Patents by Inventor Masaaki Takezawa

Masaaki Takezawa 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: 20240047104
    Abstract: A permanent magnet having excellent magnetic properties and a device including such a permanent magnet are provided. A permanent magnet consists of a sintered compact having a composition consisting of R: 23 to 27 wt % (R is a sum total of rare-earth elements including at least Sm), Fe: 22 to 27 wt %, Mn: 0.3 to 2.5 wt %, Cu: 4.0 to 5.0 wt %, and a remainder consisting of Co and unavoidable impurities, in which the sintered compact contains a plurality of crystal grains and grain boundary phases, and a concentration of Cu in at least a part of the grain boundary phases is 45 at % or higher.
    Type: Application
    Filed: July 18, 2023
    Publication date: February 8, 2024
    Inventors: Masaaki TAKEZAWA, Hiroaki MACHIDA, Teruhiko FUJIWARA, Hirokazu MAKUTA
  • Patent number: 11380465
    Abstract: A rare-earth cobalt permanent magnet with good magnetic properties is provided. A rare-earth cobalt permanent magnet contains 23 to 27 mass % R, 3.5 to 5.0 mass % Cu, 18 to 25 mass % Fe, 1.5 to 3.0 mass % Zr in mass and a remainder Co with inevitable impurities, where an element R is a rare earth element at least containing Sm. The rare-earth cobalt permanent magnet has a metal structure including a plurality of crystal grains and a continuously extending grain boundary. A content of Cu in the grain boundary is higher than a content of Cu in the crystal grains, and a content of Zr in the grain boundary is higher than a content of Zr in the crystal grains.
    Type: Grant
    Filed: October 7, 2016
    Date of Patent: July 5, 2022
    Assignees: KYUSHU INSTITUTE OF TECHNOLOGY, TOKIN Corporation
    Inventors: Masaaki Takezawa, Teruhiko Fujiwara, Hiroaki Machida, Hideyuki Yoshikawa
  • Publication number: 20200365301
    Abstract: A rare-earth cobalt permanent magnet according to the present disclosure comprises: 24 to 26 mass % of a rare-earth element R including Sm; 25 to 27 mass % of Fe; 4.0 to 7.0 mass % of Cu; 2.0 to 3.5 mass % of Zr; and Co and an unavoidable impurity as a remainder. The rare-earth element R is any one of a combination of Sm and Nd, a combination of Sm and Pr, or a combination of Sm, Nd, and Pr. The rare-earth cobalt permanent magnet includes a cell phase that includes a crystalline phase of a Th2Zn17 structure and a cell wall that includes a crystalline phase of an RCo5 structure enclosing the cell phase, and the concentration of the rare-earth element R in the cell wall is higher than the concentration of the rare-earth element R in the cell phase by no less than 25 atomic %.
    Type: Application
    Filed: May 14, 2020
    Publication date: November 19, 2020
    Inventors: Masaaki TAKEZAWA, Hiroaki MACHIDA, Teruhiko FUJIWARA, Yu KANAMORI
  • Publication number: 20200243232
    Abstract: A rare-earth cobalt permanent magnet with good magnetic properties is provided. A rare-earth cobalt permanent magnet contains 23 to 27 mass % R, 3.5 to 5.0 mass % Cu, 18 to 25 mass % Fe, 1.5 to 3.0 mass % Zr in mass and a remainder Co with inevitable impurities, where an element R is a rare earth element at least containing Sm. The rare-earth cobalt permanent magnet has a metal structure including a plurality of crystal grains and a continuously extending grain boundary. A content of Cu in the grain boundary is higher than a content of Cu in the crystal grains, and a content of Zr in the grain boundary is higher than a content of Zr in the crystal grains.
    Type: Application
    Filed: October 7, 2016
    Publication date: July 30, 2020
    Inventors: Masaaki TAKEZAWA, Teruhiko FUJIWARA, Hiroaki MACHIDA, Hideyuki YOSHIKAWA
  • Publication number: 20070122297
    Abstract: An object is to solve a problem that the smaller the number of rotations of a rotary compressor is, the more an efficiency decrease of the compressor is generated owing to an increase of a rotary vibration and an efficiency decrease of a motor. In the rotary compressor including, in a sealed vessel, a electromotive element and a rotary compression element driven by this electromotive element, on one of an upper end face of a rotor constituting the electromotive element (on a side opposite to a compression mechanism) and a lower end face of the rotor (on a compression mechanism side), a rotation inertia article capable of obtaining a rotation inertia moment is disposed. In consequence, it is possible to obtain the compressor having a high efficiency in which an increase of the rotary vibration of the compressor is suppressed even during an operation having the small number of the rotations of the compressor.
