Permanent magnet machine with segmented sleeve for magnets

A rotor assembly for a permanent magnet machine configured to rotate about a longitudinal axis, the rotor assembly comprising:

• a rotor shaft;
• and
• a plurality of rotor modules configured to generate a magnetic field, whose magnetic field interacts with a stator magnetic field to produce a torque, the plurality of rotor modules disposed about the rotor shaft in an end-to-end axial alignment, each of the plurality of rotor modules defining a rotor core comprising:
• a plurality of permanent magnets;
• and
• a sleeve component including a rotor including an axially extending radial base rotor land portion defining a dovetail coupling oriented tangentially relative to the rotor shaft and coupling the radial base rotor land portion thereto the rotor shaft, the rotor further including an axially extending radial top rotor land portion radially spaced a distance from the axially extending radial base rotor land portion, and a radially extending rotor disc portion spanning therebetween the axially extending radial top rotor land portion and the axially extending radial base rotor land portion to provide centrifugal stiffening and a plurality of cavities defined therein the sleeve component by the axially extending radial top rotor land portion and a portion of the radially extending rotor disc portion, wherein at least one of the plurality of permanent magnets is disposed within one of the plurality of cavities formed in the sleeve component to retain the at least one permanent magnet therein and form an interior permanent magnet motor,
• wherein a magnetic axial flux path is defined from the disc portion of the at least one rotor module to another disc portion of another of the at least one rotor module through a stator portion extending between each of the rotor discs portions.

A permanent magnet machine comprising:

• a stator assembly comprising a stator core and including stator windings to generate a stator magnetic field when excited with alternating currents, the stator assembly extending along a longitudinal axis with an inner surface defining a cavity;
• and
• a rotor assembly disposed inside said cavity and configured to rotate about the longitudinal axis, wherein the rotor assembly comprises at least one rotor module configured to generate a magnetic field, which magnetic field interacts with a stator magnetic field to produce a torque, the at least one rotor module comprising:
• a plurality of permanent magnets;
• and
• a sleeve component including a rotor including an axially extending radial base rotor land portion defining a dovetail coupling oriented tangentially relative to the rotor shaft and coupling the radial base rotor land portion thereto the rotor shaft, the rotor further including an axially extending radial top rotor land portion radially spaced a distance from the axially extending radial base rotor land portion, and a radially extending rotor disc portion spanning therebetween the axially extending radial top rotor land portion and the axially extending radial base rotor land portion to provide centrifugal stiffening and a plurality of cavities defined therein the sleeve component by the axially extending radial top rotor land portion and a portion of the radially extending rotor disc portion, wherein at least one of the plurality of permanent magnets is disposed within one of the plurality of cavities formed in the sleeve component to retain the at least one permanent magnet and form an interior permanent magnet motor,
• wherein an air gap is defined between the rotor assembly and the stator assembly.