Patents by Inventor Kazuo Nishihama

Kazuo Nishihama 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: 20220224270
    Abstract: A winding switching device switches parallel and series connections of windings of a rotating electric machine, and includes a plurality of electrodes that are connected to the windings and a power source, a movable portion in contact with the plurality of electrodes and includes a plurality of conductor portions, and an actuator that drives the movable portion. According to a contact state between the plurality of electrodes and the plurality of conductor portions, the windings are connected in parallel at a first position of the movable portion, and are connected in series at a second position of the movable portion. The electrodes include a first electrode connected to a first phase winding of the rotating electric machine in the plurality of windings, and a second electrode connected to a second phase winding. The first electrode and the second electrode are adjacent to each other, and form a neutral point.
    Type: Application
    Filed: March 23, 2020
    Publication date: July 14, 2022
    Applicant: Hitachi, Ltd.
    Inventors: Shinji SUGIMOTO, Akeshi TAKAHASHI, Kazuo NISHIHAMA
  • Publication number: 20220006411
    Abstract: A rotary machine driving system includes: a rotary machine including a plurality of coils; an inverter device configured to operate the rotary machine at a variable speed, including a control device for controlling power conversion by an inverter circuit, and a coil switching device for switching a connection of the coils according to the control device. The control device commands the coil switching device to switch the connection of the coils when rotation of the rotary machine transitions between a low-speed rotation range and a high-speed rotation range due to acceleration and deceleration. A starting end and a terminal end of at least one set of coils per phase of the rotary machine are drawn out in a freely connectable state. The coil switching device includes at least one movable portion driven by one actuator.
    Type: Application
    Filed: June 21, 2019
    Publication date: January 6, 2022
    Applicant: HITACHI, LTD.
    Inventors: Akeshi TAKAHASHI, Shinji SUGIMOTO, Kazuo NISHIHAMA
  • Patent number: 11183898
    Abstract: Provided is a rotary electric machine that achieves high motor efficiency with little loss. This rotary electric machine is equipped with: a stator core arranged opposing the circumferential surface of a rotor, and in which multiple slots, wherein openings opening toward the rotor are formed, are formed in the circumferential direction; and coils inserted into the slots. A mixture of a soft magnetic powder and a resin material is formed in the openings of the slots, and the relative permeability of the mixture is 5-35.
    Type: Grant
    Filed: July 7, 2017
    Date of Patent: November 23, 2021
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Genzo Iwaki, Kazuo Nishihama, Katsuya Hirata, Atsushi Abe
  • Patent number: 11075570
    Abstract: There is provided a rotary electric machine that ensures improving a maximum torque and a rated power factor while reducing an increase in a starting current. In view of this, the rotary electric machine includes a shaft, a rotor, and a stator. The rotor is fixed to an outer periphery of the shaft. The stator is located so as to surround an outer periphery of the rotor. The rotor includes a rotor iron core including a plurality of rotor slots located at predetermined intervals in a circumferential direction and rotor bars inserted into the rotor slots. Rotor slits communicate with outer peripheral sides of the rotor slots. The rotor slits have a width ws in a circumferential direction. The width ws is smaller than a height hs in a radial direction of the rotor slit, and when a rated current is denoted as I1, a turn ratio (primary/secondary) is denoted as Tr, and a magnetic permeability in a vacuum is denoted as ?0, a relationship of ws>?0×I1×Tr/0.6 is met.
    Type: Grant
    Filed: July 31, 2017
    Date of Patent: July 27, 2021
    Assignee: Hitachi Industrial Products, Ltd.
    Inventors: Kazuo Nishihama, Masanori Sawahata, Takayuki Koyama, Makoto Imura, Yuuichirou Yoshitake, Kenichi Sugimoto, Kengo Ueda
  • Publication number: 20190207460
    Abstract: Please substitute the new Abstract submitted herewith for the original Abstract: Provided is a rotary electric machine that achieves high motor efficiency with little loss. This rotary electric machine is equipped with: a stator core arranged opposing the circumferential surface of a rotor, and in which multiple slots, wherein openings opening toward the rotor are formed, are formed in the circumferential direction; and coils inserted into the slots. A mixture of a soft magnetic powder and a resin material is formed in the openings of the slots, and the relative permeability of the mixture is 5-35.
