Abstract: A rotor used in an outer rotor motor includes a rotor holder in a tubular shape extending along a center axis, a rotor core in a tubular shape extending in an axial direction and being fixed to a surface of the rotor holder, directed radially inward, and permanent magnets bonded to an inner circumferential surface of the rotor core and side by side in a circumferential direction. The rotor core includes projection portions projecting radially inward from the inner circumferential surface of the rotor core. One or more of the projection portions are in a gap between the permanent magnets adjacent to each other in the circumferential direction. Each of the projection portions has an axial length shorter than an axial length of each of the permanent magnets.

Abstract: A motor includes a rotor and a stator. The rotor is rotatable about an axially extending central axis. The stator includes a stator core radially opposing the rotor. The stator core includes core back pieces and a teeth portion. The core back pieces are arranged circumferentially about the central axis. The teeth portion extends radially. The core back pieces which are circumferentially adjacent to each other are connected circumferentially via an end on a side of the core back pieces in a radial direction of the teeth portion.

Abstract: An impeller for a centrifugal fan rotatable about a central axis extending in an axial direction includes a hub portion expanding radially outward about the central axis, and wings on a radially outer side of the hub portion. A cross-sectional shape of the wing in a circumferential direction is a wing shape.

Abstract: A motor mounted on a drone includes a rotor including a propeller mounting portion with a propeller detachably attached, the rotor being rotatable about a central axis, a stator radially facing the rotor with a gap therebetween, and an auto-balancer capable of automatically correcting dynamic balance of the rotor.

Abstract: A motor includes: a rotor including a shaft rotatable about an axis extending in a vertical direction; a bearing rotatably supporting the shaft; a stationary portion including a stator; and a lead wire electrically connected to the stator. The stationary portion includes a housing located radially outward of the bearing and radially inward of the stator, and supporting the bearing and the stator, a base portion which is located axially below the stator and to which the housing is fixed, and a fixing member fixed to the base portion. The fixing member includes a cover portion covering a shaft lower end portion located at an axially lower end of the shaft when viewed from axially below. The cover portion has an opening portion that opens in an axial direction. The opening portion is located radially more inside than an inner peripheral surface of the shaft when viewed from axially below.

Abstract: According to one aspect of the present disclosure, a rotor includes a plurality of permanent magnets and a support supporting the permanent magnet. The support includes at least one of an outside support fixed to a radial outside of the outer cores to circumferentially support an end face of the permanent magnet from both sides and an inside support fixed to a radial inside of the outer cores to circumferentially support the end face of the permanent magnet from both sides. Each of the outer cores includes an opposite face parallelly opposed to the end face of the permanent magnet in the circumferential direction. The outside support and the inside support each includes a support face circumferentially supporting the end face. The support face is disposed on a side closer to a center line of the permanent magnet than the opposite face in the circumferential direction.

Abstract: According to one aspect of the present disclosure, a rotor includes a shaft, a rotor core including an inner core and a plurality of outer cores, a mold resin unit covering, the mold resin unit, and a plurality of permanent magnets. The mold resin unit includes a gate mark in a region between the outer cores adjacent to each other in the circumferential direction, and the gate mark is provided in all regions between the adjacent outer cores or in a region between the outer cores, the region being adjacent to a region between the even-numbered adjacent outer cores in which the gate mark is not disposed in all the regions between the adjacent outer cores.

Abstract: A motor includes a rotor with one or more magnets, a rotor core holding the one or more magnets, a spacer that contacts the one or more magnets, and a rotor holder. The rotor holder includes a holder lid portion and a holder tubular portion in a tubular shape extending to one side in the axial direction from a radially outer edge of the holder lid portion. The holder lid portion includes a holder first surface that extends radially inward from an inner surface of the holder tubular portion, a holder second surface that extends radially and is radially inward of the holder first surface and on the other side in the axial direction, and a connecting surface connecting the holder first surface and the holder second surface.

Abstract: An inline axial flow fan includes a first fan including a first impeller, a first motor portion, and a first case, and a second fan including a second impeller, a second motor portion, and a second case, the first fan and the second fan being positioned in sequence from one axial side to another axial side. The first case includes multiple first slits, and the second case includes multiple second slits. The inline axial flow fan includes a flange extending radially outward from an outer peripheral surface of the first case or the second case located between the first slit and the second slit in the axial direction.

Abstract: A motor includes a rotor rotatable about a center axis extending vertically, a stator radially opposing the rotor, a bracket holding the stator, a circuit board including an upper surface with a first wiring pattern and a lower surface with a second wiring pattern, and a first fixing portion having conductivity and fixing the circuit board to the stator. The stator includes a stator core having conductivity. The first fixing portion includes a board holding portion holding the circuit board, and a stator fixed portion fixed to a portion of the stator core. The board holding portion is in contact with the first wiring pattern and the second wiring pattern.

