Patents by Inventor Shigeru Kakugawa

Shigeru Kakugawa 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: 10629355
    Abstract: A stationary induction apparatus includes a cooled magnetic material ring disposed in an end portion of each winding and that can reduce an electromagnetic-mechanical force and improve reliability. The apparatus includes an iron core; a winding outside of the iron core; a plurality of iron core clamps that sandwich the winding from a longitudinal direction of the iron core; a magnetic material ring with a silicon steel plate wound outside of the iron core; a laminated magnetic material composite ring including an insulator on an outer circumference of the magnetic material ring; and a holding-and-cooling structure between the winding and the laminated magnetic material composite ring, in which a portion of the holding-and-cooling structure protruding from between the winding and the laminated magnetic material composite ring extends in the longitudinal direction, and the holding-and-cooling structure is a recess with respect to the winding and the laminated magnetic material composite ring.
    Type: Grant
    Filed: June 8, 2018
    Date of Patent: April 21, 2020
    Assignee: Hitachi, Ltd.
    Inventors: Shigeru Kakugawa, Yasunori Ono, Mao Kawamoto, Akira Yamagishi
  • Publication number: 20180358160
    Abstract: An object of the invention is to provide a stationary induction apparatus that includes an appropriately held and cooled magnetic material ring disposed in an end portion of each winding and that can reduce an electromagnetic-mechanical force and improve reliability.
    Type: Application
    Filed: June 8, 2018
    Publication date: December 13, 2018
    Inventors: Shigeru KAKUGAWA, Yasunori ONO, Mao KAWAMOTO, Akira YAMAGISHI
  • Publication number: 20180246065
    Abstract: An eddy-current testing method comprises liftoff signal measuring step of giving liftoff to an eddy-current testing probe including one or more coils and measuring a liftoff signal of a reference specimen, phase recording step of recording a phase of a Lissajous figure obtained from the liftoff signal of the reference specimen, eddy-current testing signal measuring step of measuring an eddy-current testing signal of an object using the eddy-current testing probe, and decision step of deciding that the eddy-current testing signal detected in the eddy-current testing signal measuring step is a liftoff signal if the eddy-current testing probe detects the eddy-current testing signal in all the coils in the eddy-current testing signal measuring step and a phase of a Lissajous figure obtained from the eddy-current testing signal detected in the eddy-current testing signal measuring step coincides with the phase recorded in the phase recording step for all the coils.
    Type: Application
    Filed: January 31, 2018
    Publication date: August 30, 2018
    Inventors: Shigeru KAKUGAWA, Akira NISHIMIZU, Yutaka SUZUKI
  • Patent number: 8781763
    Abstract: A method for analyzing an operating point of a permanent magnet performs electromagnetic field analysis based on a B-H curve of the permanent magnet and element data concerning a finite number of elements into which the permanent magnet is divided to obtain the operating point of the permanent magnet. The method includes the steps of storing data of inputted B-H curve; obtaining magnetic flux densities and magnetic fields in plural regions of the permanent magnet by performing the electromagnetic field analysis based on the data of the B-H curve; and obtaining the operating point of each of the elements based on the result of the electromagnetic field analysis by employing a variable, the variable continuously varying in a first quadrant, in a second quadrant, in a third quadrant, and over these quadrants of the B-H curve and linearly varying with respect to the magnetic flux density and magnetic field.
    Type: Grant
    Filed: August 16, 2011
    Date of Patent: July 15, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Shigeru Kakugawa, Masashi Kitamura, Kohji Maki, Shinji Sugimoto
  • Publication number: 20130140930
    Abstract: Electric rotating machine suppressing narrowing of a magnetic path caused by a skin effect in a housing to increase torque, including stator core having e.g. core back and teeth; stator windings wound around the teeth; stator including stator core and stator windings; housing composed of a magnetic body accommodating the stator; rotor disposed for rotation on an inner circumferential side of the stator. An air gap is provided between an inside wall of the housing and an outer circumferential surface of core back. The core back has projections on a radial back surface of a portion where the teeth are provided. The projections are each provided to be continuous in an axial direction and have tip portions in contact with inside wall of the housing. The air gap may be defined by the inside wall of the housing, the outer circumferential surface of the core back and the projections.
    Type: Application
    Filed: August 29, 2011
    Publication date: June 6, 2013
    Inventors: Hidetoshi Koka, Satoshi Kikuchi, Yutaka Matsunobu, Shigeru Kakugawa, Kohji Maki, Shinji Sugimoto
  • Publication number: 20130127280
    Abstract: An electric rotating machine that can improve efficiency in the high-speed operation state thereof and improve the efficiency of an electric vehicle in the high-speed operation state thereof by the use of the electric rotating machine. An electric rotating machine includes a stator and a rotor. The stator has a stator core with slots and stator windings. The rotor includes a rotor core and a plurality of first permanent magnets and of second permanent magnets. The rotor core is provided with laminated electromagnetic steel sheets and formed with a plurality of magnetic poles arranged in a circumferential direction. The plurality of first and second permanent magnets form the plurality of corresponding magnetic poles. The first permanent magnet and the second permanent magnet for forming each of the magnetic poles of the rotor are different from each other in recoil permeability.
