Abstract: An axial fan includes a housing, an upper motor, and a lower motor. The housing includes an upper housing and a lower housing. A lower peripheral wall of the lower housing includes first engaging portions and lower protruding pieces. The lower protruding pieces oppose the first engaging portions in an axial direction and protrude axially upward from an axially upper surface. An upper peripheral wall of the upper housing includes upper engaging claws and upper notch grooves. The upper engaging claws extend axially downward from an axially lower surface, and include a second engaging portion that engages with the first engaging portion in a lower end portion. The upper notch grooves are notched axially upward from the axially lower surface radially inward of the upper engaging claw. At least a portion of the lower protruding pieces is located in the upper notch grooves.

Abstract: A blower includes a base, a motor attached to the base, a first impeller to be rotated by the motor, and a second impeller to be rotated by the motor and independent of the first impeller. The base includes an annular cover that covers at least a portion of the motor, a support that extends from an upper end of the cover, and a bottom extending inward from a lower end of the cover and to which the stator is fixed. The bottom includes a shaft hole to accommodate a shaft. The first impeller and the second impeller are fixed to an upper portion and a lower portion of a rotor, respectively. At least one of the first impeller and the second impeller is fixed to the shaft.

Abstract: An axial fan includes a housing, an upper motor, and a lower motor. The housing includes an upper housing and a lower housing. A lower peripheral wall of the lower housing includes first engaging portions and lower protruding pieces. The lower protruding pieces oppose the first engaging portions in an axial direction and protrude axially upward from an axially upper surface. An upper peripheral wall of the upper housing includes upper engaging claws and upper notch grooves. The upper engaging claws extend axially downward from an axially lower surface, and include a second engaging portion that engages with the first engaging portion in a lower end portion. The upper notch grooves are notched axially upward from the axially lower surface radially inward of the upper engaging claw. At least a portion of the lower protruding pieces is located in the upper notch grooves.

Abstract: An axial fan includes a housing, an upper motor, and a lower motor. The housing includes an upper housing and a lower housing. A lower peripheral wall of the lower housing includes first engaging portions and lower protruding pieces. The lower protruding pieces oppose the first engaging portions in an axial direction and protrude axially upward from an axially upper surface. An upper peripheral wall of the upper housing includes upper engaging claws and upper notch grooves. The upper engaging claws extend axially downward from an axially lower surface, and include a second engaging portion that engages with the first engaging portion in a lower end portion. The upper notch grooves are notched axially upward from the axially lower surface radially inward of the upper engaging claw. At least a portion of the lower protruding pieces is located in the upper notch grooves.

Abstract: An impeller includes Z blades, where Z is an integer equal to 5 or more, arranged in a circumferential direction of the impeller and extending radially, and pitch angles between adjacent blades are all different. In terms of an arbitrary pitch angle ?, when a pitch angle ?1 adjacent to the pitch angle ?, and a pitch angle ?2 adjacent to the pitch angle ?, different from the pitch angle ?1, satisfy a relation, ?1<?2, a pitch angle ?1 different from the pitch angle ? adjacent to the pitch angle ?1 and a pitch angle ?2 adjacent to the pitch angle ?2, different from the pitch angle ?, satisfy a relation, ?2<?1.

Abstract: An impeller includes Z blades, where Z is an integer equal to 5 or more, arranged in a circumferential direction of the impeller and extending radially, and pitch angles between adjacent blades are all different. In terms of an arbitrary pitch angle ?, when a pitch angle ?1 adjacent to the pitch angle ?, and a pitch angle ?2 adjacent to the pitch angle ?, different from the pitch angle ?1, satisfy a relation, ?1<?2, a pitch angle ?1 different from the pitch angle ? adjacent to the pitch angle ?1 and a pitch angle ?2 adjacent to the pitch angle ?2, different from the pitch angle ?, satisfy a relation, ?2<?1.

Abstract: An axial fan includes a housing, an upper motor, and a lower motor. The housing includes an upper housing and a lower housing. A lower peripheral wall of the lower housing includes first engaging portions and lower protruding pieces. The lower protruding pieces oppose the first engaging portions in an axial direction and protrude axially upward from an axially upper surface. An upper peripheral wall of the upper housing includes upper engaging claws and upper notch grooves. The upper engaging claws extend axially downward from an axially lower surface, and include a second engaging portion that engages with the first engaging portion in a lower end portion. The upper notch grooves are notched axially upward from the axially lower surface radially inward of the upper engaging claw. At least a portion of the lower protruding pieces is located in the upper notch grooves.

