Patents by Inventor Fumio Tajima
Fumio Tajima 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: 20110062813Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.Type: ApplicationFiled: November 22, 2010Publication date: March 17, 2011Applicants: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio TAJIMA, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Patent number: 7851959Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.Type: GrantFiled: March 12, 2009Date of Patent: December 14, 2010Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Patent number: 7847462Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.Type: GrantFiled: March 12, 2009Date of Patent: December 7, 2010Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Patent number: 7808144Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.Type: GrantFiled: March 12, 2009Date of Patent: October 5, 2010Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Publication number: 20100226803Abstract: A pump is driven by a compact electric motor in which a coil is disposed in a ring form around and along a stator core which has a plurality of claw magnetic poles that extend alternately from both ends of one member of the stator core toward the end of the other member thereof. A stator core can be made from a compressed powder core by molding with resin, with the molded portion able to serve as a partition separating pump and motor units.Type: ApplicationFiled: May 21, 2010Publication date: September 9, 2010Applicant: Hitachi, Ltd.Inventors: Fumio TAJIMA, Masashi Kitamura, Yuji Enomoto, Yuji Nomoto, Kenya Takarai
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Patent number: 7777389Abstract: A rotating electrical machine comprises a stator and a rotor; the stator comprising a stator core having teeth and slots, and stator windings disposed in the slots, wherein the stator core is made of laminated steel sheets, teeth and slots of the steel sheet are made by etching, and the thickness of the steel sheet is between 0.05 mm and 0.30 mm. Specifically, it is preferable that the steel sheet used herein be a silicon steel sheet containing crystalline particles.Type: GrantFiled: July 12, 2007Date of Patent: August 17, 2010Assignee: Hitachi, Ltd.Inventors: Teruyoshi Abe, Motoya Ito, Fumio Tajima, Yoshihisa Ishikawa
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Patent number: 7768158Abstract: A cylindrical linear motor includes a stator and a movable element disposed via a clearance with respect to the stator and movable rectilinearly with respect to the stator. The movable element has a plurality of permanent magnets fixed to a movable element core. The stator salient poles 3b are pitched at ?s and the permanent magnets 11 are pitched at ?p so that a relationship of 3/4<?p/?s<3/2 is established.Type: GrantFiled: June 25, 2007Date of Patent: August 3, 2010Assignee: Hitachi, Ltd.Inventors: Masashi Kitamura, Fumio Tajima, Yusuke Akami, Noriyuki Utsumi, Ken Nakamura, Kazuaki Shibahara
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Patent number: 7750529Abstract: A pump is driven by a compact electric motor in which a coil is disposed in a ring form around and along a stator core which has a plurality of claw magnetic poles that extend alternately from both ends of one member of the stator core toward the end of the other member thereof. A stator core can be made from a compressed powder core by molding with resin, with the molded portion able to serve as a partition separating pump and motor units.Type: GrantFiled: July 18, 2007Date of Patent: July 6, 2010Assignee: Hitachi, Ltd.Inventors: Fumio Tajima, Masashi Kitamura, Yuji Enomoto, Yuji Nomoto, Kenya Takarai
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Patent number: 7714466Abstract: To realize reduction in vibration and noise while utilizing reluctance torque, a rotating electrical machine includes: a rotor having permanent magnets disposed in a cylindrical surface coaxial with a rotary shaft; and a stator having an annular stator core disposed coaxially with the rotary shaft, and a annular coil for magnetizing the stator core. The stator core has an annular part covering the annular coil, claws disposed at equal intervals in an inner radius surface of the annular part and extending axially, and magnetic gaps formed between neighboring claws. The number of claws is equal to the number of permanent magnets, and magnet flux in a direction orthogonal to a center axis of the magnetic pole of the permanent magnet at right angles in electric angle is larger than magnetic flux in the center axis direction generated between neighboring permanent magnets. Metal interpoles are provided between neighboring permanent magnets.Type: GrantFiled: July 24, 2007Date of Patent: May 11, 2010Assignees: Hitachi Industrial Equipment Systems Co., Ltd., Hitachi Powdered Metals Co., Ltd., Japan Servo Co., Ltd.Inventors: Masashi Kitamura, Fumio Tajima, Shigeru Kakugawa, Yuji Enomoto, Motoya Ito, Ryoso Masaki, Shoji Ohiwa, Chio Ishihara
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Patent number: 7671502Abstract: A rotating electric machine comprises a stator having stator salient poles, three-phases windings would around said stator salient poles, a rotor rotatable held inside the said stator, and permanent magnets inserted into said rotor and positioned opposite to said stator salient poles. The three-phase windings are concentratively wound around each of the stator salient poles, with windings of each phase wound around at more than one stator salient pole. The windings of each phase have a phase difference of voltage between at least one of the windings and the other.Type: GrantFiled: July 24, 2008Date of Patent: March 2, 2010Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio Tajima, Yutaka Matsunobe, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keijiro Oda
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Publication number: 20100044144Abstract: Disclosed are a high-damping and high-thrust cylindrical linear motor and a motor-driven power steering device. A stator includes three-phase stator and a stator core. A slider includes a slider core and permanent magnets. The stator core includes stator-core salient poles, two auxiliary poles and yoke units with a small poles on its surface of the side of the slider, the auxiliary poles being deployed at both ends of the stator-core salient poles, the yoke units configuring a magnetic circuit in cooperation with the stator core and the auxiliary poles. The magnetic circuit is shared among the three phases. Polarities of magnets of the slider become an identical polarity, each of the plurality of permanent magnets being positioned at a position which is opposed to each of the plurality of small poles included in one stator-core salient pole out of the plurality of stator-core salient poles.Type: ApplicationFiled: July 23, 2009Publication date: February 25, 2010Applicant: Hitachi Automotive Systems, Ltd.Inventors: Fumio Tajima, Masashi Kitamura, Yusuke Akami, Noriyuki Utsumi, Tomoyuki Lee
