Patents by Inventor Yuji Takizawa

Yuji Takizawa 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: 11901772
    Abstract: A rotor core of a rotating electrical machine has interpole bridges each disposed on an outer circumferential side with respect to a permanent magnet in a non-magnetic portion between the poles, and interpole diameter bridges each surrounded by two permanent magnets and an interpole bridge. The outer circumferential surface of each interpole bridge is formed by a first flat surface. Thus, a path of a magnetic flux passing through a magnetic gap is lengthened, so that a q-axis inductance is reduced. In addition, a width in a radial direction of each interpole bridge and a width in a circumferential direction of each interpole diameter bridge are constant, and each interpole bridge and each interpole diameter bridge are disposed so as to be perpendicular to each other to form a T shape. Thus, the concentration of stress during press-fitting of the permanent magnet into a magnet hole can be reduced.
    Type: Grant
    Filed: November 27, 2018
    Date of Patent: February 13, 2024
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kodai Okazaki, Kenta Motoyoshi, Yuji Takizawa, Hiroko Ikeda, Hidenori Sasaki, Yu Hirotani, Satoru Akutsu, Masafumi Okazaki, Natsumi Sugi
  • Patent number: 11695366
    Abstract: Provided are a short circuit state analyzer to compare difference value when the AC excitation current is applied at a first frequency with a threshold value, to estimate a short circuit resistance from the difference value based on data indicating a relationship between the short circuit resistance and the difference value at the first frequency when the difference value is smaller than the threshold value, to cause an excitation power supply to apply the AC excitation current to the field windings at a second frequency lower than the first frequency when the difference value is equal to or greater than the threshold value, and to estimate the short circuit resistance from a difference value obtained by the AC excitation current at the second frequency based on data indicating a relationship between the short circuit resistance and the difference value at the second frequency.
    Type: Grant
    Filed: January 27, 2020
    Date of Patent: July 4, 2023
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yuji Takizawa, Haruyuki Kometani, Ryosuke Kawashima, Kohei Majima, Susumu Maeda
  • Publication number: 20230204667
    Abstract: A short-circuit detection device for a rotating electric machine sets an order lower than a fundamental order of a slot harmonic wave as a threshold value, and reduces, among the plurality of frequency components, even-order frequency components having orders higher than the threshold value and odd-order frequency components, converts a plurality of frequency components output from the specific frequency component reduction unit into a voltage signal, generates a difference waveform of voltage signals respectively corresponding to adjacent magnetic poles, detects a short-circuit of a field winding based on a shape of the difference waveform, and estimates a short-circuit position of the field winding, and determines an estimation accuracy of the short-circuit position of the field winding based on a degree of symmetry of a waveform of a maximum wave with respect to a peak angle of the difference waveform serving as a center.
    Type: Application
    Filed: July 8, 2020
    Publication date: June 29, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Atsushi YAMAMOTO, Susumu MAEDA, Nobuaki MUROKI
  • Publication number: 20230198319
    Abstract: Provided is a rotating electric machine in which stator coils can be easily inserted into slots while the effect of improving the output performance by a magnet yoke portion is enhanced. The rotating electric machine includes: a stator including a stator core having a plurality of slots, stator coils, and stator magnet, the stator coil and the stator magnet being inserted in each of the plurality of slots; a first rotor; and a second rotor. The stator core has a magnet yoke portion between the stator coil and the stator magnet, and is composed of a first stator core, and a second stator core having the magnet yoke portion.
    Type: Application
    Filed: September 7, 2020
    Publication date: June 22, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takuro YAMADA, Ryoji MIYATAKE, Haruyuki KOMETANI, Yuji TAKIZAWA
  • Publication number: 20230025203
    Abstract: Increase in weight of a rotary electric machine including a low-speed rotor in which a spacer made of metal is provided between a plurality of magnetic pole pieces, can be suppressed. The rotary electric machine includes a stator, a first rotor provided so as to be rotatable with respect to the stator, and a second rotor provided coaxially with the first rotor. The first rotor includes a plurality of magnetic pole pieces disposed so as to be arranged in the circumferential direction, a plurality of spacers respectively disposed between the plurality of magnetic pole pieces, two dampers respectively disposed at both end portions in the axial direction, and a fastening tool for fastening each spacer to a corresponding clamper. The spacer has a cavity portion. The spacer and the fastening tool are electrically insulated from each other.
