Abstract: A power conversion device includes a first inverter and a control circuit that controls on/off operations of switches in the first inverter and diagnoses disconnection failures of n-phase windings where n is an integer of three or more. The control circuit generates a control signal to turn on one low-side switch of a first specific phase among n low-side switch in the first inverter, turn off the remaining n?1 low-side switches, and turn off all n high-side switches, supplies the control signal to the n low-side switches and the n high-side switches in a state where a neutral point of a motor is provided, measures n-phase voltages that change depending on patterns of disconnection failures of the n-phase windings, and diagnoses a disconnection failure based on the measured n-phase voltages by referring to a table associating the patterns of the disconnection failures with n-phase voltage levels.

Abstract: An electric power conversion device includes a first inverter connected to one end of each phase winding of a motor, a second inverter connected to another end of each phase winding, and a control circuit to control operation of the first and second inverters. The control circuit configures a neutral point in the first inverter and applies a voltage to a path in which a high-side of the second inverter, the first-phase winding, the neutral point, the second-phase winding, and a low-side of the second inverter are connected, and diagnoses whether the first and second inverters are faulty.

Abstract: A power conversion device includes a first inverter and a control circuit that controls on/off operations of switches in the first inverter and diagnoses disconnection failures of n-phase windings where n is an integer of three or more. The control circuit generates a control signal to turn on one low-side switch of a first specific phase among n low-side switch in the first inverter, turn off the remaining n?1 low-side switches, and turn off all n high-side switches, supplies the control signal to the n low-side switches and the n high-side switches in a state where a neutral point of a motor is provided, measures n-phase voltages that change depending on patterns of disconnection failures of the n-phase windings, and diagnoses a disconnection failure based on the measured n-phase voltages by referring to a table associating the patterns of the disconnection failures with n-phase voltage levels.

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: 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 housing assembly for a fan unit includes an upper housing having a lower engaging portion adjacent to its lower end surface and a lower housing having an upper engaging portion adjacent to its upper end surface. When one of the upper and lower housings rotates relative to the other about a center axis of the housings in a first direction with the opposing end surfaces of the housings in axial contact, the lower and upper engaging portions engage with each other. While the lower and upper engaging portions are in engagement, one of the lower and upper engaging portions presses the other in both axial directions to cause elastic axial deformation of the other; and one of the lower and upper engaging portions presses the other toward both the first direction and a second direction opposite thereto to cause elastic circumferential deformation of the other.

Abstract: A spindle motor includes a shaft, a cone, a turntable provide with a disk support portion, a cylindrical closed-top rotor holder, a rotor magnet, a stator, and a bearing mechanism. The cone includes a disk holding surface inclined radially outward and downward. The turntable further includes a resin-made table body having a disk support portion and an annular groove portion depressed upward at a lower side of the disk support portion, a plurality of balls rotatably arranged within the annular groove portion, an annular closure portion arranged between the table body and the rotor holder to close a lower opening of the annular groove portion, and a disc-shaped portion arranged radially inward of the annular groove portion of the table body, the disc-shaped portion having an upper surface bonded to the table body by an adhesive agent and a lower surface bonded to the rotor holder by the adhesive agent.

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 serial axial fan includes first and second axial fans. Each of the first and second axial fans includes a base portion and a plurality of support ribs arranged to connect the base portions to housings. The first and second axial fans are coupled together with the base portions thereof either in contact with or in close proximity to each other. Each of the support ribs in each of the first and second axial fans extends over both housings of the first and second axial fans.

Abstract: A spindle motor includes a shaft, a cone, a turntable provide with a disk support portion, a cylindrical closed-top rotor holder, a rotor magnet, a stator, and a bearing mechanism. The cone includes a disk holding surface inclined radially outward and downward. The turntable further includes a resin-made table body having a disk support portion and an annular groove portion depressed upward at a lower side of the disk support portion, a plurality of balls rotatably arranged within the annular groove portion, an annular closure portion arranged between the table body and the rotor holder to close a lower opening of the annular groove portion, and a disc-shaped portion arranged radially inward of the annular groove portion of the table body, the disc-shaped portion having an upper surface bonded to the table body by an adhesive agent and a lower surface bonded to the rotor holder by the adhesive agent.

