| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that there is a risk of damaging a core during the manufacturing process of a motor or during actual use of a motor, because the strength of a molding is significantly low, when composing a dynamo-electric machine by using a conventional molding of soft magnetic dust core.SOLUTION: In the soft magnetic dust core, a cavity (hole) surrounded by three or more powder particles is impregnated with resin in a region adjoining soft magnetic powder particles, and the resin is segregated at a part of the cavity (hole), thus forming a hole and a resin part in the cavity (hole). When confining the volume of the hole within a proper range, a soft magnetic dust core having high dimensional accuracy and holding a strength of 100 MPa or higher stably with no variation is obtained without lowering the density of the soft magnetic dust core. |
