A rotor includes a first rotating body and a second rotating body. The first rotating body includes a first rotor core and first magnets arranged in a circumferential direction. An outer side surface of the first rotating body includes first outer side surfaces curved in a circular arc shape and arranged in the circumferential direction. The first outer side surface is an outer side surface of the first magnet or an outer side surface of the first rotor core. The second rotating body is positioned on a side lower than the first rotating body in an axial direction and includes a second rotor core and second magnets arranged in the circumferential direction. An outer side surface of the second rotating body includes second outer side surfaces curved in a circular arc shape and arranged in the circumferential direction.

A motor includes a stator having a winding, and a rotor. The rotor rotates by receiving a rotational magnetic field generated by drive current supplied to the winding. The winding includes a first winding and a second winding, the first and second windings both being excited at the same timing by the drive current. The first winding and the second winding are connected in series. The rotor includes a first pole section and a second pole section. The second pole section faces the second winding at the rotation position of the rotor at which the first pole section faces the first winding. The magnetic force exerted on the stator by the second pole section is weaker than that exerted by the first pole section.

Provided are rotor of permanent magnet surface affixation-type rotating machine and its manufacturing method, where permanent magnets previously magnetized are easily fixable at proper positions while restricting cost. In rotor of permanent magnet surface affixation-type rotating machine, including cylindrical rotor shaft 11, columnar guides 13 extending along axial direction of rotor shaft 11 and disposed in circumferential direction at regular intervals, and permanent magnets 12 previously magnetized and installed on surface of rotor shaft 11 and between the adjacent guides 13, axial length of guide 13 is formed longer than that of region where permanent magnets 12 are installed, guide 13 is disposed on surface of rotor shaft 11 such that guide 13 projects toward both sides in axial direction from region where permanent magnets 12 are installed, and projection portions 13a, 13b projecting in axial direction from region where permanent magnets 12 are installed are fixed to rotor shaft 11.

In a rotary dynamo-electric reluctance machine, a rotor includes regions of differing magnetic resistances. One region includes material of a first magnetic conductivity. Another region includes material of a second magnetic conductivity which is lower than the first magnetic conductivity. The region having the second magnetic conductivity includes permanent-magnetic material to increase a torque of the reluctance machine.

A permanent magnet electric machine (PM machine) for a vehicle or other system includes a rotor assembly, fixed permanent magnets, a stator, an actuator, and one or more repositionable/moveable flux-shunting elements. The flux-shunting element is repositioned to control flux at specific operating points of the PM machine. The rotor assembly has a rotor coaxially surrounding and coupled to a rotor shaft. The permanent magnets are mounted to or in the rotor, and the moveable flux-shunting element is positioned between the rotor shaft and a respective one of the permanent magnets. Inboard and outboard ends of each respective permanent magnet may be oriented toward the rotor shaft and stator, respectively. The actuator selectively positions the moveable flux-shunting element at one or more operating points of the PM machine to vary reluctance in a magnetic circuit formed by the stator and rotor assembly.

In the present electric driving apparatus, coils that constitute a first armature winding and coils that constitute a second armature winding are arranged so as to alternate in a circumferential direction, and a control portion is configured so as to perform single-system driving when one of a first system and a second system fails, the single-system driving stopping driving of an inverter of the system that has failed, and controlling driving of the inverter of the system that has not failed to supply inverter phase currents to an armature winding of the system that has not failed such that the inverter phase currents are set to a second upper limit value that is greater than a first upper limit value.

A permanent magnet synchronous motor includes a stator, a rotor rotatable relative to the stator, and a magnetic structure with a low coercive force magnet and a high coercive force magnet that are arranged magnetically in series with respect to each other to define a pole-pair of the permanent magnet synchronous motor. A magnetization level of the low coercive force magnet is changeable by a stator current pulse such that a stator magnetomotive force at a rated current is equal to or larger than a product of a magnetic field strength for fully magnetizing the low coercive force magnet and a thickness of the low coercive force magnet.

A rotor includes a first rotating body and a second rotating body. The first rotating body includes a first rotor core and first magnets arranged in a circumferential direction. An outer side surface of the first rotating body includes first outer side surfaces curved in a circular arc shape and arranged in the circumferential direction. The first outer side surface is an outer side surface of the first magnet or an outer side surface of the first rotor core. The second rotating body is positioned on a side lower than the first rotating body in an axial direction and includes a second rotor core and second magnets arranged in the circumferential direction. An outer side surface of the second rotating body includes second outer side surfaces curved in a circular arc shape and arranged in the circumferential direction.

Disclosed is a resolver, which includes a stator having at least one excitation coil and at least one output coil, and a rotor disposed at a center space in the stator with a predetermined gap from the stator, the rotor rotating based on a rotary shaft to change a gap permeance with respect to the stator, wherein an area ratio (Ar/As) between the stator and the rotor satisfies Equation 1 below to prevent magnetic saturation of the resolver, improve measurement precision and reduce manufacture costs without increasing a size or weight of the resolver:
0.22Ar/As0.37Equation 1 where As represents a sectional area of the stator, and Ar represents a sectional area of the rotor.

The present invention may provide a motor including a rotor and a stator disposed to correspond to the rotor, wherein the rotor includes a rotor core and a magnet disposed on the rotor core, a tooth of the stator includes a first surface facing the magnet, the magnet includes a second surface in contact with the rotor core and a third surface which is spaced apart from the second surface and faces the first surface, the third surface includes a flat surface, and a first length which is a shortest distance of the flat surface is in the range of 46% to 50% of a second length of a shortest distance of the first surface.