Abstract: A bearing retainer unit is formed by an insert-molding technique to cast a molded component of the bearing retainer unit utilizing a bearing bushing. A first mold die, having a circumferential surface shaped to correspond to at least a portion of the inner circumferential surface of a bearing-positioning portion of the molded component, and a second mold die, having an abutment that abuts against an axial end face of the first die, are readied. A molten material is then injected into the mold to form the molded part, thereby forming the die-parting line on the inner circumferential surface of the component's bearing positioning portion, positioned at the radially outer side of the abutment.

Abstract: Blower made up of at least two axially stacked, interlocking fans. Each fan is enclosed in a housing the axially opposite ends of which are flanged. Opposing flats on immediately neighboring flanges are formed with complementary twist-locking features. The twist-locking features are configured in such a way that when the fans are stacked, the opposing flats will not be in contact with each other unless the housings are twisted out of axial alignment to bring the opposing flats flush together, and such that with the opposing flats flush in contact, twisting the housings back into axial alignment locks them together.

Abstract: A serial axial fan includes first and second axial fans. Each of the first and second axial fans includes a base portion and a plurality of support ribs arranged to connect the base portions to housings. The first and second axial fans are coupled together with the base portions thereof either in contact with or in close proximity to each other. Each of the support ribs in each of the first and second axial fans extends over both housings of the first and second axial fans.

Abstract: A housing assembly for a fan unit includes an upper housing having a lower engaging portion adjacent to its lower end surface and a lower housing having an upper engaging portion adjacent to its upper end surface. When one of the upper and lower housings rotates relative to the other about a center axis of the housings in a first direction with the opposing end surfaces of the housings in axial contact, the lower and upper engaging portions engage with each other. While the lower and upper engaging portions are in engagement, one of the lower and upper engaging portions presses the other in both axial directions to cause elastic axial deformation of the other; and one of the lower and upper engaging portions presses the other toward both the first direction and a second direction opposite thereto to cause elastic circumferential deformation of the other.

Abstract: There is provided a fan device with improved performance such as a lower noise level and a higher strength. Such a fan device (11) includes an impeller (12) that has a plurality of rotating blades rotating to take in and exhaust air in an axial direction, a motor that drives the impeller, an external frame member (15) that houses therein the impeller, a support member (16) that is disposed within the external frame member and supports the motor, and a plurality of stator blades (17) that connect the external frame member with the support member and have a wing-like shape in a cross-section in the axial direction. At least in a partial section of each stator blade in a radial direction of the fan device, an angle at which each stator blade is tilted with respect to the axial direction decreases in such a manner that the angle is smaller at an outer side of the fan device in the radial direction than at an inner side of the fan device in the radial direction.

Abstract: A fan includes a motor, an impeller mounted to the motor and generating air flow by rotation around a rotation axis thereof, and a housing defining a passage of the air flow and supporting the motor. A wire outlet opening is provided on the housing in a manner axially penetrating the housing, and a lead wire is inserted into the wire outlet opening. A lead wire holding member is inserted into the wire outlet opening into which the lead wire is inserted, the lead wire holding member elastically presses the lead wire to the housing, and a latching portion of the lead wire holding member is latched to a portion of the housing. Therefore, the lead wire holding member fits in the wire outlet opening while firmly holding the lead wire in the wire outlet opening.

Abstract: A bearing retainer unit is formed by an insert-molding technique to cast a molded component of the bearing retainer unit utilizing a bearing bushing. A first mold die, having a circumferential surface shaped to correspond to at least a portion of the inner circumferential surface of a bearing-positioning portion of the molded component, and a second mold die, having an abutment that abuts against an axial end face of the first die, are readied. A molten material is then injected into the mold to form the molded part, thereby forming the die-parting line on the inner circumferential surface of the component's bearing positioning portion, positioned at the radially outer side of the abutment.

Abstract: Blower made up of two fans engaged in a rotational axis direction of impellers. Each fan has a housing, at each area opposed upper or lower sides of adjoining two housing, the lower side of the upper housing and the upper side of the lower housing has flat housing portions. And two fans of the blower are held as the manner that two adjoining housings are located in parallel each other while being turned in a predetermined rotational angle around the rotational axis of the impeller, for making contact the flat housing portions of the opposed housings each other. On, near or in separate area from the flat housing portions, upper and lower housing engaging portions and upper and lower housing stoppers are formed, respectively.