A rotor for an electric machine is disclosed herein. The rotor comprises: a central shaft; a rotor drum arranged radially outward of the central shaft, wherein the rotor drum comprises a hollow cylinder for carrying permanent magnets on an inner and/or outer surface of the hollow cylinder, and wherein the rotor drum is coaxial with both the central shaft and a rotational axis of the rotor; and a cap arranged to couple the central shaft to the rotor drum to enable the rotor drum and central shaft to rotate together about the rotational axis. An inner portion of the cap is coupled to the central shaft at a first position along the length of the rotational axis, and an outer portion of the cap is coupled to the rotor drum at a second position along the length of the rotational axis. The first position is at a different length along the rotational axis to the second position.

A rotor for an electric machine may include a stack of ferrous laminations and a rotor core. The stack may be divided into a plurality of segments in a circumferential direction. At least one permanent magnet may be arranged between two adjacent segments of the plurality of segments. Each of the plurality of segments may have an opening extending in a radial direction outwards from a radially inner surface. The rotor core may connect the two adjacent segments. The rotor core may be formed via casting a non-ferrous material in a space disposed radially inwards of the plurality of segments and into the radially outwards extending opening of each of the plurality of segments. The opening of each of the plurality of segments may have a generally fir-tree shaped section profile.

A rotor for an electric machine may include a stack of ferrous laminations and a rotor core. The stack may be divided into a plurality of segments in a circumferential direction. At least one permanent magnet may be arranged between two adjacent segments of the plurality of segments. Each of the plurality of segments may have an opening extending in a radial direction outwards from a radially inner surface. The rotor core may connect the two adjacent segments. The rotor core may be formed via casting a non-ferrous material in a space disposed radially inwards of the plurality of segments and into the radially outwards extending opening of each of the plurality of segments. The opening of each of the plurality of segments may have a generally fir-tree shaped section profile.

A plurality of conductive films are arranged so that their thickness directions intersect with respect to a direction of a magnetic flux generated from a plurality of magnetic poles. Each of the plurality of conductive films is configured so that a conductivity in a longitudinal direction is larger than a conductivity in a thickness direction, and a conductivity in a longitudinal direction is larger than a conductivity in a width direction.

A plurality of conductive films are arranged so that their thickness directions intersect with respect to a direction of a magnetic flux generated from a plurality of magnetic poles. Each of the plurality of conductive films is configured so that a conductivity in a longitudinal direction is larger than a conductivity in a thickness direction, and a conductivity in a longitudinal direction is larger than a conductivity in a width direction.

A motor includes a rotor rotatable about a central axis and a stator opposing the rotor in a radial direction. The rotor includes an inner core extending along the central axis, a magnetic pole portions located radially outward of the inner core and arranged along a circumferential direction, and a holder holding the inner core and the magnetic pole portions. At least a portion of the magnetic pole portions includes two layers including a magnet and an outer core located radially outward or inward of the magnet and extending along the central axis. The holder includes a flange portion located on a one axial side of the inner core and the magnetic pole portions.

A motor control apparatus excites an excitation phase targeted for excitation among a plurality of excitation phases of a motor. The motor control apparatus, in a state in which a rotor of the motor is stopped, excites an excitation phase corresponding to a stop position of the rotor among the plurality of the excitation phases, and measures a physical quantity which changes in accordance with an inductance of at least one of a plurality of coils configuring the plurality of excitation phases. The motor control apparatus estimates a temperature of the rotor from a measurement value of the measured physical quantity, and decides a parameter value for control of the motor based on the estimated temperature.

Electric machine having: a shaft; a rotor with permanent magnets that is fitted to the shaft; a stator having a magnetic core which consists of a series of laminations made of ferromagnetic material and longitudinally crossed by a plurality of stator slots; and a stator winding having a plurality of rigid bars that are inserted in corresponding stator slots and that are covered, on the outside, with an insulating coating. The rotor has a plurality of magnetic elements, which are arranged beside one another around the rotation axis so as to form a closed ring. Each magnetic element is formed by a plurality of permanent magnets which are axially arranged one after the other according to a Halbach array.

Electric machine having: a shaft; a rotor with permanent magnets that is fitted to the shaft; a stator having a magnetic core which consists of a series of laminations made of ferromagnetic material and longitudinally crossed by a plurality of stator slots; and a stator winding having a plurality of rigid bars that are inserted in corresponding stator slots and that are covered, on the outside, with an insulating coating. The rotor has a plurality of magnetic elements, which are arranged beside one another around the rotation axis so as to form a closed ring. Each magnetic element is formed by a plurality of permanent magnets which are axially arranged one after the other according to a Halbach array.

An electric motor includes a rotor and a stator core. The rotor has an outer circumferential wall around a rotational axis. The rotor includes a magnet and a groove. The magnet has a magnetic pole center. The groove is provided in the outer circumferential wall to be recessed toward the rotational axis to have a bottom point. An angle between a first virtual line connecting the bottom point of the groove and the rotational axis and a second virtual line connecting the magnetic pole center and the rotational axis viewed along the rotational axis is from 30% to 47% of an electric angle of 90 degrees. The stator core includes an inner circumferential wall. The stator core includes teeth projecting from the inner circumferential wall toward the stator axis. A cross-sectional shape of each teeth includes a first protrusion and a second protrusion.