| 摘要 |
PROBLEM TO BE SOLVED: To provide a brushless motor capable of detecting the rotational position of a rotor without need for many dedicated components by utilizing leakage flux in the axial direction arising from magnets arranged at equal intervals on the circumference of the rotor, and meeting requests for reduction in a number of parts and reduction in size. SOLUTION: The brushless motor includes the rotor 2 in which multiple magnets 20, 20... are arranged and fixed at equal intervals on the circumference of rotation; and rolling bearings 5, 6 for supporting the rotating shaft 4 of the rotor 2. The rolling bearing 6 and the rotating shaft 4 are formed of soft magnetic material. A magnetic sensor 7 is fixed and supported on a support 8 so that it is opposed to the end face of the rotor 2 on the same side. Part of the support is abutted against the outer ring of the rolling bearing 6. The rotational position of the rotor 2 is detected based on the output of the magnetic sensor 7 corresponding to leakage flux in the axial direction arising from the magnets 20, 20... on the circumference of the rotor 2. COPYRIGHT: (C)2007,JPO&INPIT
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