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: 8358040
    Abstract: A permanent magnet type electric rotating machine having a high resistance permanent magnet used for the electric rotating machine, the permanent magnet containing a magnetic powder and a fluorine compound, in which the current waveform is controlled for reducing the loss to satisfy a relation: A<C<B and restrict the 7th higher-harmonic component to 20% or less where A is the content for the 5th higher harmonic component, B is the content for the 7th higher harmonic component, and C is the content for the 11th higher harmonic component, assuming the total of contents for the fundamental components of a current supplied to the findings being 100%.
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: January 22, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Haruo Koharagi, Yuji Enomoto
  • Patent number: 8350430
    Abstract: An R—Fe—B sintered magnet has a structure including main phase crystal grains and a grain boundary area surrounding the crystal grains. The sintered magnet includes fluorine and a specified metal element selected from elements belonging to Group 2 through Group 16 of periodic table excepting the rare earth element, carbon and boron. The fluorine has a higher concentration in a region closer to a magnet surface than in the center. The specified element also has a higher concentration in the region closer to the surface. The sintered magnet includes oxyfluoride containing carbon, Dy and the metal element in a grain boundary area region at a distance of 1 ?m or greater from the magnet surface, and the carbon has a higher concentration than the concentration of the metal element in a region at a distance of 1 ?m to 500 ?m from the magnet surface.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: January 8, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Yoshii Morishita, Shigeaki Funyu, Mitsuo Katayose
  • Patent number: 8303732
    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: Grant
    Filed: January 29, 2010
    Date of Patent: November 6, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Suzuki, Takao Imagawa, Yuichi Satsu, Matahiro Komuro
  • Publication number: 20120205573
    Abstract: An R—Fe—B sintered magnet has a structure including main phase crystal grains and a grain boundary area surrounding the crystal grains. The sintered magnet includes fluorine and a specified metal element selected from elements belonging to Group 2 through Group 16 of periodic table excepting the rare earth element, carbon and boron. The fluorine has a higher concentration in a region closer to a magnet surface than in the center. The specified element also has a higher concentration in the region closer to the surface. The sintered magnet includes oxyfluoride containing carbon, Dy and the metal element in a grain boundary area region at a distance of 1 ?m or greater from the magnet surface, and the carbon has a higher concentration than the concentration of the metal element in a region at a distance of 1 ?m to 500 ?m from the magnet surface.
    Type: Application
    Filed: April 23, 2012
    Publication date: August 16, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Matahiro KOMURO, Yuichi Satsu, Yoshii Morishita, Shigeaki Funyu, Mitsuo Katayose
  • Patent number: 8226779
    Abstract: A manufacturing method of a magnetic core includes a first step of applying a treatment liquid for forming an insulating film to iron powder; a second step of heat-treating the iron powder to which the treatment liquid has been applied, at a temperature higher than 350 degrees; a third step of compacting the heat-treated iron powder to form a magnetic core; and a forth step of heat-treating the magnetic core at a temperature ranging from 600 degrees to 800 degrees.
    Type: Grant
    Filed: April 9, 2008
    Date of Patent: July 24, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Takao Imagawa, Yuichi Satsu, Matahiro Komuro, Hiroyuki Suzuki
  • Patent number: 8222785
    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: June 27, 2011
    Date of Patent: July 17, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Takao Imagawa
  • Publication number: 20120175986
    Abstract: In a ferromagnetic material containing at least one kind of rare-earth element, a layer containing at least one kind of alkaline earth element or rare-earth element and fluorine is formed at the grain boundary or near the powder surface of the ferromagnetic material. A further layer containing at least one kind of rare-earth element, having a fluorine concentration lower than that of the layer described first and having a rare-earth element concentration higher than that of the host phase of the ferromagnetic material, or an oxide layer containing a rare-earth element is formed in adjacent with a portion of the layer described first.
    Type: Application
    Filed: January 10, 2012
    Publication date: July 12, 2012
    Inventors: Matahiro Komuro, Yuichi Satsu, Kunihiro Maeda, Yuzo Kozono
  • Publication number: 20120145944
    Abstract: Disclosed is a magnetic material in which 50% by volume of the magnetic particles are accounted for by the main phase of the magnet, the main phase having a Curie temperature (Curie point) of 200° C. or higher, a saturation magnetic-flux density at around 20° C. of 1.0 T (tesla) or higher, and a coercive force of 10 kOe or higher, the crystal structure of the main phase being stable up to 200° C., and in which phases other than the main phase which are present at the grain boundaries or grain surfaces have stabilized or improved the magnetic properties. This magnetic material comprises two ferromagnetic phases, i.e., a ferromagnetic compound which is composed of fluorine, iron, and one or more rare-earth elements including yttrium and ferromagnetic iron which contains fluorine, carbon, nitrogen, hydrogen, or boron. A fluoride and an oxyfluoride have been formed at some of the boundaries or surfaces of the grains of the ferromagnetic phases.
