Patents by Inventor Hidetoshi Koka

Hidetoshi Koka 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: 9917487
    Abstract: A rotating electric machine allowing a rotor and a stator thereof to assume any of various numbers of poles and any of various numbers of slots and enabling a reduction in vibration and noise is provided. The rotating electric machine according to the present invention includes a stator having a plurality of teeth and a plurality of slots, which is configured so that the shape of the front ends of the teeth and the opening width of the slots are made to change cyclically F times along the circumferential direction (F is a natural number equal to or greater than 2).
    Type: Grant
    Filed: January 22, 2014
    Date of Patent: March 13, 2018
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Kanako Nemoto, Hidetoshi Koka, Yutaka Matsunobu, Yasuyuki Saito
  • Patent number: 9748806
    Abstract: A permanent magnet rotating electrical machine includes a rotor which has permanent magnets buried in a plurality of permanent magnet insertion slots that are provided in a rotor core, and the rotor is rotatably supported by a rotary shaft with a gap on the inner peripheral side of a stator. When the axis of magnetic flux for the permanent magnet is set as a d-axis and the position deviated from the d-axis by electrical angle of 90° is set as a q-axis, the permanent magnet insertion slot is located on the q-axis and a first permanent magnet magnetized in the direction orthogonal to the q-axis is buried in the permanent magnet insertion slot. The permanent magnet insertion slot is located on the d-axis and a second permanent magnet magnetized in the direction parallel to the d-axis is buried in the permanent magnet insertion slot, while at least one or more third permanent magnets buried in the permanent magnet insertion slots are provided between the first permanent magnet and the second permanent magnet.
    Type: Grant
    Filed: March 25, 2013
    Date of Patent: August 29, 2017
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Hidetoshi Koka, Satoshi Kikuchi, Yutaka Matsunobu, Yasuyuki Saito, Sadahiro Hamahata
  • Patent number: 9692261
    Abstract: Provided is a rotating electric machine including a rotor and stator fitted with various numbers of poles and slots and adapted to reduce vibration/noise of the machine. The rotating electric machine in accordance with an aspect of the present invention includes a stator having an S number of teeth, and a rotor disposed in the stator with a gap intervening between the stator and the rotor. The plurality of teeth in the stator are grouped in units of the number of teeth that is equal to a value “m” or a value “d”, the value “m” being obtained by dividing the number of stator slots, S, by the greatest common divisor N of the number of poles, P, and the number of stator slots, S, the value “d” being an aliquot of “m”. At least one tooth in each of the tooth groups has a distal end different in shape from distal ends of other teeth belonging to the same tooth group, and the plurality of tooth groups have the same configuration.
    Type: Grant
    Filed: June 19, 2013
    Date of Patent: June 27, 2017
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Kanako Nemoto, Hidetoshi Koka
  • Publication number: 20160056684
    Abstract: A rotating electric machine allowing a rotor and a stator thereof to assume any of various numbers of poles and any of various numbers of slots and enabling a reduction in vibration and noise is provided. The rotating electric machine according to the present invention includes a stator having a plurality of teeth and a plurality of slots, which is configured so that the shape of the front ends of the teeth and the opening width of the slots are made to change cyclically F times along the circumferential direction (F is a natural number equal to or greater than 2).
    Type: Application
    Filed: January 22, 2014
    Publication date: February 25, 2016
    Inventors: Kanako NEMOTO, Hidetoshi KOKA, Yutaka MATSUNOBU, Yasuyuki SAITO
  • Publication number: 20150295455
    Abstract: Provided is a rotating electric machine including a rotor and stator fitted with various numbers of poles and slots and adapted to reduce vibration/noise of the machine. The rotating electric machine in accordance with an aspect of the present invention includes a stator having an S number of teeth, and a rotor disposed in the stator with a gap intervening between the stator and the rotor. The plurality of teeth in the stator are grouped in units of the number of teeth that is equal to a value “m” or a value “d”, the value “m” being obtained by dividing the number of stator slots, S, by the greatest common divisor N of the number of poles, P, and the number of stator slots, S, the value “d” being an aliquot of “m”. At least one tooth in each of the tooth groups has a distal end different in shape from distal ends of other teeth belonging to the same tooth group, and the plurality of tooth groups have the same configuration.
    Type: Application
    Filed: June 19, 2013
    Publication date: October 15, 2015
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Kanako Nemoto, Hidetoshi Koka
  • Publication number: 20150115758
    Abstract: A permanent magnet rotating electrical machine includes a rotor which has permanent magnets buried in a plurality of permanent magnet insertion slots that are provided in a rotor core, and the rotor is rotatably supported by a rotary shaft with a gap on the inner peripheral side of a stator. When the axis of magnetic flux for the permanent magnet is set as a d-axis and the position deviated from the d-axis by electrical angle of 90° is set as a q-axis, the permanent magnet insertion slot is located on the q-axis and a first permanent magnet magnetized in the direction orthogonal to the q-axis is buried in the permanent magnet insertion slot. The permanent magnet insertion slot is located on the d-axis and a second permanent magnet magnetized in the direction parallel to the d-axis is buried in the permanent magnet insertion slot, while at least one or more third permanent magnets buried in the permanent magnet insertion slots are provided between the first permanent magnet and the second permanent magnet.
