Abstract: A centrifugal fan may include an impeller arranged to rotate about a rotation axis, an impeller case arranged to accommodate the impeller, a motor arranged to rotate the impeller, and a motor case arranged to accommodate the motor. The impeller may include a boss portion joined to a shaft arranged to rotate about the rotation axis, a hub arranged to extend radially outward from the boss portion, and a plurality of blades. Each blade may be arranged to extend radially outward. An inner wall of the impeller case may include an inside surface extending radially outward along an upper end portion of each blade. A side end portion of an air inlet defined in a central portion of the impeller case may include a curved surface projecting radially inward.

Abstract: A centrifugal fan may include an impeller arranged to rotate about a rotation axis, an impeller case arranged to accommodate the impeller, a motor arranged to rotate the impeller, and a motor case arranged to accommodate the motor. The impeller may include a boss portion joined to a shaft arranged to rotate about the rotation axis, a hub arranged to extend radially outward from the boss portion, and a plurality of blades. Each blade may be arranged to extend radially outward. An inner wall of the impeller case may include an inside surface extending radially outward along an upper end portion of each blade. A side end portion of an air inlet defined in a central portion of the impeller case may include a curved surface projecting radially inward.

Abstract: There is provided a blower fan including a motor. In its bearing apparatus, the inner circumferential surface of the rotor cylindrical portion 222b and the outer circumferential surface of the bearing portion are arranged to together define a seal gap 35. The bushing 26 includes a bushing base portion 260 and a bushing cylindrical portion 262. The inner circumferential surface of the bushing cylindrical portion 262 and the outer circumferential surface of the rotor cylindrical portion 222b are arranged to together define a vertical gap. The vertical gap is arranged to have a minimum radial width equal to or smaller than a maximum width of the seal gap. A lower end portion of the rotor raised portion 514 and an upper end portion of the bushing cylindrical portion 262 are arranged to together define a second horizontal gap 266a.

Abstract: A centrifugal fan may include an impeller arranged to rotate about a rotation axis, an impeller case arranged to accommodate the impeller, a motor arranged to rotate the impeller, and a motor case arranged to accommodate the motor. The impeller may include a boss portion joined to a shaft arranged to rotate about the rotation axis, a hub arranged to extend radially outward from the boss portion, and a plurality of blades. Each blade may be arranged to extend radially outward. An inner wall of the impeller case may include an inside surface extending radially outward along an upper end portion of each blade. A side end portion of an air inlet defined in a central portion of the impeller case may include a curved surface projecting radially inward.

Abstract: The second holder member includes a cover portion including, in an inner edge portion thereof, a cover portion cylindrical portion arranged to extend downward; the rotor cylindrical portion includes an annular rotor raised portion arranged to project radially outward from an outer circumferential surface thereof; the second holder member is attached to the first holder member; and a lower end portion of the cover portion cylindrical portion is arranged to be in axial contact with the rotor raised portion.

Abstract: A bearing apparatus includes a bearing portion; a shaft; an upper thrust portion; a rotor cylindrical portion extending downward from an outer edge portion, and arranged radially outward of the bearing portion; and an annular seal cover fixed to an outer circumferential surface. A seal portion having a surface of lubricating oil defined therein is defined in a seal gap defined between an inner circumferential surface of the rotor cylindrical portion and an outer circumferential surface of the bearing portion. The seal cover includes a fixing portion fixed to the outer circumferential surface of the rotor cylindrical portion; and an inner flange portion extending radially inward from the fixing portion below a lower end portion of the rotor cylindrical portion, and having an inner circumferential portion arranged opposite to the outer circumferential surface of the bearing portion to define a vertical gap together with the outer circumferential surface.

Abstract: A centrifugal fan includes an upstream side impeller, a downstream side impeller, a motor, and a housing arranged to accommodate the upstream side impeller, the downstream side impeller, and the motor. The housing includes a first intake port through which a gas is drawn from an outside, an exhaust port through which the gas is discharged to the outside, and a flow path defined within the housing to bring the first intake port and the exhaust port into communication with each other. The flow path includes a first wind tunnel portion positioned below the upstream side impeller to extend in a circumferential direction and arranged to receive a gas stream from the upstream side impeller and a second wind tunnel portion positioned above the downstream side impeller to extend in the circumferential direction and arranged to receive a gas stream from the downstream side impeller.

Abstract: A first seal portion having a surface of a lubricating oil defined therein is defined between a sleeve portion and a bearing housing. A side communicating channel arranged to bring a first seal gap and a thrust gap into communication with each other is defined either between a sleeve portion and a bearing housing or in an outer circumferential portion of a sleeve portion. A second seal portion having another surface of a lubricating oil defined therein is defined in a gap constituted by a side minute gap between a thrust plate and a bearing housing and a lower minute gap between a thrust plate and a cap member.

Abstract: A fan includes a motor including a rotating portion and a stationary portion; an impeller including a plurality of blades and a blade support portion to which the blades are fixed, and arranged to cover the motor; and a housing including a lower plate portion arranged on a lower side of the blades, a side wall portion arranged to cover sides of the blades, and an upper plate portion arranged on an upper side of the blades and including an air inlet arranged to extend through the upper plate portion in an axial direction. A lower surface of the blade support portion includes a balance correction portion arranged to extend in a circumferential direction. The lower plate portion includes a through hole arranged to overlap with the balance correction portion in the axial direction to make a portion of the balance correction portion viewable from below the lower plate portion.