    Type: Application
    Filed: April 16, 2020
    Publication date: January 26, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Haruyuki KOMETANI, Ryoji MIYATAKE, Takuro YAMADA, Kenji TANAKA, Yuji TAKIZAWA
  • Publication number: 20220407402
    Abstract: Provided is a magnetic-geared motor that can suppress eddy current flowing inside a fastening member and reduce power loss. The magnetic-geared motor includes: a stator; a first rotor provided rotatably relative to the stator and including a plurality of magnetic pole pieces and a plurality of spacers disposed so as to be arranged in a circumferential direction; and a second rotor provided coaxially with the first rotor. Each spacer is composed of a plurality of divisional spacers disposed apart from each other in an axial direction, and a plurality of fastening tools for fastening the plurality of divisional spacers in the axial direction, and the divisional spacers and the fastening tools are electrically insulated from each other.
    Type: Application
    Filed: April 16, 2020
    Publication date: December 22, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Haruyuki KOMETANI, Ryoji MIYATAKE, Takuro YAMADA, Kenji TANAKA
  • Publication number: 20220390519
    Abstract: The short-circuit detection device according to the present disclosure includes: a signal acquisition unit configured to acquire, from a magnetic flux detector configured to detect a magnetic flux generated in a gap between a rotor and a stator of a rotary electric machine, one detected signal based on the magnetic flux and set the one detected signal as a first detected signal and a second detected signal; a signal processing unit configured to perform frequency analysis on the first detected signal, and generate and decode a voltage signal simulating a voltage state assumed in a normal case; and a signal comparison unit configured to perform comparison between a decoded signal obtained through the decoding by the signal processing unit and the second detected signal transmitted from the signal acquisition unit, to detect a short-circuit in a field winding of the rotary electric machine.
    Type: Application
    Filed: December 26, 2019
    Publication date: December 8, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Haruyuki KOMETANI, Atsushi YAMAMOTO, Susumu MAEDA, Nobuaki MUROKI
  • Patent number: 11512977
    Abstract: A redundant resolver is configured of a stator and a rotor that form a pair, wherein the rotor is a rotor with a shaft angle multiplier of Nx having Nx (Nx is a natural number) salient poles, the stator is such that n teeth T1 to Tn, where n is a natural number, are disposed sequentially in a circumferential direction, configuring M systems by being divided into M in the circumferential direction, and having an angle of 360/M degrees when angles of the teeth configuring one system are totaled, a one-phase excitation winding and a two-phase output winding are wound around each of the teeth T1 to Tn, excitation signals of the same frequency are applied by differing excitation circuits to the respective excitation windings, an output order per system is Nout (Nout is a natural number), and an abnormality is detected based on output signals of the M systems.
    Type: Grant
    Filed: December 21, 2017
    Date of Patent: November 29, 2022
    Assignee: Mitsubishi Electric Cornoration
    Inventors: Hiroko Ikeda, Yuji Takizawa, Kazumasa Ito, Shinichi Yamaguchi, Toshihiro Matsunaga, Yosuke Sugino
  • Publication number: 20220376645
    Abstract: Provided are a short circuit state analyzer to compare difference value when the AC excitation current is applied at a first frequency with a threshold value, to estimate a short circuit resistance from the difference value based on data indicating a relationship between the short circuit resistance and the difference value at the first frequency when the difference value is smaller than the threshold value, to cause an excitation power supply to apply the AC excitation current to the field windings at a second frequency lower than the first frequency when the difference value is equal to or greater than the threshold value, and to estimate the short circuit resistance from a difference value obtained by the AC excitation current at the second frequency based on data indicating a relationship between the short circuit resistance and the difference value at the second frequency.
    Type: Application
    Filed: January 27, 2020
    Publication date: November 24, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Haruyuki KOMETANI, Ryosuke KAWASHIMA, Kohei MAJIMA, Susumu MAEDA
  • Patent number: 11411445
    Abstract: A permanent-magnet synchronous motor and an electric power steering device are driven by a first system including a first armature winding and a first control apparatus and by a second system including a second armature winding and a second control apparatus and are configured in such a way that if one system fails, driving by the one system is stopped but the driving is continued by the other system.
