摘要 |
<P>PROBLEM TO BE SOLVED: To provide a motor core that shows less deterioration of high-frequency iron loss characteristics even in the presence of compressive stress. <P>SOLUTION: A motor core comprises laminated magnetic steel sheets, and 40 MPa or more of compressive stress is applied to the circumferential direction of the motor core. Preferably, shot blasting treatment of spherical particles having 0.1-2 mm of a diameter at 0.1-5 MPa of projection pressure is applied to a back yoke part of the magnetic steel sheet constituting the motor core. <P>COPYRIGHT: (C)2012,JPO&INPIT |