    Type: Application
    Filed: March 25, 2013
    Publication date: April 30, 2015
    Inventors: Hidetoshi Koka, Satoshi Kikuchi, Yutaka Matsunobu, Yasuyuki Saito, Sadahiro Hamahata
  • Publication number: 20140246944
    Abstract: A rotating electrical machine includes a stator having a stator core having a plurality of slots formed therein and a plurality of stator coils to be accommodated in the respective slots, and a rotor arranged on an inner peripheral side of the stator. The plurality of slots include a first slot and a second slot, and when a first ratio between the number of coils having the same phase to be accommodated within the first slot and the number of the plurality of coils exceeds a predetermined ratio, and a second ratio between the number of coils having the same phase to be accommodated in the second slot and the number of the plurality of coils is the predetermined ratio or lower, a width of a first slot opening that the first slot has so as to face the rotor side is 0 or wider, and is smaller than a width of a second slot opening that the second slot has so as to face the rotor side.
    Type: Application
    Filed: October 3, 2012
    Publication date: September 4, 2014
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Hidetoshi Koka, Satoshi Kikuchi, Yutaka Matsunobu, Keiji Oda, Yasuyuki Saito, Manabu Oshida
  • Publication number: 20140049134
    Abstract: Induction electrical rotating machine includes a stator which has plural stator slots 114 formed at a predetermined spacing in a circumferential direction of a stator iron core 111 and in which a stator winding 120 is accommodated in the plural stator slots 114, and a rotor 130 in which a rotor bar 132 extending in an axial direction of the rotor iron core 111 is provided in a plural number at a spacing in a circumferential direction and in which a pair of end rings that shorts the plural rotor bars 132 at ends in the axial direction is provided. A shape of a stator-side end, of a sectional shape within a plane orthogonal to a rotor axial direction of the rotor bar 132, is asymmetrical and a notch 133 is formed.
    Type: Application
    Filed: May 1, 2012
    Publication date: February 20, 2014
    Inventors: Hidetoshi Koka, Satoshi Kikuchi, Yutaka Matsunobu, Noriaki Hino, Keiji Oda, Yasuyuki Saito, Manabu Oshida, Kazuo Nishihama
  • Publication number: 20130140930
    Abstract: Electric rotating machine suppressing narrowing of a magnetic path caused by a skin effect in a housing to increase torque, including stator core having e.g. core back and teeth; stator windings wound around the teeth; stator including stator core and stator windings; housing composed of a magnetic body accommodating the stator; rotor disposed for rotation on an inner circumferential side of the stator. An air gap is provided between an inside wall of the housing and an outer circumferential surface of core back. The core back has projections on a radial back surface of a portion where the teeth are provided. The projections are each provided to be continuous in an axial direction and have tip portions in contact with inside wall of the housing. The air gap may be defined by the inside wall of the housing, the outer circumferential surface of the core back and the projections.
    Type: Application
    Filed: August 29, 2011
    Publication date: June 6, 2013
    Inventors: Hidetoshi Koka, Satoshi Kikuchi, Yutaka Matsunobu, Shigeru Kakugawa, Kohji Maki, Shinji Sugimoto
  • Publication number: 20100052460
    Abstract: In a permanent magnet type electrical rotating machine having coils 12 with a deviated electrical angle phase at their magnetic pole positions, a relation of T2>T1 is satisfied where T1 is the number of turns of each of the coils and T2 is the number of turns of each of other coils, or alternatively a relation of R2<R1 is satisfied where R1 is a magnetic resistance of a tooth around which each of the coils is wound and R2 is a magnetic resistance of a tooth around which each of other coils is wound.
    Type: Application
    Filed: August 17, 2009
    Publication date: March 4, 2010
    Inventors: Hidetoshi Koka, Hiroshi Kanazawa, Susumu Terumoto, Masanori Nakagawa
  • Patent number: 7638917
    Abstract: An electrical rotating machine with permanent magnets which is configured such that the ratio of the number of magnetic poles of permanent magnets 3 to the number of magnetic poles of coils 12 is at 10:9 or 8:9. The coils 12 are configured such that a middle coil U? and two adjacent coils U+, U+ on both sides thereof are in-phase connected to be in-phase coils for each phase, and there is satisfied the relationship that T2>T1 and T2>T3, where T2 is the turn number of the middle coil U?, and T1 and T3 are the turn numbers of the adjacent coils U+, U+.
    Type: Grant
    Filed: February 27, 2008
    Date of Patent: December 29, 2009
    Assignee: Kokusan Denki Co., Ltd.
    Inventors: Hidetoshi Koka, Hiroshi Kanazawa, Susumu Terumoto, Masanori Nakagawa
  • Publication number: 20080211338
    Abstract: An electrical rotating machine with permanent magnets which is configured such that the ratio of the number of magnetic poles of permanent magnets 3 to the number of magnetic poles of coils 12 is at 10:9 or 8:9. The coils 12 are configured such that a middle coil U? and two adjacent coils U+, U+ on both sides thereof are in-phase connected to be in-phase coils for each phase, and there is satisfied the relationship that T2>T1 and T2>T3, where T2 is the turn number of the middle coil U?, and T1 and T3 are the turn numbers of the adjacent coils U+, U+.
    Type: Application
    Filed: February 27, 2008
    Publication date: September 4, 2008
    Inventors: Hidetoshi KOKA, Hiroshi Kanazawa, Susumu Terumoto, Masanori Nakagawa