Rotating electric machine
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsMakoto Gotou, Kazutsugu Kobayashi, Kenichiro Okumura
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Abstract
An electric rotating machine includes a field permanent magnet which is permanently magnetized to N and S poles alternatively and an armature core which is arranged coaxially with the magnet and has a plurality of salient poles facing to the magnet. Poly-phase coils are wound on the root of the salient poles. By providing an indented portion at the major face of the salient pole facing the magnet, the cogging torque can be remarkably reduced, and further by providing auxiliary salient poles ripple torque can be also reduced.
Claims19
A rotating electric machine comprising a field permanent magnet member of a circular form and an armature core made of a magnetic material, said magnet member being permanently magnetized as N and S poles alternately positioned around the rotary axis of said rotating electric machine to produce field fluxes, the number of said N and S poles being P which is an even number larger than or equal to 2, and said armature core being coaxial with said magnet member and having a plurality of saliencies facing said magnet member and a plurality of polyphase winding coils which generate polyphase alternate voltages during relative rotation between said armature core and said magnet member, at least one of said saliencies having at least one indented portion in the face thereof opposed to said magnet member, and the angle between a line from the center of said indented portion to said rotary axis and a line from the center of a neighbouring indented portion or from the center of a neighboring space between two neighbouring saliencies to said rotary axis is not equal to an integral multiple of the quotient of (360/P).degree..
Dependencies are inferred from the claim text.