| 摘要 |
PURPOSE:To obtain an excellent commutating property even when the subject machine is driven by a pulsating voltage using a method wherein a nonmagnetic section, to be used for reducing the magnetic flux circulating cross section, is provided at a point between the main poles and the intered poles on the inner circumference of a circular yoke. CONSTITUTION:A plurality of main poles 4 and inter poles 7 are provided on the inner surface of a circular yoke 1, and on the inner surface of the yoke 1 located between each main pole 4 and inter pole 7, a cut slit 9 directing from the inner circumference toward the outer circumference and extending to the axial direction, for instance, or a nonmagnetic section, which has been formed by filling up a nonmagnetic material in the slit 9, is provided. Hereby, the magnetic flux circulating cross section of the yoke 1 on the external side of the nonmagnetic section is reduced, the AC magnetic flux, to be contained in the field magnetic flux and having the property of running the inner circumference of the yoke 1, is sharply decreased, thereby enabling to reduce the transformer electromotive force which will be generated at an armature. |