    Type: Application
    Filed: July 7, 2017
    Publication date: July 4, 2019
    Applicant: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Genzo IWAKI, Kazuo NISHIHAMA, Katsuya HIRATA, Atsushi ABE
  • Publication number: 20190140530
    Abstract: There is provided a rotary electric machine that ensures improving a maximum torque and a rated power factor while reducing an increase in a starting current. In view of this, the rotary electric machine includes a shaft, a rotor, and a stator. The rotor is fixed to an outer periphery of the shaft. The stator is located so as to surround an outer periphery of the rotor. The rotor includes a rotor iron core including a plurality of rotor slots located at predetermined intervals in a circumferential direction and rotor bars inserted into the rotor slots. Rotor slits communicate with outer peripheral sides of the rotor slots. The rotor slits have a width ws in a circumferential direction. The width ws is smaller than a height hs in a radial direction of the rotor slit, and when a rated current is denoted as I1, a turn ratio (primary/secondary) is denoted as Tr, and a magnetic permeability in a vacuum is denoted as ?0, a relationship of ws>?0×I1×Tr/0.6 is met.
    Type: Application
    Filed: July 31, 2017
    Publication date: May 9, 2019
    Inventors: Kazuo NISHIHAMA, Masanori SAWAHATA, Takayuki KOYAMA, Makoto IMURA, Yuuichirou YOSHITAKE, Kenichi SUGIMOTO, Kengo UEDA
  • Patent number: 10243430
    Abstract: The invention provides a rotating electrical machine system in which an air volume of a refrigerant is increased near the center of a rotating electrical machine in the axial direction is improved. The rotating electrical machine includes a rotor and a stator, in which the stator core, laminated electromagnetic steel sheets formed by laminating a plurality of electromagnetic steel sheets in the axial direction are divided into a plurality of sets of packet cores, and between one of the packet cores of the plurality of sets and another packet core adjacent to it, there is formed a duct providing a flow channel of the stator, and in a duct situated at the center side from both ends in the axial direction among the duct, there is a portion of two packet cores facing each other across the duct, a diameter direction length of the two packet cores becoming long.
    Type: Grant
    Filed: December 16, 2016
    Date of Patent: March 26, 2019
    Assignee: Hitachi, Ltd.
    Inventors: Daisuke Kori, Ryuichiro Iwano, Masanori Sawahata, Kazuo Nishihama, Motonobu Iizuka, Takayuki Koyama, Kenichi Sugimoto
  • Publication number: 20170187264
    Abstract: The invention provides a rotating electrical machine system in which an air volume of a refrigerant is increased near the center of a rotating electrical machine in the axial direction is improved. The rotating electrical machine includes a rotor and a stator, in which the stator core, laminated electromagnetic steel sheets formed by laminating a plurality of electromagnetic steel sheets in the axial direction are divided into a plurality of sets of packet cores, and between one of the packet cores of the plurality of sets and another packet core adjacent to it, there is formed a duct providing a flow channel of the stator, and in a duct situated at the center side from both ends in the axial direction among the duct, there is a portion of two packet cores facing each other across the duct, a diameter direction length of the two packet cores becoming long.
    Type: Application
    Filed: December 16, 2016
    Publication date: June 29, 2017
    Inventors: Daisuke KORI, Ryuichiro IWANO, Masanori SAWAHATA, Kazuo NISHIHAMA, Motonobu IIZUKA, Takayuki KOYAMA, Kenichi SUGIMOTO
  • Patent number: 8841812
    Abstract: An object of the present invention is to provide a squirrel-cage induction motor with high efficiency. In a squirrel-cage induction motor including a stator in which stator windings are wound in a number of stator slots arranged at intervals in the vicinity of the inner periphery of a stator core and a rotor in which rotor conductors are embedded in a number of rotor slots arranged at intervals in the vicinity of the outer periphery of a rotor core and end rings are provided at both ends of the rotor core, the rotor core is formed of a plurality of blocks, an annular short-circuit ring is provided between respective blocks of the rotor core to short-circuit the rotor conductors, and laminated thickness of the rotor core is made larger than laminated thickness of the stator core.
