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).
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Publication number: 20230373320Abstract: An object of the present invention is to provide a drive system for a dump truck capable of suppressing increase in size of a converter that controls a two-winding induction generator. To this end, the drive system for a dump truck includes a DC-DC converter connected to a main side DC bus and an auxiliary side DC bus, and a controller controls the DC-DC converter such that electric power of the main side DC bus is supplied to the auxiliary side DC bus via the DC-DC converter.Type: ApplicationFiled: February 8, 2022Publication date: November 23, 2023Inventors: Satoru KANEKO, Kazuo NISHIHAMA, Masatoshi YOSHIMURA, Kosuke MATSUO, Seiji ISHIDA, Toshihiko WATANABE, Tokuma IKEGAMI
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Publication number: 20230370008Abstract: It is an object of the present invention to provide a drive system including an induction generator comprising some primary windings that has a main winding and an auxiliary winding, the drive system being capable of supplying electric power required by an auxiliary inverter, even in a regenerative mode of operation in which only the auxiliary winding is energized. The maximum current value of a converter for power generating is set on the basis of the maximum output power of the auxiliary winding of the induction generator and the minimum voltage applied to the auxiliary winding unless a traction inverter is in a regenerative mode of operation, and the non-load current value of the induction generator is set such that the maximum current in the auxiliary winding under the situation of the traction inverter being in the regenerative mode of operation does not exceed the maximum current in the converter for power generating.Type: ApplicationFiled: February 18, 2022Publication date: November 16, 2023Inventors: Kazuo NISHIHAMA, Masatoshi YOSHIMURA, Kosuke MATSUO, Satoru KANEKO, Tokuma IKEGAMI, Seiji ISHIDA, Toshihiko WATANABE
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Publication number: 20230253858Abstract: An object of the present invention is to provide a drive system that is provided with an induction generator having a primary winding including a main winding and an auxiliary winding and a secondary conductor, can vary the voltage of the main winding, and can increase the maximum output power of the auxiliary winding. Therefore, provided is a drive system, which is provided with an induction generator having a primary winding including a main winding and an auxiliary winding and a secondary conductor, including: a starting battery that starts the induction generator; a traction inverter that drives a traction motor; an auxiliary device inverter that drives an auxiliary device motor; a rectifier the input side of which is connected to the main winding and the output side of which is connected to the traction inverter; and a power generation inverter the output side of which is connected to the auxiliary winding and the input side of which is connected to the auxiliary device inverter and the starting battery.Type: ApplicationFiled: May 20, 2021Publication date: August 10, 2023Inventors: Kazuo NISHIHAMA, Masatoshi YOSHIMURA, Toshihiko WATANABE, Toshihiko ISHIDA, Seiji ISHIDA
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Patent number: 11716039Abstract: An object of the present invention is to provide a winding switching device capable of enhancing the reliability of electrical contact between a movable unit and a fixed unit, and a rotating electrical machine drive system including such a winding switching device.Type: GrantFiled: August 14, 2020Date of Patent: August 1, 2023Assignee: Hitachi Astemo, Ltd.Inventors: Kazuo Nishihama, Akeshi Takahashi, Katsuhiro Hoshino, Noriyuki Maekawa
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Patent number: 11601082Abstract: 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: GrantFiled: June 21, 2019Date of Patent: March 7, 2023Assignee: HITACHI, LTD.Inventors: Akeshi Takahashi, Shinji Sugimoto, Kazuo Nishihama
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Publication number: 20220416709Abstract: The present invention addresses the problem of providing a rotating machine drive system comprising a winding switching device, wherein the rotating machine drive system has a relatively simple configuration, allows wear of electrical contacts during switching and sliding to be minimized, and is highly reliable.Type: ApplicationFiled: September 8, 2020Publication date: December 29, 2022Inventors: Akeshi TAKAHASHI, Kazuo NISHIHAMA, Noriyuki MAEKAWA, Katsuhiro HOSHINO
