Patents by Inventor Matahiro Komuro

Matahiro Komuro 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: 7914695
    Abstract: The object of the present invention is to both reduce costs and improve magnetic characteristics of rare-earth bond magnets in which magnetic material is bound with a binding agent. In order to achieve this object, magnetic characteristics of a magnet are improved by performing cold forming on rare-earth magnetic powder by itself with no resin added. Then, in order to provide strength for the magnet, a low-viscosity SiO2 precursor is infiltrated and thermoset in the magnet shaped body. As a result, it is possible to obtain a rare-earth bond magnet in which magnetic characteristics are improved and costs are reduced.
    Type: Grant
    Filed: March 12, 2007
    Date of Patent: March 29, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Yuichi Satsu, Matahiro Komuro, Takao Imagawa, Takashi Yasuhara, Yutaka Matsunobu
  • Patent number: 7906881
    Abstract: It is desired to design a coreless motor in which a gap size is set to be as small as possible, and a magnet having a large energy product is used in order to increase the gap magnetic flux density since the coreless motor has no iron core so that the magnetic flux density is small in the gap part. A rotor core of the motor has a permanent magnet rotor which is formed by a compression molding means, and which is formed of a compact formed by molding a powder material, the compact comprising a bond magnetic portion mainly composed of a binder and a magnetic powder, and a soft magnetic portion mainly composed of a binder and a soft magnetic powder, the bond magnetic portion having magnetic poles having at least one surface which is mechanically bonded to the soft magnetic portion, in order to solve the inherent problems.
    Type: Grant
    Filed: May 9, 2006
    Date of Patent: March 15, 2011
    Assignees: Hitachi, Ltd., Hitachi Industrial Equipment Systems Co., Ltd., Hitachi Metals, Ltd.
    Inventors: Yuji Enomoto, Motoya Ito, Ryoso Masaki, Koichiro Ohara, Masahiro Mita, Matahiro Komuro, Masahiro Masuzawa
  • Patent number: 7880357
    Abstract: A sintered magnet and a rotating machine equipped therewith are disclosed, which include: crystal grains of a ferromagnetic material consisting mainly of iron, and a fluoride compound or an oxyfluoride compound, containing at least one element selected from the group consisting of an alkali metal element, an alkaline earth metal element, and a rare earth element, the fluoride compound or the oxyfluoride compound being formed inside some of the crystal grains or in a part of a grain boundary part. The oxyfluoride compound or the fluoride compound contains carbon, and a grain boundary width of the ferromagnetic material is smaller than a grain boundary width of the ferromagnetic material in which the fluoride compound or the oxyfluoride compound is formed.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: February 1, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Suzuki, Takao Imagawa, Yuichi Satsu, Matahiro Komuro, Takashi Yasuhara, Yutaka Matsunobu
  • Patent number: 7876012
    Abstract: A dynamoelectric machine comprising a stator having a plurality of slots and teeth, armature windings wound around the teeth, and a rotor disposed inside the stator, wherein an alloy member is disposed in the inner periphery of the stator and the magnetic compensator has its surface or inside thereof a high resistance layer.
    Type: Grant
    Filed: December 20, 2006
    Date of Patent: January 25, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Noriaki Hino
  • Patent number: 7871475
    Abstract: The object of the present invention is to provide a rare earth magnet which enables to achieve a good balance between high coercive force and high residual magnetic flux density, and its manufacturing method. The present invention provides a rare earth magnet in which a layered grain boundary phase is formed on a surface or a potion of a grain boundary of Nd2Fe14B which is a main phase of an R—Fe—B (R is a rare-earth element) based magnet, and wherein the grain boundary phase contains a fluoride compound, and wherein a thickness of the fluoride compound is 10 ?m or less, or a thickness of the fluoride compound is from 0.1 ?m to 10 ?m, and wherein the coverage of the fluoride compound over a main phase particle is 50% or more on average.
