Patents by Inventor Junji KITAO
Junji KITAO has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 12249873Abstract: The rotary electric machine includes: a rotor core configured having electromagnetic steel sheets; a stator core having electromagnetic steel sheets; a magnet inserted in each of a plurality of through holes; and a magnetic end plate in contact with one or each of an end surface on one side in the axial direction of the rotor core and an end surface on another side in the axial direction of the rotor core, and having a single magnetic sheet or a plurality of magnetic sheets stacked in the axial direction, wherein heat generated from the magnetic end plate owing to eddy current that is generated in the magnetic end plate by magnetic flux from the stator core is equal to or lower than heat generated from the rotor core owing to eddy current that is generated in the rotor core by magnetic flux from the stator core.Type: GrantFiled: June 28, 2022Date of Patent: March 11, 2025Assignee: Mitsubishi Electric CorporationInventors: Yoshihiro Miyama, Tomohira Takahashi, Junji Kitao, Shinji Nishimura
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Publication number: 20240429805Abstract: A magnetic flux modulated type magnetic gear includes a small number of poles mechanism which has a plurality of magnetic poles, a large number of poles mechanism which has more magnetic poles than the small number of poles mechanism, and a pole piece which is provided between the small number of poles mechanism and the large number of poles mechanism, wherein, in the magnetic pole of the large number of poles mechanism, a permanent magnet and a magnetic field coil are provided. And the magnetic field coil is connected to a direct current power supply, which can be turned on and off.Type: ApplicationFiled: March 12, 2021Publication date: December 26, 2024Applicant: Mitsubishi Electric CorporationInventors: Kodai OKAZAKI, Junji KITAO
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Publication number: 20240283310Abstract: Provided is a rotor that enables reduction in iron loss due to harmonics. One magnetic pole is formed by arranging three or more magnetic-pole layers each having a pair of V-shaped magnet slots and permanent magnets. An angle between a q axis and a line parallel to a magnetic-flux output surface of the permanent magnet is defined as a magnetic-pole-layer angle. The magnetic-pole-layer angles in one magnetic pole become smaller as the magnetic-pole layers become closer to a rotary shaft. A shortest distance from the magnet slot to the outer circumferential surface of a rotor core is defined as a bridge width and a shortest distance between the adjacent magnetic-pole layers is defined as a magnetic-pole-layer interval. The magnetic-pole-layer interval is set to be smaller than a sum of the bridge widths of the adjacent magnetic-pole layers.Type: ApplicationFiled: August 23, 2021Publication date: August 22, 2024Applicant: Mitsubishi Electric CorporationInventors: Yu HIRAI, Junji KITAO, Tatsuo NISHIMURA
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Publication number: 20240088752Abstract: Provided is a rotating electric machine in which the coolant is efficiently circulated, thus having improved cooling performance. A rotating electric machine has a coolant pump-up mechanism provided with a motive-power transmission mechanism for transmitting rotational motive power of a rotor and an impeller which rotates via the motive-power transmission mechanism and efficiently pumps up a coolant. The motive-power transmission mechanism is provided at one end of a first shaft forming a rotation axis of the rotor and one end of a second shaft forming a rotation axis of the impeller and crossing the axial-length direction of the first shaft. In the coolant pump-up mechanism, a heat exchanger for cooling a coolant is provided at a lower part of the impeller, and through rotation of the rotor, the impeller supplies the coolant cooled by the heat exchanger to the first shaft side, thereby cooling a stator and the rotor.Type: ApplicationFiled: July 31, 2020Publication date: March 14, 2024Applicant: Mitsubishi Electric CorporationInventors: Yusuke KIMOTO, Tadashi MURAKAMI, Junji KITAO
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Patent number: 11894726Abstract: In a rotating electric machine, a rotor core includes; a gap surface; a plurality of magnet insertion holes; a slit which is formed in a core region between the gap surface and, among the plurality of magnet insertion holes, a magnet insertion hole into which a permanent magnet forming one magnetic pole is inserted, and divides the core region into a plurality of divided core regions in the circumferential direction; and a cutout formed by denting the gap surface of a divided core region, wherein a shortest distance between a stator core imaginary gap surface which is in contact with distal end surfaces of the plurality of teeth, and a bottom point of the cutout is longer than a shortest distance between the stator core imaginary gap surface and each of two intersections between the cutout and the gap surface.Type: GrantFiled: March 22, 2019Date of Patent: February 6, 2024Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Junji Kitao, Kosho Yamane, Tomohira Takahashi, Yoshihiro Miyama