    Type: Application
    Filed: November 27, 2006
    Publication date: May 31, 2007
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Kazuya Sato, Masaaki Takezawa
  • Patent number: 7102264
    Abstract: A synchronous induction motor features improved assemblability of a rotor, significantly reduced production cost, and improved operation performance of the motor. A plurality of die-cast secondary conductors is provided around a rotor yoke constituting the rotor of the synchronous induction motor. End rings are die-cast integrally with the secondary conductors on the peripheral portions of both end surfaces of the rotor yoke. Permanent magnets are inserted into slots formed such that they penetrate the rotor yoke. The openings of both ends of the slots are closed by a pair of end surface members formed of a non-magnetic constituent. One of the end surface members is secured to the rotor yoke by one of the end rings when the secondary conductors and the end rings are formed. The other end surface member is secured to the rotor yoke by a fixture.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: September 5, 2006
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Toshihito Yanashima, Keijiro Igarashi, Masaaki Takezawa, Kazuhiko Arai, Eiichi Murata, Noboru Onodera, Shigemi Koiso, Kazuhiro Enomoto, Yoshitomo Nakayama
  • Publication number: 20050253474
    Abstract: A synchronous induction motor features improved assemblability of a rotor, significantly reduced production cost, and improved operation performance of the motor. A plurality of die-cast secondary conductors is provided around a rotor yoke constituting the rotor of the synchronous induction motor. End rings are die-cast integrally with the secondary conductors on the peripheral portions of both end surfaces of the rotor yoke. Permanent magnets are inserted into slots formed such that they penetrate the rotor yoke. The openings of both ends of the slots are closed by a pair of end surface members formed of a non-magnetic constituent. One of the end surface members is secured to the rotor yoke by one of the end rings when the secondary conductors and the end rings are formed. The other end surface member is secured to the rotor yoke by a fixture.
    Type: Application
    Filed: July 29, 2004
    Publication date: November 17, 2005
    Inventors: Toshihito Yanashima, Keijiro Igarashi, Masaaki Takezawa, Kazuhiko Arai, Eiichi Murata, Noboru Onodera, Shigemi Koiso, Kazuhiro Enomoto, Yoshitomo Nakayama
  • Patent number: 6873081
    Abstract: A concentrated winding type brushless DC motor has a stator formed by a slack of laminations of a ferro-magnetic material having an outer ring from which a plurality of spaced teeth extend inwardly and have slots between adjacent teeth. A drive coil is wound around each tooth in the presence of a spacer provided between an end surface of a stator tooth and the drive coil to reduce stress applied to a tooth by the coil as it is being wound. The final form of the motor has the spacer removed leaving a space between the coil and the tooth to form a magnetic pole of the stator.
    Type: Grant
    Filed: May 13, 2002
    Date of Patent: March 29, 2005
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Kazuhiko Arai, Keijiro Igarashi, Masaaki Takezawa
  • Patent number: 6737783
    Abstract: A sealed motor compressor in which a motor running efficiency is largely enhanced with a single-phase bipolar constitution, an electromotive element is fixed to a sealed container, and formed of a stator provided with a stator winding, and a rotor which rotates in the stator, and the rotor is formed of a squirrel-cage secondary conductor disposed in a peripheral portion of a rotor yoke, and a permanent magnet is embedded in the rotor yoke.
    Type: Grant
    Filed: March 27, 2001
    Date of Patent: May 18, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Toshihito Yanashima, Yoshitomo Nakayama, Masaaki Takezawa, Shigemi Koiso, Kazuhiko Arai, Keijiro Igarashi
  • Publication number: 20040084984
    Abstract: A synchronous induction motor features improved assemblability of a rotor, significantly reduced production cost, and improved operation performance of the motor. A plurality of die-cast secondary conductors is provided around a rotor yoke constituting the rotor of the synchronous induction motor. End rings are die-cast integrally with the secondary conductors on the peripheral portions of both end surfaces of the rotor yoke. Permanent magnets are inserted into slots formed such that they penetrate the rotor yoke. The openings of both ends of the slots are closed by a pair of end surface members formed of a non-magnetic constituent. One of the end surface members is secured to the rotor yoke by one of the end rings when the secondary conductors and the end rings are formed. The other end surface member is secured to the rotor yoke by a fixture.
