Patent ID: 7276832

Claim:
A permanent magnet rotary motor comprising: a rotor having a rotor core and P rotor magnetic pole sections (P: an even natural number of 4 or more) formed of permanent magnets mounted to said rotor core, said P rotor magnetic pole sections being arranged at equal angle intervals of 360°/P in a peripheral direction of said rotor core; and a stator comprising a stator core including N magnetic pole sections (N: a multiple of 6) and N slots, and N winding sections with exciting windings thereof concentratedly wound on said N stator magnetic pole sections, said N stator magnetic pole sections facing said rotor core and including magnetic pole surfaces having equal lengths in the peripheral direction, each of said N slots including an opening portion that opens toward said rotor core, each of said N stator magnetic pole sections and each of said N slots being alternately arranged at equal angle intervals of 360°/2N in the peripheral direction; said P and said N being so set that a least common multiple LCM (P, N) of the P and the N is different from a least common multiple LCM (P/2, N) of ½ of the P and the N; and currents flowing through three of said winding sections adjacent to one another in the peripheral direction having a phase difference of an electrical angle of 120° from one another; wherein said N slots are grouped into first and second slot groups, wherein N/2 slots of N slots constituting the first slot group and the other N/2 of N slots constituting the second slot group, the opening portion of each of said N/2 slots in said first slot group having an open angle in the peripheral direction as a first angle and the opening portion of each of said N/2 slots in said second slot group having an open angle smaller than the first angle as a second angle; said stator core comprises a plurality of divided cores, said plurality of divided cores being grouped into N/2 divided cores belonging to a first divided core group and N/2 divided cores belonging to a second divided core group; each of said N/2 divided cores belonging to said first divided core group and each of said N/2 divided cores belonging to said second divided core group are alternately arranged in the peripheral direction; and cross-sectional shapes of the divided cores belonging to said first divided core group and said second divided core group arranged on each of the both sides of each of said N slots taken in a direction perpendicular to an axis line passing through a center of said rotor are shaped to be axisymmetrical with respect to a virtual line, the virtual line passing through the center of the opening portion of said each of said N slots and said axis line of said rotor, thereby alternately being arranged each of said N/2 slots of said first slot group and each of said N/2 slots of said second slot group in the peripheral direction.