Patents by Inventor Keijiro Igarashi

Keijiro Igarashi 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: 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
  • Patent number: 6147428
    Abstract: It is an object to provide a rotor of an electric motor in which an adverse influence due to through holes for caulking and fixing is reduced, and moreover, the number of parts is small and an assembling operation is simple, so that high characteristics can be obtained, which is constructed by: a rotor core constructed by laminating a plurality of iron plates for the rotor; at least two slots which are formed in the rotor core along the axial direction of a rotation axis; and at least four flat permanent magnets which are inserted to the slots, and in which as the permanent magnets, each pair of magnets which face each other between adjacent magnetic poles are arranged in parallel at predetermined intervals so as to sandwich a normal line of the rotor. In addition, the permanent magnet rotor is made to satisfy the condition: L/D being between 0.3 and 1.2 and t/I being between 0.02 and 0.
    Type: Grant
    Filed: April 14, 1998
    Date of Patent: November 14, 2000
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Nasaaju Takezawa, Masaharu Uchibori, Keijiro Igarashi, Kazuhiko Arai
  • Patent number: 5666015
    Abstract: A rotor of an electric motor for a compressor which can prevent the generation of an eddy current, reduce the flux leakage between adjacent magnetic poles, thereby enhancing the operation efficiency of the motor and reducing the size of the compressor. A first end surface member formed from a nonmagnetic material, a second end surface member formed from a nonmagnetic member and a rotor core are integrally caulked by a caulking member. The rotor core is provided with a gap for preventing the short circuit of the magnetic flux caused between adjacent magnetic poles. The gap communicates with a through hole into which the caulking member is inserted.
    Type: Grant
    Filed: April 21, 1994
    Date of Patent: September 9, 1997
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Masaharu Uchibori, Keijiro Igarashi, Tomonori Kinoshita, Takashi Miyauchi, Kazuhiko Arai