    Type: Grant
    Filed: September 7, 2017
    Date of Patent: August 9, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuji Takizawa, Hiroko Ikeda, Kazumasa Ito, Shinichi Yamaguchi, Yu Hirotani, Satoru Akutsu
  • Patent number: 11404925
    Abstract: A permanent magnet motor includes a stator, and a rotor having a rotor core disposed opposing an inner side of the stator across an air gap, a permanent magnet disposed in a circumferential direction of the rotor core, and a field pole of the rotor core in which the permanent magnet is disposed, wherein the field pole has a radius smaller than an arc centered on a shaft attached to an inner side of the rotor, a multiple of a slit whose longitudinal axial direction is a radial direction of the rotor core are formed in the field pole, and an interval between a first central line positioned between a multiple of the slit and a second central line positioned between a neighboring multiple of the slit is enlarged as the first central line and the second central line head toward an outer peripheral side of the rotor core.
    Type: Grant
    Filed: April 26, 2017
    Date of Patent: August 2, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuji Takizawa, Satoru Akutsu, Masafumi Okazaki, Natsumi Sugi
  • Publication number: 20220146593
    Abstract: Provided is a short-circuit detection device including: a signal acquisition unit configured to acquire, from a magnetic flux detector configured to detect a magnetic flux generated in an air gap between a rotor and a stator of a rotating electric machine, a detection signal corresponding to the magnetic flux; a signal processing unit configured to subject the detection signal acquired by the signal acquisition unit to filtering of removing at least one component of odd-order components included in the detection signal, to thereby generate a filtered signal being the detection signal subjected to the filtering; and a short-circuit detection unit configured to detect a short circuit of a field winding through use of the filtered signal generated by the signal processing unit.
    Type: Application
    Filed: April 12, 2019
    Publication date: May 12, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Haruyuki KOMETANI, Kenta MOTOYOSHI, Atsushi YAMAMOTO, Susumu MAEDA, Nobuaki MUROKI
  • Publication number: 20220120822
    Abstract: Provided is a short-circuit detection device configured to detect a short circuit of a field winding wound in a plurality of rotor slots in a rotor of a rotating electric machine, the short-circuit detection device including: a signal conversion unit configured to convert a detection signal in which a circumferential distribution of a magnetic flux of the rotor is detected into an energy equivalent signal corresponding to a circumferential distribution of magnetic energy of the rotor; and a short-circuit detection unit configured to detect a rotor slot in which the short circuit has occurred through use of the energy equivalent signal.
    Type: Application
    Filed: March 12, 2019
    Publication date: April 21, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Haruyuki KOMETANI, Atsushi YAMAMOTO, Susumu MAEDA, Nobuaki MUROKI
  • Patent number: 11264880
    Abstract: A permanent magnet motor includes a rotor having a field pole of a rotor core, wherein the field pole has a radius smaller than an arc centered on a shaft of the rotor, a multiple of slits are formed in the field pole, the multiple of slits are disposed so that an interval between a first central line positioned between a multiple of the slits and a second central line positioned between a neighboring multiple of the slits increases as the first central line and the second central line head toward an outer peripheral side of the rotor core, and of the multiple of slits of the field pole, a first slit disposed in a central position of the field pole, and a second slit and a third slit disposed on either side of the first slit, are disposed within 20% of a circumferential direction width of the permanent magnet.
    Type: Grant
    Filed: February 28, 2018
    Date of Patent: March 1, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuji Takizawa, Hiroko Ikeda, Shinichi Yamaguchi, Yu Hirotani, Masafumi Okazaki, Satoru Akutsu
  • Publication number: 20220037942
    Abstract: A rotor core of a rotating electrical machine has interpole bridges each disposed on an outer circumferential side with respect to a permanent magnet in a non-magnetic portion between the poles, and interpole diameter bridges each surrounded by two permanent magnets and an interpole bridge. The outer circumferential surface of each interpole bridge is formed by a first flat surface. Thus, a path of a magnetic flux passing through a magnetic gap is lengthened, so that a q-axis inductance is reduced. In addition, a width in a radial direction of each interpole bridge and a width in a circumferential direction of each interpole diameter bridge are constant, and each interpole bridge and each interpole diameter bridge are disposed so as to be perpendicular to each other to form a T shape. Thus, the concentration of stress during press-fitting of the permanent magnet into a magnet hole can be reduced.
