a stator sub - assembly comprises : a coil bobbin which is composed of a cylinder having a winding of a magnet wire therearound , and a terminal block provided with terminal pins connected to lead wires of the winding and coupled stator yokes housing said coil bobbin therein and having a cutout for allowing the terminal block to protrude therethrough . the cutout has a width adapted to allow the terminal block to circumferentially shift rotationally about the center of an axial direction of the coil bobbin .