US Patent 10381889 Permanent magnet machine with segmented sleeve for magnets

A permanent magnet machine and a rotor assembly for the permanent magnet machine. The permanent magnet machine includes a stator assembly including a stator core configured to generate a magnetic field and extending along a longitudinal axis with an inner surface defining a cavity and a rotor assembly including a rotor core and a rotor shaft. The rotor core is disposed inside the stator cavity and configured to rotate about the longitudinal axis. The rotor assembly further including a plurality of permanent magnets for generating a magnetic field which interacts with the stator magnetic field to produce torque. The permanent magnets are disposed within one or more cavities formed in a sleeve component. The sleeve component configured to include a plurality of cavities or voids therein and thus provide minimal weight to the permanent magnet machine. The permanent magnet machine providing increased centrifugal load capacity, increased power density and improved electrical performance.