Abstract: A centrifugal fan includes: a casing having an upper casing with an air suction opening, a lower casing, and a plurality of support members disposed between the lower casing and the upper casing with air discharge openings provided between the support members; an impeller disposed between the upper and lower casings, and including an annular upper shroud provided on an upper casing side, a base plate integrally formed with the annular upper shroud, and a plurality of blades arranged along a circumferential direction between the annular upper shroud and the base plate; and a fan motor which rotates the impeller. A plurality of recesses are provided on the upper surface of the upper casing, and formed to surround the air suction opening, and a plurality of ribs are radially provided around the air suction opening and between the adjacent recesses.

Abstract: A centrifugal fan includes: an impeller; an upper casing that is disposed above the impeller; a lower casing that is disposed below the impeller; an outlet port that is provided between the upper casing and the lower casing and from which an air suctioned by rotation of the impeller is discharged, wherein the upper casing is provided with a flange that protrudes in an outer radial direction of the impeller from an outer circumferential edge of the upper casing, and wherein the flange partially covers the outlet port when viewed from a direction perpendicular to a rotation axis of the impeller.

Abstract: A centrifugal fan includes an impeller and a motor which rotates the impeller. The impeller includes an upper shroud, a lower shroud, and blades arranged therebetween. A rotor of the motor is attached to an attachment part of the lower shroud. In a section passing a rotary shaft of the impeller, the rotor and the attachment part are provided at a more outer side than a circle having a center on a line passing an upper end portion of an inlet opening at an inner side and parallel to the rotary shaft of the impeller, having a radius of 80% of a distance from the upper end portion of the inlet opening to a surface of the lower shroud below the upper end portion, and being tangent to the surface of the lower shroud or passing an end edge portion of the lower shroud.

Abstract: There is provided a centrifugal fan that effectively cools an electronic component with a simple structure. The centrifugal fan comprises an impeller 8 having a plurality of pins extending in an axial direction, a rotor yoke 18 formed with a plurality of through-holes through which the pins penetrate, the rotor yoke 18 being joined to the impeller 8 as the pins penetrate through the through-holes, and a circuit board 10 arranged in a state having a gap with respect to the rotor yoke 18, wherein an end 11c? of the pin protrudes from the rotor yoke to a side of the circuit board, and the plurality of pins are arranged with uneven pitch in a circumferential direction of the impeller.

Abstract: A centrifugal fan comprises a rotor that has a rotor yoke, an impeller that has a blade and is coupled to the outer periphery of the rotor yoke, a motor that rotates the rotor and a casing that has a suction opening and a discharge opening, and houses the rotor, the impeller, and the motor. The impeller rotating together with the rotor discharges air sucked in through the suction opening to the outside of the casing through the discharge opening. An inner periphery part of the blade on the rotor yoke side extends to the inner periphery side, in such a manner as to overlap with an outer peripheral surface of the rotor yoke in the axial direction of the motor.

Abstract: A centrifugal fan includes an impeller, and a lower casing provided below the impeller. The impeller includes an upper shroud having an upper portion formed with an inlet, a lower shroud, and a plurality of blades arranged along a circumference direction between the upper shroud and the lower shroud. The blades extend from an inner side area to an outer side area in a radial direction, and are only connected to the lower shroud with the inner side area such that at least an outer circumferential side portion of each blade faces an upper surface of the lower casing. A surface of the lower casing, which faces the impeller, configures a portion of a wall surface which guides the fluid introduced from the inlet. A surface of each blade at a side of a leading edge portion is formed with a discontinuous portion having a step shape.

Abstract: The present invention provides a centrifugal fan that can be easily positioned when it is installed in a device or apparatus, which can further improve positioning accuracy, and which can decrease noise, even if it is made thin. In the centrifugal fan in which an impeller is received inside a casing and air drawn in from a suction port formed on the casing by rotating the impeller is discharged from the casing to the outside of a blowing port, a circular protruded portion is formed on a peripheral edge of the suction port, and protrudes upwardly in a shaft direction from an upper surface of the casing.

