Patents by Inventor Minori NAGATA

Minori NAGATA 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: 11209487
    Abstract: A rotor diagnostic apparatus includes a parameter selection part that calculates evaluation values indicating how much sensor values of a rotor at a given time point deviate from a reference value at which the rotor is known to be in a normal state, the given time point being after the rotor is known to be in the normal state and before the rotor is to be diagnosed, and selects a plurality of parameters to be used for abnormality diagnosis of the rotor from the sensor values based on the calculated evaluation values. A diagnosis part outputs an abnormality value which is indicative of how abnormal the rotor is and which is obtained based on a distance, in a multidimensional space having the selected parameters as coordinate axes, between a figure represented by sensor values in the normal state and a figure represented by sensor values targeted for diagnosis.
    Type: Grant
    Filed: March 27, 2017
    Date of Patent: December 28, 2021
    Assignee: HITACHI, LTD.
    Inventors: Tetsuji Kato, Kohji Maki, Minori Nagata
  • Publication number: 20210384779
    Abstract: An object of the present invention is to provide a highly efficient and highly reliable rotary electric machine. A rotary electric machine includes: a stator around which a plurality of coils are wound; and a rotor which is supported to be freely rotatable with a predetermined gap with respect to the stator. The coil has at least one connection portion per turn in a slot of the stator. Conductors to be connected mutually have steps at the connection portion, and are fitted with other conductors so as to mutually fill the steps. The steps have contact surfaces that come into contact with each other in the slot to be electrically conducted. A thermally expandable sheet capable of pressurizing the coil in a radial direction of the stator is arranged in the slot.
    Type: Application
    Filed: January 8, 2020
    Publication date: December 9, 2021
    Inventors: Akeshi TAKAHASHI, Minori NAGATA, Masanori SAWAHATA
  • Patent number: 11047882
    Abstract: Provided are a non-contact voltage measurement device and diagnosis system capable of acquiring the voltage of an electric wire without disconnecting the wire. The non-contact voltage measurement device (100) includes: a cylindrical fixing part (110) for holding an electric wire (10) by clipping the same from both sides; a first electrode (121) and a second electrode (122) provided on the inner peripheral surface of the electric-wire-holding side of the fixing part (110) so as to be separated by a distance (D2); a first measurement capacitor (C3) and a voltage division capacitor (C2) connected to the first electrode (121); a second measurement capacitor (C3?) connected to the second electrode (122); a terminal (131) for measuring the voltage (V1) applied to the first measurement capacitor (C3); and a terminal (132) for measuring the voltage (V2) applied to the second measurement capacitor (C3?).
    Type: Grant
    Filed: November 15, 2016
    Date of Patent: June 29, 2021
    Assignee: HITACHI, LTD.
    Inventors: Tetsuji Kato, Minori Nagata, Kohji Maki
  • Publication number: 20200191833
    Abstract: Provided are a non-contact voltage measurement device and diagnosis system capable of acquiring the voltage of an electric wire without disconnecting the wire. The non-contact voltage measurement device (100) includes: a cylindrical fixing part (110) for holding an electric wire (10) by clipping the same from both sides; a first electrode (121) and a second electrode (122) provided on the inner peripheral surface of the electric-wire-holding side of the fixing part (110) so as to be separated by a distance (D2); a first measurement capacitor (C3) and a voltage division capacitor (C2) connected to the first electrode (121); a second measurement capacitor (C3?) connected to the second electrode (122); a teminal (131) for measuring the voltage (V1) applied to the first measurement capacitor (C3); and a terminal (132) for measuring the voltage (V2) applied to the second measurement capacitor (C3?).
    Type: Application
    Filed: November 15, 2016
    Publication date: June 18, 2020
    Applicant: HITACHI, LTD.
    Inventors: Tetsuji KATO, Minori NAGATA, Kohji MAKI
  • Publication number: 20190146036
    Abstract: A rotor diagnostic apparatus includes a parameter selection part that calculates evaluation values indicating how much sensor values of a rotor at a given time point deviate from a reference value at which the rotor is known to be in a normal state, the given time point being after the rotor is known to be in the normal state and before the rotor is to be diagnosed, and selects a plurality of parameters to be used for abnormality diagnosis of the rotor from the sensor values based on the calculated evaluation values. A diagnosis part outputs an abnormality value which is indicative of how abnormal the rotor is and which is obtained based on a distance, in a multidimensional space having the selected parameters as coordinate axes, between a figure represented by sensor values in the normal state and a figure represented by sensor values targeted for diagnosis.
    Type: Application
    Filed: March 27, 2017
    Publication date: May 16, 2019
    Inventors: Tetsuji KATO, Kohji MAKI, Minori NAGATA
  • Patent number: 10209310
    Abstract: A rotary machine diagnostic system includes: a current measurement unit for measuring a leakage current of a rotary machine; a voltage measurement unit for measuring a voltage of the rotary machine corresponding to the flowing leakage current; and a data processing unit. The data processing unit has a function of performing transient response analysis on a predetermined equivalent circuit model, which is equivalent to a leakage current path of the rotary machine, using current data and voltage data having a predetermined time width which are respectively measured at predetermined time intervals by the current measurement unit and the voltage measurement unit, and a function of extracting parameters of the equivalent circuit of the leakage current path.
    Type: Grant
    Filed: September 15, 2016
    Date of Patent: February 19, 2019
    Assignee: Hitachi, Ltd.
    Inventors: Tetsuji Kato, Kohji Maki, Minori Nagata
  • Publication number: 20170089983
    Abstract: A rotary machine diagnostic system includes: a current measurement unit for measuring a leakage current of a rotary machine; a voltage measurement unit for measuring a voltage of the rotary machine corresponding to the flowing leakage current; and a data processing unit. The data processing unit has a function of performing transient response analysis on a predetermined equivalent circuit model, which is equivalent to a leakage current path of the rotary machine, using current data and voltage data having a predetermined time width which are respectively measured at predetermined time intervals by the current measurement unit and the voltage measurement unit, and a function of extracting parameters of the equivalent circuit of the leakage current path.
    Type: Application
    Filed: September 15, 2016
    Publication date: March 30, 2017
    Inventors: Tetsuji KATO, Kohji MAKI, Minori NAGATA