A feature of the present invention resides in that when a value of a ratio of a central angle of an outer magnetic pole portion to a central angle of each magnetized pole of a magnet portion is referred to as Y, and a value of a ratio of a thickness of the magnet portion in a diameter direction to a circumferential length of each magnetized pole of the magnet portion is referred to as X, the following condition is satisfied: −0.3X+0.63>Y.