Patents by Inventor Koki Naka

Koki Naka 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).

  • Publication number: 20220344981
    Abstract: A laminated core for an electric machine includes a plurality of laminated core pieces. Each of the plurality of core pieces includes a first portion and a second portion having a plate thickness smaller than a plate thickness of the first portion.
    Type: Application
    Filed: January 21, 2020
    Publication date: October 27, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takayuki ONIHASHI, Koki NAKA, Hiroki DAITO, Kenji FUKUI, Akira WATARAI, Masaya INOUE
  • Patent number: 9935523
    Abstract: To maximize a power consumption reduction effect in a case of using a high-efficiency induction motor, when a conventional induction motor is changed to a high-efficiency induction motor, a mechanical device including an induction motor and a speed reduction mechanism related to the present invention increases the reduction ratio of the speed reducer such that the rotation speed of the mechanical device is equal to that in a case of using a conventional induction motor and thus the output of the mechanical device is made equal to that in a case of using a conventional inductor motor; therefore, the load conditions of the mechanical device such as a pump and a fan can be made equal to those in a case of using a conventional induction motor. Accordingly, the power consumption reduction effect by improving the efficiency of the induction motor can be maximized.
    Type: Grant
    Filed: March 18, 2014
    Date of Patent: April 3, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shinichi Yamaguchi, Koki Naka, Takuro Isogai
  • Patent number: 9812912
    Abstract: A rotor for a permanent magnet motor, includes a magnetic pole portion that includes a magnetic body formed in an annular shape; and a field portion that is disposed adjacent to the magnetic pole portion in an axial direction, that includes a permanent magnet formed in an annular shape and having a multipole structure or a plurality of permanent magnets formed in an annular shape and having a monopole structure and a magnetic body, and that causes a magnetic flux generated by the permanent magnet to flow in the axial direction so as to generate magnetic poles on an outer circumferential surface of the magnetic pole portion.
    Type: Grant
    Filed: March 18, 2014
    Date of Patent: November 7, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hiroki Kobayashi, Kentaro Horisaka, Kenta Ozaki, Koki Naka, Hisashi Otsuka
  • Publication number: 20170098971
    Abstract: A rotor for a permanent magnet motor, includes a magnetic pole portion that includes a magnetic body formed in an annular shape; and a field portion that is disposed adjacent to the magnetic pole portion in an axial direction, that includes a permanent magnet formed in an annular shape and having a multipole structure or a plurality of permanent magnets formed in an annular shape and having a monopole structure and a magnetic body, and that causes a magnetic flux generated by the permanent magnet to flow in the axial direction so as to generate magnetic poles on an outer circumferential surface of the magnetic pole portion.
    Type: Application
    Filed: March 18, 2014
    Publication date: April 6, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hiroki KOBAYASHI, Kentaro HORISAKA, Kenta OZAKI, Koki NAKA, Hisashi OTSUKA
  • Patent number: 9608501
    Abstract: A rotary electric machine is a rotary electric machine including a stator of a distributed winding type including a plurality of first slots, in each of which winding wires of a plurality of same phases or a winding wire of one phase are arranged, and a plurality of second slots, in each of which winding wires of a plurality of different phases are arranged. The total number of turns in each of the first slots is same as one another. The total number of turns in each of the second slots is same as one another. The total number of turns in the first slot and the total number of turns in the second slot are different from each other.
    Type: Grant
    Filed: December 13, 2012
    Date of Patent: March 28, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shinichi Yamaguchi, Koki Naka, Kazuaki Ando
  • Publication number: 20170054339
    Abstract: A stator of a rotary electrical machine according to the invention includes a core back, a plurality of teeth, a plurality of slots, and a coil. The coil is configured by a plurality of conductor wires. Between inside of the slot and outside of the slot, the plurality of conductor wires are bent at an angle smaller than 180° in a circumferential direction of the core back, and between the bent part and the inside of the slot, the plurality of conductor wires are bent in the circumferential direction of the core back and in an opposite direction to a bending direction of the bent part.
    Type: Application
    Filed: April 24, 2014
    Publication date: February 23, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Masaya HARAKAWA, Kenta OZAKI, Shinichi YAMAGUCHI, Kentaro HORISAKA, Kazuaki ANDO, Koki NAKA
  • Publication number: 20170019041
    Abstract: A control device converts phase currents supplied to a permanent-magnet rotary motor into a d-axis current and a q-axis current on a dq coordinate axis, and calculates a current command (a d-axis current command or a q-axis current command) for changing at least one of values of the d-axis current and the q-axis current according to a rotor position, based on a torque command, the d-axis current and the q-axis current, so as to cause a magnitude of a reverse magnetic field acting on a permanent-magnet end part to be equal to or lower than a magnetic coercive force of a permanent magnet.
    Type: Application
    Filed: February 28, 2014
    Publication date: January 19, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Makoto SUGIYAMA, Koki NAKA, Hisashi OTSUKA, Shinichi YAMAGUCHI, Eigo TOTOKI
  • Patent number: 9515528
    Abstract: A permanent magnet rotary electric machine includes: a stator in which a plurality of teeth and a plurality of slots are formed on an inner periphery of a cylindrical stator core, and a winding wire is wound around the teeth so as to be disposed in the slots; and a rotor disposed in a hollow portion of the stator with an air gap between the rotor and the stator. In the rotor, 2n or more (n is a natural number equal to or larger than 1) radial projections are provided on an outer periphery of a rotor core, and a ferrite magnet is disposed between adjacent projections. A radial height of the projection is less than a thickness of middle of the ferrite magnet.
