To accurately perform the lead angle control of a rotating magnetic field of a stator by accurately detecting the rotating state of a rotor of a brushless motor by using leakage magnetic flux.
The brushless motor includes the rotor 19 rotatably contained in the stator for generating a rotating magnetic field of the brushless motor and radially supporting a plurality of permanent magnets 25 in a rotor core 24, and a magnetic path 24b formed between adjacent permanent magnets 25. Since a width W1 in a circumferential direction is narrower than a width W2 in a radial direction, leakage magnetic flux passing a Hall element 27 disposed at a position opposed to the magnetic path 24b increases, and the rotating state of the rotor 19 can be accurately detected. The torque of the brushless motor can be increased by controlling the lead angle of the rotating magnetic field of the stator based on the rotating state of the rotor 19 detected by the Hall element 27.
| JP3285318 | DRIVER OF BRUSHLESS DC MOTOR |
NODA TATSUYA
KATO HISASHI
Kazuaki Niki