Abstract: A centrifugal fan includes: a casing including an upper casing, a lower casing, and struts disposed between the upper casing and the lower casing; and an impeller that is provided in the casing, the impeller having an annular shroud, a plurality of blades, and a main plate, wherein the main plate of the impeller has an inclined surface between an inner circumference side and an outer circumference side of the impeller, and wherein the inner circumference side of the impeller is located at an upward position in an axial direction of the impeller, and the outer circumference side of the impeller is located at an downward position in the axial direction of the impeller.

Abstract: A centrifugal fan includes a casing having an upper casing and a lower casing, and an impeller disposed between the upper and lower casing. The impeller includes an upper shroud having an upper portion formed with an inlet, a lower shroud, and a plurality of blades arranged along a circumference direction between the upper shroud and the lower shroud. The lower shroud is provided only on a portion at a side of a rotation axis of the impeller such that at least an outer circumferential side portion of each blade faces an upper surface of the lower casing. A surface of the lower casing, which faces the impeller, configures a portion of a wall surface which guides the fluid introduced from the inlet. Each blade has a shape which becomes thinner as increasing a distance from the upper shroud in a direction parallel to the rotation axis.

Abstract: A centrifugal fan includes: a casing having an upper casing with an air suction opening, a lower casing, and a plurality of support members disposed between the lower casing and the upper casing with air discharge openings provided between the support members; an impeller disposed between the upper and lower casings, and including an annular upper shroud provided on an upper casing side, a base plate integrally formed with the annular upper shroud, and a plurality of blades arranged along a circumferential direction between the annular upper shroud and the base plate; and a fan motor which rotates the impeller. A plurality of recesses are provided on the upper surface of the upper casing, and formed to surround the air suction opening, and a plurality of ribs are radially provided around the air suction opening and between the adjacent recesses.

Abstract: A centrifugal fan includes: an impeller; an upper casing that is disposed above the impeller; a lower casing that is disposed below the impeller; an outlet port that is provided between the upper casing and the lower casing and from which an air suctioned by rotation of the impeller is discharged, wherein the upper casing is provided with a flange that protrudes in an outer radial direction of the impeller from an outer circumferential edge of the upper casing, and wherein the flange partially covers the outlet port when viewed from a direction perpendicular to a rotation axis of the impeller.

Abstract: A centrifugal fan includes: a motor; an impeller having an inlet port, the impeller being configured to be rotated by the motor and to discharge air suctioned from the inlet port outward from an outer circumferential portion of the impeller; a lower casing that is located below the impeller; a circuit board disposed between the lower casing and the impeller, the circuit board being, mounted with an electrical component including a drive circuit that drives the motor, wherein the impeller has a recessed portion formed in an annular shape around a rotational axis and on a lower face that faces the lower casing and the circuit hoard, and wherein at least a part of the electrical component is located inside the recessed portion of the impeller.

Abstract: There is provided a centrifugal fan including an upper casing which has an air suction opening, a lower casing, and an impeller which is disposed between the upper casing and the lower casing. The impeller includes an upper shroud which is provided on an upper casing side, and a plurality of blades which are arranged along a circumference direction below the upper shroud, and is rotatable around a rotary shaft. The upper casing and the lower casing configure an open-type casing. A surface of the upper shroud facing the upper casing includes a first portion which becomes closer to the lower casing as separating further from the rotary shaft. A surface of the upper casing facing the upper shroud includes a second portion which faces the first portion of the upper shroud and becomes closer to the lower casing as separating further from the rotary shaft.

Abstract: In a centrifugal fan, a casing includes: a top plate; a motor base configured to serve as a bottom plate; and a plurality of support members provided between the top plate and the motor base, wherein an opening functioning as an air outlet opening is formed at each side of the casing so as to be surrounded by adjacent support members, the top plate and the motor base, and an impeller, which is housed between the top plate and the motor base of the casing, includes: an annular shroud; and a plurality of blades arranged in the circumferential direction and provided under the shroud, wherein at least one part of each blade opposes directly the motor base of the casing, and wherein the motor base opposes the lower parts of the blades in the direction of a rotary shaft of the impeller with a predetermined air gap provided therebetween.