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Patent number: 11855490Abstract: In a rotor in which magnet slots arranged in a V shape so as to open toward the outer circumferential side and having permanent magnets inserted therein are formed in a two-layer structure in a radial direction, the magnet slots in each layer are composed of a pair of slots formed between a center bridge located at the center and respective ones of two radially-outer bridges located between the outer surface of the rotor and the respective slots. Of magnetic fluxes generated from the permanent magnets, magnetic fluxes excluding magnetic fluxes for magnetically saturating the bridges are defined as effective magnetic fluxes. The rotor is configured such that the effective magnetic flux generated from the permanent magnet on the radially outer side is not greater than half the effective magnetic flux generated from the permanent magnet on the radially inner side.Type: GrantFiled: January 10, 2022Date of Patent: December 26, 2023Assignee: Mitsubishi Electric CorporationInventors: Shinsuke Kayano, Tatsuo Nishimura, Junji Kitao, Hitoshi Isoda
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Patent number: 11799337Abstract: A rotating electric machine including a rotor including a rotor core arranged coaxially with a stator core via an air gap formed between the stator core and the rotor core, and a plurality of permanent magnet groups each forming one magnetic pole, A flux barrier is formed between one set of permanent magnets adjacent to each other in the circumferential direction in each permanent magnet group forming one magnetic pole. A pair of ribs is formed of regions of the rotor core between the flux barrier and the one set of permanent magnets. A first slit is formed in a region of the rotor core on the air gap side in a radial direction of the each permanent magnet group, and an end portion of the first slit on the flux barrier side is positioned between extension lines of the pair of ribs.Type: GrantFiled: February 4, 2019Date of Patent: October 24, 2023Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Junji Kitao, Kosho Yamane, Tomohira Takahashi, Yoshihiro Miyama
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Publication number: 20230246536Abstract: In the magnetic flux modulation type magnetic gear which uses pole pieces, improvement in demagnetization resistance and suppression of the reduction in torque were issues. Therefore, to the pole pieces provided in a torus shape, a magnetic flux modulation type magnetic gear arranges concentrically a first rotator on the inside of the pole piece and a second rotator on the outside, so that the rotors can be rotated relatively, with the center of the pole pieces as the rotation axis, wherein a first hole part stores, on the inside of the rotator, a first permanent magnet prepared in the rotator, having inclination of a predetermined angle, with respect to the line segment which shows a magnetic pole center, when viewed from the rotation axis. The magnetic gear is configured so as to use the amount of permanent magnets as much as possible.Type: ApplicationFiled: December 1, 2020Publication date: August 3, 2023Applicant: Mitsubishi Electric CorporationInventors: Kodai OKAZAKI, Junji KITAO, Yoshihiro MIYAMA
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Publication number: 20230179043Abstract: A rotor core includes: a bypass barrier which is a nonmagnetic region provided on the q-axis; a first magnet provided in a region of the rotor core that is closer to the d-axis than the q-axis is; and a second magnet at least a portion of which is provided in a region, of the rotor core, on a radially inner side relative to the first magnet. The second magnet is provided in a region of the rotor core that is closer to the q-axis than the first magnet is. An end point of the second magnet that is closest to the q-axis is located on the radially inner side, in the rotor core, relative to a radially innermost surface which is a surface on a radially innermost side of the bypass barrier.Type: ApplicationFiled: March 5, 2021Publication date: June 8, 2023Applicant: Mitsubishi Electric CorporationInventors: Junji KITAO, Yu HIRAI
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Publication number: 20230123457Abstract: The rotary electric machine includes: a rotor core configured having electromagnetic steel sheets; a stator core having electromagnetic steel sheets; a magnet inserted in each of a plurality of through holes; and a magnetic end plate in contact with one or each of an end surface on one side in the axial direction of the rotor core and an end surface on another side in the axial direction of the rotor core, and having a single magnetic sheet or a plurality of magnetic sheets stacked in the axial direction, wherein heat generated from the magnetic end plate owing to eddy current that is generated in the magnetic end plate by magnetic flux from the stator core is equal to or lower than heat generated from the rotor core owing to eddy current that is generated in the rotor core by magnetic flux from the stator core.Type: ApplicationFiled: June 28, 2022Publication date: April 20, 2023Applicant: Mitsubishi Electric CorporationInventors: Yoshihiro MIYAMA, Tomohira TAKAHASHI, Junji KITAO, Shinji NISHIMURA
