A downhole rotating machine includes a stator having stator windings and corresponding magnetic flux guides and a rotor having a plurality of magnets configured to cooperate with the stator windings and the corresponding magnetic flux guides to generate a magnetic field in a magnetic gap that is substantially parallel to an axis of rotation of the rotor, wherein the magnetic gap provides a magnetic gap separation between the plurality of magnets and the corresponding magnetic flux guides that is at least five percent of an overall diameter of the downhole rotating machine. A method of operating a downhole tool in a wellbore and a downhole tool are also provided.

A rotor for an electrical machine includes a rotor body and an axis of revolution which extends in an axial direction and about which the rotor body is rotatable. The rotor further includes an outer casing surface which delimits the rotor body, at least one pole arrangement, and a movement mechanism for the at least one pole arrangement. The movement mechanism is designed such that the at least one pole arrangement is movable about a rotation axis which is oriented substantially parallel to the axis of revolution of the rotor. The at least one pole arrangement is also movable about the rotation axis in addition to rotation about the axis of revolution of the rotor.

An internal rotor for an electric machine includes a rotational axis, an outer circumferential face which delimits the internal rotor, a pole arrangement comprising a centroid, and an actuating mechanism for moving the pole arrangement towards the rotational axis or away from the rotational axis to set a first spacing between the outer circumferential face and the centroid. In an example embodiment, the actuating mechanism has an actuator for moving the pole arrangement. The actuator has a hydraulically operable piston, a pneumatically operable piston, an electric motor actuator, or converts an axial force to a radial force. In an example embodiment, the actuating mechanism is operatively connected to the pole arrangement. The actuating mechanism is arranged between the rotational axis and the pole arrangement, or the actuating mechanism is arranged between the outer circumferential face and the pole arrangement.

The present invention relates to a variable-flux motor comprising: a stator having stator coils; and a rotor disposed to be rotatable with respect to the stator with an air gap interposed therebetween, wherein the rotor comprises: a rotor core; a fixed magnet disposed along the radial direction of the rotor core, and of which one end portion is disposed adjacently to the air gap; and a variable magnet disposed inside the fixed magnet along the radial direction of the rotor core, and the variable magnet is formed such that a magnetic flux thereof varies when a preset current is applied to the stator coils. Therefore, use of an expensive permanent magnet can be excluded.

A movement device comprising a first and a second assembly, the first assembly being composed of a plurality of subassemblies. Two directly adjacent subassemblies are conterminous with each other at a boundary line. The two subassemblies form at least one first pair of directly adjacent first permanent-magnet arrangements that are separated from each other by the boundary line. The two first permanent-magnet arrangements of the first pair are each arranged with a boundary distance from the boundary line that is reduced with respect to a spacing distance, such that they mutually have the spacing distance. There are present in each case within the said two subassemblies at least one second pair of directly adjacent first permanent-magnet arrangements that mutually have the spacing distance.

A voltage limit ellipse is defined in a d-q coordinate system of a rotating electric machine by d-axis and q-axis currents flowing through an armature coil when the magnitude of a voltage vector applied to the armature coil is equal to a voltage limit value. The product of the number of electrical conductor sections per pole in each phase and the number of poles of the rotating electric machine is set to have, when the rotational speed of the rotating electric machine is equal to a maximum rotational speed, the center of the voltage limit ellipse located outside an electric-current limit circle and in a negative d-axis region in the d-q coordinate system and a positive-d-axis-side vertex of the voltage limit ellipse located inside or on the electric-current limit circle.

A current supply system configured to receive a rotational driving force and supply a current for driving an electrical load device in accordance with a current requirement. The current supply system includes a rotor, including a permanent magnet, configured to receive the rotational driving force, and a stator including a stator core with a winding wound thereon, a magnetic circuit for the winding passing through the stator core, the rotational driving force causing the rotor and the stator to generate the current. The current supply system further includes a supply current adjustment device configured to change magnetic resistance of the magnetic circuit for the winding in accordance with the current requirement, to thereby change an inductance of the winding to adjust the generated current.

A transmission for outputting a rotational torque in accordance with a torque requirement. The transmission includes a generator, a motor and a control device. The generator includes a rotor configured to receive first rotational power from an engine, a stator including a stator core with a 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 a current outputted by the generator. The motor is driven by the current outputted from the generator, to thereby output second rotational power. The control device controls the supply current adjustment device to change the inductance of the winding, in accordance with the torque requirement.

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 vehicle includes a vehicle body, an electromotive driving unit mounted on the vehicle body, an engine operable with a liquid fuel, a generator that generates electric power, and a control device including a power generation control unit and an electric power output unit. The power generation control unit outputs a signal for controlling the engine and the generator, the electric power output unit outputting electric power generated by the generator to the electromotive driving unit. The control device in combination with the engine and the generator constitutes a physically integrated unit that is mountable to and dismountable from the vehicle body. The control device is configured to output a store visit promotion signal to an informing device while the physically integrated unit is mounted on the vehicle body, to prompt a visit to a store where the physically integrated unit is replaceable.