| 摘要 |
<P>PROBLEM TO BE SOLVED: To increase the strength of a motor by reducing a stress exerted on a rotor core during high speed rotation, and achieve sufficiently high torque. <P>SOLUTION: A plurality of permanent magnet insertion holes 8, which is embedded with a permanent magnet, provided at the rotor core 7 in parallel to the rotational center of a rotor 3 and extending in such a direction as to cross a cross line "a" orthogonally crossing the rotational center of the rotor 3 so as to have a line symmetry, and a cavity portion 11 continuous to both the ends in such a direction crossing the cross line "a" in the permanent magnet insertion holes 8 are formed at the rotor core 7. An insertion hole outer edge portion which crosses the cross line "a" of the permanent magnet insertion holes 8 and faces an outer periphery side of the rotor 3 is protruded on the outer periphery side of the rotor 3 along the cross line "a" so as to be stepped relative to the cavity portion outer edge portion of the cavity portion 11. Therefore, the strength of the rotor 3 is increased by preventing stress concentration from occurring on the rotor core 7, and the torque of the permanent magnet embedded type motor 1 is increased because of the cavity portion 11. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
