Abstract: A motor includes a stator core held on a core holder, the stator core includes a stacked magnetic body having a plurality of magnetic plates with the magnetic plates being piled up in an axial direction. The motor also includes a core support portion provided in the core holder with the core support portion including a core mounting face and a core locating face. The core locating face is formed near a magnetic center of the stator core with respect to the axial direction and formed flat in the core holder in a radial direction. The stacked magnetic body is divided into two stacked magnetic bodies with a boundary position of the two stacked magnetic bodies being set near the magnetic center of the stator core and the boundary surface of one of the two stacked bodies abuts against the core locating face of the core holder in the axial direction.

Abstract: A brushless motor speed detector requires no FG pattern or FG magnetization so that a motor structure is not restricted. The detector includes a simple detection circuit and a simple detection signal processing circuit, and is capable of obtaining a high-accuracy detection signal by using a variable signal output circuit for providing a signal alternately varied due to the rotation of a motor, a constant signal output circuit for providing a signal not varied due to the rotation of the motor, and a comparator for comparing an output signal of the variable signal output means with output signals of the constant signal output means or for comparing output signals of the first and second variable signal output circuit with each other to provide speed detection signals for one turn of the motor more than the number of driving magnetized poles.