| 摘要 |
<p>A brushless D.C. motor is provided with a stator (1) and a rotor (2) incorporating an annular magnet (9) provided with arcuate steel flux return strips (10). A hall effect device (5) acts to sense the angular position of the rotor magnet (9) and controls switching of the current to the stator windings (11). The electronic components of the circuit are mounted on a printed circuit board which is integrally moulded with a support body (3) which provides a bearing housing (6) for the rotor shaft (7). This enables the rotor (2) to be mounted with very great accuracy with respect to the electrical circuitry and in particular the sensor (5). The magnet (9) incorporates castellations (20) which create a desired offset of the magnetic field.</p> |