    Type: Application
    Filed: July 30, 2010
    Publication date: May 23, 2013
    Inventors: Shinji Sugimoto, Akiyoshi Komura, Shigeru Kakugawa, Satoshi Kikuchi
  • Publication number: 20120053866
    Abstract: A method for analyzing an operating point of a permanent magnet performs electromagnetic field analysis based on a B-H curve of the permanent magnet and element data concerning a finite number of elements into which the permanent magnet is divided to obtain the operating point of the permanent magnet. The method includes the steps of storing data of inputted B-H curve; obtaining magnetic flux densities and magnetic fields in plural regions of the permanent magnet by performing the electromagnetic field analysis based on the data of the B-H curve; and obtaining the operating point of each of the elements based on the result of the electromagnetic field analysis by employing a variable, the variable continuously varying in a first quadrant, in a second quadrant, in a third quadrant, and over these quadrants of the B-H curve and linearly varying with respect to the magnetic flux density and magnetic field.
    Type: Application
    Filed: August 16, 2011
    Publication date: March 1, 2012
    Inventors: Shigeru KAKUGAWA, Masashi KITAMURA, Kohji MAKI, Shinji SUGIMOTO
  • Publication number: 20120038236
    Abstract: A permanent magnet rotating electric machine comprises a stator having stator windings wound round a stator iron core and a permanent magnet rotor having a plurality of inserted permanent magnets in which the polarity is alternately arranged in the peripheral direction in the rotor iron core. The rotor iron core of the permanent magnets is composed of magnetic pole pieces, auxiliary magnetic poles, and a stator yoke, and furthermore has concavities formed on the air gap face of the magnetic pole pieces of the rotor iron core of the permanent magnets, gently tilting from the central part of the magnetic poles to the end thereof. In a permanent magnet rotating electric machine, effects of iron loss are reduced, and an electric car using highly efficient permanent magnet rotating electric machine are realized.
    Type: Application
    Filed: October 24, 2011
    Publication date: February 16, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Masashi Kitamura, Noriaki Hino, Takashi Kobayashi, Shigeru Kakugawa, Takashi Yasuhara
  • Patent number: 8067871
    Abstract: A permanent magnet rotating electric machine comprises a stator having stator windings wound round a stator iron core and a permanent magnet rotor having a plurality of inserted permanent magnets in which the polarity is alternately arranged in the peripheral direction in the rotor iron core. The rotor iron core of the permanent magnets is composed of magnetic pole pieces, auxiliary magnetic poles, and a stator yoke, and furthermore has concavities formed on the air gap face of the magnetic pole pieces of the rotor iron core of the permanent magnets, gently tilting from the central part of the magnetic poles to the end thereof. In a permanent magnet rotating electric machine, effects of iron loss are reduced, and an electric car using highly efficient permanent magnet rotating electric machine are realized.
    Type: Grant
    Filed: March 18, 2009
    Date of Patent: November 29, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Masashi Kitamura, Noriaki Hino, Takashi Kobayashi, Shigeru Kakugawa, Takashi Yasuhara
  • Patent number: 7714466
    Abstract: To realize reduction in vibration and noise while utilizing reluctance torque, a rotating electrical machine includes: a rotor having permanent magnets disposed in a cylindrical surface coaxial with a rotary shaft; and a stator having an annular stator core disposed coaxially with the rotary shaft, and a annular coil for magnetizing the stator core. The stator core has an annular part covering the annular coil, claws disposed at equal intervals in an inner radius surface of the annular part and extending axially, and magnetic gaps formed between neighboring claws. The number of claws is equal to the number of permanent magnets, and magnet flux in a direction orthogonal to a center axis of the magnetic pole of the permanent magnet at right angles in electric angle is larger than magnetic flux in the center axis direction generated between neighboring permanent magnets. Metal interpoles are provided between neighboring permanent magnets.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: May 11, 2010
    Assignees: Hitachi Industrial Equipment Systems Co., Ltd., Hitachi Powdered Metals Co., Ltd., Japan Servo Co., Ltd.