Abstract: An impeller includes Z blades, where Z is an integer equal to 5 or more, arranged in a circumferential direction of the impeller and extending radially, pitch angles between adjacent blades being all different. In terms of an arbitrary pitch angle ?, when a pitch angle ?1 adjacent to the pitch angle ?, and a pitch angle ?2 adjacent to the pitch angle ?, different from the pitch angle ?1, satisfy a relation, ?1<?2, a pitch angle ?1 different from the pitch angle ? adjacent to the pitch angle ?1 and a pitch angle ?2 adjacent to the pitch angle ?2, different from the pitch angle ?, satisfy a relation, ?2<?1.

Abstract: An axial fan includes an upper impeller disposed in an axially upper portion of a housing, and an upper circuit board disposed axially below the upper impeller. An upper impeller cup of the upper impeller includes an upper cylindrical portion and an upper lid. The axial fan includes a lower impeller disposed in an axially lower portion of the housing, and a lower circuit board disposed axially above the lower impeller. A lower impeller cup of the lower impeller includes a lower cylindrical portion and a lower lid. An axial upper end outer diameter of the upper cylindrical portion is smaller than an axial lower end outer diameter of the upper cylindrical portion. An axial lower end outer diameter of the lower cylindrical portion is smaller than an axial upper end outer diameter of the lower cylindrical portion.

Abstract: An impeller includes Z blades, where Z is an integer equal to 5 or more, arranged in a circumferential direction of the impeller and extending radially, pitch angles between adjacent blades being all different. In terms of an arbitrary pitch angle ?, when a pitch angle ?1 adjacent to the pitch angle ?, and a pitch angle ?2 adjacent to the pitch angle ?, different from the pitch angle ?1, satisfy a relation, ?1<?2, a pitch angle ?1 different from the pitch angle ? adjacent to the pitch angle ?1 and a pitch angle ?2 adjacent to the pitch angle ?2, different from the pitch angle ?, satisfy a relation, ?2<?1.

Abstract: An axial fan includes a motor, an impeller, and a housing including a tubular air channel wall portion. The impeller includes a tubular impeller hub, and arranged in a circumferential direction on the impeller hub. Each blade includes a first portion where all of an inner circumferential developed blade, an outer circumferential developed blade, and an intermediate circumferential developed blade superimposed on each other overlap. The inner circumferential developed blade is a junction of the blade with the outer surface of the impeller hub. The outer circumferential developed blade is a radially outermost portion. The intermediate circumferential developed blade is a radially intermediate portion of the blade between the junction and the radially outermost portion. The radially outermost portion is at the shortest radial distance from the air channel wall portion in at least a portion of the first portion.

Abstract: An axial fan includes an upper impeller disposed in an axially upper portion of a housing, and an upper circuit board disposed axially below the upper impeller. An upper impeller cup of the upper impeller includes an upper cylindrical portion and an upper lid. The axial fan includes a lower impeller disposed in an axially lower portion of the housing, and a lower circuit board disposed axially above the lower impeller. A lower impeller cup of the lower impeller includes a lower cylindrical portion and a lower lid. An axial upper end outer diameter of the upper cylindrical portion is smaller than an axial lower end outer diameter of the upper cylindrical portion. An axial lower end outer diameter of the lower cylindrical portion is smaller than an axial upper end outer diameter of the lower cylindrical portion.

Abstract: An axial fan includes a rotor portion, a stator portion arranged radially opposite to the rotor portion, and an impeller hub fixed to the rotor portion, and arranged to be capable of rotating integrally with the rotor portion. The impeller hub includes a hub top plate portion; a hub tubular portion being tubular, and arranged to extend axially downward from an outer edge of the hub top plate portion; a plurality of blades arranged in a circumferential direction; a plurality of wall portions arranged in the circumferential direction radially inside of the hub tubular portion; and a joining portion arranged to join a corresponding one of the wall portions to the hub tubular portion. A radially outer surface of the rotor tubular portion is arranged to be in contact with an inner surface of at least one of the wall portions.