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Publication number: 20220337184Abstract: An object of the present invention is to provide a winding switching device capable of enhancing the reliability of electrical contact between a movable unit and a fixed unit, and a rotating electrical machine drive system including such a winding switching device.Type: ApplicationFiled: August 14, 2020Publication date: October 20, 2022Inventors: Kazuo NISHIHAMA, Akeshi TAKAHASHI, Katsuhiro HOSHINO, Noriyuki MAEKAWA
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Publication number: 20220224270Abstract: 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: ApplicationFiled: March 23, 2020Publication date: July 14, 2022Applicant: Hitachi, Ltd.Inventors: Shinji SUGIMOTO, Akeshi TAKAHASHI, Kazuo NISHIHAMA
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Publication number: 20220006411Abstract: 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: ApplicationFiled: June 21, 2019Publication date: January 6, 2022Applicant: HITACHI, LTD.Inventors: Akeshi TAKAHASHI, Shinji SUGIMOTO, Kazuo NISHIHAMA
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Patent number: 11183898Abstract: 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: GrantFiled: July 7, 2017Date of Patent: November 23, 2021Assignee: Hitachi Industrial Equipment Systems Co., Ltd.Inventors: Genzo Iwaki, Kazuo Nishihama, Katsuya Hirata, Atsushi Abe
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Patent number: 11075570Abstract: 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: GrantFiled: July 31, 2017Date of Patent: July 27, 2021Assignee: Hitachi Industrial Products, Ltd.Inventors: Kazuo Nishihama, Masanori Sawahata, Takayuki Koyama, Makoto Imura, Yuuichirou Yoshitake, Kenichi Sugimoto, Kengo Ueda
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Publication number: 20190207460Abstract: 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: ApplicationFiled: July 7, 2017Publication date: July 4, 2019Applicant: Hitachi Industrial Equipment Systems Co., Ltd.Inventors: Genzo IWAKI, Kazuo NISHIHAMA, Katsuya HIRATA, Atsushi ABE
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Publication number: 20190140530Abstract: 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: ApplicationFiled: July 31, 2017Publication date: May 9, 2019Inventors: Kazuo NISHIHAMA, Masanori SAWAHATA, Takayuki KOYAMA, Makoto IMURA, Yuuichirou YOSHITAKE, Kenichi SUGIMOTO, Kengo UEDA
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Patent number: 10243430Abstract: 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: GrantFiled: December 16, 2016Date of Patent: March 26, 2019Assignee: Hitachi, Ltd.Inventors: Daisuke Kori, Ryuichiro Iwano, Masanori Sawahata, Kazuo Nishihama, Motonobu Iizuka, Takayuki Koyama, Kenichi Sugimoto
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Publication number: 20170187264Abstract: 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: ApplicationFiled: December 16, 2016Publication date: June 29, 2017Inventors: Daisuke KORI, Ryuichiro IWANO, Masanori SAWAHATA, Kazuo NISHIHAMA, Motonobu IIZUKA, Takayuki KOYAMA, Kenichi SUGIMOTO
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Patent number: 8841812Abstract: 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: GrantFiled: February 24, 2011Date of Patent: September 23, 2014Assignee: Hitachi LtdInventors: Kazuo Nishihama, Hiroyuki Mikami, Tadahiro Shimozono, Keiichiro Kaihatsu, Atsushi Abe
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Publication number: 20140252910Abstract: 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: ApplicationFiled: March 6, 2014Publication date: September 11, 2014Applicant: Hitachi, Ltd.Inventors: Naoki KUNIHIRO, Kazuo NISHIHAMA, Motonobu IIZUKA, Kenichi SUGIMOTO, Masanori SAWAHATA, Akiyoshi KOMURA
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Patent number: 8816559Abstract: 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: GrantFiled: August 20, 2009Date of Patent: August 26, 2014Assignee: Hitachi Industrial Equipment Systems Co., Ltd.Inventors: Kazuo Nishihama, Hiroyuki Mikami, Tadahiro Shimozono, Keiichiro Kaihatsu
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Publication number: 20140049134Abstract: 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: ApplicationFiled: May 1, 2012Publication date: February 20, 2014Inventors: Hidetoshi Koka, Satoshi Kikuchi, Yutaka Matsunobu, Noriaki Hino, Keiji Oda, Yasuyuki Saito, Manabu Oshida, Kazuo Nishihama
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Patent number: 8546991Abstract: 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: GrantFiled: July 22, 2009Date of Patent: October 1, 2013Assignee: Hitachi, Ltd.Inventors: Masanori Sawahata, Kazuo Nishihama, Hiroyuki Mikami, Tetsuo Fujigaki, Motonobu Iizuka, Shuji Mizutani