Patents by Inventor Hiroki Hijikata

Hiroki Hijikata 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).

  • Patent number: 11811340
    Abstract: Provided is a control device for a rotating electric machine, the control device being configured to control an inverter configured to apply a voltage to each phase winding of a rotating electric machine, to thereby control, for the each phase winding, a current to be supplied to the each phase winding, the control device including a control unit configured to: calculate a voltage command value to be applied to the each phase winding so that a phase difference between harmonic components of the same order in a radial magnetic flux density and a circumferential magnetic flux density of an air gap portion between a stator core and a rotor core of the rotating electric machine becomes a phase difference target value determined in advance, and to control the inverter in accordance with the calculated voltage command value.
    Type: Grant
    Filed: April 18, 2019
    Date of Patent: November 7, 2023
    Assignees: MITSUBISHI ELECTRIC CORPORATION, SHIBAURA INSTITUTE OF TECHNOLOGY
    Inventors: Yoshihiro Miyama, Kan Akatsu, Yuki Sakai, Hiroki Hijikata
  • Publication number: 20230318382
    Abstract: A stator capable of controlling an increase in a size of a motor is provided. The stator includes a stator core and coils. The stator core includes mounted teeth on which the coils are mounted and non-mounted teeth on which the coils are not mounted. Each of the coils includes a coil end portion that protrudes in an axial direction from the stator core, and a terminal portion connected to a connecting wire that connects the coils to each other. The terminal portion protrudes in a circumferential direction from the coil end portion in such a manner as to overlap with at least a part of the non-mounted teeth in the axial direction.
    Type: Application
    Filed: September 17, 2021
    Publication date: October 5, 2023
    Applicant: Komatsu Ltd.
    Inventors: Hiroki Hijikata, Natsuki Watanabe
  • Publication number: 20230283134
    Abstract: A stator includes: a stator core having teeth and slots; and coils including outer coils arranged at a first distance from a center of the stator core and inner coils arranged at a second distance shorter than the first distance, wherein the slots include first slots that the outer coils are arranged and second slots that the inner coils are arranged, a depth of the first slots is deeper than that of the second slots, each of coil sets is formed of each of the inner coil and the outer coil arranged to overlap with a part of the inner coil, phases of the inner and outer coils are different in each of the coil sets, the coil sets include first, second, and third coil sets, and a combination of the phases of the inner and outer coils varies among the first, second and third coil sets.
    Type: Application
    Filed: September 22, 2021
    Publication date: September 7, 2023
    Applicant: Komatsu Ltd.
    Inventors: Hiroki Hijikata, Natsuki Watanabe
  • Publication number: 20220294283
    Abstract: A coil includes a first coil piece, and a second coil piece coupled to the first coil piece. Each of the first coil piece and the second coil piece has a center portion arranged in a slot of a stator core, and an end portion protruding in an axial direction from the stator core. In the coil end portion, the end portion of the first coil piece and at least a part of the end portion of the second coil piece are arranged in the axial direction.
    Type: Application
    Filed: August 24, 2020
    Publication date: September 15, 2022
    Applicant: Komatsu Ltd.
    Inventors: Hiroki Hijikata, Natsuki Watanabe, Teiichirou Chiba
  • Publication number: 20220263356
    Abstract: A motor includes a stator core, a coil disposed in slots of the stator core, and a rotor facing the stator core. When the number of poles of the rotor is P, the number of the slots of the stator core is S, and a natural number is N, conditions of P=7×N and S=12×N are satisfied.
    Type: Application
    Filed: August 20, 2020
    Publication date: August 18, 2022
    Applicant: Komatsu Ltd.
    Inventors: Hiroki Hijikata, Natsuki Watanabe, Teiichirou Chiba
  • Publication number: 20220255386
    Abstract: A coil includes a center portion arranged in a slot of a stator core, and an end portion protruding in an axial direction from the stator core. The end portion has a first portion, and a second portion thinner than the thickness of the first portion.
    Type: Application
    Filed: August 24, 2020
    Publication date: August 11, 2022
    Applicant: Komatsu Ltd.
    Inventors: Hiroki Hijikata, Natsuki Watanabe, Teiichirou Chiba
  • Publication number: 20220209697
    Abstract: Provided is a control device for a rotating electric machine, the control device being configured to control an inverter configured to apply a voltage to each phase winding of a rotating electric machine, to thereby control, for the each phase winding, a current to be supplied to the each phase winding, the control device including a control unit configured to: calculate a voltage command value to be applied to the each phase winding so that a phase difference between harmonic components of the same order in a radial magnetic flux density and a circumferential magnetic flux density of an air gap portion between a stator core and a rotor core of the rotating electric machine becomes a phase difference target value determined in advance, and to control the inverter in accordance with the calculated voltage command value.
