A stator and a rotor suitable for use in an electric motor or generator. The stator comprises a plurality of stator cons and a support for holding the coils around a rotor of the motor. A cylindrical sleeve is mounted radially inwardly on the support to form a barrier in use between cooling fluid passing over the coils and a rotor located within the stator. The rotor comprises a hub, a plurality of rotor segments, and a plurality of permanent magnets. The segments are arranged around the hub in a ring, with the permanent magnets disposed between the segments. A radially outwardly facing exposed surface of each magnet is spaced radially inwardly from an outer cylindrical profile defined by the segments.

A stator and a rotor suitable for use in an electric motor or generator. The stator comprises a plurality of stator cons and a support for holding the coils around a rotor of the motor. A cylindrical sleeve is mounted radially inwardly on the support to form a barrier in use between cooling fluid passing over the coils and a rotor located within the stator. The rotor comprises a hub, a plurality of rotor segments, and a plurality of permanent magnets. The segments are arranged around the hub in a ring, with the permanent magnets disposed between the segments. A radially outwardly facing exposed surface of each magnet is spaced radially inwardly from an outer cylindrical profile defined by the segments.

A permanent magnet carrier, which could be a rotor or stator of an electric machine, includes a first non-magnetic ring and a second non-magnetic ring. Between the rings are soft magnetic pole elements. The soft magnetic pole elements each connect to the first and second non-magnetic rings and the soft magnetic pole elements are separated from each other by the first and second non-magnetic rings. Permanent magnets are disposed between the soft magnetic pole elements.

A permanent magnet carrier, which could be a rotor or stator of an electric machine, includes a first non-magnetic ring and a second non-magnetic ring. Between the rings are soft magnetic pole elements. The soft magnetic pole elements each connect to the first and second non-magnetic rings and the soft magnetic pole elements are separated from each other by the first and second non-magnetic rings. Permanent magnets are disposed between the soft magnetic pole elements.

A rotor includes a rotor core in which magnetic steel plates widening in a radial direction with respect to a central axis of the rotor core are laminated in an axial direction, and magnets provided to the rotor core. Each of the magnetic steel plates includes a base portion positioned outside the central axis in the radial direction and piece-shaped portions each spaced by a gap from an outer side in the radial direction of the base portion and arranged in a circumferential direction of the base portion at predetermined intervals. The magnets are positioned at the gaps and arranged in the circumferential direction at predetermined intervals, a length in the radial direction from a central portion of the magnet in the circumferential direction is a central portion length in a cross section perpendicular to the axial direction, a length in the radial direction from an end portion of the magnet in the circumferential direction is an end portion length, the central portion length and the end portion length are lengths in parallel or substantially in parallel, and the central portion length is greater than the end portion length.

A rotor includes a rotary shaft, a first permanent magnet supported by the rotary shaft, and a second permanent magnet supported by an outer periphery of the first permanent magnet and having a magnetic pole stronger than a magnetic pole of the first permanent magnet . The second permanent magnet includes a plurality of magnet parts arranged at intervals in a circumferential direction of the first permanent magnet. A first width as a width in the circumferential direction of each of the plurality of magnet parts at a central part of the first permanent magnet in an axial direction of the rotary shaft is wider than a second width as a width in the circumferential direction of each of the magnet parts at an end part of the first permanent magnet in the axial direction.

A rotor includes a rotary shaft, a first permanent magnet supported by the rotary shaft, and a second permanent magnet supported by an outer periphery of the first permanent magnet and having a magnetic pole stronger than a magnetic pole of the first permanent magnet . The second permanent magnet includes a plurality of magnet parts arranged at intervals in a circumferential direction of the first permanent magnet. A first width as a width in the circumferential direction of each of the plurality of magnet parts at a central part of the first permanent magnet in an axial direction of the rotary shaft is wider than a second width as a width in the circumferential direction of each of the magnet parts at an end part of the first permanent magnet in the axial direction.

An electric motor includes a case, a stator having stator windings, a rotor having a rotor shaft, and at least one main rotor bearing coupling the rotor shaft to the case. Common mode charge builds up on the rotor due to imbalances of the stator. The at least one main rotor bearing has a first electrical resistance between the rotor shaft and the case. The electric motor further includes a rotor discharge bearing coupling the rotor shaft to the case. The rotor discharge bearing has a second electrical resistance between the rotor shaft and the case that is less than the first electrical resistance, causing the common mode charge to discharge through the rotor discharge bearing. In a differing embodiment, a rotor discharge brush coupled between the case and the rotor shaft along the longitudinal axis of the rotor shaft discharges the common mode charge.

An electric motor includes a case, a stator having stator windings, a rotor having a rotor shaft, and at least one main rotor bearing coupling the rotor shaft to the case. Common mode charge builds up on the rotor due to imbalances of the stator. The at least one main rotor bearing has a first electrical resistance between the rotor shaft and the case. The electric motor further includes a rotor discharge bearing coupling the rotor shaft to the case. The rotor discharge bearing has a second electrical resistance between the rotor shaft and the case that is less than the first electrical resistance, causing the common mode charge to discharge through the rotor discharge bearing. In a differing embodiment, a rotor discharge brush coupled between the case and the rotor shaft along the longitudinal axis of the rotor shaft discharges the common mode charge.

A ventilator for a control device for a vehicle may include a stator having a plurality of coils and a rotor comprising a hollow cylinder. An impeller may include a plurality of blades, the impeller being coupled to the hollow cylinder such that a rotation of the hollow cylinder causes a rotation of the impeller. The hollow cylinder may have a plurality of magnets. The stator may partially encompasses the rotor.