. The device includes two rotary drums or discs fitted with a certain spacing on the drive side and load side of the shaft, with a plurality of magnetic poles for generating magnetic signals being formed on the surface thereof, and a magnetic sensor disposed to confront the surface of the rotary drums or discs, with magnetic resistance effect elements which vary in internal resistance in response to the magnetism of the magnetic poles being provided thereon. The amount of torsion created by the load on the load side of the rotary shaft is measured as a phase difference of outputs of the magnetic sensor, and the torque is detected in terms of the angular difference between the magnetic drums or discs.

Abstract: The present invention provides a large-thrust stepping motor improved in thrust constant by provision of slots at equal intervals between adjacent N and S poles of a permanent magnet disposed on a movable member of the motor or by division of the winding for each phase of a stator of the motor into two or more sections to pass currents independently through the divisional sections in accordance with the speed of the motor.Further, the invention provides a large-thrust stepping motor using a field magnet having large magnetomotive force, the field magnet being formed by combination of a magnet substrate and permanent magnets independent from the magnet substrate.

Abstract: Magnetic poles are provided continuously with a pitch .lambda. on the peripheral portion of a drum rotated in accordance with a movement of a moving body. A magnetic sensor is provided in opposition to these poles. The sensor is formed of two magnetoresistive element pairs which are spaced from each other at .lambda./6, and the two elements in each pair are arranged in positions spaced from each other at .lambda./2. The two elements in each pair are connected in series to form a bridge circuit. The signals obtained from the nodes of the series-connected elements in the two element pairs are differentially amplified so that third harmonic wave components are eliminated, and a signal having no distortion and representative of the position or speed of the moving body can be obtained.

Abstract: A linear motor comprises a first magnetic pole having a plurality of uneven magnetic pole teeth of magnetic material arranged longitudinally at predetermined regular intervals of length, and a second magnetic pole having a yoke and plurality of uneven magnetic pole teeth made of magnetic material opposed to the first magnetic pole with a slight gap and a coil wound on each magnetic pole tooth and the permanent magnets, in which the relative position of the first and second magnetic poles in the longitudinal direction can be varied. The longitudinal lengths of the protruded portion of the second magnetic pole are substantially equal with each other. The longitudinal length of the recessed portion of the second magnetic pole is set to about one-third of the longitudinal length of the protruded portion of the first magnetic pole. The number of the protruded portions of the first magnetic pole is set to be a multiple of two.

Abstract: A synchronized induction motor comprises a stator including a cylindrical armature core having an armature winding wound thereon for generating a rotating magnetic field, a cylindrical housing for housing the stator therein, end brackets mounted at opposite open ends of the housing and having a bearing mounted at a center portion thereof a rotor shaft concentrically arranged in the stator axially of the armature core and rotatably supported by bearings, a rotor core mounted concentrically with the rotor shaft on the rotor shaft and magnetically coupled to the armature core through an air gap, end plates mounted to sandwich the rotor core, starting secondary conductors arranged axially of the rotor shaft in the vicinity of an outer circumference of the rotor core and adapted to cooperate with the stator which is held by the end plate to form an induction motor, end rings for shorting the ends of the secondary conductors on the end plates, balance rings mounted on the rotor shaft in the vicinity of the bearings

Abstract: In a stator provided with interpoles, a magnetic flux adjusting winding is provided adjacent to the radially inner end of each interpole core for adjusting the magnetic flux passing through the half of the circumferential width of the interpole core, so that the intensity of the magnetic flux passing through the radially inner end of the interpole core becomes substantially uniform along the end face of the interpole core, whereby the waveform of the commutating emf is simulated to that of the reactance voltage to widen the width of the no-spark zone during commutation thereby improving the commutation performance without appreciably modifying the original shape or structure of the stator.