    Type: Grant
    Filed: February 24, 2011
    Date of Patent: September 23, 2014
    Assignee: Hitachi Ltd
    Inventors: Kazuo Nishihama, Hiroyuki Mikami, Tadahiro Shimozono, Keiichiro Kaihatsu, Atsushi Abe
  • Publication number: 20140252910
    Abstract: There is provided an induction machine having a squirrel-cage rotor, the rotor including: a rotor core; a plurality of rotor slots formed on the rotor core and aligned circumferentially at a predetermined interval; a plurality of rotor bars inserted into one of the plurality of rotor slots; and a plurality of rotor slits formed adjacent to the plurality of rotor slots on an outer circumferential side of the rotor core. The each rotor slit is formed as a hollow such that a cross sectional shape thereof is distinguished into three parts of a slit outer circumferential part, a slit intermediate part, and a slit inner circumferential part. A circumferential width of the each rotor slit on an innermost circumferential side is larger than that on an outermost circumferential side. A circumferential width of the slit intermediate part increases from an outer circumferential side toward an inner circumferential side.
    Type: Application
    Filed: March 6, 2014
    Publication date: September 11, 2014
    Applicant: Hitachi, Ltd.
    Inventors: Naoki KUNIHIRO, Kazuo NISHIHAMA, Motonobu IIZUKA, Kenichi SUGIMOTO, Masanori SAWAHATA, Akiyoshi KOMURA
  • Patent number: 8816559
    Abstract: A squirrel cage induction motor includes: a stator core (11); a plurality of stator slots (12) radially disposed in a circumferential direction of the stator core (11) with predetermined intervals; a plurality of stator windings (13) housed in the stator slots respectively; a rotor core (21); a plurality of rotor slots (22) radially disposed in a circumferential direction of the rotor core (22) with predetermined intervals; a plurality of rotor conductors (23) housed in the rotor slots (22) respectively. The stator windings (13) and the rotor conductors (23) includes electrically conductive materials mainly composed of copper. An area ratio of a total area of the stator slots (12) to a total area of the rotor slots (22) is not smaller than 2.7 and not greater than 8.0 to provide compatibility between the starting characteristic (starting torque) and the steady characteristic (for a high efficiency) can be provided.
    Type: Grant
    Filed: August 20, 2009
    Date of Patent: August 26, 2014
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Kazuo Nishihama, Hiroyuki Mikami, Tadahiro Shimozono, Keiichiro Kaihatsu
  • 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
  • Patent number: 8546991
    Abstract: A synchronous generator 1 including a rotor having a field winding placed in the slots thereof and a stator having an armature winding placed in the slots thereof, wherein the value of the number of slots per two poles in stator minus the number of slots per two poles in rotor is equal to or greater than +9, or equal to or smaller than ?9.
    Type: Grant
    Filed: July 22, 2009
    Date of Patent: October 1, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Masanori Sawahata, Kazuo Nishihama, Hiroyuki Mikami, Tetsuo Fujigaki, Motonobu Iizuka, Shuji Mizutani
  • Publication number: 20110234039
    Abstract: An object of the present invention is to provide a squirrel-cage induction motor with high efficiency. In a squirrel-cage induction motor including a stator in which stator windings are wound in a number of stator slots arranged at intervals in the vicinity of the inner periphery of a stator core and a rotor in which rotor conductors are embedded in a number of rotor slots arranged at intervals in the vicinity of the outer periphery of a rotor core and end rings are provided at both ends of the rotor core, the rotor core is formed of a plurality of blocks, an annular short-circuit ring is provided between respective blocks of the rotor core to short-circuit the rotor conductors, and laminated thickness of the rotor core is made larger than laminated thickness of the stator core.
    Type: Application
    Filed: February 24, 2011
    Publication date: September 29, 2011
    Inventors: Kazuo Nishihama, Hiroyuki Mikami, Tadahiro Shimozono, Keiichiro Kaihatsu, Atsushi Abe
  • Publication number: 20110210692
    Abstract: A squirrel cage induction motor includes: a stator core (11); a plurality of stator slots (12) radially disposed in a circumferential direction of the stator core (11) with predetermined intervals; a plurality of stator windings (13) housed in the stator slots respectively; a rotor core (21); a plurality of rotor slots (22) radially disposed in a circumferential direction of the rotor core (22) with predetermined intervals; a plurality of rotor conductors (23) housed in the rotor slots (22) respectively. The stator windings (13) and the rotor conductors (23) includes electrically conductive materials mainly composed of copper. An area ratio of a total area of the stator slots (12) to a total area of the rotor slots (22) is not smaller than 2.7 and not greater than 8.0 to provide compatibility between the starting characteristic (starting torque) and the steady characteristic (for a high efficiency) can be provided.
