Abstract: A method of manufacturing a sintered gear includes preparing a green compact having two gear-shaped end surfaces, one on each of two sides in an axial direction of the green compact, and having a plurality of teeth on an outer peripheral surface formed between the two end surfaces; chamfering an edge of the teeth by a brush; and sintering the green compact. The brush is a wheel-type brush including a disk-shaped wheel and a bristle member radially protruding from an outer periphery of the wheel. The chamfering includes disposing the brush with respect to the green compact such that the axial direction of the green compact and an axial direction of the wheel intersect with each other; bringing a tip of the bristle member into contact with a tooth bottom edge; and relatively moving the brush in a circumferential direction of the green compact while rotating the brush.

Abstract: A method for producing a coated magnetic powder in which particle surfaces of a soft magnetic powder are coated with a silicone resin includes a preparation step of preparing a silicone emulsion by mixing a silicone resin with water containing a surfactant and dispersing the silicone resin in the water, an application step of applying the silicone emulsion onto particle surfaces of a soft magnetic powder, and a drying step of drying the soft magnetic powder after the silicone emulsion is applied.

Abstract: A core piece includes a first member in a column form and a second member in a plate form, the first member and the second member being configured by a green compact in which the first member and the second member are integrally formed, the green compact includes a plurality of soft magnetic particles having a flat shape, a first average aspect ratio of the soft magnetic particles is greater than or equal to 1.2 in a first cross section of the first member, a second average aspect ratio of the soft magnetic particles is greater than or equal to 1.2 in a second cross section of the second member, each of the first average aspect ratio and the second average aspect ratio is related to an average of lengths of soft magnetic particles in a direction of the stator core.

Abstract: A core piece that is circularly arranged to construct a stator core of an axial gap type rotary electric machine includes: a first member in a column form extending in an axial direction of the stator core; a second member in a plate form disposed on a first end side of the axial direction in the first member; and a third member in a plate form disposed on a second end side of the axial direction in the first member, the first member has a peripheral surface connecting with the second member and the third member, the second member has a protruding portion projecting outwardly from the peripheral surface of the first member, the third member has a protruding portion projecting outwardly from the peripheral surface of the first member, and the first member, the second member, and the third member are configured by an integrally molded green compact.

Abstract: A method for manufacturing a powder magnetic core, including a step of compacting a raw material powder to form a compact, a step of performing a first heat treatment on the compact to obtain a first heat-treated body, and a step of performing a second heat treatment on the first heat-treated body to obtain a second heat-treated body, wherein the raw material powder contains a soft magnetic powder and a lubricant that has a melting point Tm, the first heat treatment is performed in a temperature range from Tm to Tm+50° C. inclusive for a time longer than 10 minutes, and the second heat treatment is performed in a temperature range from 400° C. to 900° C. inclusive for a time of 3 minutes to 90 minutes inclusive, the temperature range of the second heat treatment being higher than the temperature range of the first heat treatment.

Abstract: An iron-based sintered body includes a metal matrix and complex oxide particles contained in the metal matrix. When a main viewing field having an area of 176 ?m×226 ?m is taken on a cross section of the iron-based sintered body and divided into a 5×5 array of 25 viewing fields each having an area of 35.2 ?m×45.2 ?m, the complex oxide particles have an average equivalent circle diameter of from 0.3 ?m to 2.5 ?m inclusive, and a value obtained by dividing the total area of the 25 viewing fields by the total number of complex oxide particles present in the 25 viewing fields is from 10 ?m2/particle to 1,000 ?m2/particle inclusive. The number of viewing fields in which no complex oxide particle is present is 4 or less out of the 25 viewing fields.

Abstract: A core piece that is circularly arranged to construct a stator core of an axial gap type rotary electric machine includes: a first member in a column form extending in an axial direction of the stator core; a second member in a plate form disposed on a first end side of the axial direction in the first member; and a third member in a plate form disposed on a second end side of the axial direction in the first member, the first member has a peripheral surface connecting with the second member and the third member, the second member has a protruding portion projecting outwardly from the peripheral surface of the first member, the third member has a protruding portion projecting outwardly from the peripheral surface of the first member, and the first member, the second member, and the third member are configured by an integrally molded green compact.

Abstract: A core piece that is circularly arranged to construct a stator core of an axial gap type rotary electric machine includes: a first member in a column form extending in an axial direction of the stator core; a second member in a plate form disposed on a first end side of the axial direction in the first member; and a third member in a plate form disposed on a second end side of the axial direction in the first member, the first member has a peripheral surface connecting with the second member and the third member, the second member has a protruding portion projecting outwardly from the peripheral surface of the first member, the third member has a protruding portion projecting outwardly from the peripheral surface of the first member, and the first member, the second member, and the third member are configured by an integrally molded green compact.

Abstract: Provided is an axial gap-type rotary electric machine in which a first stator, a second stator, and a rotor are arranged in a direction of a rotary shaft of the rotor. The first stator includes a first coil and a first core. The second stator includes a second coil and a second core. The first core includes an annular first yoke, a plurality of first teeth, and a first mark indicating a reference position in a circumferential direction of the first yoke. The second core includes an annular second yoke, a plurality of second teeth, and a second mark indicating a reference position in a circumferential direction of the second yoke. When viewed in the direction of the rotary shaft, the first mark and the second mark are symmetrically positioned with respect to the rotary shaft.

Abstract: A method for manufacturing a sintered gear comprising the steps of: preparing a cylindrical green compact; gear-cutting the green compact with a hob; and sintering the gear-hobbed green compact, wherein the hob is such that a ratio of a number of cutting edges thereof per round to a number of starts thereof exceeds 8.

