# US 2021/0344237 A1 · Stator core, rotating electric device, and stator core manufacturing method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0344237 A1 - Document ID: US20210344237A1 - Status: Published application - Kind: A1 - Application number: 17/273,125 - Filed: 2019-09-05 - Published: 2021-11-04 - Earliest claimed: 2018-09-18 - Assignees: Sumitomo Electric Industries, Ltd.; Sumitomo Electric Sintered Alloy, Ltd. - Applicants: Sumitomo Electric Industries, Ltd.; Sumitomo Electric Sintered Alloy, Ltd. - Inventors: Yuuichi NAKAMURA; Tomoyuki UENO; Tatsuya SAITO - Web page: https://patentgrep.com/patent/US20210344237A1 ## CPC - H02K 1/02: characterised by the magnetic material - H01F 1/24: the particles being insulated - H01F 3/08: made from powder (powder coatings on sheets H01F3/02; on strips or ribbons H01F3/04; on wires H01F3/06) - H01F 27/255: made from particles (H01F27/26 takes precedence) - H02K 1/14: Stator cores with salient poles - H02K 1/148: {Sectional cores (H02K1/141 takes precedence)} - H02K 21/24: with magnets axially facing the armatures, e.g. hub-type cycle dynamos - H02K 2213/03: Machines characterised by numerical values, ranges, mathematical expressions or similar information - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES ## 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. ## Claims ### Claim 1 A stator core for a rotating electric machine of an axial gap type, the stator core comprising: 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. ### Claim 2 (depends on 1) The stator core according to claim 1, wherein the body portion includes a plate-shaped yoke having one surface and a back surface crossing an axial direction of the rotating electric machine, and a plurality of tooth portions protruding along the axial direction from the one surface, and the one or plurality of through holes penetrate along the axial direction from the one surface to the back surface. ### Claim 3 (depends on 2) The stator core according to claim 2, wherein the plurality of tooth portions are arranged at predetermined intervals along a circumferential direction, and when the one surface is viewed straightly from the axial direction, a part or an entirety of the one through hole or each of the plurality of through holes is located outside an area between a pair of the tooth portions arranged adjacently to each other among the plurality of tooth portions on the one surface. ### Claim 4 (depends on 2) The stator core according to claim 2, wherein in a cross-section of the yoke along one plane or each of a plurality of planes including an axis of the rotating electric machine and a center line of the one or plurality of through holes, a proportion of a sectional area based on a contour of the one or plurality of through holes in a sectional area based on an outer contour of the yoke is 50 percent or less. ### Claim 5 (depends on 1) The stator core according to claim 1, wherein the body portion includes a plate-shaped yoke having one surface and a back surface crossing an axial direction of the rotating electric machine, and a plurality of tooth portions protruding along the axial direction from the one surface, and the one or plurality of through holes penetrate along the axial direction from end surfaces of the plurality of tooth portions to the back surface. ### Claim 6 (depends on 5) The stator core according to claim 5, wherein in a cross-section of each tooth portion along a plane crossing an axis of the rotating electric machine, a proportion of a sectional area based on a contour of the one or plurality of through holes in a sectional area based on an outer contour of the tooth portion provided with the one or plurality of through holes is 50 percent or less. ### Claim 7 (depends on 1) The stator core according to claim 1, wherein the through hole has a circular sectional shape or a polygonal sectional shape. ### Claim 8 (depends on 1) The stator core according to claim 1, wherein at least one of both ends of the through hole is formed to be a stepped hole. ### Claim 9 (depends on 1) The stator core according to claim 1, wherein the through hole is formed to be a tapered hole. ### Claim 10 A stator core for a rotating electric machine of an axial gap type, the stator core comprising: a body portion formed by a compaction-molded body of soft magnetic powder whose surfaces are coated with insulating films; and one or a plurality of bolts fixed to the body portion, wherein the bolt is fixed such that a screw portion of the bolt protrudes from an outer surface of the body portion and a head portion of the bolt is embedded in the body portion. ### Claim 11 (depends on 1) A rotating electric machine of an axial gap type, comprising the stator core according to claim 1. ### Claim 12 A stator core manufacturing method for manufacturing a stator core for a rotating electric machine of an axial gap type, the method comprising: a compaction-molding step of compaction-molding soft magnetic powder whose surfaces are coated with insulating films, to obtain a green compact of the stator core having one or a plurality of through holes, wherein in the compaction-molding step, the soft magnetic powder is compaction-molded using a mold capable of forming an outer shape of the green compact and the one or plurality of through holes. ### Claim 13 (depends on 12) The stator core manufacturing method according to claim 12, wherein the one or plurality of through holes are provided with chamfers or fillets at outer ends thereof, and the mold is capable of forming the one or plurality of through holes provided with the chamfers or the fillets at the outer ends thereof.