    Type: Grant
    Filed: August 3, 2009
    Date of Patent: January 18, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu
  • Patent number: 7862654
    Abstract: A fluoride coating film formed with a fluoride-containing solution wherein a rare earth fluoride or an alkaline earth metal fluoride, in particular, fluoride of Pr, Nd, Dy, Tb and Ho, is swollen in a solvent comprising a major amount of an alcohol, and the solution is a colloidal solution in which the rare earth fluoride or the alkaline earth metal fluoride is dispersed homogeneously in the solvent comprising a major amount of an alcohol improves magnetic properties of NdFeB rare earth magnets including not only sintered magnets but also bonded magnets.
    Type: Grant
    Filed: August 4, 2010
    Date of Patent: January 4, 2011
    Assignee: Hitachi Chemical Company, Ltd.
    Inventors: Yuichi Satsu, Matahiro Komuro, Yoshii Morishita, Shigeaki Funyu, Mitsuo Katayose
  • Patent number: 7847555
    Abstract: A magnet which includes ferromagnetic powder to be mainly a mother phase containing iron or cobalt. The ferromagnetic powder is provided with a high-resistance layer which has a resistance higher than or equal to ten times as high as a resistance of the mother phase and a Vickers hardness lower than a Vickers hardness of the mother phase. The high-resistance layer is being formed partially or entirely on the surface of the ferromagnetic powder.
    Type: Grant
    Filed: March 18, 2008
    Date of Patent: December 7, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Takao Imagawa, Katsumi Ishikawa, Takeyuki Itabashi
  • Publication number: 20100297343
    Abstract: A fluoride coating film formed with a fluoride-containing solution wherein a rare earth fluoride or an alkaline earth metal fluoride, in particular, fluoride of Pr, Nd, Dy, Tb and Ho, is swollen in a solvent comprising a major amount of an alcohol, and the solution is a colloidal solution in which the rare earth fluoride or the alkaline earth metal fluoride is dispersed homogeneously in the solvent comprising a major amount of an alcohol improves magnetic properties of NdFeB rare earth magnets including not only sintered magnets but also bonded magnets.
    Type: Application
    Filed: August 4, 2010
    Publication date: November 25, 2010
    Inventors: Yuichi SATSU, Matahiro KOMURO, Yoshii MORISHITA, Shigeaki FUNYU, Mitsuo KATAYOSE
  • Publication number: 20100289366
    Abstract: The present invention makes it possible to increase the residual magnetic flux density and the coercive force of a rare earth magnet; and raise the Curie temperature. In a magnet formed by compressing magnetic particles, the surface of a magnetic particle is covered with a metal fluoride film, the magnetic particle has a crystal structure containing a homo portion formed by bonding adjacent iron atoms and a hetero portion formed by bonding two iron atoms via an atom other than iron, and the distance between the two iron atoms in the hetero portion is different from the distance between the adjacent iron atoms in the homo portion.
    Type: Application
    Filed: May 11, 2010
    Publication date: November 18, 2010
    Applicant: Hitachi, Ltd.
    Inventors: Matahiro KOMURO, Yuichi SATSU, Hiroyuki SUZUKI
  • Patent number: 7816820
    Abstract: A compacted magnetic core with a high resistance, which comprises compacted magnetic powder of an iron powder or an alloy powder containing iron as a main ingredient and a layer of a rare earth metal fluoride or an alkaline earth metal fluoride on the surface of the powder, wherein the rare earth metal fluoride or the alkaline earth metal fluoride contains fluorine-depleted crystal lattice at a rate of 10% or less.
