Brushless motor and electric power steering apparatus

A brushless motor comprising:

• a rotor rotating integrally with a rotating shaft and having a plurality of permanent magnets circumferentially arranged to serve as magnetic poles;
• a stator having a plurality of phase coils arranged to face the rotor with a gap therebetween;
• a rotational phase sensor configured to detect, as a rotational phase, a rotational position of a magnetic pole of one of the permanent magnets in accordance with the rotation of the rotor, and to generate an energization phase signal that changes an output thereof at every predetermined rotational phase, the predetermined rotational phase corresponding to a stepwise change in the rotational phase;
• a torque sensor attached to the rotating shaft and configured to detect an actual motor torque;
• and
• a motor controller configured to pass a phase current to the respective phase coils,
• wherein, on the basis of the energization phase signal that changes the output thereof at the every predetermined rotational phase, the motor controller switches the phase current passing through the respective phase coils, and changes the magnitude of the phase current passing through the respective phase coils such that the actual motor torque detected by the torque sensor coincides with a target motor torque.