Interior permanent magnet machine with pole-to-pole asymmetry of rotor slot placement

An interior permanent magnet machine comprising:

• a rotor having a center and a plurality of slots, the rotor being configured to magnetically interact with a stator;
• a first and a second pole having centrally-located first and second pole axes in the rotor, respectively;
• wherein the plurality of slots includes first, second, third and fourth slots, the first and second slots being disposed in the first pole and the third and fourth slots being disposed in the second pole;
• a first barrier defined by the first, second, third and fourth slots;
• wherein the plurality of slots includes fifth, sixth, seventh and eighth slots, the fifth and sixth slots being disposed in the first pole and the seventh and eighth slots being disposed in the second pole;
• a second barrier defined by the fifth, sixth, seventh and eighth slots;
• wherein the first, second, third, fourth, fifth, sixth, seventh and eighth slots are substantially arc-shaped;
• a first angle defined between respective centerlines of the first and second slots and a second angle defined between respective centerlines of the third and fourth slots;
• a third angle defined between respective centerlines of the fifth and sixth slots and a fourth angle defined between respective centerlines of the seventh and eighth slots;
• wherein each of the first, second, third and fourth angles are different from one another.

An interior permanent magnet machine comprising:

• a rotor having a center and a plurality of slots, the rotor being configured to magnetically interact with a stator;
• a first and a second pole having centrally-located first and second pole axes in the rotor, respectively;
• wherein the plurality of slots includes first, second, third and fourth slots, the first and second slots being disposed in the first pole and the third and fourth slots being disposed in the second pole;
• a first barrier defined by the first, second, third and fourth slots;
• wherein the plurality of slots includes fifth, sixth, seventh and eighth slots, the fifth and sixth slots being disposed in the first pole and the seventh and eighth slots being disposed in the second pole;
• a second barrier defined by the fifth, sixth, seventh and eighth slots;
• wherein the first, second, third, fourth, fifth, sixth, seventh and eighth slots are substantially arc-shaped;
• a first angle defined between respective centerlines of the first and second slots and a second angle defined between respective centerlines of the third and fourth slots;
• a third angle defined between respective centerlines of the fifth and sixth slots and a fourth angle defined between respective centerlines of the seventh and eighth slots;
• wherein each of the first, second, third and fourth angles are different from one another;
• wherein the plurality of slots further includes ninth, tenth, eleventh and twelfth slots, the ninth and tenth slots being disposed in the first pole and the eleventh and twelfth slots being disposed in the second pole;
• wherein the first, second, third, fourth, fifth, sixth, seventh and eighth slots are substantially arc-shaped;
• wherein the second barrier in the first and second poles defines respective outermost circumferential points;
• and further comprising:
• a first span angle defined between first edge lines connecting the center of the rotor and the respective outermost circumferential points of the second barrier in the first pole;
• a second span angle defined between second edge lines connecting the center of the rotor and the respective outermost circumferential points of the second barrier in the second pole, the second span angle being different from the first span angle.