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Publication number: 20230120571Abstract: A rotary electric machine comprises: a rotor which has a rotor core and permanent magnets arranged in the rotor core on its outer circumference side, and which is supported rotatably; and a stator which has a stator core having teeth projecting toward a radial center and arranged circumferentially, and which is located coaxially with the rotor to be spaced apart from the outer circumferential surface of the rotor; wherein, on a condition that a ratio of the circumferential width of each of sub poles to the circumferential width of each of main poles is 0.625 or less, a top width of each of the teeth is set on the basis of two calculation formulas to be used differently according to the rotor skew angle.Type: ApplicationFiled: August 15, 2022Publication date: April 20, 2023Applicant: Mitsubishi Electric CorporationInventors: Kodai OKAZAKI, Junji KITAO, Yoshihiro MIYAMA, Kengo KUMAGAI
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Publication number: 20230111062Abstract: A rotor includes a rotor core fixed to a shaft, a pair of magnet slots arranged in a V-shape in the rotor core so as to be separated away from each other toward a radially outer side, permanent magnets inserted into the magnet slots, and a hole provided on the radially outer side of the magnet slots. The distance between each permanent magnet and the hole increases toward the radially outer side. The distance between an outer circumference of the rotor core and the hole is not less than the distance between each magnet slot and the outer circumference of the rotor core.Type: ApplicationFiled: January 27, 2021Publication date: April 13, 2023Applicant: Mitsubishi Electric CorporationInventors: Yoshihiro MIYAMA, Kosho YAMANE, Junji KITAO, Kodai OKAZAKI, Tatsuo NISHIMURA, Tomohira TAKAHASHI
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Publication number: 20220320924Abstract: In a rotor in which magnet slots arranged in a V shape so as to open toward the outer circumferential side and having permanent magnets inserted therein are formed in a two-layer structure in a radial direction, the magnet slots in each layer are composed of a pair of slots formed between a center bridge located at the center and respective ones of two radially-outer bridges located between the outer surface of the rotor and the respective slots. Of magnetic fluxes generated from the permanent magnets, magnetic fluxes excluding magnetic fluxes for magnetically saturating the bridges are defined as effective magnetic fluxes. The rotor is configured such that the effective magnetic flux generated from the permanent magnet on the radially outer side is not greater than half the effective magnetic flux generated from the permanent magnet on the radially inner side.Type: ApplicationFiled: January 10, 2022Publication date: October 6, 2022Applicant: Mitsubishi Electric CorporationInventors: Shinsuke KAYANO, Tatsuo NISHIMURA, Junji KITAO, Hitoshi ISODA
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Patent number: 11456633Abstract: A rotor of the permanent magnet rotating electric machine includes a rotor core, a plurality of magnets, and magnetic slits. Each of the magnetic slits is formed in a core region being a region between magnets of the plurality of magnets, and a gap. The magnetic slits are regions having a lower magnetic permeability than a magnetic permeability of the core region. One end of each of the magnetic slits, which is closer to an outer periphery of the rotor, is positioned in a portion of the core region on the same direction side as a direction of a force in a circumferential direction of the rotor, and another end closer to the rotation axis center of the rotor is positioned on the magnetic pole center or in a portion of the core region on a side opposite to the direction of the force.Type: GrantFiled: July 6, 2018Date of Patent: September 27, 2022Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Tomohira Takahashi, Junji Kitao, Yoshihiro Miyama, Masatsugu Nakano, Kosho Yamane
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Patent number: 11451102Abstract: A rotary electric machine including a rotor including a rotor core; permanent magnets to be embedded in the rotor core; and a one end-side end plate configured to support one end side of the rotor core. The rotor core has rotor refrigerant passages through which refrigerant for cooling the permanent magnets flows in an axial direction of the shaft. The one end-side end plate has an end plate refrigerant passage communicating with the rotor refrigerant passages. The end plate refrigerant passage has refrigerant reservoirs, each projecting to an outer side in a radial direction of the shaft.Type: GrantFiled: February 28, 2018Date of Patent: September 20, 2022Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Yusuke Kimoto, Junji Kitao, Tomohira Takahashi, Yoshihiro Miyama, Junichi Nakazono
