Abstract: A seal cover includes an axially opposing portion arranged to extend radially outward from a outer circumferential surface of a bearing portion, and arranged axially opposite a lower end portion of a rotor cylindrical portion; and a radially opposing portion arranged to extend upward continuously from a axially opposing portion, and arranged opposite to an outer circumferential surface of a rotor cylindrical portion to define a vertical gap together with a rotor cylindrical portion.

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 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 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 motor includes a coming-off preventing portion including an inner circumferential edge defining a through hole, inside which a substantially cylindrical bearing housing is inserted, and being arranged axially above an insulator. The inner circumferential edge has at least two different radial dimensions. A boss portion includes a columnar portion inserted inside the through hole, and a collar portion extending radially outward from a lower end of the columnar portion. The collar portion includes an outside surface having at least two different radial dimensions, and an upper surface arranged axially opposite a bottom portion of the inner circumferential edge. The radial dimensions of the inner circumferential edge and those of the collar portion are arranged to allow the collar portion to be axially inserted through the inner circumferential edge only when the inner circumferential edge and the collar portion are arranged in a predetermined circumferential orientation relative to each other.

Abstract: An electric motor includes a stator portion, a rotor portion, and a bearing mechanism, wherein the rotor portion includes a rotor holder having a substantially cylindrical shape with a closed end, and a field magnet fixed to an inner circumference of the rotor holder; the stator portion includes a stator, a base portion to which the stator is fixed, and a magnetic member; and the magnetic member includes a cylindrical portion having a substantially cylindrical shape into which a lower end portion of an insulator of the stator is inserted, the lower end portion being a portion of an outer portion of the insulator and opposing the base portion, and a flat portion having a substantially annular shape which spreads outwardly in a radial direction from a lower edge of the cylindrical portion and opposes a lower edge of the field magnet.

Abstract: A centrifugal fan includes a motor having an impeller and a housing for accommodating the motor. The housing has a sidewall surrounding an outer circumference of the impeller. An air inlet is formed in the housing and opposed to a center portion of the impeller. An air outlet is formed in the sidewall of the housing and opposed to an outer surface of the impeller. The housing includes a housing body and a housing cover. The housing body has a bottom with the motor secured thereon. The housing cover, formed by a pressed metal member, has an upper part and a cover sidewall extending from the upper part toward the bottom of the housing body and forming at least a part of the sidewall of the housing.

Abstract: An arrangement of a low air inlet and a circuit for driving a torque generator in an ultra-compact centrifugal fan is disclosed. In the ultra-compact centrifugal fan, a region occupied by the circuit is not completely arranged radially inside a cup-shaped portion to which an impeller is attached. At least a part of the low air inlet provided on a bottom of a housing of the centrifugal fan is arranged in a range of predetermined angle in an imaginary ring-shaped portion surrounding a base portion covered by the cup-shaped portion. A part of the circuit, that is not covered by the cup-shaped portion, is arranged upstream of the range of the predetermined angle in a flowing direction of airflow.

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 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 motor includes a coming-off preventing portion including an inner circumferential edge defining a through hole, inside which a substantially cylindrical bearing housing is inserted, and being arranged axially above an insulator. The inner circumferential edge has at least two different radial dimensions. A boss portion includes a columnar portion inserted inside the through hole, and a collar portion extending radially outward from a lower end of the columnar portion. The collar portion includes an outside surface having at least two different radial dimensions, and an upper surface arranged axially opposite a bottom portion of the inner circumferential edge. The radial dimensions of the inner circumferential edge and those of the collar portion are arranged to allow the collar portion to be axially inserted through the inner circumferential edge only when the inner circumferential edge and the collar portion are arranged in a predetermined circumferential orientation relative to each other.

