The purpose of the present invention is to provide a electric generator which has a simple structure while sufficiently suppressing cogging torque. A electric generator is constituted by a rotor section comprising a plurality of protrusions which is arranged linearly with constant pitch at mutually separated positions sandwiching permanent magnets, and a stator section which has a stator member comprising stator yokes, permanent magnets facing the permanent magnets, and protrusions which protrude closer to the rotor section than the permanent magnets and are arranged linearly with constant pitch at mutually separated positions sandwiching the permanent magnets, the stator member being configured such that the protrusions and the protrusions are shifted from each other by a half pitch between adjoining stator members. Further, the rotor section-side protrusions may be shifted by a half pitch instead of the stator section-side protrusions.

An axial flux electric machine has a rotatable shaft, a fixed stator core comprising a ferromagnetic material and defining an axis of rotation, and a rotor assembly comprising a plurality of permanent magnets. The rotor assembly is rotatable about the axis of rotation. An axial air gap is defined between the stator core and the rotor assembly. The rotor assembly is axially displaceable towards and away from the stator core. The rotor assembly has a first position wherein the axial gap is a predetermined width greater than zero, and a second position wherein the axial gap is zero, such that the rotor assembly and the stator core contact each other.

An electric power supply system configured to supply electric power to an electrical load device in accordance with a current requirement. The electric power supply system includes an engine configured to output rotational power, a generator configured to receive the rotational power and to supply a current to the electrical load device. The generator includes a rotor, and a stator including a winding and a stator core with the winding wound thereon, a magnetic circuit for the winding passing through the stator core, and a supply current adjustment device configured to adjust magnetic resistance of the magnetic circuit for the winding, to thereby change an inductance of the winding to adjust the supplied current. The electric power supply system further includes a control device configured to control the engine to adjust the output rotational power and to control the supply current adjustment device to adjust the inductance of the winding.

A rotary electric machine includes: a stator; a rotor; a control device that causes the stator to generate a rotating magnetic field; and a magnetic flux supply element supported by a rotary shaft so as to be rotatable relative to the rotary shaft, disposed radially inward of the rotor across a gap, and having auxiliary magnets. Each auxiliary magnet is formed such that opposite end portions thereof in the circumferential direction are radially opposed to holding magnets when the relative rotation angle of the magnetic flux supply element is a strengthening angle. The control device executes field weakening control or field strengthening control, thereby changing the relative rotation angle of the magnetic flux supply element.

In a rotating electric machine, a field element has magnetic poles of which polarities alternate in a circumferential direction. An armature includes an armature core having a circular cylindrical shape, and an armature winding of multiple phases. The field element and the armature are provided to oppose each other in a radial direction with an air gap therebetween. Either of the field element and the armature serving as a rotor. The armature winding has a coil-side conductor portion that opposes the magnetic pole of the field element in the radial direction. The coil-side conductor portions are arranged in an array in the circumferential direction. The armature winding is provided with a protruding portion that, between an inner side and an outer side in the radial direction, protrudes towards the field element, and is located further towards an outer side in an axial direction than the coil-side conductor portion is.

A linear drive unit and a machine tool having the linear drive unit, capable of being applied to various applications, while taking into consideration the balance between the thrust force and the cogging of a linear motor. The linear drive unit has a magnetic gap changing mechanism which is configured to change a magnitude of a magnetic gap between a coil and a magnet, by displacing at least one of the coil and the magnet so that the coil and the magnet approach or are separated from each other.

An electric motor having low vibration and/or noise comprises a rotor or stator comprising permanent magnets each comprising at least two pole pairs, with an internal flux gap within the permanent magnets between adjacent internal pole pairs. The internal flux gap between the internal pole pairs may be similar to an external pole to pole physical spacing between adjacent poles of adjacent magnets. The motor is suitable for use in for example a laundry washing machine or dryer or washer-dryer.

Various embodiments provide a system for moving optical elements. The system includes a first rotor and a second rotor configured to rotate in opposite directions. The system further includes a first plurality of paddles coupled to the first rotor, each of the plurality of paddles having an aperture configured to receive a first optical element, and a second plurality of paddles coupled to the second rotor, each of the plurality of paddles having an aperture configured to receive a second optical element. The first rotor and the second rotor are configured to move the first optical element between a retracted position and a desired position and to move the second optical element between the desired position and a retracted position substantially simultaneously such that a reaction torque of the first rotor cancels a reaction torque of the second rotor.

A magnetically reconfigurable robot joint motor includes a coil stator, a permanent magnet rotor and a magnetic reconfiguration unit. The magnetic reconfiguration unit is arranged around an outer periphery of the permanent magnet rotor, and a coil connected to a control circuit is wound on an outer layer of the magnetic reconfiguration unit. When it is necessary to execute low rotation speed or zero rotation speed operating conditions, the control circuit inputs current pulses of different strengths, so that the magnetic reconfiguration unit obtains permanent magnetization of corresponding degree, and generates a magnetic field which acts together with a magnetic field of the permanent magnet rotor, so as to maintain a torque required for output.

A permanent-magnet synchronous machine comprises a rotor and a stator for holding at least one first stator winding and a second stator winding which is electrically insulated from said first stator winding. The second stator winding has a smaller conductor cross section and a larger number of turns than the first stator winding, wherein a first operating voltage is provided for motor operation of the first stator winding and a second operating voltage is provided for motor operation of the second stator winding. The second operating voltage has a higher rated voltage than a rated voltage of the first operating voltage.