Patent ID: 7157872

Claim:
A ceiling fan with an outer-rotor type DC brushless motor, comprising: a center base with multiple blades; and an outer-rotor type DC brushless motor as a driving source for the ceiling fan, wherein the outer-rotor type DC brushless motor mounted on the center base and comprises: a stator having an axis and multiple stator windings; a rotor assembly rotatably mounted on the axis of the stator and comprising: a hub mounted on the center base having a top and an inner periphery; multiple permanent magnets mounted on the inner periphery and interacting with the stator windings of he stator; and a pad with multiple induction magnets mounted on the top of the hub; and a controller connects to magnetism sensors that are in a position above the induction magnets, wherein the controller detects polarity of the permanent magnet that is below the magnetism sensors through the induction magnets, and based on detected results, the controller accordingly changes current of the stator windings to produce an inductive magnetic field with poles the same to the permanent magnets to drive the rotor assembly and the blades.