Abstract: An inline axial flow fan includes a first fan including a first impeller, a first motor portion, and a first case, and a second fan including a second impeller, a second motor portion, and a second case, the first fan and the second fan being positioned in sequence from one axial side to another axial side. The first case and the second case are accommodated in a housing, and only one of the first case and the second case includes multiple slits that connect the inside and the outside of the first case and the second case in the radial direction.

Abstract: A rotor used in an outer rotor motor includes a rotor holder in a tubular shape extending along a center axis, a rotor core in a tubular shape extending in an axial direction and being fixed to a surface of the rotor holder, directed radially inward, and permanent magnets bonded to an inner circumferential surface of the rotor core and side by side in a circumferential direction. The rotor core includes projection portions projecting radially inward from the inner circumferential surface of the rotor core. One or more of the projection portions are in a gap between the permanent magnets adjacent to each other in the circumferential direction. Each of the projection portions has an axial length shorter than an axial length of each of the permanent magnets.

Abstract: A motor includes a stationary structure, and a rotor rotatable about a central axis with respect to the stationary structure. The stationary structure includes a stator including a coil, a bracket that supports the stator, and a circuit board disposed between the stator and the bracket. The bracket includes a board support that holds the circuit board between the bracket and the stator in an axial direction. The board support includes a wiring through hole that penetrates the board support in the axial direction and through which a wire extending from the circuit board passes, a lid that partially covers the wiring through hole, and a guide bridge that is located inside the wiring through hole when viewed in the axial direction and holds the wire between the lid and the guide bridge.

Abstract: A drive device includes a hollow hub rotatable about hub shafts extending parallel to a center axis, a motor housed in the hub and fixed to the hub shafts, and a speed reducer connected to the motor and the hub. The motor includes a rotor including a motor shaft extending parallel to the hub shafts, a stator disposed outside the rotor in a radial direction, and a motor housing holding the stator therein. The drive device includes thermal grease thermally connecting the hub and the motor housing to each other.

Abstract: A motor includes a rotor rotatable about a center axis extending vertically, a stator radially opposing the rotor, a bracket holding the stator, a circuit board including an upper surface with a first wiring pattern and a lower surface with a second wiring pattern, and a first fixing portion having conductivity and fixing the circuit board to the stator. The stator includes a stator core having conductivity. The first fixing portion includes a board holding portion holding the circuit board, and a stator fixed portion fixed to a portion of the stator core. The board holding portion is in contact with the first wiring pattern and the second wiring pattern.

Abstract: A motor includes a rotor with one or more magnets, a rotor core holding the one or more magnets, a spacer that contacts the one or more magnets, and a rotor holder. The rotor holder includes a holder lid portion and a holder tubular portion in a tubular shape extending to one side in the axial direction from a radially outer edge of the holder lid portion. The holder lid portion includes a holder first surface that extends radially inward from an inner surface of the holder tubular portion, a holder second surface that extends radially and is radially inward of the holder first surface and on the other side in the axial direction, and a connecting surface connecting the holder first surface and the holder second surface.

Abstract: A motor includes a stationary portion, a rotating portion that includes a shaft rotating about a vertically extending central axis, and a bearing portion that rotatably supports the shaft with respect to the stationary portion. The stationary portion includes a cylindrical bearing housing portion that holds the bearing portion, a stator that is radially outward of the bearing housing portion, a circuit board that is below the stator, and an annular spacer that is between the stator and the bearing housing portion. The stator includes a stator core that includes an annular core back and multiple teeth that extend radially outward from the core back and are arranged in a circumferential direction, an insulating film that covers a surface of the teeth, extends radially inward from a lower surface of the teeth, and covers a lower outer edge portion of the core back, and a coil provided on the teeth.

Abstract: A motor includes a stationary portion, a rotating portion that includes a shaft rotating about a vertically extending central axis, and a bearing portion that rotatably supports the shaft with respect to the stationary portion. The stationary portion includes a cylindrical bearing housing portion that holds the bearing portion, a stator that is radially outward of the bearing housing portion and includes a stator core, a circuit board that is below the stator core, and an annular spacer that is between the stator core and the bearing housing portion. The spacer includes multiple side wall portions that contact a radially inner surface of the stator core and a flange portion that protrudes radially outward more than the side wall portion and contacts a lower surface of the stator core.

Abstract: A motor mounted on a drone includes a rotor including a propeller mounting portion with a propeller detachably attached, the rotor being rotatable about a central axis, a stator radially facing the rotor with a gap therebetween, and an auto-balancer capable of automatically correcting dynamic balance of the rotor.

Abstract: A form cutting method includes a first cutting step of moving a semi-finishing tool having a first cutting edge in a tool feeding direction Dt orthogonal to a first axis while rotating the semi-finishing tool in a first direction about the axis to form a blade groove 120 having a contour shape of the semi-finishing tool and being continuous in the tool feeding direction Dt on a workpiece 100, and a second cutting step of moving a final finishing tool 20 having a second cutting edge 24s opposite to the semi-finishing tool in the tool feeding direction Dt while rotating the final finishing tool in a second direction R2 about a second axis O2 to finish groove inner peripheral surfaces 120x and 120y of the blade groove 120.