Brushless DC motor
AssigneeKoyo Seiko Co., Ltd.
InventorsHirohide Inayama, Tomofumi Takahashi, Minoru Kitabayashi
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Abstract
In a brushless DC motor constructed by a rotor 2 to which a permanent magnet 3 is attached; and a stator 1 having a plurality of slots, when an effective opening angle of magnetic pole of the rotor 2 that was set to a predetermined opening angle whose base is the rotation axis of the rotor 2 is θ2 and a salient area opening angle of magnetic pole formed within the effective opening angle θ2 of magnetic pole is θ3, the opening angles θ2 and θ3 are set so that cogging torque generated by the effective opening angle θ2 of magnetic pole and cogging torque generated by the salient area opening angle θ3 of magnetic pole are mutually in antiphase. Accordingly, a brushless DC motor capable of reducing cogging torque is realized.
Claims8
A brushless DC motor comprising a rotor to which a permanent magnet is attached;
- and a stator having a plurality of slots, characterized in that:
- when an effective opening angle of magnetic pole of said rotor that was set to a predetermined opening angle whose base is a center of a shaft hole of said rotor is θ2 and a salient area opening angle of magnetic pole formed within the effective opening angle θ2 of magnetic pole is θ3, the opening angles θ2 and θ3 are set so that cogging torque generated by said effective opening angle θ2 of magnetic pole and cogging torque generated by said salient area opening angle θ3 of magnetic pole are mutually in antiphase.
Dependencies are inferred from the claim text.