Brushless motor.

摘要

A brushless motor (10) comprises a stator yoke plate (16) made of a magnetic material, to which both main surfaces the first and the second flexible printed circuit boards (20) (22) formed integrally including a connecting part (24) are stuck respectively. On the first flexible printed circuit board (20), a plurality of driving coils (30) are arranged annularly and a conductor pattern for a speed detecting coil is formed inside the driving coils (30). On the integrated stator yoke plate (16) and the first and second flexible printed circuit boards (20) (22), a penetrated hole (18) for passing through a rotor shaft (54) is formed generally in the center. A tongue (36) is formed generally in protrusion inwardly from the periphery defining the penetrated hole (18) on which a connecting conductor pattern connected to the speed detecting coil is formed. The tongue (36) is folded back toward the side of the second flexible printed circuit board (22) through the penetrated hole (18) and the connecting conductor pattern is connected to the second flexible printed circuit board (22). An alternating signal induced in the speed detecting coil is withdrawn from the second flexible printed circuit board (22).