Abstract: A motor is basically provided with a stator, a rotor, a low permeability layer and a current control device. The stator includes a magnetic stator core and a stator winding. The rotor includes a rotor core and a plurality of permanent magnets arranged to form N and S poles of the rotor. The low permeability layer has a lower magnetic permeability than the rotor core and extends between each of the N and S poles in a direction generally parallel to the magnetic flux paths of the permanent magnets such that the permanent magnets and the low permeability are arranged to obstruct the magnetic flux between the N and S poles to provide a forward salient pole characteristic. The current control device produces a current whose phase is shifted such that the magnetic flux of the permanent magnets intensifies.

Abstract: A motor is basically provided with a stator, a rotor, a low permeability layer and a current control device. The stator includes a magnetic stator core and a stator winding. The rotor includes a rotor core and a plurality of permanent magnets arranged to form N and S poles of the rotor. The low permeability layer has a lower magnetic permeability than the rotor core and extends between each of the N and S poles in a direction generally parallel to the magnetic flux paths of the permanent magnets such that the permanent magnets and the low permeability are arranged to obstruct the magnetic flux between the N and S poles to provide a forward salient pole characteristic. The current control device produces a current whose phase is shifted such that the magnetic flux of the permanent magnets intensifies.

Abstract: A rotor for a rotary electric machine includes a rotor core made of magnetic material, and being in the form of a disk, and a plurality of magnet sets each including a pair of permanent magnets whose polarities are identical to each other. The magnet sets are arranged circumferentially in the rotor core so that the polarities of the magnet sets change alternately. The rotor core includes nonmagnetic portions each formed between adjacent two of the magnet sets.

Abstract: A rotary electric machine includes a rotor including a plurality of magnet sections arranged along a rotational direction of the rotor so that polarities of the magnet sections change alternately, and a stator including armature coils, and being disposed to confront the rotor across an air gap. Permanent magnet flux which is not linked with one of the air gap and the armature coils is higher than permanent magnet flux which is linked with the air gap and the armature coils in a no-load state.

Abstract: A stator for a two rotor single stator type electric motor is described. The electric motor has inner and outer rotors that are rotated independently within and around a stator upon application of current to the stator. The stator comprises a stator core including a plurality of stator teeth that are circumferentially arranged around a common axis. Each stator tooth includes a plurality of flat magnetic steel plates that are aligned along the common axis while intimately and closely contacting to one another. The stator further comprises at least one connecting ring plate that is coaxially installed in the stator core in such a manner that the ring plate is intimately put between adjacent two of the flat magnetic steel plates of each stator tooth. The ring plate is of an endless annular member.

Abstract: An electric rotating machine, including a stator including circumferentially arranged stator teeth, inner and outer rotors disposed coaxially with the stator inside and outside thereof, an inner armature coil group including a plurality of inner armature coils wound on the stator teeth on a side of the inner rotor, the inner armature coil group being energized to drive the inner rotor, and an outer armature coil group including a plurality of outer armature coils wound on the stator teeth on a side of the outer rotor, the outer armature coil group being energized to drive the outer rotor. The inner and outer armature coil groups have electric connections between the inner armature coils and between the outer armature coils so as to prevent occurrence of magnetic interference between the inner and outer armature coil groups, respectively.

Abstract: In a rotating machine, a plurality of laminated electromagnetic steel sheets constitutes at least one of a stator and a rotor and a plurality of permanent joining portions to unit each of the laminated electromagnetic steel sheets to form a corresponding one of the stator and the rotor, the plurality of permanent joining portions being set to be located at positions at which an integration value of a magnetic flux density with respect to a plane enclosed with the permanent joining portions is always zeroed.

Abstract: A rotary electric machine includes inner and outer rotors each including permanent magnets, and a stator including stator coils, disposed between the inner and outer rotors. The inner rotor further includes outer surface portions serving as a yoke portion of an outer magnetic circuit for magnetic flux synchronous with the outer rotor, and the outer rotor further includes outer portions each located on an outer side of one of the outer permanent magnet, and arranged to serve as a yoke portion of an inner magnetic circuit for magnetic flux synchronous with the inner rotor.

Abstract: A rotary electric motor is provided which comprises an annular first rotor, an annular stator disposed concentric with and radially outside the first rotor, and an annular second rotor disposed concentric with and radially outside the stator, the stator including a stator core made up of a plurality of stator pieces that are arranged in a circular array and electrically independently from each other, coils wound around the respective stator pieces, annular first and second brackets disposed on opposite axial ends of the stator core, a fastening device passing through holes of the first and second brackets and fixedly holding the stator core between the first and second brackets, and an induction current suppressing device suppressing an induction current that is produced in response to a variation of magnetic flux of each of the coils and flows through the fastening device.

Abstract: A rotary electric machine includes a rotor including a plurality of magnet sections arranged along a rotational direction of the rotor so that polarities of the magnet sections change alternately, and a stator including armature coils, and being disposed to confront the rotor across an air gap. Permanent magnet flux which is not linked with one of the air gap and the armature coils is higher than permanent magnet flux which is linked with the air gap and the armature coils in a no-load state.

