Patents by Inventor Eigo Totoki

Eigo Totoki 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: 20260121487
    Abstract: A motor system includes a motor and a control unit that controls the motor. The motor includes: a rotor in which a magnetic flux generator is disposed; a stator including a back yoke and a plurality of teeth disposed side by side at intervals in a rotation direction of the rotor; a winding wound around the stator; and a plurality of magnetic sensors provided in slots that are spaces between adjacent ones of the teeth. The control unit includes a computation unit that obtains a rotation angle and/or an eccentricity of the rotor based on signals of the plurality of magnetic sensors, and a signal of the magnetic sensor used by the computation unit is a signal of the magnetic sensor provided in the slot in which the windings on both sides have the same phase and directions of energization opposite to each other.
    Type: Application
    Filed: October 18, 2022
    Publication date: April 30, 2026
    Applicants: Mitsubishi Electric Corporation, TOKYO DENKI UNIVERSITY
    Inventors: Masahito MIYOSHI, Yuichiro NAKAMURA, Eigo TOTOKI, Hiroya SUGIMOTO
  • Publication number: 20250343454
    Abstract: A permanent magnet synchronous electric motor includes a stator, a rotor, and a plurality of permanent magnets. Each of the plurality of permanent magnets has a first magnet end and a second magnet end in a circumferential direction. A recessed portion of each of the plurality of permanent magnets has a first recessed-portion end and a second recessed-portion end in the circumferential direction. L1?L2 is satisfied provided that a distance between the first magnet end and the first recessed-portion end is L1 and a distance between the second magnet end and the second recessed-portion end is L2.
    Type: Application
    Filed: July 14, 2022
    Publication date: November 6, 2025
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuki NISHIMURA, Eigo TOTOKI, Yuichiro NAKAMURA, Shohei FUJIKURA
  • Patent number: 11855500
    Abstract: When the number of teeth included in an in-phase teeth group is represented by T, a first half-slot adjacent to a k-th tooth is represented by A(k, 1), and a second half-slot adjacent to the k-th tooth is represented by A(k, 2), the number of turns of the coil arranged in A(1, 1) is the same as the number of turns of the coil arranged in A(T, 2), the number of turns of the coil arranged in A(1, 1) is different from the number of turns of the coil arranged in A(1, 2). The number of turns of the coil arranged in A(k, 2) is different from the number of turns of the coil arranged in A(k+1, 1), and the number of turns of the coils provided in the slot is twice the number of turns of the coil arranged in A(1, 1).
    Type: Grant
    Filed: March 4, 2019
    Date of Patent: December 26, 2023
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Junka Otosaka, Eigo Totoki, Toshinori Tanaka
  • Publication number: 20220085678
    Abstract: When the number of teeth included in an in-phase teeth group is represented by T, a first half-slot adjacent to a k-th tooth is represented by A(k, 1), and a second half-slot adjacent to the k-th tooth is represented by A(k, 2), the number of turns of the coil arranged in A(1, 1) is the same as the number of turns of the coil arranged in A(T, 2), the number of turns of the coil arranged in A(1, 1) is different from the number of turns of the coil arranged in A(1, 2). The number of turns of the coil arranged in A(k, 2) is different from the number of turns of the coil arranged in A(k+1, 1), and the number of turns of the coils provided in the slot is twice the number of turns of the coil arranged in A(1, 1).
    Type: Application
    Filed: March 4, 2019
    Publication date: March 17, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Junka OTOSAKA, Eigo TOTOKI, Toshinori TANAKA
  • Publication number: 20180076675
    Abstract: Two teeth on which windings are wound, and a teeth connecting portion disposed between the two teeth, connecting the teeth together, and having a mounting hole formed therein, are arranged in a line in a second direction, which is an arrangement direction. The teeth connecting portion has a support that supports the windings. The support has projections protruding from both end portions in the second direction of the teeth connecting portion to both sides in a first direction which is a width direction, and spaces formed between the projections in the second direction.
    Type: Application
    Filed: May 26, 2015
    Publication date: March 15, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hiroshi WAKAYAMA, Eigo TOTOKI, Shinichi YAMAGUCHI, Kenta MOTOYOSHI, Yosuke TAKAISHI
  • Patent number: 9912204
    Abstract: In conventional rotors having a shape in which permanent magnets are skewed, a configuration in which, for example, the thicknesses of both ends of each magnet are increased is used in order to make the rotors symmetric between the forward and reverse directions, thereby causing excessive increase in the thicknesses. In a rotor 2 in which permanent magnets form magnet poles and the permanent magnets are skewed with respect to the axial direction, the thickness of each permanent magnet is increased at a portion that is most likely to be demagnetized, that is, a positive side portion F in a rotor part 2A skewed in the positive direction and a negative side portion F in a rotor part 2B skewed in the negative direction, whereby a demagnetization resistance strengthened portion is formed.
    Type: Grant
    Filed: December 9, 2013
    Date of Patent: March 6, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Eigo Totoki, Toshinori Tanaka, Tomoya Tachibana
  • Patent number: 9716411
    Abstract: A rotor core includes low permeability areas having lower permeability than that of a material of the rotor core, between an outer circumference of each magnetic pole and a side surface of each permanent magnet. The low permeability areas are formed asymmetrically with respect to a geometric center of each magnetic pole so that a magnetic center of the magnetic pole is displaced toward one side with respect to the geometric center. The rotor cores are placed upside down relative to each other so that a relative position in the circumferential direction of the low permeability areas with respect to the permanent magnets differs.