    Type: Grant
    Filed: October 26, 2007
    Date of Patent: October 19, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Takao Imagawa, Yuichi Satsu, Matahiro Komuro
  • Patent number: 7815726
    Abstract: A fluoride coating film formed with a fluoride-containing solution wherein a rare earth fluoride or an alkaline earth metal fluoride, in particular, fluoride of Pr, Nd, Dy, Tb and Ho, is swollen in a solvent comprising a major amount of an alcohol, and the solution is a colloidal solution in which the rare earth fluoride or the alkaline earth metal fluoride is dispersed homogeneously in the solvent comprising a major amount of an alcohol improves magnetic properties of NdFeB rare earth magnets including not only sintered magnets but also bonded magnets.
    Type: Grant
    Filed: September 27, 2007
    Date of Patent: October 19, 2010
    Assignee: Hitachi Chemical Company, Ltd.
    Inventors: Yuichi Satsu, Matahiro Komuro, Yoshii Morishita, Shigeaki Funyu, Mitsuo Katayose
  • Patent number: 7806991
    Abstract: A lamellar high resistance layer having resistivity ten times or higher than that of a mother phase containing iron or cobalt is formed and an oxygen content is controlled to 10 to 10000 ppm so that the reliability and residual magnetic flux density are increased.
    Type: Grant
    Filed: December 20, 2006
    Date of Patent: October 5, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Takao Imagawa, Katsumi Ishikawa, Takeyuki Itabashi, Yuzo Kozono
  • Patent number: 7800271
    Abstract: The sintered magnet and the rotating machine equipped with the same are disclosed. The sintered magnet includes crystal grains of a ferromagnetic material consisting mainly of iron, and a fluoride compound or oxyfluoride compound layer containing at least one element selected from an alkali metal element, an alkali earth metal element, and a rare earth element. The layer is formed inside some of the crystal grains or in a part of a grain boundary part. An oxyfluoride compound or fluoride compound layer containing carbon in a stratified form is formed on an outermost surface of the crystal grains. The fluoride compound or oxyfluoride compound layer has a concentration gradient of carbon, contains at least one light rare earth element and at least one heavy rare earth element. The heavy rare earth element has a concentration lower than that of the light rare earth element.
    Type: Grant
    Filed: January 28, 2009
    Date of Patent: September 21, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Yutaka Matsunobu, Takashi Yasuhara
  • Publication number: 20100194509
    Abstract: A rare earth magnet having a composition represented by RTB wherein R denotes a rare earth element, T a transition metal and B boron, the magnet being composed of magnet powder constituted by crystalline particles. The particles of the magnetic powder have a ratio of a short diameter being 10 ?m or more to a long diameter is 0.5 or less. An element Rm having a magnetic anisotropy higher than that of the rare earth element is contained in the surface and inside of the magnet constituted by the magnet powder in an approximately constant concentration. An oxy-fluoride and carbon are present at boundaries of the particles of the magnet powder.
    Type: Application
    Filed: January 29, 2010
    Publication date: August 5, 2010
    Inventors: Hiroyuki SUZUKI, Takao Imagawa, Yuichi Satsu, Matahiro Komuro
  • Publication number: 20100141367
    Abstract: A magnet comprising grains of a ferromagnetic material whose main component is iron and a fluorine compound layer or an oxy-fluorine compound layer of fluoride compound particles of alkali metals, alkaline earth metals and rare earth elements, present on the surface of the ferromagnetic material grains, wherein an amount of iron atoms in the fluorine compound particles is 1 to 50 atomic %.
    Type: Application
    Filed: February 19, 2010
    Publication date: June 10, 2010
    Inventors: Matahiro Komuro, Yuichi Satsu, Takao Imagawa
  • Patent number: 7696662
    Abstract: A magnet comprising grains of a ferromagnetic material whose main component is iron and a fluorine compound layer or an oxy-fluorine compound layer of fluoride compound particles of alkali metals, alkaline earth metals and rare earth elements, present on the surface of the ferromagnetic material grains, wherein an amount of iron atoms in the fluorine compound particles is 1 to 50 atomic %.