    Type: Application
    Filed: August 11, 2010
    Publication date: June 14, 2012
    Inventors: Matahiro Komuro, Yuichi Satsu, Hiroyuki Suzuki
  • Publication number: 20120111232
    Abstract: A conventional method for forming an insulating film on a magnet has a difficulty in achieving sufficient improvement in magnetic characteristics due to nonuniformity of a coating film, and an extended time and higher temperature which are required in a thermal treatment. In order to solve the problems, the present invention provides a treating solution composed of an alcohol based solvent and a rare earth fluoride or alkaline earth metal fluoride dispersing in the solvent. In the treating solution, at least one X-ray diffraction peak has a half-value width larger than 1°. The present invention also provides a method for forming an insulating film using the treating solution.
    Type: Application
    Filed: January 17, 2012
    Publication date: May 10, 2012
    Inventors: Matahiro Komuro, Yuichi Satsu, Yoshii Morishita, Shigeaki Funyu, Mitsuo Katayose
  • Patent number: 8119260
    Abstract: In a ferromagnetic material containing at least one kind of rare-earth element, a layer containing at least one kind of alkaline earth element or rare-earth element and fluorine is formed at the grain boundary or near the powder surface of the ferromagnetic material. A further layer containing at least one kind of rare-earth element, having a fluorine concentration lower than that of the layer described first and having a rare-earth element concentration higher than that of the host phase of the ferromagnetic material, or an oxide layer containing a rare-earth element is formed in adjacent with a portion of the layer described first.
    Type: Grant
    Filed: July 27, 2005
    Date of Patent: February 21, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Kunihiro Maeda, Yuzo Kozono
  • Publication number: 20120025651
    Abstract: A sintered magnet according to the present invention is a sintered magnet configured from a magnetic powder grain having Nd2Fe14B as a main component, in which: fluorine, a heavy rare earth element, oxygen, and carbon are segregated in part of grain-boundary regions of said sintered magnetic powder grain; concentration of the carbon is higher than concentration of the fluorine at a grain-boundary triple junction of the grain-boundary region; and concentration of the heavy rare earth element decreases from said grain-boundary triple junction toward an inside of said magnetic powder grain.
    Type: Application
    Filed: February 18, 2010
    Publication date: February 2, 2012
    Inventors: Matahiro Komuro, Yuichi Satsu, Hiroyuki Suzuki, Takao Imagawa
  • Patent number: 8084128
    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 portion 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: December 9, 2010
    Date of Patent: December 27, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu
  • Publication number: 20110254646
    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: June 27, 2011
    Publication date: October 20, 2011
    Inventors: Matahiro KOMURO, Yuichi Satsu, Takao Imagawa
  • Publication number: 20110240909
    Abstract: Characteristics of a magnetic material are improved without using a heavy rare earth element as a scarce resource. By incorporating fluorine into a magnetic powder and controlling the crystal orientation in crystal grains, a magnetic material securing magnetic characteristics such as coercive force and residual flux density can be fabricated. As a result, the resource problem with heavy rare earth elements can be solved, and the magnetic material can be applied to magnetic circuits that require a high energy product, including various rotating machines and voice coil motors of hard discs.
    Type: Application
    Filed: February 17, 2011
    Publication date: October 6, 2011
    Inventors: Takayuki KANDA, Matahiro Komuro, Hiroyuki Suzuki, Yuichi Satsu
  • Patent number: 7972450
    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: February 19, 2010
    Date of Patent: July 5, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Takao Imagawa
  • Publication number: 20110133112
    Abstract: A ferromagnetic compound magnet in accordance with the present invention includes a ferromagnetic compound based on a binary alloy containing R—Fe system (R is a 4f transition element or Y) or a ternary allay containing R—Fe-T system (R is a 4f transition element or Y, and T is a 3d transition element except for Fe, or Mo, Nb or W), the ferromagnetic compound being characterized by: atomic percentage of the element R to the element Fe or to the elements Fe and T is 15% or lower; an element F is incorporated into an interstitial position in a crystal lattice of the alloy. The ferromagnetic compound is expressed in a chemical formula of: R2Fe17Fx; R2(Fe,T)17Fx; R3Fe29Fy; R3(Fe,T)29Fy; RFe12Fz; or R(Fe,T)12Fz (0<x?3, 0<y?4, 0<z?1).
    Type: Application
    Filed: November 30, 2010
    Publication date: June 9, 2011
    Inventors: Hiroyuki SUZUKI, Matahiro Komuro, Yuichi Satsu, Takao Imagawa
  • Patent number: 7927501
    Abstract: A magnet comprising magnetic powder containing at least one rare earth metal element, and an oxide binder for binding the magnetic powder, wherein an inter-face distance of the binder determined by diffraction analysis is 0.25 to 2.94 nm. The disclosure also discloses a method of manufacturing a magnet comprising; compacting magnetic powder containing at least one rare earth element under pressure in a mold; impregnating the compacted magnetic powder molding with a precursor solution of an oxide material; and heat-treating the compacted magnetic molding impregnated with the precursor thereby to impart an inter-face distance determined by diffraction analysis to the binder in the compacted molding. The distance is 0.25 to 2.94 nm.
    Type: Grant
    Filed: November 20, 2007
    Date of Patent: April 19, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Takao Imagawa, Hiroyuki Suzuki
  • Publication number: 20110079327
    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 portion 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: Application
    Filed: December 9, 2010
    Publication date: April 7, 2011
    Inventors: Matahiro KOMURO, Yuichi Satsu
  • 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