    Type: Application
    Filed: October 27, 2003
    Publication date: May 6, 2004
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Toshihito Yanashima, Keijiro Igarashi, Masaaki Takezawa, Kazuhiko Arai, Eiichi Murata, Noboru Onodera, Shigemi Koiso, Kazuhiro Enomoto, Yoshitomo Nakayama
  • Patent number: 6703748
    Abstract: A stator core for a concentrated winding type brushless DC motor that has a plurality of spaced teeth extending inwardly of the core outer diameter to a core inner diameter to define slots between two adjacent teeth for a winding. Each tooth has right and left distal ends projecting in opposite directions transverse to the tooth with the opposite distal ends of two adjacent teeth each being linear and defining an aperture into a slot between the two teeth. The distal end of each tooth also has an angled edge at the side facing the core outer diameter so that the distal end is wider at the aperture than at the point where the distal end extends from the tooth. Also, there is a distance T between a line connnecting the end points of the right and left distal ends of a tooth facing the core outer diameter at the aperture defined by each said distal end and a tangent line at an inner core diameter of the tooth and such that T≧0.
    Type: Grant
    Filed: May 13, 2002
    Date of Patent: March 9, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Kazuhiko Arai, Keijiro Igarashi, Masaaki Takezawa
  • Patent number: 6700270
    Abstract: A synchronous induction motor realizing a great reluctance torque by concentrating a magnetomotive force generated by a rotor provided with a permanent magnet having a two-pole structure, and having a high efficiency. The synchronous induction motor has a stator provided with a stator winding, a rotor rotating within the stator, a cage-type secondary electric conductor provided in a peripheral portion of a rotor yoke portion constituting the rotor, and a permanent magnet inserted into the rotor yoke portion and having a two-pole structure, and the magnetomotive force generated by one pole of the rotor is set to a value equal to or less than 10% of a peak value in a predetermined range near an electrical angle of 0 degrees or 180 degrees.
    Type: Grant
    Filed: December 5, 2001
    Date of Patent: March 2, 2004
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Toshihito Yanashima, Kazuhiko Arai, Masaaki Takezawa, Keijiro Igarashi, Eiichi Murata, Masanori Yamashita, Yoshitomo Nakayama, Shigemi Koiso, Noboru Onodera
  • Patent number: 6582207
    Abstract: An objective of the present invention is to provide a motor compressor that reduces noise by lessening a contact area between a stator and a shell, wherein a motor element is constituted of a stator having a stator core that contacts and is fixed to an internal wall of the closed vessel, and a rotator having a magnetic substance, which is attached to the rotating shaft and is rotatably supported in the inside of the stator construct. It is essential that H<Ho is satisfied wherein H is a dimension in a rotating shaft direction of an area in which the stator core contacts the closed vessel and Ho is a dimension in a rotating shaft direction of the stator core.
    Type: Grant
    Filed: May 24, 2001
    Date of Patent: June 24, 2003
    Assignee: Sanyo Electric Co., LTD
    Inventors: Kenzo Matsumoto, Manabu Takenaka, Tsuyoshi Higuchi, Kazuaki Fujiwara, Keijiro Igarashi, Masaaki Takezawa, Kazuhiko Arai
  • Publication number: 20020140307
    Abstract: An object of the invention is to provide a synchronous induction motor realizing a great reluctance torque by concentrating a magnetomotive force generated by a rotor provided with a permanent magnet having a two-pole structure, and having a high efficiency. The synchronous induction motor has a stator provided with a stator winding, a rotor rotating within the stator, a cage-type secondary electric conductor provided in a peripheral portion of a rotor yoke portion constituting the rotor, and a permanent magnet inserted into the rotor yoke portion and having a two-pole structure, and the magnetomotive force generated by one pole of the rotor is set to a value equal to or less than 10% of a peak value in a predetermined range near an electrical angle 0 degree or 180 degrees.
    Type: Application
    Filed: December 5, 2001
    Publication date: October 3, 2002
    Inventors: Toshihito Yanashima, Kazuhiko Arai, Masaaki Takezawa, Keijiro Igarashi, Eiichi Murata, Masanori Yamashita, Yoshitomo Nakayama, Shigemi Koiso, Noboru Onodera
  • Publication number: 20020140309
    Abstract: A synchronous induction motor features improved assemblability of a rotor, significantly reduced production cost, and improved operation performance of the motor. A plurality of die-cast secondary conductors is provided around a rotor yoke constituting the rotor of the synchronous induction motor. End rings are die-cast integrally with the secondary conductors on the peripheral portions of both end surfaces of the rotor yoke. Permanent magnets are inserted into slots formed such that they penetrate the rotor yoke. The openings of both ends of the slots are closed by a pair of end surface members formed of a non-magnetic constituent. One of the end surface members is secured to the rotor yoke by one of the end rings when the secondary conductors and the end rings are formed. The other end surface member is secured to the rotor yoke by a fixture.
