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).

  • 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
  • Publication number: 20210075273
    Abstract: A stator includes a core back portion, a plurality of teeth extending inward in a radial direction of the stator from the core back portion, a first system coil portion and a second system coil portion wound on each of the teeth, and a magnetic interference reduction member provided between the first system coil portion and the second system coil portion to reduce magnetic interference between the first system coil portion and the second system coil portion. Further, the first system coil portion and the second system coil portion are connected to mutually different power supply sources, that is, the first system coil portion and the second system coil portion are each connected to a first system power supply source or a second system power supply source.
    Type: Application
    Filed: March 20, 2019
    Publication date: March 11, 2021
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Hiroko IKEDA, Shinichi YAMAGUCHI, Yuji TAKIZAWA, Yu HIROTANI, Kazumasa ITO
  • Publication number: 20210075305
    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: Application
    Filed: February 28, 2018
    Publication date: March 11, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuji TAKIZAWA, Hiroko IKEDA, Shinichi YAMAGUCHI, Yu HIROTANI, Masafumi OKAZAKI, Satoru AKUTSU
  • Patent number: 10944347
    Abstract: Provided is a rotary electrical machine, which is reduced in size of a motor through use of reluctance torque being a feature of an IPM motor, and in which, in driving in times other than a rated time, a current phase angle is shifted from an angle at which a total torque is maximized so that an increase in torque ripple is suppressed even when the current phase angle changes, to thereby provide characteristics of small size, high output, and low torque ripple.
    Type: Grant
    Filed: February 16, 2017
    Date of Patent: March 9, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuji Takizawa, Yu Hirotani, Masafumi Okazaki, Satoru Akutsu
  • Patent number: 10916983
    Abstract: A permanent-magnet motor includes a through-hole expansion portion provided in a through-hole for inserting a permanent magnet into the rotor core of a permanent-magnet motor, and a bridge portion that surrounds adjacent through-hole expansion portions and forms part of the outer circumferential surface of the rotor core; the bridge portion has a small-thickness portion that is formed to be smaller than that of a portion, other than the bridge portion, of the rotor core.
    Type: Grant
    Filed: May 10, 2016
    Date of Patent: February 9, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hiroshi Aida, Masafumi Okazaki, Satoru Akutsu, Yoshihito Asao, Yuji Takizawa
  • Patent number: 10910892
    Abstract: In the rotary electric machine according to the present invention, a plurality of core sheets include linked core sheets that include linking portions that protrude circumferentially from flange portions so as to link together tip portions of adjacent tooth portions, at least one sheet of the linked core sheets is formed such that a tooth tip portion shape is mirror-asymmetrical relative to a tooth central axis that passes through a circumferential center of the tooth portions, and a stator core is configured by laminating the linked core sheets such that circumferential positions of the linking portions are offset.
    Type: Grant
    Filed: April 22, 2015
    Date of Patent: February 2, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yu Hirotani, Kazumasa Ito, Yuji Takizawa, Satoru Akutsu, Hiroshi Aida, Shusuke Hori
  • Patent number: 10903724
    Abstract: The present invention provides a rotation angle detector capable of detecting a rotation angle of a rotor in the same manner as at normal time even when abnormality such as disconnection or a short circuit occurs, and capable of reducing the number of terminals. When one spatial order cycle of the output winding is an electrical angle of 360°, a phase difference between a first output winding and a second output winding and a phase difference between the second output winding and a third output winding are set at an electrical angle ?, and ??180°×n (n is an integer).
    Type: Grant
    Filed: December 28, 2015
    Date of Patent: January 26, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hiroko Ikeda, Yusuke Morita, Kazumasa Ito, Yu Hirotani, Kodai Okazaki, Satoru Akutsu, Yuji Takizawa
  • Patent number: 10903769
    Abstract: Provided is a rotary electrical machine, which is reduced in size of a motor through use of reluctance torque being a feature of an IPM motor, and in which, in driving in times other than a rated time, a current phase angle is shifted from an angle at which a total torque is maximized so that an increase in torque ripple is suppressed even when the current phase angle changes, to thereby provide characteristics of small size, high output, and low torque ripple.
    Type: Grant
    Filed: February 16, 2017
    Date of Patent: January 26, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuji Takizawa, Yu Hirotani, Masafumi Okazaki, Satoru Akutsu
  • Patent number: 10871365
    Abstract: Included are: a sensor magnet which rotates integrally with a rotating shaft centering on the rotating shaft, and generates a magnetic field for angle detection which is for detecting the angle of rotation; a first sensor and a second sensor each of which is arranged opposite to the sensor magnet at a position separated in angle by 90 degrees on the circumference centered on the rotating shaft, and outputs a signal corresponding to the magnetic field for angle detection; and an angle calculator that calculates a rotation angle by using the signals from the first sensor and the second sensor.
    Type: Grant
    Filed: May 31, 2016
    Date of Patent: December 22, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Akira Furukawa, Yu Kawano, Yuji Takizawa
  • Publication number: 20200363233
    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: Application
    Filed: December 21, 2017
    Publication date: November 19, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hiroko IKEDA, Yuji TAKIZAWA, Kazumasa ITO, Shinichi YAMAGUCHI, Toshihiro MATSUNAGA, Yosuke SUGINO
  • Patent number: 10840756
    Abstract: A front iron core includes a first iron core main body and a plurality of first projecting sections which project to a radial outer side from the first iron core main body. A second iron core includes a second iron core main body which overlaps with the first iron core main body and a plurality of second projecting sections which project to a radial outer side from the second iron core main body. When a rotor iron core is viewed along the axis line, portions of the second projecting sections protrude as extension sections to outward in the circumferential direction, from the first projecting sections. Furthermore, when the rotor iron core is viewed along the axis line, radial-direction outer side end surfaces of the extension parts are smoothly continuous with radial-direction outer side end surfaces of the first projecting sections.
    Type: Grant
    Filed: March 2, 2015
    Date of Patent: November 17, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuji Takizawa, Satoru Akutsu, Shusuke Hori
  • Patent number: 10644573
    Abstract: Provided is a permanent magnet motor including an armature, a rotor, and an angle detector. The angle detector includes a sensor magnet and a semiconductor sensor. The sensor magnet is magnetized into two poles and is provided in an end portion of a rotation shaft, and has the same rotation center as that of the rotation shaft. The semiconductor sensor is opposed to the sensor magnet in an extension direction of the rotation shaft. The semiconductor sensor and the sensor magnet have a gap formed therebetween, and a plate member made of a magnetic substance is provided between the semiconductor sensor and an end portion of the armature iron core on the semiconductor sensor side.
    Type: Grant
    Filed: December 25, 2015
    Date of Patent: May 5, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuji Takizawa, Kentaro Urimoto, Satoru Akutsu