    Type: Grant
    Filed: December 9, 2013
    Date of Patent: July 25, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Toshinori Tanaka, Tomoya Tachibana, Eigo Totoki
  • Patent number: 9705366
    Abstract: R1>R2>R3 is satisfied, where R1 is a radius of curvature of a cylindrical surface that contacts circular arc-shaped curved surfaces arranged circumferentially, R2 is a radius of curvature of the circular arc-shaped curved surfaces, and R3 is a radius of curvature of an upper surface of permanent magnets, air gaps are formed on radially outer portions of two circumferential side portions of magnet housing apertures, surfaces that contact two circumferential side surfaces of the permanent magnets so as to be parallel to a radial direction are disposed on radially inner portions of the two circumferential end portions, and B2>B1 is satisfied, where B1 is a thickness of a core portion of the rotor core between the circular arc-shaped curved surfaces and the magnet housing apertures at a magnetic pole center, and B2 is a thickness of a circumferential end portion of the core portion.
    Type: Grant
    Filed: February 24, 2015
    Date of Patent: July 11, 2017
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Toshinori Tanaka, Eigo Totoki, Ryuichi Takiguchi
  • Publication number: 20170085143
    Abstract: R1>R2>R3 is satisfied, where R1 is a radius of curvature of a cylindrical surface that contacts circular arc-shaped curved surfaces arranged circumferentially, R2 is a radius of curvature of the circular arc-shaped curved surfaces, and R3 is a radius of curvature of an upper surface of permanent magnets, air gaps are formed on radially outer portions of two circumferential side portions of magnet housing apertures, surfaces that contact two circumferential side surfaces of the permanent magnets so as to be parallel to a radial direction are disposed on radially inner portions of the two circumferential end portions, and B2>B1 is satisfied, where B1 is a thickness of a core portion of the rotor core between the circular arc-shaped curved surfaces and the magnet housing apertures at a magnetic pole center, and B2 is a thickness of a circumferential end portion of the core portion.
    Type: Application
    Filed: February 24, 2015
    Publication date: March 23, 2017
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Toshinori TANAKA, Eigo TOTOKI, Ryuichi TAKIGUCHI
  • 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: 9537380
    Abstract: A permanent-magnet type rotating electrical machine, including a rotor including a plurality of magnetic poles arranged at an equal interval, and a stator including a plurality of teeth and a plurality of armature windings. A high frequency voltage different in frequency and amplitude from voltages for generating a torque is applied to the armature windings. A magnetic pole position of the rotor is estimated by using a current trajectory of a measured high frequency current. When dq transform is applied to the measured high frequency current, a current trajectory forms an ellipse on d and q axes. Angular variation ranges of a major axis of the ellipse with respect to a load current and a rotor position are set so as to acquire a predetermined position estimation resolution.
    Type: Grant
    Filed: January 18, 2012
    Date of Patent: January 3, 2017
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Shinichi Yamaguchi, Eigo Totoki, Masato Ito, Daisuke Nishijima, Toshinori Tanaka
  • Publication number: 20150270750
    Abstract: In conventional rotors having a shape in which permanent magnets are skewed, a configuration in which, for example, the thicknesses of both ends of each magnet are increased is used in order to make the rotors symmetric between the forward and reverse directions, thereby causing excessive increase in the thicknesses. In a rotor 2 in which permanent magnets form magnet poles and the permanent magnets are skewed with respect to the axial direction, the thickness of each permanent magnet is increased at a portion that is most likely to be demagnetized, that is, a positive side portion F in a rotor part 2A skewed in the positive direction and a negative side portion F in a rotor part 2B skewed in the negative direction, whereby a demagnetization resistance strengthened portion is formed.
    Type: Application
    Filed: December 9, 2013
    Publication date: September 24, 2015
    Applicant: Mitsubishi Electric Corporation
    Inventors: Eigo Totoki, Toshinori Tanaka, Tomoya Tachibana
  • Publication number: 20150270752
    Abstract: A rotor core includes low permeability areas having lower permeability than that of a material of the rotor core, between an outer circumference of each magnetic pole and a side surface of each permanent magnet. The low permeability areas are formed asymmetrically with respect to a geometric center of each magnetic pole so that a magnetic center of the magnetic pole is displaced toward one side with respect to the geometric center. The rotor cores are placed upside down relative to each other so that a relative position in the circumferential direction of the low permeability areas with respect to the permanent magnets differs.
    Type: Application
    Filed: December 9, 2013
    Publication date: September 24, 2015
    Applicant: Mitsubishi Electric Corporation
    Inventors: Toshinori Tanaka, Tomoya Tachibana, Eigo Totoki
  • Publication number: 20140001908
    Abstract: A permanent-magnet type rotating electrical machine, including a rotor including a plurality of magnetic poles arranged at an equal interval, and a stator including a plurality of teeth and a plurality of armature windings. A high frequency voltage different in frequency and amplitude from voltages for generating a torque is applied to the armature windings. A magnetic pole position of the rotor is estimated by using a current trajectory of a measured high frequency current. When dq transform is applied to the measured high frequency current, a current trajectory forms an ellipse on d and q axes. Angular variation ranges of a major axis of the ellipse with respect to a load current and a rotor position are set so as to acquire a predetermined position estimation resolution.
    Type: Application
    Filed: January 18, 2012
    Publication date: January 2, 2014
    Applicant: Mitsubishi Electric Corporation
    Inventors: Shinichi Yamaguchi, Eigo Totoki, Masato Ito, Daisuke Nishijima, Toshinori Tanaka