BRUSHLESS MOTOR

PURPOSE:To control torque ripple, by properly selecting the combination of coil element assemblies to change the output characteristics of a motor with multiple stator coils composed of multiple coil element assemblies respectively. CONSTITUTION:At the bottom end of a rotating shaft 4 passing through a secured flat plate 1 and rotatably supported to the secured flat plate 1, a disc rotor yoke 5 is journalled, of which on the upper surface is provided a ring- shaped magnet 7 alternately magnetized with N-and S-poles at equal angles circumferentially. On the other hand, on the underside of the secured flat plate 1 are provided multiple stator coils 8 at equal angles on an identical circumference with a rotating shaft 4 at its centre. This stator coil 8 is composed of the first coil element assembly 11 and the second coil element 12 and selectively electrified to either of the coil element assemblies 11 and 12 according to the driving voltage of a motor. As a result, the output characteristics of the motor can be changed according to the driving voltage and the torque ripple rate can always be minimized.