    Inventors: Masashi Kitamura, Fumio Tajima, Shigeru Kakugawa, Yuji Enomoto, Motoya Ito, Ryoso Masaki, Shoji Ohiwa, Chio Ishihara
  • Publication number: 20090179518
    Abstract: A permanent magnet rotating electric machine comprises a stator having stator windings wound round a stator iron core and a permanent magnet rotor having a plurality of inserted permanent magnets in which the polarity is alternately arranged in the peripheral direction in the rotor iron core. The rotor iron core of the permanent magnets is composed of magnetic pole pieces, auxiliary magnetic poles, and a stator yoke, and furthermore has concavities formed on the air gap face of the magnetic pole pieces of the rotor iron core of the permanent magnets, gently tilting from the central part of the magnetic poles to the end thereof. In a permanent magnet rotating electric machine, effects of iron loss are reduced, and an electric car using highly efficient permanent magnet rotating electric machine are realized.
    Type: Application
    Filed: March 18, 2009
    Publication date: July 16, 2009
    Applicant: Hitachi, Ltd.
    Inventors: Fumio TAJIMA, Yutaka MATSUNOBU, Masashi KITAMURA, Noriaki HINO, Takashi KOBAYASHI, Shigeru KAKUGAWA, Takashi YASUHARA
  • Patent number: 7521832
    Abstract: A permanent magnet rotating electric machine comprises a stator having stator windings wound round a stator iron core and a permanent magnet rotor having a plurality of inserted permanent magnets in which the polarity is alternately arranged in the peripheral direction in the rotor iron core. The rotor iron core of the permanent magnets is composed of magnetic pole pieces, auxiliary magnetic poles, and a stator yoke, and furthermore has concavities formed on the air gap face of the magnetic pole pieces of the rotor iron core of the permanent magnets, gently tilting from the central part of the magnetic poles to the end thereof. In a permanent magnet rotating electric machine, effects of iron loss are reduced, and an electric car using highly efficient permanent magnet rotating electric machine are realized.
    Type: Grant
    Filed: December 15, 2006
    Date of Patent: April 21, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Masashi Kitamura, Noriaki Hino, Takashi Kobayashi, Shigeru Kakugawa, Takashi Yasuhara
  • Patent number: 7492159
    Abstract: In a nuclear magnetic resonance spectrometer, the shape of a detection coil is changed from a conventional cage type to a solenoid type of higher sensitivity. Accordingly, differing from the conventional superconductive magnet of multilayer air core solenoids, a superconductive magnet is right and left divided to split magnets for generating 11 T preferably, 14.1 T in the horizontal direction, and the magnetic field uniformity is set to 0.001 ppm or less and the temporal stability is set to 0.001 ppm or less.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: February 17, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Michiya Okada, Tsuyoshi Wakuda, Shigeru Kakugawa, Hiroshi Morita, Katsuzo Aihara
  • Publication number: 20080018289
    Abstract: A single-phase permanent magnet motor control apparatus, in particular, a low price, flat output torque, low vibration, low noise single-phase permanent magnet motor control apparatus, and a fan and pump using such a single-phase permanent magnet motor control apparatus are provided. In a single-phase permanent magnet motor control apparatus for driving a single-phase permanent magnet motor by using a DC power supply, a converter for converting DC to AC, and a control circuit for controlling the converter, a motor current measuring unit, a terminal voltage measuring unit, a correction unit for correcting an impedance drop in motor constants, and a calculation unit for finding an induced voltage to be obtained by control are included, and a polarity of a terminal voltage is determined on the basis of a value of the found induced voltage.
    Type: Application
    Filed: July 19, 2007
    Publication date: January 24, 2008
    Inventors: Fumio Tajima, Shigeru Kakugawa, Masashi Kitamura, Shoichi Kawamata, Hiroshi Kanazawa, Takayuki Koyama, Shoji Ohiwa, Osamu Sekiguchi
  • Publication number: 20080018194
    Abstract: A single-phase claw-pole type motor comprises a stator, which comprises a claw-pole type stator core and toroidally-wound single-phase stator windings, and a rotor that has alternate polarities, wherein a concave part or a convex part is provided on an air-gap surface of claws of the stator core. In addition, the stator core may be configured by compacting magnetic powder, and the single-phase claw-pole type motor may be driven by a converter that converts a direct current to an alternate current according to a position of the rotor.