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Patent number: 11283332Abstract: In a rotating electric machine, a rotor core has a rotor core cooling hole under a state of being coupled to a first gap at a position on a radially inner side with respect to a center portion of a first inner wall surface in a length direction. The rotor core has a radially-outer-side refrigerant flow path formed under a state of being coupled to a radially-outer-side end portion of the first gap. A first end plate has a communication path formed so as to extend from an inner end surface of the first end plate to the rotor core cooling hole. A second end plate has a discharge path formed so as to allow the radially-outer-side refrigerant flow path to communicate with an outside.Type: GrantFiled: February 26, 2018Date of Patent: March 22, 2022Assignee: Mitsubishi Electric CorporationInventors: Junji Kitao, Tomohira Takahashi, Yusuke Kimoto, Yoshihiro Miyama, Masatsugu Nakano, Yuya Tanaka
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Publication number: 20220060070Abstract: In a rotating electric machine, a rotor core includes; a gap surface; a plurality of magnet insertion holes; a slit which is formed in a core region between the gap surface and, among the plurality of magnet insertion holes, a magnet insertion hole into which a permanent magnet forming one magnetic pole is inserted, and divides the core region into a plurality of divided core regions in the circumferential direction; and a cutout formed by denting the gap surface of a divided core region, wherein a shortest distance between a stator core imaginary gap surface which is in contact with distal end surfaces of the plurality of teeth, and a bottom point of the cutout is longer than a shortest distance between the stator core imaginary gap surface and each of two intersections between the cutout and the gap surface.Type: ApplicationFiled: March 22, 2019Publication date: February 24, 2022Applicant: Mitsubishi Electric CorporationInventors: Junji KITAO, Kosho YAMANE, Tomohira TAKAHASHI, Yoshihiro MIYAMA
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Patent number: 11171523Abstract: In a rotary electric machine, slots are formed between teeth of a stator core. A ratio of a number of poles to a number of slots is 2:3. When an electrical angle of a tooth tip width, which is a width dimension of a tip of each of the teeth in a circumferential direction of the stator, is represented by ?, an electrical angle of a pole arc angle, which is an angle formed by two straight lines that connect a rotation center of a rotor to corners on a rotor surface side of one permanent magnet, is represented by ?, and a number of pole pairs is represented by P, the tooth tip width is within a range of (electrical angle)±0.2°×P for a value that satisfies the following expression: ?=?2.5?+319.7 (0<??180) [deg].Type: GrantFiled: November 29, 2016Date of Patent: November 9, 2021Assignee: Mitsubishi Electric CorporationInventors: Moriyuki Hazeyama, Junji Kitao, Yoshihiro Miyama, Shogo Okamoto, Shinji Nishimura, Ryuichi Kitora, Ryuji Kitamura, Hitoshi Isoda
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Publication number: 20210218301Abstract: A rotating electric machine including a rotor including a rotor core arranged coaxially with a stator core via an air gap formed between the stator core and the rotor core, and a plurality of permanent magnet groups each forming one magnetic pole, A flux barrier is formed between one set of permanent magnets adjacent to each other in the circumferential direction in each permanent magnet group forming one magnetic pole. A pair of ribs is formed of regions of the rotor core between the flux barrier and the one set of permanent magnets. A first slit is formed in a region of the rotor core on the air gap side in a radial direction of the each permanent magnet group, and an end portion of the first slit on the flux barrier side is positioned between extension lines of the pair of ribs.Type: ApplicationFiled: February 4, 2019Publication date: July 15, 2021Applicant: Mitsubishi Electric CorporationInventors: Junji KITAO, Kosho YAMANE, Tomohira TAKAHASHI, Yoshihiro MIYAMA
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Publication number: 20200274411Abstract: A rotary electric machine including a rotor including a rotor core; permanent magnets to be embedded in the rotor core; and a one end-side end plate configured to support one end side of the rotor core. The rotor core has rotor refrigerant passages through which refrigerant for cooling the permanent magnets flows in an axial direction of the shaft. The one end-side end plate has an end plate refrigerant passage communicating with the rotor refrigerant passages. The end plate refrigerant passage has refrigerant reservoirs, each projecting to an outer side in a radial direction of the shaft.Type: ApplicationFiled: February 28, 2018Publication date: August 27, 2020Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Yusuke KIMOTO, Junji KITAO, Tomohira TAKAHASHI, Yoshihiro MIYAMA, Junichi NAKAZONO