A motor for an air compressor is provided. The motor includes a stator including a first coil to generate a magnetic flux for driving the motor and a second coil positioned in a space the same as a space for the first coil to increase an inductance, and a rotator to mutually interact with the stator to rotate.

A rotating electrical machine capable of obtaining a higher torque while limiting the amount of permanent magnets used. A magnetic pole of a rotor includes an auxiliary magnet embedded in a rotor core and at least one main magnet arranged on an outer circumferential side than the auxiliary magnet of the rotor. In each magnetic pole, the distance from an end of the main magnet, the end facing the auxiliary magnet, to the auxiliary magnet facing the main magnet is shorter than the length of the main magnet in the radial direction. In a cross-section orthogonal to the rotation axis of the rotating electrical machine, the main magnets of each magnetic pole are arranged so as to be asymmetrical about a virtual line passing the rotation axis and axisymmetrically dividing the auxiliary magnet.

There are presented various embodiments disclosed in this application, including methods and systems of arranging permanent magnets to switch from a first configuration designed for a first torque output to a second configuration designed for a second torque output.

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 rotary electrical machine including an annular stator having a stator core around which an armature winding is wound, and a rotor arranged on an inner circumference of the stator, a permeance of a q-axis magnetic circuit is made larger than a permeance of a d-axis magnetic circuit. The machine includes a switch for supplying power to a field winding and controller. The controller calculates the duty ratio on the condition that an upper limit of the duty ratio of the switch is a predetermined value and turns on/off the switch based on the calculated ratio. The predetermined value is set to a value larger than the duty ratio corresponding to the field current that gives the maximum reduction amount of the inductance of the field winding with respect to an increasing amount of the field current in a range that the current can take and is less than 100%.

A rotary electrical machine includes a switch for supplying power to a field winding and controller. A ratio of an on-time to one switching cycle of the switch is defined as a duty ratio, and a duty ratio which is larger than the duty ratio corresponding to the field current that gives the maximum reduction amount of the inductance of the field winding with respect to an increasing amount of the field current in a range that the current can take and has a value less than 100% is set as a predetermined value. The controller calculates the duty ratio wherein an upper limit of the ratio is the predetermined value and turns on/off the switch based on the calculated duty ratio. Also, a relay and abnormality detection part that detects abnormality in the switch. The relay is switched to off in response to the occurrence of abnormality being detected.

Provided is a variable magnetic flux-type permanent magnet rotary electric machine wherein a leakage magnetic flux leaking from a certain permanent magnet included in the rotor core to a permanent magnet circumferentially adjacent on either side of the certain permanent magnet is controlled by q-axis current and thereby a magnetic flux emanating from the certain permanent magnet and linking with the armature coil wound on the stator is controlled without forming a mechanically weak part in the rotor core.

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 rotating electrical machine capable of obtaining a higher torque while limiting the amount of permanent magnets used. A magnetic pole of a rotor includes an auxiliary magnet embedded in a rotor core and at least one main magnet arranged on an outer circumferential side than the auxiliary magnet of the rotor. In each magnetic pole, the distance from an end of the main magnet, the end facing the auxiliary magnet, to the auxiliary magnet facing the main magnet is shorter than the length of the main magnet in the radial direction. In a cross-section orthogonal to the rotation axis of the rotating electrical machine, the main magnets of each magnetic pole are arranged so as to be asymmetrical about a virtual line passing the rotation axis and axisymmetrically dividing the auxiliary magnet,

A motor for an air compressor is provided. The motor includes a stator including a first coil to generate a magnetic flux for driving the motor and a second coil positioned in a space the same as a space for the first coil to increase an inductance, and a rotator to mutually interact with the stator to rotate.