    Type: Application
    Filed: July 20, 2007
    Publication date: January 24, 2008
    Inventors: Shigeru KAKUGAWA, Fumio Tajima, Masashi Kitamura, Yuji Enomoto, Motoya Ito, Ryoso Masaki, Shoji Ohiwa, Chio Ishihara
  • Publication number: 20080018195
    Abstract: The present invention realizes reduction in vibration and noise while utilizing reluctance torque. A rotating electrical machine of the present invention includes: a rotor in which a plurality of permanent magnets are disposed in a cylindrical surface coaxial with a rotary shaft; and a stator having a annular stator core disposed coaxially with the rotary shaft, and a annular coil for magnetizing the stator core. The stator core has a annular part covering the annular coil, a plurality of claws disposed at equal intervals in an inner radius surface of the annular part and extending in the axial direction, and a plurality of magnetic gaps formed between the neighboring claws. The number of the claws is equal to the number of permanent magnets, and magnet flux in a direction orthogonal to a center axis direction of the magnetic pole of the permanent magnet at right angles in electric angle is larger than magnetic flux in the center axis direction generated between the neighboring permanent magnets.
    Type: Application
    Filed: July 24, 2007
    Publication date: January 24, 2008
    Inventors: Masashi Kitamura, Fumio Tajima, Shigeru Kakugawa, Yuji Enomoto, Motoya Ito, Ryoso Masaki, Shoji Ohiwa, Chio Ishihara
  • Publication number: 20070279059
    Abstract: A first room-temperature space is formed penetrating through a cryostat along a center axis of a split-type multi-layer cylindrical superconducting coil system which has a ratio of the maximum empirical magnetic field to the central magnetic filed of not larger than 1.3 and is horizontally arranged such that the center axis of the coil is in the horizontal direction, a room-temperature shim coil system is arranged in said first room-temperature space to improve the homogeneity of the magnetic field, a second room-temperature space is formed penetrating through the cryostat and passing through the center of said split gap in the vertical direction, and a sample to be measured and an NMR probe having a solenoid-type probe coil are inserted in said second room-temperature space. Further, the NMR analyzer has a new function constituted by a system for irradiating and detecting the electromagnetic waves having wavelengths of shorter than 0.1 mm.
    Type: Application
    Filed: March 13, 2007
    Publication date: December 6, 2007
    Inventors: Katsuzou Aihara, Michiya Okada, Shigeru Kakugawa, Hiroshi Morita, Tsuyoshi Wakuda
  • Patent number: 7292040
    Abstract: A superconducting magnet configured for an NMR spectrometer includes a split type superconducting magnet having left solenoid superconducting magnets and right solenoid superconducting magnets with a center space therebetween for receiving a sample tube. A permanent current switch is provided and the left and right solenoid superconducting magnets are arranged symmetrically with respect to a center face of the center space. The left and right solenoid superconducting magnets are constituted by an outermost magnet and a plurality of innermost magnets and are arranged in concentric relation with respect to a vertical axis of the center space. A direction of current in at least one of the plurality of innermost magnets is minus when a direction of current in the outermost magnet is plus.
    Type: Grant
    Filed: July 20, 2006
    Date of Patent: November 6, 2007
    Assignee: Hitachi, Ltd.
    Inventors: Shigeru Kakugawa, Michiya Okada, Katsuzou Aihara, Hiroshi Morita, Tsuyoshi Wakuda
  • Publication number: 20070241644
    Abstract: A single-phase motor comprising a rotor magnet, a stator core having salient poles, and a coil wound around the stator core, a rising portion and a falling portion of a voltage applied to the coil have different inclinations, wherein the salient pole is separated into three angle portions, a radius of an outer shape of the salient pole is reduced little by little with respect to a rotating direction of the rotor in a first angle portion with respect to the rotating direction of the rotor, is increased little by little with respect to the rotating direction of the rotor in a second angle portion with respect to the rotating direction of the rotor, and is increased little by little with respect to the rotating direction of the rotor in a third angle portion with respect to the rotating direction of the rotor, and a rate of increase of the third angle portion is gentler than that of the second angle portion.
    Type: Application
    Filed: April 12, 2007
    Publication date: October 18, 2007
    Inventors: Shigeru Kakugawa, Shoichi Kawamata, Fumio Tajima, Osamu Sekiguchi, Shoji Ohiwa, Yukinari Takahashi
  • Patent number: RE44037
    Abstract: A permanent magnet rotating electric machine comprises a stator having stator windings wound round a stator iron core and a permanent magnet rotor having a plurality of inserted permanent magnets in which the polarity is alternately arranged in the peripheral direction in the rotor iron core. The rotor iron core of the permanent magnets is composed of magnetic pole pieces, auxiliary magnetic poles, and a stator yoke, and furthermore has concavities formed on the air gap face of the magnetic pole pieces of the rotor iron core of the permanent magnets, gently tilting from the central part of the magnetic poles to the end thereof. In a permanent magnet rotating electric machine, effects of iron loss are reduced, and an electric car using highly efficient permanent magnet rotating electric machine are realized.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: March 5, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Fumio Tajima, Yutaka Matsunobu, Masashi Kitamura, Noriaki Hino, Takashi Kobayashi, Shigeru Kakugawa, Takashi Yasuhara