Selective permeability rotor structure for interior permanent magnet machine

A motor vehicle comprising:

• a radial flux electric motor configured to generate torque for propulsion of the motor vehicle, the radial flux electric motor including:
• a stator having a radially inner stator surface and stator windings arranged thereon;
• and
• a rotor mounted inside the stator and configured to rotate relative thereto about a rotational axis, wherein the rotor includes:
• a rotor core constructed from a ferromagnetic material and defined by a rotor outer surface establishing an airgap between the rotor and the stator;
• a plurality of magnetic poles set in the rotor core and configured to generate magnetic flux;
• and
• inserts constructed from a material having relatively low magnetic permeability in at least one geometric direction, wherein each insert is mechanically fixed to the rotor core to thereby control magnetic flux distribution and minimize flux leakage inside the rotor, and each insert defines a radial magnetic permeability and a circumferential magnetic permeability relative to the rotational axis, and wherein magnitude of the radial magnetic permeability is different from magnitude of the circumferential magnetic permeability.

A radial flux electric motor comprising:

• a stator having a radially inner stator surface and stator windings arranged thereon;
• and
• a rotor mounted inside the stator and configured to rotate relative thereto about a rotational axis, wherein the rotor includes:
• a rotor core constructed from a ferromagnetic material having relatively high magnetic permeability and defined by a rotor outer surface establishing an airgap between the rotor and the stator, wherein:
• the rotor core includes multiple adjacent rotor laminations arranged along the rotational axis;
• and
• the adjacent rotor laminations are electrically isolated from one another via a dielectric element;
• a plurality of magnetic poles set in each of the adjacent rotor laminations and configured to generate magnetic flux;
• and
• inserts constructed from a material having relatively low magnetic permeability in at least one geometric direction, wherein:
• each insert is mechanically fixed to the rotor core to thereby control magnetic flux distribution and minimize flux leakage inside the rotor;
• each insert defines a radial magnetic permeability and a circumferential magnetic permeability relative to the rotational axis, and wherein magnitude of the radial magnetic permeability is different from magnitude of the circumferential magnetic permeability;
• and
• the inserts of adjacent rotor laminations are arranged out of phase with one another.