Abstract: When an induction motor is speed-controlled with a variable frequency power supply including thyristor inverters, operating loss due to harmonics components is increased in a rotor of the induction motor. In order to diverge additional operating loss into an appreciable depth of the rotor to thereby suppress the increase in the operating loss, the rotor comprises a cylindrical member having a circumferential resistivity which is larger than axial and radial resistivities and circumferential permeability which is smaller than axial and radial permeabilities, and a core disposed in the cylindrical member and having an axial permeability which is smaller than circumferential and radial permeabilities.

Abstract: A permanent magnet rotor used in a synchronous motor or the like comprising a shaft, an iron core and permanent magnets is disclosed. Each of the permanent magnets which is mounted on the hollow rotor core has an arc shape, and the radial center of the arc shape is positioned on the axis of the shaft or at a point slightly deviated from the shaft axis.

Abstract: At least one circumferential slot is provided at a predetermined axial position on an armature core so as to cross axial slots receiving a plurality of coil sides of an armature winding and to communicate adjacent axial slots, and the plurality of coil sides to be generally mounted in the same axial slot are partially shifted from one slot to an adjacent one through the circumferential slot so that the coil sides of the armature winding are partially arranged to extend through adjacent slots at a fixed, predetermined circumferential distance. In this manner, the generation of commutating spark is substantially prevented and the commutating performance is improved.

Abstract: The present invention relates to a slotless, brushless motor comprising a permanent magnet rotor rotationary together with a shaft and a stationary armature coil disposed in opposition to the rotor.The armature coil comprises a coil portion concentrically wound, an adjacent coil portion formed in sequence from the coil portion and concentrically wound, a coil performed on a plane by a plurality of the coil portions, N coils (N is integer) laid on each other and different in a phase respectively, sheets disposed between said N coils and a supporting member supporting the coils and the sheets made integral.

Abstract: A magnetron comprising a cathode, an anode cylinder having a plurality of vanes disposed around the cathode for defining an interaction space between the cathode and the vanes, and a pair of permanent magnets disposed opposite to each other for producing a magnetic field in the interaction space. One of the permanent magnets is annular in shape, and this annular magnet is magnetized relative to the other magnet so that their same poles confront each other thereby reducing the size of the magnetron.

Abstract: A rotor of a permanent magnet type synchronous motor comprises a rotary shaft, a rotary supported by the rotary shaft and including an alternate disposition of a core section in the form of a lamination of a magnetic material which is stacked in the axial direction and a reinforcement section of a non-magnetic material and cavities axially formed in the core and reinforcement sections by passing therethrough, permanent magnets received in the cavities, and a strap interposed at least between the radial outer surface of respective permanent magnets and the opposing inner wall of the cavity, whereby distribution of pressures resulting from a centrifugal force due to the rotation of the rotor, which pressures are imparted on the inner wall of the cavity by the outer surface of the permanent magnet, is uniformed or shared by the strap, thereby preventing the permanent magnet from being fractured.

Abstract: A cooling device for use in a low inertia electric motor, in which there are provided a plurality of main passages for cooling air, around the outer circumferential surface of a cylindrical armature which surface is surrounded by magnetic pole pieces with gaps left therebetween. The main passages extend in the axial direction of the armature, so that cooling air is introduced under pressure from the ends of the aforesaid main passages on one side and then discharged from the other ends of the main passages, so as to cool the outer circumferential surface of the armature. At least half of those main passages are of such an arrangement that the cross sectional areas of the main passages are gradually varied from inlets of the main passages towards the outlets thereof, respectively so that a circumferential flow of air through said gaps is created.

Abstract: Magnetic poles are provided continuously with a pitch .lambda. on the peripheral portion of a drum rotated in accordance with a movement of a moving body. A magnetic sensor is provided in opposition to these poles. The sensor is formed of two magnetoresistive element pairs which are spaced from each other at .lambda./6, and the two elements in each pair are arranged in positions spaced from each other at .lambda./2. The two elements in each pair are connected in series to form a bridge circuit. The signals obtained from the nodes of the series-connected elements in the two element pairs are differentially amplified so that third harmonic wave components are eliminated, and a signal having no distortion and representative of the position or speed of the moving body can be obtained.