Abstract: A method for producing a raw material of grease, including: preparing first thickener raw material; second thickener raw material; first lubricating oil; second lubricating oil; first solvent with a boiling point lower than those of the oils, dissolves the first oil, and does not dissolve a produced thickener; and a second solvent with a boiling point lower than those of the oils, dissolves the second oil, and does not dissolve the produced thickener; dissolving the first lubricating oil in the first solvent, and dissolving or dispersing the first thickener raw material in the first solvent to obtain a first mixed solution; dissolving the second lubricating oil in the second solvent, and dissolving or dispersing the second thickener raw material in the second solvent to obtain a second mixed solution; and mixing the first and second mixed solutions, and reacting the first and second thickener raw materials producing a thickener.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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: L s = ? i ? ? ( t i L i × ( 1.5 ) m ) ? ? m = 40 - max ? ( 40 , K i ) 10 , where Ls represents the elapsed service life ratio, ti represents a driving time in a section i, Li represents a service life expectancy at a duty cycle Di in the section i and at an environmental temperature of the motor being 40° C., and Ki represents a temperature in the section i.

Abstract: A centrifugal fan that sends out in a radial direction a fluid sucked from an axial direction, includes an impeller rotatable about a center axis extending in a top-bottom direction, and a motor that rotates the impeller. The motor includes a rotor rotatable about the center axis, and a stator that faces at least a portion of the rotor in the radial direction. The impeller includes an impeller hub fixed to the rotor, centrifugal vanes disposed in a circumferential direction on a radial-direction outer side of the impeller hub, and axial flow vanes disposed in the circumferential direction on a radial-direction inner side of the impeller hub. The axial flow vanes are disposed on an axial-direction upper side of the stator.

Abstract: An axial fan includes a motor, an impeller capable of rotating about a central axis, and a housing including a tubular air channel wall portion arranged radially outside of the impeller. The impeller includes a tubular impeller hub, and a plurality of blades arranged in a circumferential direction on an outer surface of 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 when viewed in a radial direction. The inner circumferential developed blade is a circumferential development of a junction of the blade with the outer surface of the impeller hub. The outer circumferential developed blade is a circumferential development of a radially outermost portion of the blade.

Abstract: An axial fan includes a rotor portion including a shaft arranged to extend along a central axis extending in a vertical direction; 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 is an injection molded article, and includes a hub top plate portion arranged to extend perpendicularly to an axial direction; 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 on an outer surface of the hub tubular portion; and an inner fixing portion arranged radially inward of the hub tubular portion. The rotor portion includes a rotor tubular portion being tubular and arranged to extend in the axial direction.

Abstract: 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.

Abstract: An axial fan includes a rotor portion including a shaft arranged to extend along a central axis extending in a vertical direction, 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 arranged to extend perpendicularly to an axial direction; 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 on an outer surface of the hub tubular portion; a plurality of wall portions arranged in the circumferential direction radially inside of the hub tubular portion, with a gap between every adjacent ones of the wall portions; and joining portions each of which is arranged to join a corresponding one of the wall portions to the hub tubular portion.

Abstract: 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: L s = ? i ? ? ( t i L i × ( 1.5 ) m ) ? ? m = 40 - max ? ( 40 , K i ) 10 , where Ls represents the elapsed service life ratio, ti represents a driving time in a section i, Li represents a service life expectancy at a duty cycle Di in the section i and at an environmental temperature of the motor being 40° C., and Ki represents a temperature in the section i.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A covered arc welding electrode includes a steel core wire and a flux which is applied to the outside periphery of said steel core wire. The welding electrode can form a superior crack-resisting weld zone even if fluctuating stresses are continually applied to a base metal while the base metal is welded. The flux includes 40 to 60% metal carbonate, 10 to 25% metal fluoride and 4 to 25 metal oxide by weight. The flux comprises 24 to 32% of the total weight of said electrode. The composition of the welding electrode includes 0.005 to 0.05% carbon, 0.1 to 1.1% silicon, 1.5 to 2.5% manganese, not more than 0.007% sulfur and not more than 0.25% nickel by weight and the manganese/sulfur ratio is more than or equal to 350 to 1. In addition, the welding electrode can include 0.01 to 0.10% rare earth metal by weight. In which case, the Mn content may be 1.0 to 2.5% by weight and the manganese/sulfur ratio may be more than or equal to 270 to 1.

Abstract: An improved welding method for welding an inner seam of a longitudinally welded steel pipe along an inner groove by welding electrodes held by a boom which is supported by a tracing roller moving along the inner groove of the steel pipe. According to the invention, at least one metal plate is urged against at least one end of the steel pipe after tack welding the seam on an opposite side of the inner groove of the steel pipe to be welded. Lateral angular deformations of the end of the steel pipe are prevented on both sides of the seam. Such deformations are due to the load of the boom when the tracing roller leaves the end of the steel pipe for the metal plate. Thus, the invention provides for prevention of hot cracking at the end of the pipe.