Rotor barrier shaping for demagnetization mitigation in an internal permanent magnet machine

摘要

A rotor core for an Internal Permanent Magnet (IPM) machine includes a cavity having a magnet disposed therein. The cavity defines an air slot adjacent a radially outermost edge of the magnet disposed therein. A leakage flux path extends across the air slot and connects opposing sides of the cavity. The leakage flux path is oriented in an approximate tangential relationship relative to an axis of rotation of the rotor core, and is angled relative to the radially outermost edge of the magnet disposed within the cavity to direct flux away from the magnet. The cavity further includes an air pocket disposed along a radial inner surface of the magnet relative to the axis of rotation, adjacent the air slot of the cavity.

主权项

1. An interior permanent magnet machine comprising:
a wound stator; a rotor core defining a plurality of cavities and configured for magnetically interacting with the wound stator to rotate about an axis of rotation; and a plurality of magnets, with one of the plurality of magnets disposed within each of the plurality of cavities; wherein at least one of the plurality of cavities includes an end cavity arranged along an arcuate path oriented convexly outward relative to the axis of rotation and defining an arcuate end to the arcuate path; wherein the end cavity defines an air slot disposed at the arcuate end of the end cavity adjacent a radially outermost edge of the magnet disposed within the end cavity relative to the axis of rotation; and wherein the end cavity includes a leakage flux path extending across the air slot and spaced from the radially outermost edge of the magnet disposed within the end cavity, and configured for directing flux away from the magnet.