Abstract: In manufacturing of the stator unit 2 according to one preferred embodiment of the present invention, a plurality of terminal pins are arranged in an axially spaced manner from a plurality of the coils during a twining process of the wires from the coils 232 to the terminal pins 241. Then, after the wire is twined to the terminal pins, the terminal pins connected to the coils are moved along the outer side face of the sleeve housing, functioning to as a guide portion 2201 for the terminal pins. By virtue of the configuration, the terminal pins 241 may be approximated to the coils without applying the tension on wire, and the stator unit may be made thin with preventing the open circuit of the wires.

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.

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: An electric motor includes a stator portion, a rotor portion, and a bearing mechanism, wherein the rotor portion includes a rotor holder having a substantially cylindrical shape with a closed end, and a field magnet fixed to an inner circumference of the rotor holder; the stator portion includes a stator, a base portion to which the stator is fixed, and a magnetic member; and the magnetic member includes a cylindrical portion having a substantially cylindrical shape into which a lower end portion of an insulator of the stator is inserted, the lower end portion being a portion of an outer portion of the insulator and opposing the base portion, and a flat portion having a substantially annular shape which spreads outwardly in a radial direction from a lower edge of the cylindrical portion and opposes a lower edge of the field magnet.

Abstract: A rotor unit of a brushless motor includes a substantially cylindrical rotor magnet and a rotor holder arranged to retain an outer circumferential portion of the rotor magnet. A stator unit of the same includes a stator core around which coils are wound and a Hall IC for sensing magnetic flux generated from the rotor magnet. The stator core includes teeth disposed at positions separated in the circumferential direction, each of which has an arm portion extending outward in the radial direction around which the coil is wound, and a stretching portion extending from the arm portion outward in the radial direction and in the circumferential direction on both sides.

Abstract: A rotor unit of a brushless motor includes a substantially cylindrical rotor magnet and a rotor holder arranged to retain an outer circumferential portion of the rotor magnet. A stator unit of the same includes a stator core around which coils are wound and a Hall IC for sensing magnetic flux generated from the rotor magnet. The stator core includes teeth disposed at positions separated in the circumferential direction, each of which has an arm portion extending outward in the radial direction around which the coil is wound, and a stretching portion extending from the arm portion outward in the radial direction and in the circumferential direction on both sides.

Abstract: A centrifugal fan includes a motor having an impeller and a housing for accommodating the motor. The housing has a sidewall surrounding an outer circumference of the impeller. An air inlet is formed in the housing and opposed to a center portion of the impeller. An air outlet is formed in the sidewall of the housing and opposed to an outer surface of the impeller. The housing includes a housing body and a housing cover. The housing body has a bottom with the motor secured thereon. The housing cover, formed by a pressed metal member, has an upper part and a cover sidewall extending from the upper part toward the bottom of the housing body and forming at least a part of the sidewall of the housing.

Abstract: An arrangement of a low air inlet and a circuit for driving a torque generator in an ultra-compact centrifugal fan is disclosed. In the ultra-compact centrifugal fan, a region occupied by the circuit is not completely arranged radially inside a cup-shaped portion to which an impeller is attached. At least a part of the low air inlet provided on a bottom of a housing of the centrifugal fan is arranged in a range of predetermined angle in an imaginary ring-shaped portion surrounding a base portion covered by the cup-shaped portion. A part of the circuit, that is not covered by the cup-shaped portion, is arranged upstream of the range of the predetermined angle in a flowing direction of airflow.

Abstract: In manufacturing of the stator unit 2 according to one preferred embodiment of the present invention, a plurality of terminal pins are arranged in an axially spaced manner from a plurality of the coils during a twining process of the wires from the coils 232 to the terminal pins 241. Then, after the wire is twined to the terminal pins, the terminal pins connected to the coils are moved along the outer side face of the sleeve housing, functioning to as a guide portion for the terminal pins. By virtue of the configuration, the terminal pins 241 may be approximated to the coils without applying the tension on wire, and the stator unit may be made thin with preventing the open circuit of the wires.