Abstract: A centrifugal fan that sends out in a radial direction a fluid sucked from an axial direction, includes an impeller rotatable about a center axis extending in a top-bottom direction, and a motor that rotates the impeller. The motor includes a rotor rotatable about the center axis, and a stator that faces at least a portion of the rotor in the radial direction. The impeller includes an impeller hub fixed to the rotor, centrifugal vanes disposed in a circumferential direction on a radial-direction outer side of the impeller hub, and axial flow vanes disposed in the circumferential direction on a radial-direction inner side of the impeller hub. The axial flow vanes are disposed on an axial-direction upper side of the stator.

Abstract: An axial fan includes a rotor portion including a shaft arranged to extend along a central axis extending in a vertical direction; a stator portion arranged radially opposite to the rotor portion; and an impeller hub fixed to the rotor portion, and arranged to be capable of rotating integrally with the rotor portion. The impeller hub is an injection molded article, and includes a hub top plate portion arranged to extend perpendicularly to an axial direction; a hub tubular portion being tubular, and arranged to extend axially downward from an outer edge of the hub top plate portion; a plurality of blades arranged in a circumferential direction on an outer surface of the hub tubular portion; and an inner fixing portion arranged radially inward of the hub tubular portion. The rotor portion includes a rotor tubular portion being tubular and arranged to extend in the axial direction.

Abstract: An axial fan includes a motor, an impeller capable of rotating about a central axis, and a housing including a tubular air channel wall portion arranged radially outside of the impeller. The impeller includes a tubular impeller hub, and a plurality of blades arranged in a circumferential direction on an outer surface of the impeller hub. Each blade includes a first portion where all of an inner circumferential developed blade, an outer circumferential developed blade, and an intermediate circumferential developed blade superimposed on each other overlap when viewed in a radial direction. The inner circumferential developed blade is a circumferential development of a junction of the blade with the outer surface of the impeller hub. The outer circumferential developed blade is a circumferential development of a radially outermost portion of the blade.

Abstract: An axial fan includes a rotor portion, a stator portion arranged radially opposite to the rotor portion, and an impeller hub fixed to the rotor portion, and arranged to be capable of rotating integrally with the rotor portion. The impeller hub includes a hub top plate portion; a hub tubular portion being tubular, and arranged to extend axially downward from an outer edge of the hub top plate portion; a plurality of blades arranged in a circumferential direction; a plurality of wall portions arranged in the circumferential direction radially inside of the hub tubular portion; and a joining portion arranged to join a corresponding one of the wall portions to the hub tubular portion. A radially outer surface of the rotor tubular portion is arranged to be in contact with an inner surface of at least one of the wall portions.

Abstract: An axial fan includes a rotor portion including a shaft arranged to extend along a central axis extending in a vertical direction, a stator portion arranged radially opposite to the rotor portion, and an impeller hub fixed to the rotor portion, and arranged to be capable of rotating integrally with the rotor portion. The impeller hub includes a hub top plate portion arranged to extend perpendicularly to an axial direction; a hub tubular portion being tubular, and arranged to extend axially downward from an outer edge of the hub top plate portion; a plurality of blades arranged in a circumferential direction on an outer surface of the hub tubular portion; a plurality of wall portions arranged in the circumferential direction radially inside of the hub tubular portion, with a gap between every adjacent ones of the wall portions; and joining portions each of which is arranged to join a corresponding one of the wall portions to the hub tubular portion.

Abstract: A motor includes a rotor and a stator. A shaft of the rotor is received in a sleeve. A face of the sleeve and a face of the shaft, that are opposed to each other, form a bearing supporting the rotor in a rotatable manner relative to the stator. A sleeve-retaining portion that retains the sleeve has a bottom portion opposed to an axial end of the sleeve. A magnet holder is arranged in the bottom portion to accommodate an attracting magnet magnetically attracting the axial end of the shaft. The magnet holder is held between the axial end of the sleeve and the bottom portion of the sleeve-retaining portion.

Abstract: A cooling device includes a fan, a heat sink, and an attaching portion arranged to attach the fan to the heat sink. The fan includes an impeller rotating about a center axis, a motor arranged to rotate the impeller, and a base portion supporting the motor. The attaching portion includes a frame surrounding a portion of the impeller opposed to the heat sink, a plurality of supports projecting from the frame to a side opposite to the heat sink, and a plurality of supporting ribs connecting the supports and the base portion to each other, arranged about the center axis, and extending from the base portion away from the center axis. Each supporting rib has a first primary surface and a second primary surface arranged opposite to the impeller. The first and second primary surfaces are inclined with respect to a plane substantially perpendicular to the center axis.