Abstract: A ventilation fan arranged to reduce vibrations includes an impeller rotating around a center axis, a motor portion arranged to rotate the impeller, a motor supporting portion arranged to support the motor portion, and a housing arranged to accommodate the impeller and the motor portion. The motor supporting portion includes a substantially disk-shaped base portion, and a substantially cylindrical bearing holding portion axially extending with the center axis as the center. At least the base portion is made from resin. On the surface of the base portion, a plurality of recessed portions which are axially recessed are arranged in the form of a net, a staggered pitch, a grid, or a honeycomb. A flat portion of the base portion excluding the recessed portions does not have a continuous region extending in a straight line radially from the center of the base portion.

Abstract: A bearing apparatus includes a bearing portion; a shaft; an upper thrust portion; a rotor cylindrical portion extending downward from an outer edge portion, and arranged radially outward of the bearing portion; and an annular seal cover fixed to an outer circumferential surface. A seal portion having a surface of lubricating oil defined therein is defined in a seal gap defined between an inner circumferential surface of the rotor cylindrical portion and an outer circumferential surface of the bearing portion. The seal cover includes a fixing portion fixed to the outer circumferential surface of the rotor cylindrical portion; and an inner flange portion extending radially inward from the fixing portion below a lower end portion of the rotor cylindrical portion, and having an inner circumferential portion arranged opposite to the outer circumferential surface of the bearing portion to define a vertical gap together with the outer circumferential surface.

Abstract: A centrifugal fan may include an impeller arranged to rotate about a rotation axis, an impeller case arranged to accommodate the impeller, a motor arranged to rotate the impeller, and a motor case arranged to accommodate the motor. The impeller may include a boss portion joined to a shaft arranged to rotate about the rotation axis, a hub arranged to extend radially outward from the boss portion, and a plurality of blades. Each blade may be arranged to extend radially outward. An inner wall of the impeller case may include an inside surface extending radially outward along an upper end portion of each blade. A side end portion of an air inlet defined in a central portion of the impeller case may include a curved surface projecting radially inward.

Abstract: A centrifugal fan includes an impeller arranged to rotate about a rotation axis, a motor arranged to rotate the impeller, and a case arranged to accommodate the impeller and the motor. The case includes an upper case, a lower case, and a joint portion at which the upper and lower cases are fixed to each other. An interior of the case includes a first annular space positioned radially outward of the motor. The first annular space includes a second annular space defined by a portion of a space defined by an annularly continuous collection of imaginary circles each of whose diameter is the shortest distance between an inner circumferential edge of the joint portion and a radially outermost circumferential portion of a motor accommodating portion and each of which touches the inner circumferential edge of the joint portion.

Abstract: In a motor, a bearing housing is made of a thermoplastic resin material. A bottom portion of the bearing housing includes a first large diameter portion, a small diameter portion, and a second large diameter portion. The first large diameter portion of the bearing housing is arranged on an upper surface of the base. An outer circumferential surface of the small diameter portion of the bearing housing is arranged radially opposite a side peripheral surface of a base hole. The second large diameter portion is arranged to be in direct contact with a lower surface of the base through caulking.

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 blades and a motor. The motor includes a rotor holder; a shaft; a sleeve; a holder; and a thrust plate. A radial bearing portion arranged to support the shaft in a radial direction is defined in a radial gap defined between the shaft and the sleeve. A lower seal portion having a lower surface of a lubricating oil defined therein is defined between the thrust plate and the holder, while an upper seal portion having an upper surface of the lubricating oil defined therein is defined between the holder and the sleeve. The holder includes a connection channel defining portion arranged to define a connection channel to connect an upper space defined between the upper seal portion and an inside of the rotor holder with a lower space at which the lower seal portion is arranged.

Abstract: A sleeve support portion is arranged to support a sleeve having a rotating shaft inserted therein such that the rotating shaft is rotatable. A plurality of ribs extending in an axial direction is provided on an inner surface of the sleeve support portion. The ribs are preferably spaced from each other in a circumferential direction centered on the rotating shaft, and arranged to make contact with at least a portion of the sleeve. The ribs include a plurality of types of ribs, each type of the ribs having a different axial position of an axial edge, on an axially opening portion side, of a contact surface thereof which is arranged to make contact with the sleeve.

Abstract: A first seal portion having a surface of a lubricating oil defined therein is defined between a sleeve portion and a bearing housing. A side communicating channel arranged to bring a first seal gap and a thrust gap into communication with each other is defined either between a sleeve portion and a bearing housing or in an outer circumferential portion of a sleeve portion. A second seal portion having another surface of a lubricating oil defined therein is defined in a gap constituted by a side minute gap between a thrust plate and a bearing housing and a lower minute gap between a thrust plate and a cap member.

Abstract: A centrifugal fan includes a housing including a base, a side wall portion having an air outlet defined therein, and a cover arranged above the side wall portion and having an air inlet defined therein. A circuit board is arranged on an upper surface of the base, and includes a circuit board protruding portion arranged to protrude radially outward of the housing. At least one of electronic components to be mounted on the circuit board is arranged radially outward from an inner circumferential surface of the side wall portion.

Abstract: A serial axial fan preferably includes a first impeller and a second impeller each having a plurality of blades radially extending with a predetermined rotation axis as the center, a first motor portion, a second motor portion, a first housing, and a second housing. The first motor portion has a first circuit board on which at least one electronic component arranged to control the driving of the first impeller is mounted. The second motor portion has a second circuit board on which at least one electronic component arranged to control the driving of the second impeller is mounted. The first and second circuit boards are electrically connected. The driving of the first impeller and the driving of the second impeller are controlled by the electronic component disposed on at least one of the first and second circuit boards.