    Type: Grant
    Filed: August 14, 2007
    Date of Patent: April 13, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Takao Imagawa
  • Publication number: 20100079024
    Abstract: A rotating machine is equipped with a sintered magnet. The sintered magnet includes: a ferromagnetic material consisting mainly of iron; a layer of a fluoride compound or a layer of an oxyfluoride compound formed inside crystal grains or in a portion of grain boundary area of the ferromagnetic material; at least one element selected from the group consisting of alkalis, alkaline earth elements, and rare earth elements and carbon contained in the layer of the fluoride compound or the layer of the oxyfluoride compound; and a continuously extending layer formed by a portion of the layer of the fluoride compound or the layer of the oxyfluoride layer, the continuously extending layer extending from a surface of the ferromagnetic material through the inside of the ferromagnetic material to an opposite side surface of the ferromagnetic material.
    Type: Application
    Filed: July 27, 2009
    Publication date: April 1, 2010
    Applicant: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Yoshii Morishita, Shigeaki Funyu, Mitsuo Katayose
  • Publication number: 20100079025
    Abstract: A sintered magnet and a rotating machine equipped therewith are disclosed, which include: crystal grains of a ferromagnetic material consisting mainly of iron, and a fluoride compound or an oxyfluoride compound, containing at least one element selected from the group consisting of an alkali metal element, an alkaline earth metal element, and a rare earth element, the fluoride compound or the oxyfluoride compound being formed inside some of the crystal grains or in a part of a grain boundary part. The oxyfluoride compound or the fluoride compound contains carbon, and a grain boundary width of the ferromagnetic material is smaller than a grain boundary width of the ferromagnetic material in which the fluoride compound or the oxyfluoride compound is formed.
    Type: Application
    Filed: August 18, 2009
    Publication date: April 1, 2010
    Applicant: Hitachi, Ltd
    Inventors: Hiroyuki Suzuki, Takao Imagawa, Yuichi Satsu, Matahiro Komuro, Takashi Yasuhara, Yutaka Matsunobu
  • Publication number: 20100007232
    Abstract: Disclosed herein is a sintered magnet motor having a sintered magnet rotor, the rotor comprising: a ferromagnetic material comprising iron as a main ingredient to be sintered; a fluorine compound or an oxyfluoride compound formed in the inside of a crystal grain or to a portion of a grain boundary of the ferromagnetic material; and at least one of alkalis, alkaline earth elements, and rare earth elements contained in the fluorine compound or the oxyfluoride compound; a portion of the fluorine compound or the oxyfluoride compound being distributed with a concentration gradient established from the surface to the inside of the ferromagnetic material, and a rare earth element being distributed with a concentration gradient established between the grain boundary surface and the parent phase of the ferromagnetic material, wherein the concentration distribution of the fluorine compound is asymmetrical when viewed from the pole center of the sintered magnet rotor.
    Type: Application
    Filed: May 26, 2009
    Publication date: January 14, 2010
    Applicant: Hitachi Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Yutaka Matsunobu, Takashi Yasuhara
  • Publication number: 20090224615
    Abstract: The sintered magnet and the rotating machine equipped with the same are disclosed. The sintered magnet includes crystal grains of a ferromagnetic material consisting mainly of iron, and a fluoride compound or oxyfluoride compound layer containing at least one element selected from an alkali metal element, an alkali earth metal element, and a rare earth element. The layer is formed inside some of the crystal grains or in a part of a grain boundary part. An oxyfluoride compound or fluoride compound layer containing carbon in a stratified form is formed on an outermost surface of the crystal grains. The fluoride compound or oxyfluoride compound layer has a concentration gradient of carbon, contains at least one light rare earth element and at least one heavy rare earth element. The heavy rare earth element has a concentration lower than that of the light rare earth element.
    Type: Application
    Filed: January 28, 2009
    Publication date: September 10, 2009
    Applicant: Hitachi, Ltd.
    Inventors: Matahiro KOMURO, Yuichi SATSU, Yutaka MATSUNOBU, Takashi YASUHARA