Abstract: An interconnected assembly includes a first member formed from a compressed mass of soft magnetic powder, a second member that is a separate piece from the first member, and a self-tapping screw extending through the second member to reach the first member to interconnect the first member and the second member, wherein at least the first member, among the first member and the second member, has a pilot hole into which a thread of the self-tapping screw bites, wherein an inner diameter of the pilot hole is greater than or equal to 83% and less than or equal to 95% of a major diameter of the self-tapping screw, and is greater than a minor diameter of the self-tapping screw, and wherein a helical gap is formed between an outer circumferential surface of the self-tapping screw and an inner circumferential surface of the pilot hole.

Abstract: A method of making a sintered part includes a step of applying a machining process to a compacted part with a tool to make a machined compacted part having a cogwheel shape, and a step of sintering the machined compacted part to make a sintered part, wherein the machining process is such that a surface of the compacted part on a side where the tool exits is supported by a plate member having a tooth pattern with same specifications as a tooth pattern of the cogwheel shape, and the tool is used to machine portions of the compacted part corresponding to tooth spaces of the plate member.

Abstract: A core for use in an axial gap rotating electric machine, the core including: a yoke having an annular plate shape; and a plurality of teeth having a columnar shape arranged at intervals in a circumferential direction of the yoke, wherein the yoke has: an outer-circumferential face; an inner-circumferential face; a first face having a flat shape connecting the outer-circumferential face and the inner-circumferential face to each other; and a plurality of recessed portions connected to the first face, each of the plurality of teeth has an outer-circumferential face protruding in an axial direction of the yoke with respect to the first face, each of the plurality of recessed portions are connected to at least a portion of each one of the plurality of teeth in a circumferential direction of the outer-circumferential face, all shortest distances between at least one of an outer-circumferential edge of the first face and an inner-circumferential edge of the first face and the outer-circumferential faces of the plu

Abstract: A core used in an axial-gap rotating electric device includes an annular back yoke and a plurality of teeth protruding in an axial direction that is perpendicular to a first flat surface of the back yoke. The plurality of teeth are provided on the first flat surface at intervals in a circumferential direction. The back yoke and the teeth are constituted of an integrally-molded powder compact. A first curved section that connects a peripheral surface of each tooth and the first flat surface of the back yoke is provided at a corner between the tooth and the back yoke. The first curved section has a curvature radius ranging between 0.2 mm and 1.5 mm inclusive.

Abstract: A method for manufacturing a powder magnetic core includes: a step of preparing a soft magnetic powder and an oxide powder and preparing, as a raw material powder, a mixed powder of the soft magnetic powder and the oxide powder, the soft magnetic powder containing composite soft magnetic particles containing pure iron and an Fe-? alloy having an element ? more oxidizable than Fe, the composite soft magnetic particles each having a core-shell structure where a core is made of one of pure iron and the Fe-? alloy and a shell is made of the other, the oxide powder containing oxide particles containing at least one selected from Fe and an element ? that forms an oxide having higher electrical resistance than Fe3O4; a step of compacting the mixed powder into a green compact; and a step o sintering the green compact at 900° C. or more and 1300° C. or less.

Abstract: A core used in an axial gap type rotating electrical machine includes an annular yoke having a plurality of through-holes disposed in a circumferential direction, and a plurality of columnar teeth disposed in the circumferential direction of the yoke, each of the plurality of columnar teeth including one end inserted into each of the plurality of through-holes. The yoke and each of the teeth are composed of a powder compact separate from each other, and the one end of each of the teeth is off-center in the through-hole.

Abstract: A core that is used in an axial-gap rotary electric machine and that includes a body, and frame-shaped flange portions. The body includes an annular yoke and columnar teeth that are arranged in a circumferential direction of the yoke. The flange portions are fixed to end portions of the respective teeth. The yoke and the teeth are composed of a single powder compact. Each of the flange portions is composed of a powder compact that has a through-hole. The end portion of each of the teeth is inserted in the through-hole, and an end surface of each of the teeth is exposed from the through-hole. A ratio of an area of the end surface of each of the teeth to an area within an outer circumferential edge of each of the flange portions is 7.5% or more in a plan view in an axial direction of the yoke.

Abstract: A powder compaction mold includes a die and upper and lower punches configured to fit into the die and is configured to compress a powder between the upper and lower punches to manufacture a powder compact. Of the members forming the powder compaction mold, at least one of two members in sliding contact with each other has therein a vent passage through which gas is vented from a filling space for the powder surrounded by the die and the lower punch to an outside of the powder compaction mold. The vent passage has a gas intake port that is open to a clearance section formed between the two members and connecting to the filling space.

Abstract: A core for use in an axial-gap rotary electric machine is annular and includes a plurality of core pieces into which the core is divided in a circumferential direction. Each core piece includes a yoke portion and a tooth portion that is formed integrally with the yoke portion and that projects from the yoke portion in an axial direction. Each yoke portion includes a plurality of protrusions provided on one side surface connected to the yoke portion of an adjacent one of the core pieces, and a plurality of recesses provided on other side surface connected to the yoke portion of another adjacent one of the core pieces, the recesses corresponding to the protrusions. An interval between the protrusions is 80% or less of a length of the one side surface of the yoke portion, the length being a direct distance between inner and outer peripheries of the yoke portion.

Abstract: This stator core is a stator core for a rotating electric machine of an axial gap type and includes a body portion formed by a compaction-molded body of soft magnetic powder whose surfaces are coated with insulating films, wherein the body portion is provided with one or a plurality of through holes.