Abstract: A rotor for a rotary electric machine includes a rotor core made of magnetic material, and being in the form of a disk, and a plurality of magnet sets each including a pair of permanent magnets whose polarities are identical to each other. The magnet sets are arranged circumferentially in the rotor core so that the polarities of the magnet sets change alternately. The rotor core includes nonmagnetic portions each formed between adjacent two of the magnet sets.

Abstract: In driving method and system for an electrical rotating machine, the electrical rotating machine comprising two rotors, each rotor being independently driven by means of a compound current generated by a multi-phase inverter, and a stator on which a plurality of stator coils are wound, the respective stator coils are divided into a plurality of groups thereof, a total current sum of each group thereof being zeroed and neutral points of the stators belonging to the respective groups being interconnected and drive pulses are supplied to a plurality of inverter arms of the inverter associated with one group of the stator coils independently of those supplied to other inverter arms of the inverter associated with the other group of the stator coils.

Abstract: An electric rotating machine, including a stator including circumferentially arranged stator teeth, inner and outer rotors disposed coaxially with the stator inside and outside thereof, an inner armature coil group including a plurality of inner armature coils wound on the stator teeth on a side of the inner rotor, the inner armature coil group being energized to drive the inner rotor, and an outer armature coil group including a plurality of outer armature coils wound on the stator teeth on a side of the outer rotor, the outer armature coil group being energized to drive the outer rotor. The inner and outer armature coil groups have electric connections between the inner armature coils and between the outer armature coils so as to prevent occurrence of magnetic interference between the inner and outer armature coil groups, respectively.

Abstract: A multi-shaft, multi-layer motor has a stator coaxially disposed between inner and outer rotors which are driven independently by a compound current. For cooling stator coils, first through last branch coolant passages are arranged around the axis. The upstream ends of the first through last branch passages are arranged in sequence circumferentially along a distributing circumferential passage in a direction away from a common introduction port for introducing the coolant into the distributing circumferential passage, and the downstream ends of the first through last branch passages are distributed in sequence circumferentially along a collecting circumferential passage in a direction toward a common discharge port for discharging the coolant from the collecting circumferential passage.

Abstract: In method and apparatus for controlling a current of an electrical rotating machine, at least one high-order higher harmonic wave current is superposed on a fundamental wave current, the high-order higher harmonic wave current having current components one phase of which is different by 90 [el. deg] from a high-order high harmonic wave component included in a magnetic flux distribution generated by at least one magnet of the rotating machine and the other phase of which is the same as that of the high-order higher harmonic wave component included therein and the high-order harmonic wave current component is superposed on the fundamental wave current to the rotating machine.

Abstract: A rotary electric machine includes inner and outer rotors each including permanent magnets, and a stator including stator coils, disposed between the inner and outer rotors. The inner rotor further includes outer surface portions serving as a yoke portion of an outer magnetic circuit for magnetic flux synchronous with the outer rotor, and the outer rotor further includes outer portions each located on an outer side of one of the outer permanent magnet, and arranged to serve as a yoke portion of an inner magnetic circuit for magnetic flux synchronous with the inner rotor.

Abstract: A rotary electric machine having a plurality of rotors is driven by a compound current. A voltage to be applied to a stator of the rotary electric machine is in the form of a compound rectangular or stepwise voltage composed of a plurality of superposed components each of which is a rectangular or stepwise wave having a frequency corresponding to the revolution speed of a unique one of the rotors.

Abstract: In a rotating machine, a plurality of laminated electromagnetic steel sheets constitutes at least one of a stator and a rotor and a plurality of permanent joining portions to unit each of the laminated electromagnetic steel sheets to form a corresponding one of the stator and the rotor, the plurality of permanent joining portions being set to be located at positions at which an integration value of a magnetic flux density with respect to a plane enclosed with the permanent joining portions is always zeroed.

Abstract: A current detection device used for a plurality of rotating electric machines is provided. The rotating electric machines are supplied with a composite current containing a plurality of frequency components from an single inverter and the frequency is set in response to the rotational angular velocity of one rotating electric machine. The current detection device is provided with a current sensor which detects only current components at a single frequency in the composite current. The current sensor detects the currents in a set of supply lines, the supply lines of which being collected and passing through the current sensor so that the current components of the frequency different from the single frequency cancel out to zero in the set of supply lines.

Abstract: In a method of connecting an electric rotating machine, a second predetermined number of feeders on each of which a total sum of a current flow is zeroed is selected when the second predetermined number of the feeders are interconnected at a neutral point by a third predetermined number of groups from among a first predetermined number of the feeders and each coil of the rotating machine is connected between a corresponding one of the first predetermined number of the feeders and a corresponding one of the second predetermined number of the feeders for each of the third predetermined number of the groups, a product between the second predetermined number and the third predetermined number corresponding to that between a number of current phases in the compound current for driving a corresponding one of rotors and a number of pole pairs of the corresponding one of the rotors.