Ipm rotor magnet slot geometry for improved heat transfer

A method of facilitating heat transfer in a rotor, comprising:

• forming a plurality of metal laminations each having a plurality of magnet slots, selected ones of the magnet slots having at least one feature protruding from at least one long side thereof;
• stacking the laminations and thereby aligning the magnet slots to form longitudinal channels in the rotor;
• placing magnets in the longitudinal channels, the magnets each having at least one long side in cross-section;
• and
• providing a thermal conductor contiguously between one of the long magnet slot sides having at least one feature and the long side of the corresponding magnet.

A rotor, comprising:

• a stack of metal laminations each having a plurality of magnet slots, the stacked laminations being substantially aligned with one another so that corresponding aligned magnet slots form longitudinal channels in the rotor, selected ones of the magnet slots having at least one feature in the periphery thereof;
• a plurality of magnets each having a side, each magnet being disposed in a respective one of the longitudinal channels;
• and
• a thermal conductor connecting the side of one of the magnets with the peripheral surface of one of the selected magnet slots having at least one protruding feature;
• wherein the feature abuts and thereby spaces the magnet side from the peripheral side of the respective magnet slot.