# US 2025/0096629 A1 · Permanent magnet embedded motor and pump device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0096629 A1 - Document ID: US20250096629A1 - Status: Published application - Kind: A1 - Application number: 18/749,603 - Filed: 2024-06-20 - Published: 2025-03-20 - Earliest claimed: 2023-09-20 - Assignees: Mikuni Corporation - Applicants: Mikuni Corporation - Inventors: Shin SUZUKI - Web page: https://patentgrep.com/patent/US20250096629A1 ## CPC - H02K 1/28: Means for mounting or fastening rotating magnetic parts on to, or to, the rotor structures - F04C 2/10: of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member - F04C 15/008: {Prime movers} - H02K 1/276: Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM] - H02K 15/03: having permanent magnets - H02K 21/16: having annular armature cores with salient poles (with homopolar co-operation H02K21/20) - F04C 2240/40: Electric motor - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS ## Abstract A permanent magnet embedded motor includes: a stator of an annular shape; a rotor, arranged inside the stator, including a rotor core and a permanent magnet, and rotating about a predetermined axis. The rotor core includes an insertion hole arranged in a circumferential direction and a filling part provided adjacent to the insertion hole for filling with an adhesive. The permanent magnet is inserted into the insertion hole. The insertion hole includes a wall surface to which the permanent magnet adheres. At one opening end of the insertion hole, the filling part is of a shape obtained by cutout in a stepped-down manner in an inner edge area of the insertion hole corresponding to the wall surface. ## Claims ### Claim 1 A permanent magnet embedded motor, comprising: a stator of an annular shape; and a rotor, arranged inside the stator, comprising a rotor core and permanent magnets, and rotating about a predetermined axis, the rotor core comprising insertion holes arranged in a circumferential direction and filling parts provided adjacent to the insertion holes respectively for filling with an adhesive, each of the permanent magnets being inserted into the corresponding insertion hole, wherein each of the insertion holes comprises a wall surface to which the permanent magnet adheres; and at one opening end of the insertion hole, the corresponding filling part is of a shape obtained by cutout in a stepped-down manner in an inner edge area of the insertion hole corresponding to the wall surface. ### Claim 2 (depends on 1) The permanent magnet embedded motor according to claim 1, wherein a cross section of the insertion hole perpendicular to the axis is of a rectangular shape comprising a long side and a short side; a cross section of the permanent magnet perpendicular to the axis is of a rectangular flat plate shape comprising a long side and a short side; and the filling part is of a shape obtained by cutout in a stepped-down manner in an inner edge area along the long side of the insertion hole. ### Claim 3 (depends on 2) The permanent magnet embedded motor according to claim 2, wherein the insertion hole has a cross-sectional shape long in a vertical direction with respect to a radial direction of the rotor; the permanent magnet has a cross-sectional shape long in the vertical direction; and the filling part comprises a bottom surface long in the vertical direction and flat in a direction perpendicular to the axis. ### Claim 4 (depends on 2) The permanent magnet embedded motor according to claim 2, wherein the filling part is formed adjacent to and radially inside the corresponding insertion hole. ### Claim 5 (depends on 2) The permanent magnet embedded motor according to claim 2, wherein 0.05≤Gd/RT≤0.06 is satisfied, where Gd denotes a depth dimension of the filling part in a direction of the axis, and RT denotes a thickness dimension of the rotor core in the direction of the axis. ### Claim 6 (depends on 2) The permanent magnet embedded motor according to claim 2, wherein 0.1 mm≤Cf≤0.2 mm is satisfied, where Mt denotes a thickness dimension of the permanent magnet in a direction of the short side, Ht denotes a pore dimension of the insertion hole in the direction of the short side, Cf denotes a gap dimension between the permanent magnet and the insertion hole, and Cf=Ht−Mt. ### Claim 7 (depends on 2) The permanent magnet embedded motor according to claim 2, wherein 0.05≤Gd/RT≤0.06 and 0.1 mm≤Cf≤0.2 mm are satisfied, where Gd denotes a depth dimension of the filling part in a direction of the axis, RT denotes a thickness dimension of the rotor core in the direction of the axis, Mt denotes a thickness dimension of the permanent magnet in a direction of the short side, Ht denotes a pore dimension of the insertion hole in the direction of the short side, Cf denotes a gap dimension between the permanent magnet and the insertion hole, and Cf=Ht−Mt. ### Claim 8 (depends on 2) The permanent magnet embedded motor according to claim 2, wherein the insertion hole has a cross-sectional shape long in a vertical direction with respect to a radial direction of the rotor; the permanent magnet has a cross-sectional shape long in the vertical direction; the filling part comprises a bottom surface long in the vertical direction and flat in a direction perpendicular to the axis; and the rotor core comprises a gap continuous with both ends of the insertion hole in the vertical direction. ### Claim 9 (depends on 2) The permanent magnet embedded motor according to claim 2, wherein the rotor core comprises an isolation wall that separates the filling part from a wall surface that defines the short side of the insertion hole in the vicinity of both ends of the insertion hole in a direction of the long side. ### Claim 10 (depends on 2) The permanent magnet embedded motor according to claim 2, wherein the rotor core comprises a receiving part that contacts and receives the permanent magnet inserted into the insertion hole at the other opening end of the insertion hole. ### Claim 11 (depends on 2) The permanent magnet embedded motor according to claim 2, wherein the adhesive filled in the filling part is paste-like. ### Claim 12 (depends on 1) The permanent magnet embedded motor according to claim 1, further comprising: a housing, fixing the stator and rotatably supporting the rotor. ### Claim 13 (depends on 12) A pump device, comprising: a pump unit, suctioning and discharging a fluid; a rotating shaft, connected to the pump unit; and a drive source, exerting a driving force on the rotating shaft, wherein the drive source is the permanent magnet embedded motor according to claim 12. ### Claim 14 (depends on 13) The pump device according to claim 13, wherein the pump unit is a trochoid pump comprising an inner rotor to which the rotating shaft is connected and an outer rotor engaged with the inner rotor.