    Type: Application
    Filed: August 20, 2009
    Publication date: September 1, 2011
    Applicant: HITACHI INDUSTRIAL EQUIPMENT SYSTEMS CO., LTD.
    Inventors: Kazuo Nishihama, Hiroyuki Mikami, Tadahiro Shimozono, Keiichiro Kaihatsu
  • Patent number: 7737593
    Abstract: An electric rotation machine for windmill power generation equipped with a stator slot structure having distributed windings and a rotor pole structure having permanent magnets, wherein the number of slots per pole per phase (Nspp) is undividable by 3 times P (where P is the number of poles), and pole width rate Pw obtained by dividing pole piece width Tp by pole pitch Tr at the outermost diameters of the adjoining poles of the rotor is satisfied any of Pw?0.6, 0.67?Pw?0.71, and 0.78?Pw. The distortion factors of induced voltages in a permanent magnet type electrical rotation machine, particularly for windmill power generation, can be reduced.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: June 15, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Mamoru Kimura, Kazumasa Ide, Kazuo Nishihama, Tetsuo Fujigaki, Shuji Mizutani
  • Publication number: 20100026008
    Abstract: A synchronous generator 1 including a rotor having a field winding placed in the slots thereof and a stator having an armature winding placed in the slots thereof, wherein the value of the number of slots per two poles in stator minus the number of slots per two poles in rotor is equal to or greater than +9, or equal to or smaller than ?9.
    Type: Application
    Filed: July 22, 2009
    Publication date: February 4, 2010
    Applicant: HITACHI, LTD.
    Inventors: Masanori SAWAHATA, Kazuo NISHIHAMA, Hiroyuki MIKAMI, Tetsuo FUJIGAKI, Motonobu IIZUKA, Shuji MIZUTANI
  • Publication number: 20090160284
    Abstract: An electric rotation machine for windmill power generation equipped with a stator slot structure having distributed windings and a rotor pole structure having permanent magnets, wherein the number of slots per pole per phase (Nspp) is undividable by 3 times P (where P is the number of poles), and pole width rate Pw obtained by dividing pole piece width Tp by pole pitch Tr at the outermost diameters of the adjoining poles of the rotor is satisfied any of Pw?0.6, 0.67?Pw?0.71, and 0.78?Pw. The distortion factors of induced voltages in a permanent magnet type electrical rotation machine, particularly for windmill power generation, can be reduced.
    Type: Application
    Filed: February 18, 2009
    Publication date: June 25, 2009
    Inventors: Mamoru Kimura, Kazumasa Ide, Kazuo Nishihama, Tetsuo Fujigaki, Shuji Mizutani
  • Patent number: 7541710
    Abstract: Provided is a rotating electric machine which can restrain vibration and noise induced by a radial electromagnetic force of the rotating electric machine, and in which a rotor is divided into first to fourth four rotating pieces having axial lengths of 0.29L, 0.71L, 0.71L and 0.29L where 2L is an axial length of a rotor or stator core, and secondary conductors defining effective magnetic pole opening angles, are arranged being shifted by a value which is equal to a phase difference of electric angle between axial sections of the rotor pieces in order to define skews so that phase differences of electric angles are continuous between axial sections of the first and second rotor pieces, the skews being continuous between the third and fourth rotor pieces but being not continuous between the second and third rotor pieces arranged being shifted by a value which is equal to a phase difference of electric angle between axial sections of the rotor.
    Type: Grant
    Filed: November 30, 2005
    Date of Patent: June 2, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Kanako Nemoto, Yasushi Takano, Kazuhiko Takahashi, Kazuo Shima, Kazuo Nishihama
  • Patent number: 7498707
    Abstract: An electric rotation machine for windmill power generation equipped with a stator slot structure having distributed windings and a rotor pole structure having permanent magnets, wherein the number of slots per pole per phase (Nspp) is undividable by 3 times P (where P is the number of poles), and pole width rate Pw obtained by dividing pole piece width Tp by pole pitch Tr at the outermost diameters of the adjoining poles of the rotor is satisfied any of Pw?0.6, 0.67?Pw?0.71, and 0.78?Pw. The distortion factors of induced voltages in a permanent magnet type electrical rotation machine, particularly for windmill power generation, can be reduced.
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: March 3, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Mamoru Kimura, Kazumasa Ide, Kazuo Nishihama, Tetsuo Fujigaki, Shuji Mizutani