Thin DC brushless motor having an air gap formed therein

摘要

A thinned DC brushless motor (50) has a base plate 52 of magnetic material, a rotatable shaft (58) supported perpendicular to the base plate, an annular hub (68) coaxially fixed on the shaft, a stator (60) fixed on the base plate, and a rotor (70) coaxially fixed on the shaft through the annular hub. The rotor (70) includes an first wall portion (72) extended radially from the shaft above the stator and parallel to the base plate and a second wall portion (74) extended from a peripheral edge of the circular potion towards the base plate to enclose the stator. An annular magnet (78) is fixed on an inner surface of the second wall of the rotor with leaving a small gap from a peripheral edge of the stator. The upper wall has a bent portion (80) extended outward away from the annular magnet in the vicinity of an inner edge of the annular magnet.