Cooling fan dust seal

A cooling fan dust structure comprising a fan blade unit, a frame having at its center a motor base, a stator coil unit fixed in the motor base, a bush in the stator coil unit, a bearing in the bushing and a through hole on the end surface of the bearing to permit penetration by a spindle from the fan blade unit characterized by that:

• the spindle extending from the center of the inner surface;
• two or more than two ribs being concentrically provided between the spindle and a magnet;
• those ribs protruding from the inner surface of the fan blade unit at a height when assembled approximately close to the horizontal defined by multiples of upper magnetic bit of the stator coil unit so to form a winding slit;
• an opening of the bushing at the center of the stator coil unit above the horizontal defined by those upper magnetic bits extending toward the inner surface of the fan blade unit at a height when assembled approximately close to the inner surface of the fan blade unit for both of the opening of the bushing and the inner surface of the fan blade unit to form another winding slit;
• and when assembled, an overcut height different formed by those ribs provided on the inner surface of the fan blade unit and the protruded opening of the bushing increasing the length of the route for airflow to prevent an easy ingression by the airflow carrying dust;
• meanwhile, as the fan blade unit to rotate, the winding slit created by those ribs and upper magnetic bits to stops the ingression of flying dust into the spindle.