Patents by Inventor Yoshimi Kurahara

Yoshimi Kurahara 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: 9705372
    Abstract: A rotating electric machine includes: a stator including a stator core, slots provided in the stator core at equal intervals along the circumferential direction, and coils placed in the stator slots and configured to generate a rotating magnetic field; and a rotor rotatably provided with a predetermined rotation gap between the stator core and the rotor, wherein the rotating electric machine further includes a first varnish applied between the slots in the stator core and the coils for impregnation, and a second varnish applied directly onto enamel coating of the coils outside of the slots in the axial direction, the first varnish is a thermosetting varnish having a shear bond strength of a flat wire between the coils and the varnish is higher than that of the second varnish, and the second varnish is a thermosetting varnish having a glass transition temperature of approximately 104° C.
    Type: Grant
    Filed: May 21, 2012
    Date of Patent: July 11, 2017
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Yoshimi Kurahara, Koji Obata, Shuya Hagiwara
  • Publication number: 20140183985
    Abstract: A large peeling force due to heat occurs at the boundary between the insulation coating over the coil end and the coil conductor when the stator coil emits heat and reaches a high temperature due to the high output of the rotating electric machine that causes the insulation coating to peel from the conductor consequently causing insulation defects. A sloped surface is formed on the insulation coating so that the thickness of the tip of the insulation coating on the coil end has a shape having a slope that becomes gradually thinner towards the welded coupling section made by welding the conductor.
    Type: Application
    Filed: June 11, 2012
    Publication date: July 3, 2014
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Yoshimi Kurahara, Koji Obata, Shuya Hagiwara
  • Publication number: 20140117805
    Abstract: A rotating machine includes a stator including a stator core having a plurality of slots arrayed in the circumferential direction, a plurality of conductors for stator winding wire inserted respectively into the slots, and slot liners comprising a sheet-shaped insulator surrounding the conductors for stator winding wire; and a rotor rotatably arranged concentrically with the stator. In the rotating machine the slots of which are filled with an electrically insulative resin, concavo-convex is formed on both the top and bottom surfaces of the slot liners.
    Type: Application
    Filed: June 15, 2012
    Publication date: May 1, 2014
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Shuya Hagiwara, Koji Obata, Yoshimi Kurahara
  • Publication number: 20140084713
    Abstract: A rotating electric machine includes: a stator including a stator core, slots provided in the stator core at equal intervals along the circumferential direction, and coils placed in the stator slots and configured to generate a rotating magnetic field; and a rotor rotatably provided with a predetermined rotation gap between the stator core and the rotor, wherein the rotating electric machine further comprising a first varnish applied between the slots in the stator core and the coils for impregnation, and a second varnish applied directly onto enamel coating of the coils outside of the slots in the axial direction, the first varnish is a thermosetting varnish having a shear bond strength of a flat wire between the coils and the varnish is higher than that of the second varnish, and the second varnish is a thermosetting varnish having a glass transition temperature of approximately 104° C.
    Type: Application
    Filed: May 21, 2012
    Publication date: March 27, 2014
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Yoshimi Kurahara, Koji Obata, Shuya Hagiwara
  • Publication number: 20120038230
    Abstract: A rotating electric machine includes: a stator in which a stator coil is mounted to a plurality of slots formed on a stator core; and a rotor that is rotatably disposed inside the stator. A slot groove, having a predetermined depth and a predetermined width from an end face of the stator core and forming a space between the stator coil and the stator core, is formed around each of the plurality of slots. The stator coil includes a straight-shaped straight section which is inserted into the slot and is provided with an insulating material, and a coil end section which extends outside of the slot and is bent at a same height as the end face of the stator core.
    Type: Application
    Filed: November 20, 2009
    Publication date: February 16, 2012
    Inventors: Yoshimi Kurahara, Koji Obata, Shuya Hagiwara, Kazumasa Ide
  • Publication number: 20110184672
    Abstract: Partial discharge occurring in a continuously operated electric machine is monitored all the time. Even when the electric machine is mounted in mobility equipment, the partial discharge is monitored all the time.
    Type: Application
    Filed: January 24, 2011
    Publication date: July 28, 2011
    Inventors: Shuya Hagiwara, Koji Obata, Yoshimi Kurahara, Chie Omatsu
  • Publication number: 20110156504
    Abstract: A motor comprises a rotor having a permanent magnet, a stator core having a stator coil and a frame for accommodating therein the rotor and the stator core. The stator coil has a shape of a concentrated winding being fitted and wound to a tooth of an one-slot core as one slot per one phase in the stator core and has a molded high thermal conductivity resin for covering the stator coil. Both end faces of the stator coil are respectively provided with insulating and heat-transfer layers which are constituted by a part of the molded high thermal conductivity resin, and each of the electric insulating and heat-transfer layers is put in contact with the frame.
    Type: Application
    Filed: December 28, 2010
    Publication date: June 30, 2011
    Inventors: YOSHIMI KURAHARA, KOJI OBATA
  • Patent number: 7804218
    Abstract: When a rotating electrical machine winding is inserted into a slot with a protective insulation intervening between them, a semiconductive insulating layer is lap-wound between an interlayer insulating layer of the rotating electrical machine winding and the protective insulation, the semiconductive insulating layer being formed by center-folding a continuous semiconductive sheet in the longitudinal direction. A thermal stress relaxation layer is provided inside the center-folded continuous semiconductive sheet so that thermal stress exerted in thickness direction of the insulating layers is absorbed.
    Type: Grant
    Filed: November 7, 2007
    Date of Patent: September 28, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Yutaka Higashimura, Yoshimi Kurahara, Hiroshi Miyao, Keiji Suzuki, Mitsuru Onoda, Nobuaki Tanaka
  • Publication number: 20080106157
    Abstract: When a rotating electrical machine winding is inserted into a slot with a protective insulation intervening between them, a semiconductive insulating layer is lap-wound between an interlayer insulating layer of the rotating electrical machine winding and the protective insulation, the semiconductive insulating layer being formed by center-folding a continuous semiconductive sheet in the longitudinal direction. A thermal stress relaxation layer is provided inside the center-folded continuous semiconductive sheet so that thermal stress exerted in thickness direction of the insulating layers is absorbed.
    Type: Application
    Filed: November 7, 2007
    Publication date: May 8, 2008
    Inventors: Yutaka Higashimura, Yoshimi Kurahara, Hiroshi Miyao, Keiji Suzuki, Mitsuru Onoda, Nobuaki Tanaka