    Type: Application
    Filed: March 28, 2002
    Publication date: October 3, 2002
    Applicant: SANYO ELECTRIC CO., LTD.
    Inventors: Toshihito Yanashima, Keijiro Igarashi, Masaaki Takezawa, Kazuhiko Arai, Eiichi Murata, Noboru Onodera, Shigemi Koiso, Kazuhiro Enomoto, Yoshitomo Nakayama
  • Publication number: 20020130580
    Abstract: A brushless DC motor minimizes a chance of dislocation of or damage to an insulator used in the brushless DC motor. Slant portions are provided at end portions of the insulator; therefore, even if a nozzle of a machine for installing a winding should hit the insulator while moving between teeth, the insulator moves in a direction for coming in close contact with a slot aperture, i.e., in a direction substantially at right angles to a direction in which the nozzle moves. This arrangement prevents the insulator from moving by being pushed by the nozzle, making it possible to minimize a chance of occurrence of an insulation failure caused by a damaged or dislocated insulator.
    Type: Application
    Filed: May 13, 2002
    Publication date: September 19, 2002
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Kazuhiko Arai, Keijiro Igarashi, Masaaki Takezawa
  • Publication number: 20020130581
    Abstract: A brushless DC motor minimizes a chance of dislocation of or damage to an insulator used in the brushless DC motor. Slant portions are provided at end portions of the insulator; therefore, even if a nozzle of a machine for installing a winding should hit the insulator while moving between teeth, the insulator moves in a direction for coming in close contact with a slot aperture, i.e., in a direction substantially at right angles to a direction in which the nozzle moves. This arrangement prevents the insulator from moving by being pushed by the nozzle, making it possible to minimize a chance of occurrence of an insulation failure caused by a damaged or dislocated insulator.
    Type: Application
    Filed: May 13, 2002
    Publication date: September 19, 2002
    Applicant: Sanyo Electric Co., Ltd.
    Inventors: Kazuhiko Arai, Keijiro Igarashi, Masaaki Takezawa
  • Patent number: 6414413
    Abstract: A brushless DC motor minimizes a chance of dislocation of or damage to an insulator used in the brushless DC motor. Slant portions are provided at end portions of the insulator; therefore, even if a nozzle of a machine for installing a winding should hit the insulator while moving between teeth, the insulator moves in a direction for coming in close contact with a slot aperture, i.e., in a direction substantially at right angles to a direction in which the nozzle moves. This arrangement prevents the insulator from moving by being pushed by the nozzle, making it possible to minimize a chance of occurrence of an insulation failure caused by a damaged or dislocated insulator.
    Type: Grant
    Filed: June 28, 2000
    Date of Patent: July 2, 2002
    Assignee: Sanyo Electric. Co,. Ltd.
    Inventors: Kazuhiko Arai, Keijiro Igarashi, Masaaki Takezawa
  • Publication number: 20020051715
    Abstract: An objective of the present invention is to provide a motor compressor that reduces noise by lessening a contact area between a stator and a shell, wherein a motor element is constituted of a stator having a stator core that contacts and is fixed to an internal wall of the closed vessel, and a rotator having a magnetic substance, which is attached to the rotating shaft and is rotatably supported in the inside of the stator construct. It is essential that H<Ho is satisfied wherein H is a dimension in a rotating shaft direction of an area in which the stator core contacts the closed vessel and Ho is a dimension in a rotating shaft direction of the stator core.
    Type: Application
    Filed: May 24, 2001
    Publication date: May 2, 2002
    Inventors: Kenzo Matsumoto, Manabu Takenaka, Tsuyoshi Higuchi, Kazuaki Fujiwara, Keijiro Igarashi, Masaaki Takezawa, Kazuhiko Arai
  • Publication number: 20010050541
    Abstract: There is disclosed a sealed motor compressor in which a motor running efficiency is largely enhanced with a single-phase bipolar constitution, an electromotive element is fixed to a sealed container, and constituted of a stator provided with a stator winding, and a rotor which rotates in the stator, and the rotor is constituted of a squirrel-cage secondary conductor disposed in a peripheral portion of a rotor yoke, and a permanent magnet embedded in the rotor yoke.
    Type: Application
    Filed: March 27, 2001
    Publication date: December 13, 2001
    Inventors: Toshihito Yanashima, Yoshitomo Nakayama, Masaaki Takezawa, Shigemi Koiso, Kazuhiko Arai, Keijiro Igarashi