Nidec Corporation

Junya Matsuyama

Kazuhiro Inouchi

Sakae Nogami

Hideki Aoi

Jumpei Kitamura

Megumi Michishita

Kazuhiro Ono

Shoki Yamazaki

Tatsuya Tatara

Yuichiro Yokoyama

Shinnosuke Gokan

An axial fan includes an upper impeller disposed in an axially upper portion of a housing, and an upper circuit board disposed axially below the upper impeller. An upper impeller cup of the upper impeller includes an upper cylindrical portion and an upper lid. The axial fan includes a lower impeller disposed in an axially lower portion of the housing, and a lower circuit board disposed axially above the lower impeller. A lower impeller cup of the lower impeller includes a lower cylindrical portion and a lower lid. An axial upper end outer diameter of the upper cylindrical portion is smaller than an axial lower end outer diameter of the upper cylindrical portion. An axial lower end outer diameter of the lower cylindrical portion is smaller than an axial upper end outer diameter of the lower cylindrical portion.

Axial fan

An axial fan includes a motor, an impeller, and a housing including a tubular air channel wall portion. The impeller includes a tubular impeller hub, and arranged in a circumferential direction on the impeller hub. Each blade includes a first portion where all of an inner circumferential developed blade, an outer circumferential developed blade, and an intermediate circumferential developed blade superimposed on each other overlap. The inner circumferential developed blade is a junction of the blade with the outer surface of the impeller hub. The outer circumferential developed blade is a radially outermost portion. The intermediate circumferential developed blade is a radially intermediate portion of the blade between the junction and the radially outermost portion. The radially outermost portion is at the shortest radial distance from the air channel wall portion in at least a portion of the first portion.

A stator unit included in a motor includes a base member, an armature, a circuit board, and a mold resin portion. The base member extends substantially perpendicularly to a vertically extending center axis. The armature and the circuit board are positioned above the base member. The circuit board is electrically connected to the armature. The mold resin portion covers the armature and the circuit board. In a process of forming the mold resin portion, the base member is supported by a first mold. Then, the first mold is joined to a second mold such that a cavity is provided therebetween. In this step, the second mold is pressed against a projection provided on an upper surface of the base member and on a radially outer side with respect to the circuit board in plan view. The projection thus pressed is squashed. Subsequently, molten resin is injected into the cavity.

Stator unit, motor, and method of manufacturing stator unit

A stator unit included in a motor includes a base member, an armature, a circuit board, and a mold resin portion. The base member extends substantially perpendicularly to a vertically extending center axis. The armature and the circuit board are positioned above the base member. The circuit board is electrically connected to the armature. The mold resin portion covers the armature and the circuit board. In a process of forming the mold resin portion, the base member is firstly supported by a first mold.

An electric machine with a casing includes a circuit board arranged inside the casing and on which an electronic component is mounted, and a sealing member covering the circuit board. The sealing member includes, at a part of a boundary surface thereof coming into contact with air, a first inclined surface inclined downwardly in a vertical direction. The casing includes a front wall covering a side of the sealing member on a downward side of the first inclined surface, a rear wall covering a side of the sealing member on an upward side of the first inclined surface, and a pair of side walls covering sides of the sealing member in a direction perpendicular to a direction in which the first inclined surface is inclined. The front wall has a groove concaved from an upper side to a lower side, and the first inclined surface is inclined toward the groove.

Electric machine

An axial fan includes a rotor portion, a stator portion arranged radially opposite to the rotor portion, and an impeller hub fixed to the rotor portion, and arranged to be capable of rotating integrally with the rotor portion. The impeller hub includes a hub top plate portion; a hub tubular portion being tubular, and arranged to extend axially downward from an outer edge of the hub top plate portion; a plurality of blades arranged in a circumferential direction; a plurality of wall portions arranged in the circumferential direction radially inside of the hub tubular portion; and a joining portion arranged to join a corresponding one of the wall portions to the hub tubular portion. A radially outer surface of the rotor tubular portion is arranged to be in contact with an inner surface of at least one of the wall portions.

A method for estimating a service life of a motor that is driven by variable duty cycle control. The method includes calculating an elapsed service life ratio representing a ratio of an elapsed service life to all service life according to the following formula to estimate the service life of the motor: where Lrepresents the elapsed service life ratio, trepresents a driving time in a section i, Lrepresents a service life expectancy at a duty cycle Din the section i and at an environmental temperature of the motor being 40&#xb0; C., and Krepresents a temperature in the section i.

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Kyoto, Japan

Junya Matsuyama