    Type: Grant
    Filed: January 6, 2014
    Date of Patent: December 6, 2016
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shinichi Yamaguchi, Yoshiki Maeda, Kazuaki Ando, Koki Naka, Masaya Harakawa
  • Publication number: 20160261167
    Abstract: To maximize a power consumption reduction effect in a case of using a high-efficiency induction motor, when a conventional induction motor is changed to a high-efficiency induction motor, a mechanical device including an induction motor and a speed reduction mechanism related to the present invention increases the reduction ratio of the speed reducer such that the rotation speed of the mechanical device is equal to that in a case of using a conventional induction motor and thus the output of the mechanical device is made equal to that in a case of using a conventional inductor motor; therefore, the load conditions of the mechanical device such as a pump and a fan can be made equal to those in a case of using a conventional induction motor. Accordingly, the power consumption reduction effect by improving the efficiency of the induction motor can be maximized.
    Type: Application
    Filed: March 18, 2014
    Publication date: September 8, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Shinichi YAMAGUCHI, Koki NAKA, Takuro ISOGAI
  • Publication number: 20160254713
    Abstract: A permanent magnet rotary electric machine includes: a stator in which a plurality of teeth and a plurality of slots are formed on an inner periphery of a cylindrical stator core, and a winding wire is wound around the teeth so as to be disposed in the slots; and a rotor disposed in a hollow portion of the stator with an air gap between the rotor and the stator. In the rotor, 2n or more (n is a natural number equal to or larger than 1) radial projections are provided on an outer periphery of a rotor core, and a ferrite magnet is disposed between adjacent projections. A radial height of the projection is less than a thickness of middle of the ferrite magnet.
    Type: Application
    Filed: January 6, 2014
    Publication date: September 1, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Shinichi YAMAGUCHI, Yoshiki MAEDA, Kazuaki ANDO, Koki NAKA, Masaya HARAKAWA
  • Patent number: 9413200
    Abstract: A stator according to the present invention includes: a cylindrical stator core; a plurality of tooth portions provided along a circumferential direction of the stator core; and windings disposed in a plurality of slots provided between the tooth portions and wound around the tooth portions. The windings are configured by materials having different electrical resistivities. A ratio of a sectional area of a material having a high electrical resistivity to a sectional area of a material having a low electrical resistivity in the slot is equal to or larger than 1 and equal to or smaller than a ratio of the electrical resistivity of the material having the high electrical resistivity to the electrical resistivity of the material having the low electrical resistivity.
    Type: Grant
    Filed: May 20, 2013
    Date of Patent: August 9, 2016
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kentaro Horisaka, Koki Naka, Shinichi Yamaguchi, Masaya Harakawa, Kazuaki Ando, Kenta Ozaki
  • Publication number: 20160105061
    Abstract: A stator according to the present invention includes: a cylindrical stator core; a plurality of tooth portions provided along a circumferential direction of the stator core; and windings disposed in a plurality of slots provided between the tooth portions and wound around the tooth portions. The windings are configured by materials having different electrical resistivities. A ratio of a sectional area of a material having a high electrical resistivity to a sectional area of a material having a low electrical resistivity in the slot is equal to or larger than 1 and equal to or smaller than a ratio of the electrical resistivity of the material having the high electrical resistivity to the electrical resistivity of the material having the low electrical resistivity.
    Type: Application
    Filed: May 20, 2013
    Publication date: April 14, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kentaro HORISAKA, Koki NAKA, Shinichi YAMAGUCHI, Masaya HARAKAWA, Kazuaki ANDO, Kenta OZAKI
  • Publication number: 20150326084
    Abstract: A rotary electric machine is a rotary electric machine including a stator of a distributed winding type including a plurality of first slots, in each of which winding wires of a plurality of same phases or winding wires of one phase are arranged, and a plurality of second slots, in each of which winding wires of a plurality of different phases are arranged. The total number of turns in each of the first slots is same as one another. The total number of turns in each of the second slots is same as one another. The total number of turns in the first slot and the total number of turns in the second slot are different from each other.
    Type: Application
    Filed: December 13, 2012
    Publication date: November 12, 2015
    Applicant: Mitsubishi Electric Corporation
    Inventors: Shinichi YAMAGUCHI, Koki NAKA, Kazuaki ANDO
  • Patent number: 8274182
    Abstract: A linear motor includes a stator having field poles arranged linearly with opposing polarities arranged in an alternating manner; and a rotor having an armature core with teeth that faces a pole face of the field poles with a gap, and coils wound around the teeth. The stator and the rotor are supported in a slidable manner, a direction perpendicular to a sliding direction of the rotor and in parallel with the pole face is defined as a stacking direction. A head of each of the teeth has an extended portion extended in the sliding direction. At least heads of the teeth arranged at both ends of the armature core along the sliding direction is divided into a plurality of areas along the stacking direction. At least one of extended portions arranged on adjacent areas is extended by a different length along the sliding direction.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: September 25, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventors: Misa Nakayama, Shinichi Yamaguchi, Koki Naka, Kazumasa Ito, Toshinori Tanaka
  • Publication number: 20100201210
    Abstract: A linear motor includes a stator having field poles arranged linearly with opposing polarities arranged in an alternating manner; and a rotor having an armature core with teeth that faces a pole face of the field poles with a gap, and coils wound around the teeth. The stator and the rotor are supported in a slidable manner, a direction perpendicular to a sliding direction of the rotor and in parallel with the pole face is defined as a stacking direction. A head of each of the teeth has an extended portion extended in the sliding direction. At least heads of the teeth arranged at both ends of the armature core along the sliding direction is divided into a plurality of areas along the stacking direction. At least one of extended portions arranged on adjacent areas is extended by a different length along the sliding direction.
    Type: Application
    Filed: September 30, 2008
    Publication date: August 12, 2010
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Misa Nakayama, Shinichi Yamaguchi, Koki Naka, Kazumasa Ito, Toshinori Tanaka