    Type: Application
    Filed: November 27, 2018
    Publication date: February 3, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Kodai OKAZAKI, Kenta MOTOYOSHI, Yuji TAKIZAWA, Hiroko IKEDA, Hidenori SASAKI, Yu HIROTANI, Satoru AKUTSU, Masafumi OKAZAKI, Natsumi SUGI
  • Patent number: 11211838
    Abstract: According to the present invention, provided is an IPM rotor of the present invention, which includes a plurality of core sheets, having hole portions configured to accommodate magnets and being laminated on one another, and the magnets are inserted in the hole portions. The IPM rotor includes a first core sheet having a spring plate portion provided to the hole portion, and a second core sheet having a recessed portion provided the hole portion. A protruding portion is provided to the hole portion of at least one of the plurality of the laminated core sheets. The protruding portion is provided to at least one of the hole portion of the first core sheet, the hole portion of the second core sheet, or a hole portion of a third core sheet to be further arranged.
    Type: Grant
    Filed: April 12, 2017
    Date of Patent: December 28, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hiroshi Aida, Masafumi Okazaki, Yuji Takizawa, Satoru Akutsu, Hideya Nishikawa, Akihiko Mori
  • Patent number: 11108312
    Abstract: Each of a plurality of permanent-magnet pairs is configured with a pair of permanent magnets that are arranged in a v-shaped manner in such a way that the distance between the portions of the permanent magnets, facing each other at the outer side in the radial direction of the rotor core, is smaller than the distance between the portions thereof, facing each other at the inner side in the radial direction of the rotor core; a magnetic-field pole is formed of part, of the rotor core, that is situated between the adjacent permanent-magnet pairs.
    Type: Grant
    Filed: May 10, 2016
    Date of Patent: August 31, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuji Takizawa, Yu Hirotani
  • Patent number: 11018616
    Abstract: In the present electric driving apparatus, coils that constitute a first armature winding and coils that constitute a second armature winding are arranged so as to alternate in a circumferential direction, and a control portion is configured so as to perform single-system driving when one of a first system and a second system fails, the single-system driving stopping driving of an inverter of the system that has failed, and controlling driving of the inverter of the system that has not failed to supply inverter phase currents to an armature winding of the system that has not failed such that the inverter phase currents are set to a second upper limit value that is greater than a first upper limit value.
    Type: Grant
    Filed: January 26, 2017
    Date of Patent: May 25, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yu Hirotani, Kazumasa Ito, Yusuke Morita, Yuji Takizawa, Satoru Akutsu, Masafumi Okazaki
  • Patent number: 11001297
    Abstract: To provide an electric motor control system and an electric power steering apparatus that torque of the electric motor can be increased for ensuring of steering performance even at the time of abnormality occurrence. The controller is provided with 2 sets of control systems which control a supply current to each set of the windings. When abnormality occurs in one set of the windings and the control system, the electric motor control system sets 0 to supply current to all phase or partial phase windings of abnormality occurrence set, and increase supply current to normal set of the windings up to an irreversible current that increase an irreversible demagnetizing factor of the permanent magnet more than the normal time.
    Type: Grant
    Filed: March 14, 2016
    Date of Patent: May 11, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuji Takizawa, Satoru Akutsu, Yoshihito Asao
  • Publication number: 20210135513
    Abstract: A permanent-magnet synchronous motor and an electric power steering device are driven by a first system including a first armature winding and a first control apparatus and by a second system including a second armature winding and a second control apparatus and are configured in such a way that if one system fails, driving by the one system is stopped but the driving is continued by the other system.
    Type: Application
    Filed: September 7, 2017
    Publication date: May 6, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Hiroko IKEDA, Kazumasa ITO, Shinich YAMAGUCHI, Yu HIROTANI, Satoru AKUTSU