| 摘要 |
A simple brushless DC motor uses an annular permanent magnet (14) which is magnetised in segments arranged in the circumferential direction. The successive segments in the circumferential direction are magnetised radially and in opposite directions. Fan vanes (17) are located inside the annular magnet (14). A coil (41) and a magnet construction having two pole pieces (48, 49) are arranged outside the permanent-magnet annulus (41). A Hall-effect device (X1) switches the coil (41) off and on as a result of the passage of the segments of the rotor magnet (14). The single coil (41) which is commutated in this manner produces a rotation of the rotor (11) and fan vanes (17). A permanent magnet (50), which is mounted on the stator, ensures a specific magnetic alignment of the rotor (11) when it is at rest, as a result of which the starting of the motor is ensured.
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