# US 2021/0242732 A1 · Rotor of rotating electrical machine and arc magnet manufacturing method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0242732 A1 - Document ID: US20210242732A1 - Status: Published application - Kind: A1 - Application number: 17/167,569 - Filed: 2021-02-04 - Published: 2021-08-05 - Earliest claimed: 2020-02-05 - Assignees: Honda Motor Co., Ltd. - Applicants: Honda Motor Co., Ltd. - Inventors: Shingo SOMA; Yoshihisa KUBOTA; Tatsuya OHZU - Web page: https://patentgrep.com/patent/US20210242732A1 ## CPC - H02K 1/276: Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM] - H02K 15/03: having permanent magnets - H02K 2213/03: Machines characterised by numerical values, ranges, mathematical expressions or similar information - Y02T 10/64: Electric machine technologies in electromobility - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A rotor of a rotating electrical machine includes a substantially annular rotor core and a plurality of magnetic pole portions formed at predetermined intervals in a circumferential direction of the rotor core. Each magnetic pole portion includes an outer diameter side magnet portion configured by an outer diameter side circular arc magnet arranged so as to protrude radially inward and an inner diameter side magnet portion located radially inward of the outer diameter side magnet portion and configured by a pair of inner diameter side arc magnets arranged so as to radially inward of the radially outer magnet portion. Each arc magnet is an arc magnet in which an inner peripheral surface and an outer peripheral surface have the same arc center. ## Claims ### Claim 1 A rotor of a rotating electrical machine, comprising: a substantially annular rotor core; and a plurality of magnetic pole portions formed at predetermined intervals in a circumferential direction of the rotor core, wherein each magnetic pole portion including: an outer diameter side magnet portion configured by an outer diameter side circular arc magnet arranged so as to protrude radially inward; and an inner diameter side magnet portion located radially inward of the outer diameter side magnet portion and configured by a pair of inner diameter side arc magnets arranged so as to radially inward of the radially outer magnet portion, each arc magnet is an arc magnet in which an inner peripheral surface and an outer peripheral surface have the same arc center, in a case where a center axis of each magnetic pole portion is set as a d-axis, and an axis separated from the d-axis by 90 electrical degrees is set as a q-axis, the outer diameter side magnet portion and the inner diameter side magnet portion are formed symmetrically with respect to the d-axis, the outer diameter side arc magnet is disposed so as to be symmetrical with respect to the d-axis in the circumferential direction, the pair of inner diameter side arc magnets including: a first inner diameter side arc magnet located on one side with respect to the d-axis in the circumferential direction; and a second inner diameter side arc magnet located on the other side with respect to the d-axis in the circumferential direction, the first inner diameter side arc magnet and the second inner diameter side arc magnet are arranged so as to be symmetrical with respect to the d-axis, the outer diameter side arc magnet, the first inner diameter side arc magnet, and the second inner diameter side arc magnet have substantially the same shape as viewed in the axial direction, an arc center of the outer diameter side arc magnet is located on the d-axis, an arc center of the first inner diameter side arc magnet is located on the other side with respect to the d-axis in the circumferential direction, and an arc center of the second inner diameter side arc magnet is located on the one side with respect to the d-axis in the circumferential direction. ### Claim 2 (depends on 1) The rotor of a rotating electrical machine according to claim 1, wherein the outer diameter side arc magnet includes a first end portion located on the one side with respect to the d-axis and a second end portion located on the other side with respect to the d-axis in the circumferential direction, the first inner diameter side arc magnet includes a d-axis side end portion on the d-axis side and a q-axis side end portion on the q-axis side in the circumferential direction, the second inner diameter side arc magnet includes a d-axis side end portion on the d-axis side and a q-axis side end portion on the q-axis side in the circumferential direction, the angle centered on the arc center of the outer diameter side arc magnet and formed by the first end portion and the second end portion of the outer diameter side arc magnet when viewed from the axial direction is an angle of 360 degrees when multiplied by an integer, and an angle centered on the arc center of the first inner diameter side arc magnet and formed by the q-axis side end portion and the d-axis side end portion and an angle centered on the arc center of the second inner diameter side arc magnet and formed by the q-axis side end portion and the d-axis side end portion are an angle of 360 degrees when multiplied by an integer. ### Claim 3 (depends on 1) The rotor of a rotating electrical machine according to claim 1, wherein when the outer peripheral radii of the outer diameter side arc magnet, the first inner diameter side arc magnet, and the second inner diameter side arc magnet are set to r [mm], and the thicknesses of the outer diameter side arc magnet, the first inner diameter side arc magnet, and the second inner diameter side arc magnet are set to t [mm], 40 [mm]≤r≤83 [mm], and, ( 1/30)×r+0.4 [mm]≤t≤( 1/20)×r+0.5 [mm]. ### Claim 4 (depends on 1) An arc magnet manufacturing method for manufacturing each arc magnet of the rotor of the rotating electrical machine according to any one of claim 1, including: a ring magnet molding step of molding a ring magnet having a substantially annular shape; and a cutting step of cutting the ring magnet formed by the ring magnet molding step in a radial direction, in which in the ring magnet molding step, the ring magnet is formed by hot working, and in the cutting step, the outer diameter side arc magnet, the first inner diameter side arc magnet and the second inner diameter side arc magnet can be manufactured by cutting the ring magnet in the radial direction at an interval of a predetermined angle centered on the ring center of the ring magnet. ### Claim 5 (depends on 4) The arc magnet manufacturing method according to claim 4, wherein the predetermined angle is an angle of 360 degrees when multiplied by an integer. ### Claim 6 (depends on 4) The arc magnet manufacturing method according to claim 4, when the outer radius of the ring magnet is set to r [mm], and the thickness is set to t [mm], 40 [mm]≤r≤83 [mm], and, ( 1/30)×r+0.4 [mm]≤t≤( 1/20)×r+0.5 [mm].