# US 2021/0083531 A1 · Stator, motor, and method for manufacturing stator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0083531 A1 - Document ID: US20210083531A1 - Status: Published application - Kind: A1 - Application number: 17/014,156 - Filed: 2020-09-08 - Published: 2021-03-18 - Earliest claimed: 2019-09-18 - Assignees: Nidec Corporation - Applicants: Nidec Corporation - Inventors: Akira ICHIEN; Yusuke ARAO - Web page: https://patentgrep.com/patent/US20210083531A1 ## CPC - H02K 1/148: {Sectional cores (H02K1/141 takes precedence)} - H02K 1/16: Stator cores with slots for windings - H02K 15/02: of stator or rotor bodies - H02K 15/022: with salient poles - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A stator is formed by laminating electrical steel sheets punched into a predetermined shape. The stator includes split cores that are punched out from the electrical steel sheets to have an annular shape. A first group of the split cores adjacent to each other in the circumferential direction have the same rolling direction, and a second group of the split cores adjacent to each other in the circumferential direction have different rolling directions. ## Claims ### Claim 1 A stator comprising: a laminate including electrical steel sheets punched into a specific shape; and a plurality of split cores each with an annular shape; wherein a first group of the plurality of split cores adjacent to each other in a circumferential direction have a same rolling direction, and a second group of the plurality of split cores adjacent to each other in the circumferential direction have different rolling directions. ### Claim 2 (depends on 1) The stator according to claim 1, wherein linear flaws continue across the first group of the plurality of split cores adjacent to each other in the circumferential direction. ### Claim 3 (depends on 1) The stator according to claim 1, wherein linear flaws of the second group of the plurality of split cores adjacent to each other in the circumferential direction intersect each other; and intersections of the linear flaws are located at equal or substantially equal intervals in the circumferential direction. ### Claim 4 (depends on 2) The stator according to claim 2, wherein the linear flaws of the plurality of split cores are 3n sets, where n is a natural number. ### Claim 5 (depends on 2) The stator according to claim 2, wherein a number of the split cores in which the linear flaws continue is 4n, where n is a natural number. ### Claim 6 (depends on 2) The stator according to claim 2, wherein a number of the split cores in which the linear flaws continue is a number obtained by dividing a number of slots, which are portions in which coils are mounted, by a number of phases. ### Claim 7 (depends on 1) A motor comprising: the stator according to claim 1; and a rotor facing the stator. ### Claim 8 A method for manufacturing a stator including X split cores punched out from an electrical steel sheet to have an annular shape, where X is a natural number of two or more, the method comprising: punching out the split cores from the electrical steel sheet in group units of Y less than X with arc-shaped core backs extending in a same circumferential direction and connected to each other, where Y is a natural number of two or more. ### Claim 9 (depends on 8) The method for manufacturing a stator according to claim 8, wherein the split cores are punched out from the electrical steel sheet in a state where the split core of one group and located at an end portion on one side in a circumferential direction is alternately arranged between the split cores of another group and located at both end portions in the circumferential direction. ### Claim 10 (depends on 8) The method for manufacturing a stator according to claim 8, wherein the split cores are punched out from the electrical steel sheet in a state where the split core of one group and located at an end portion on one side in a circumferential direction is arranged on a core back side of the split core of another group relative to a line segment connecting radially inner portions of the split cores of another group and located at both end portions in the circumferential direction. ### Claim 11 (depends on 8) The method for manufacturing a stator according to claim 8, wherein the split core of one group and the split core of another group are located closer to a mutual core back side than a mutual tooth side. ### Claim 12 (depends on 8) The method for manufacturing a stator according to claim 8, further comprising: causing Y split cores of one group to be subjected to push-back processing. ### Claim 13 (depends on 12) The method for manufacturing a stator according to claim 12, wherein the Y split cores of the one group are punched out from the electrical steel sheet after being subjected to the push-back processing. ### Claim 14 (depends on 12) The method for manufacturing a stator according to claim 12, wherein the Y split cores of the one group are subjected to the push-back processing after being punched out from the electrical steel sheet. ### Claim 15 (depends on 13) The method for manufacturing a stator according to claim 13, further comprising: forming, by the push-back processing, a connection concave portion on one of the adjacent split cores, and a connection convex portion, which fits into the connection concave portion, on the other of the adjacent split cores. ### Claim 16 (depends on 15) The method for manufacturing a stator according to claim 15, further comprising: splitting the split core subjected to the push-back processing from the adjacent split core, mounting a coil on the split core, and rejoining the split core to the adjacent split core before having been split.