| 摘要 |
A d.c. dynamoelectric machine of permanent magnet type comprises an armature and a plurality of field poles, wherein each of the poles comprises a main pole part (a permanent magnet) composed by an integral combination of a first magnet formed of a magnetic material having a large coercive force and a second magnet formed of a magnetic material providing a high residual flux density and having an axial length larger than that of the armature core, and an auxiliary pole part juxtaposed and coupled to the permanent magnet and having a permeability higher than the reversible permeability of the permanent magnet, and an air gap for intercepting the path of leakage flux is defined between the permanent magnet and the auxiliary pole part.
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