Patent ID: 8294320

Claim:
An interior permanent magnet (IPM) machine comprising: a stator having a plurality of conductors, the stator disposed concentrically around an axis; and a rotor disposed concentrically around the axis and internally with respect to the stator, and configured to rotate about the axis relative to the stator, the rotor including a radially outer barrier having a first pocket disposed at a first angle relative to a second pocket thereby forming the outer barrier having a first v-shaped configuration, and a radially inner barrier having a third pocket disposed at a second angle relative to a fourth pocket thereby forming the inner barrier having a second v-shaped configuration; wherein: at least one of the first and the second pockets is characterized by a shape of an irregular quadrilateral, and is devoid of magnets; and at least one of the third and the fourth pockets contains a permanent magnet and is characterized by a general shape of a polygon having a first side generally parallel to a second side, and the first side has a portion slanted relative to the second side, such that demagnetization of the magnet contained within at least one of the third and the fourth pockets is limited when operating temperatures and electrical current of the IPM machine exceed operating conditions prescribed by design specifications.