Abstract: A fan includes a motor and an impeller. The motor includes a stationary portion and a rotating portion rotatably supported by the stationary portion. The stationary portion includes a stator and a bearing portion arranged inside of the stator. The rotating portion includes a rotor magnet arranged radially outside the stator; a shaft inserted in the bearing portion, and having an upper portion fixed to the impeller directly or through one or more members; and a thrust portion arranged axially opposite the bearing portion, and including an annular surface arranged around the shaft.

Abstract: A side wall of a centrifugal fan includes a gap expanding portion arranged to gradually expand a gap between an impeller and the side wall from an upstream end toward a downstream end with respect to a rotation direction of a rotating portion. In the centrifugal fan, an electronic component arranging portion of a board is arranged in an area surrounded by the gap expanding portion, the impeller, and an air outlet, and accordingly does not overlap with a motor or the impeller in an axial direction. The electronic component arranging portion is arranged in an area extending, in a circumferential direction about a central axis, from a position 180 degrees upstream from a middle of the air outlet downstream to the middle of the air outlet, that is, in an area where a wind channel has a large width.

Abstract: A fan includes a motor and an impeller. The motor includes a stationary portion and a rotating portion rotatably supported by the stationary portion. The stationary portion includes a stator and a bearing portion arranged inside of the stator. The rotating portion includes a rotor magnet arranged radially outside the stator; a shaft inserted in the bearing portion, and having an upper portion fixed to the impeller directly or through one or more members; and a thrust portion arranged axially opposite the bearing portion, and including an annular surface arranged around the shaft.

Abstract: A blower fan includes a motor unit including a rotary unit; a plurality of blades fixed to an outer surface of the rotary unit and arranged to be rotated about a center axis by the motor unit; and a lower plate portion defined by a magnetic body and positioned below the motor unit and the blades. The lower plate portion includes a motor fixing portion, a curved portion, a peripheral portion, and a plurality of ribs arranged to interconnect the motor fixing portion and the peripheral portion either directly or through the curved portion, the curved portion including a standing portion extending upward from the outer edge portion of the motor fixing portion and an upper surface portion extending radially outward from an upper end of the standing portion, a plurality of openings positioned below the blades being defined by the curved portion, the peripheral portion, and the ribs.