Direct axis aiding permanent magnets for a laminated synchronous motor rotor

摘要

A permanent magnet rotor for a permanent magnet synchronous-run induction-state motor is disclosed. The rotor has Rare Earth magnets disposed in apertures in unitary laminations and parallel to a tangent to the shaft. The magnets are magnetized outwardly so that the direct flux of the magnets is additive to the direct axis flux of the stator at no load. The rotor has a squirrel cage winding and the ends of each magnet aperture are in communication through a flux barrier space to the inner end of an adjacent conductor bar aperture of the squirrel cage winding. The unitary laminations each have an even plurality of radially directed reinforcing ribs disposed along the magnetic neutral axes. The flux barriers are wide relative to the circumferential width of the reinforcing ribs for a minimum of circumferential leakage flux. The leakage flux from one magnet radially through a rib is in opposition to the leakage flux through that rib from the adjacent magnet for substantially zero net leakage flux therein.