Abstract: A centrifugal fan is provided. The centrifugal fan is configured such that an impeller having plural blades disposed between a disk-shaped main plate and an annular shroud along a circumferential direction is accommodated 5 in a casing, and that an air suctioned from a suction opening is discharged outward in a radial direction of the impeller by a centrifugal force due to a rotation of the impeller, and thereby discharging the air from the casing. The casing includes an upper plate, a lower plate, and plural supporting struts interposed between the upper plate and the lower plate, and 10 lateral sides of the casing have only the supporting struts to form a discharge opening.

Abstract: An impeller includes: a main plate; a shroud; and a plurality of blades provided between the main plate and the shroud and arranged circumferentially; wherein the impeller is configured to rotated about a rotation axis; wherein the plurality of blades include a pressure surface and a negative pressure surface; and the pressure surface has a shape, in which at least three types of circular arcs are connected, as viewed from a rotation axial direction. A centrifugal fan includes the above-described impeller; and three or more pillars, wherein an interval between one adjacent pillars of the three or more pillars is different from an interval between the other adjacent pillars of the three or more pillars.

Abstract: A centrifugal fan is provided. The centrifugal fan is configured such that an impeller having a plurality of blades along a circumferential direction and disposed between a disk-shaped main plate and an annular shroud is housed in a casing configured by an upper casing and a lower casing, and that an air suctioned from a suction opening is discharged outward in a radial direction of the impeller by a centrifugal force due to a rotation of the impeller. The shroud has a curved surface formed from an outer edge portion toward a center thereof. The shroud has a plurality of protrusions which are formed on the surface of the shroud such that a gap is formed between each of the protrusion portions and the upper casing.

Abstract: There is provided a centrifugal fan including a casing having an upper casing with an opening and a lower casing with a recess, a motor disposed in the recess, and an impeller housed in the casing. The impeller includes an annular shroud formed with an inlet, plural blades which are arranged between the annular shroud and the lower casing, and a hub which is connected to respective inner sides of the blades. Each of the blades includes, at a pressure surface side, a first inclined surface which is inclined toward a negative pressure surface of the blade as approaching the lower casing from the annular shroud; and a second inclined surface which is provided closer to the lower casing than the first inclined surface, and is inclined toward the negative pressure surface at an angle steeper than that of the first inclined surface.

Abstract: A centrifugal fan includes an impeller, and a lower casing provided below the impeller. The impeller includes an upper shroud having an upper portion formed with an inlet, a lower shroud, and a plurality of blades arranged along a circumference direction between the upper shroud and the lower shroud. The blades extend from an inner side area to an outer side area in a radial direction, and are only connected to the lower shroud with the inner side area such that at least an outer circumferential side portion of each blade faces an upper surface of the lower casing. A surface of the lower casing, which faces the impeller, configures a portion of a wall surface which guides the fluid introduced from the inlet. A surface of each blade at a side of a leading edge portion is formed with a discontinuous portion having a step shape.

Abstract: A centrifugal fan includes a casing having an upper casing and a lower casing, and an impeller disposed between the upper and lower casing. The impeller includes an upper shroud having an upper portion formed with an inlet, a lower shroud, and a plurality of blades arranged along a circumference direction between the upper shroud and the lower shroud. The lower shroud is provided only on a portion at a side of a rotation axis of the impeller such that at least an outer circumferential side portion of each blade faces an upper surface of the lower casing. A surface of the lower casing, which faces the impeller, configures a portion of a wall surface which guides the fluid introduced from the inlet. Each blade has a shape which becomes thinner as increasing a distance from the upper shroud in a direction parallel to the rotation axis.