# US 2019/0356185 A1 · Electric motor, compressor, air blower, and air conditioner > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0356185 A1 - Document ID: US20190356185A1 - Status: Published application - Kind: A1 - Application number: 16/463,477 - Filed: 2017-01-31 - Published: 2019-11-21 - Earliest claimed: 2017-01-31 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Koji YABE; Yoshikazu FUJISUE; Kazuya KUMAGAI; Takahiro TSUTSUMI - Web page: https://patentgrep.com/patent/US20190356185A1 ## CPC - H02K 1/2766: {having a flux concentration effect} - H02K 21/16: having annular armature cores with salient poles (with homopolar co-operation H02K21/20) - F04D 13/06: the pump being electrically driven - F04D 25/0606: {the electric motor being specially adapted for integration in the pump} - H02K 1/276: Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM] - H02K 21/14: with magnets rotating within the armatures - H02K 29/03: with a magnetic circuit specially adapted for avoiding torque ripples or self-starting problems - 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}) - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) ## Abstract An electric motor includes a stator and a rotor including a permanent magnet and an electromagnetic steel sheet. The electromagnetic steel sheet includes a magnet insertion hole, a first outer peripheral surface including an inter-pole part of the rotor, a second outer peripheral surface including a magnetic pole center part of the rotor, a first slit elongated in a circumferential direction of the rotor, and a first portion formed between the first slit and the magnet insertion hole. A distance from the first outer peripheral surface to the stator is larger than a distance from the second outer peripheral surface to the stator. The electric motor satisfies θa<θb, where θa is a first angle formed by a first line and a second line and θb is a second angle formed by a third line and the second line. ## Claims ### Claim 1 An electric motor comprising: a stator; and a rotor disposed inside the stator, including a permanent magnet and an electromagnetic steel sheet, and having a plurality of magnetic poles, wherein the electromagnetic steel sheet includes a magnet insertion hole in which the permanent magnet is inserted, a first outer peripheral surface including an inter-pole part located at a position between two adjacent magnetic poles of the plurality of magnetic poles, a second outer peripheral surface adjacent to the first outer peripheral surface and including a magnetic pole center part located at a center of the permanent magnet, and a first slit formed outside the magnet insertion hole in a radial direction of the rotor, the first slit being elongated in a circumferential direction of the rotor, a minimum distance from the first outer peripheral surface to the stator is larger than a minimum distance from the second outer peripheral surface to the stator, the electric motor satisfies θa<θb where θa is a first angle formed, on a first plane that is a plane perpendicular to an axial direction, by a first line from a boundary between the first outer peripheral surface and the second outer peripheral surface to a rotation center of the rotor on the first plane and a second line passing through the inter-pole part of the rotor and the rotation center, and θb is a second angle formed, on the first plane, by the second line and a third line passing through the rotation center and an end portion of the first slit on a magnetic pole center side in the circumferential direction. ### Claim 2 (depends on 1) The electric motor according to claim 1, wherein a width of the electromagnetic steel sheet outside the first slit in the radial direction increases from the inter-pole part toward the magnetic pole center part. ### Claim 3 (depends on 1) The electric motor according to claim 1, wherein the electromagnetic steel sheet is formed outside the magnet insertion hole in the radial direction, and includes a plurality of second slits each extending in the radial direction. ### Claim 4 (depends on 1) The electric motor according to claim 1, wherein the stator includes a plurality of slots, a ratio of the number of the plurality of magnetic poles to the number of the plurality of slots is 2:3, and the first angle is greater than or equal to an electrical angle of 30 degrees. ### Claim 5 (depends on 1) The electric motor according to claim 1, wherein the stator includes a tooth, and the electric motor satisfies 0.88≤(180−(2×θb))/θd≤1.08 where θd is an angle formed by a line passing through one end portion of the tooth in the circumferential direction and the rotation center and a line passing through another end of the tooth in the circumferential direction and the rotation center, on the first plane. ### Claim 6 (canceled) ### Claim 7 (depends on 1) The electric motor according to claim 1, wherein the first outer peripheral surface includes a depression that is depressed inward in the radial direction. ### Claim 8 (depends on 1) A compressor comprising: the electric motor according to claim 1; a compression mechanism to be driven by the electric motor; and a housing covering the electric motor and the compression mechanism. ### Claim 9 (depends on 1) An air blower comprising: the electric motor according to claim 1; and an air blowing unit to be driven by the electric motor. ### Claim 10 (depends on 1) An air conditioner comprising: an indoor unit; and an outdoor unit connected to the indoor unit, wherein at least one of the indoor unit or the outdoor unit includes the electric motor according to claim 1. ### Claim 11 (depends on 1) The electric motor according to claim 1, wherein the electromagnetic steel sheet includes a first portion formed between the first slit and the magnet insertion hole, the first portion being a portion of the electromagnetic steel sheet. ### Claim 12 (depends on 11) The electric motor according to claim 11, wherein the first portion is formed along the first slit and is elongated in the circumferential direction.