    Type: Application
    Filed: April 18, 2019
    Publication date: June 30, 2022
    Applicants: Mitsubishi Electric Corporation, Shibaura Institute of Technology
    Inventors: Yoshihiro MIYAMA, Kan AKATSU, Yuki SAKAI, Hiroki HIJIKATA
  • Publication number: 20220037945
    Abstract: The basic coil segment is arranged in the slot such that at least part of the basic coil bent portion is arranged outside the insertion end, in an axial direction parallel to a center axis of the stator core and the pair of the basic coil insertion end portions is arranged outside the welded end, in the axial direction. The power coil segment is arranged in the slot such that the power coil lead end portion and at least part of the power coil connection portion are arranged outside the insertion end, in the axial direction and the power coil insertion end portion is arranged outside the welded end, in the axial direction. The height of an end surface of the basic coil segment from the insertion end is equal to the height of an end surface of the power coil segment from the insertion end.
    Type: Application
    Filed: October 23, 2019
    Publication date: February 3, 2022
    Applicant: Komatsu Ltd.
    Inventors: Atsuyoshi Koshiba, Hiroki Hijikata, Takuya Fujikawa, Teiichirou Chiba
  • Patent number: 10469003
    Abstract: One end of each of phase conductors wound around a stator core in a wave winding arrangement is connected to a positive electrode terminal of a DC power supply through a first positive electrode side switch and is connected to a negative electrode terminal of the DC power supply through a second negative electrode side switch. The other end of the phase conductor is connected to the negative electrode terminal of the DC power supply through a first negative electrode side switch and is connected to the positive electrode terminal of the DC power supply through a second positive electrode side switch. The first positive electrode side switch, the second negative electrode side switch, the first negative electrode side switch, and the second positive electrode side switch are controlled by a controller, whereby amplitude and phase of current passing through each of the phase conductors are individually controlled.
    Type: Grant
    Filed: July 27, 2015
    Date of Patent: November 5, 2019
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yoshihiro Miyama, Hideaki Arita, Akihiro Daikoku, Kan Akatsu, Hiroki Hijikata
  • Publication number: 20180145617
    Abstract: One end of each of phase conductors wound around a stator core in a wave winding arrangement is connected to a positive electrode terminal of a DC power supply through a first positive electrode side switch and is connected to a negative electrode terminal of the DC power supply through a second negative electrode side switch. The other end of the phase conductor is connected to the negative electrode terminal of the DC power supply through a first negative electrode side switch and is connected to the positive electrode terminal of the DC power supply through a second positive electrode side switch. The first positive electrode side switch, the second negative electrode side switch, the first negative electrode side switch, and the second positive electrode side switch are controlled by a controller, whereby amplitude and phase of current passing through each of the phase conductors are individually controlled.
    Type: Application
    Filed: July 27, 2015
    Publication date: May 24, 2018
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yoshihiro MIYAMA, Hideaki ARITA, Akihiro DAIKOKU, Kan AKATSU, Hiroki HIJIKATA
  • Patent number: 9287745
    Abstract: There is provided a single motor which performs plural driving characteristics and can expand output range thereof. Three coils are wounded around each of the stator teeth A to F, and provided to each stator tooth A to F are switches for providing a concentrated winding state by connecting the three coils in series in each stator tooth A to F, and switches for providing a distributed winding state by connecting in series the coils of any one of units through the stator teeth A to F Depending on the rotating speed, the torque or the like, the coils are changed between the concentrated winding state and the distributed winding state.
    Type: Grant
    Filed: January 27, 2012
    Date of Patent: March 15, 2016
    Assignee: SHIBAURA INSTITUTE OF TECHNOLOGY
    Inventors: Kan Akatsu, Hiroki Hijikata
  • Publication number: 20130307455
    Abstract: There is provided a single motor which performs plural driving characteristics and can expand output range thereof. Three coils are wounded around each of the stator teeth A to F, and provided to each stator tooth A to F are switches for providing a concentrated winding state by connecting the three coils in series in each stator tooth A to F, and switches for providing a distributed winding state by connecting in series the coils of any one of units through the stator teeth A to F Depending on the rotating speed, the torque or the like, the coils are changed between the concentrated winding state and the distributed winding state.
    Type: Application
    Filed: January 27, 2012
    Publication date: November 21, 2013
    Applicant: SHIBAURA INSTITUTE OF TECHNOLOGY
    Inventors: Kan Akatsu, Hiroki Hijikata