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Patent number: 7667365Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.Type: GrantFiled: July 18, 2008Date of Patent: February 23, 2010Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio Tajima, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Publication number: 20090309449Abstract: A rotating electric machine comprises a stator having stator salient poles, three-phases windings would around said stator salient poles, a rotor rotatable held inside the said stator, and permanent magnets inserted into said rotor and positioned opposite to said stator salient poles. The three-phase windings are concentratively wound around each of the stator salient poles, with windings of each phase wound around at more than one stator salient pole. The windings of each phase have a phase difference of voltage between at least one of the windings and the other.Type: ApplicationFiled: August 14, 2009Publication date: December 17, 2009Applicants: HITACHI, LTD., HITACHI CAR ENGINEERING CO., LTD.Inventors: Fumio Tajima, Yutaka Matsunobe, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keijiro Oda
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Publication number: 20090230802Abstract: The present invention comprises a stator, and a rotor which is disposed oppositely to the stator with a gap interposed. The stator comprises a stator core, and a distributed stator winding mounted to the stator core. The stator core comprises a ring-like yoke core, and a plurality of teeth cores which protrude from the yoke core in the radial direction. The rotor comprises a rotor core, and a plurality of permanent magnets embedded in the rotor core. A pair of non-magnetic portions is created inside the rotor core and on both sides of the circumferential width of a permanent magnet for one magnetic pole. In the rotor core located on the stator side of the pair of non-magnetic portions, a pair of magnetic paths is created as the result of the creation of the pair of non-magnetic portions. Furthermore, a groove or hole is created on the outer circumferential portion of the rotor core and between the adjacent magnetic poles.Type: ApplicationFiled: February 18, 2009Publication date: September 17, 2009Inventors: Akinori Kamiya, Noriaki Hino, Fumio Tajima, Tsutomu Miyoshi, Hideki Nihei
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Publication number: 20090189471Abstract: A spindle motor having a stator and a rotor includes: a stator core provided in the stator having salient-poles; a stator coil arranged between the salient-poles; a rotor; and a permanent magnet provided in the rotor. The stator core includes a stack of steel sheets whose salient-poles are formed by etching. The permanent magnet includes a ferromagnetic material consisting mainly of iron. The ferromagnetic material has formed in laminae on a surface thereof a layer of a fluorine compound containing an alkali element, an alkaline earth element or a rare earth element formed in laminae. Near an interface between the ferromagnetic material and the layer of the fluorine compound, iron exists in the layer of the fluorine compound such that a basic crystal structure of the fluorine compound is not changed and the fluorine compound containing the iron exists in the layer of the fluorine compound.Type: ApplicationFiled: July 29, 2008Publication date: July 30, 2009Applicant: Hitachi, Ltd.Inventors: Hisato Amano, Yuji Enomoto, Matahiro Komuro, Yuichi Satsu, Fumio Tajima
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Publication number: 20090179518Abstract: A permanent magnet rotating electric machine comprises a stator having stator windings wound round a stator iron core and a permanent magnet rotor having a plurality of inserted permanent magnets in which the polarity is alternately arranged in the peripheral direction in the rotor iron core. The rotor iron core of the permanent magnets is composed of magnetic pole pieces, auxiliary magnetic poles, and a stator yoke, and furthermore has concavities formed on the air gap face of the magnetic pole pieces of the rotor iron core of the permanent magnets, gently tilting from the central part of the magnetic poles to the end thereof. In a permanent magnet rotating electric machine, effects of iron loss are reduced, and an electric car using highly efficient permanent magnet rotating electric machine are realized.Type: ApplicationFiled: March 18, 2009Publication date: July 16, 2009Applicant: Hitachi, Ltd.Inventors: Fumio TAJIMA, Yutaka MATSUNOBU, Masashi KITAMURA, Noriaki HINO, Takashi KOBAYASHI, Shigeru KAKUGAWA, Takashi YASUHARA
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Publication number: 20090174275Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.Type: ApplicationFiled: March 12, 2009Publication date: July 9, 2009Applicants: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio TAJIMA, Yataka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Publication number: 20090174276Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.Type: ApplicationFiled: March 12, 2009Publication date: July 9, 2009Applicants: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio TAJIMA, Yataka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Publication number: 20090174274Abstract: A magnetic gap is provided between a permanent magnet of a rotor and an auxiliary magnet pole portion which is arranged adjacent to the permanent magnet in a peripheral direction. A gradual change in a magnetic flux density distribution of a surface of the rotor is obtained and a cogging torque and a torque pulsation are restrained. By obtaining a reluctance torque according to the auxiliary magnetic pole, a permanent magnet electric rotating machine in which the cogging torque and the torque pulsation are restrained can be obtained and further an electromotive vehicle having the permanent magnet electric rotating machine can be provided.Type: ApplicationFiled: March 12, 2009Publication date: July 9, 2009Applicants: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Fumio TAJIMA, Yutaka Matsunobu, Shouichi Kawamata, Suetaro Shibukawa, Osamu Koizumi, Keiji Oda
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Patent number: 7521832Abstract: A permanent magnet rotating electric machine comprises a stator having stator windings wound round a stator iron core and a permanent magnet rotor having a plurality of inserted permanent magnets in which the polarity is alternately arranged in the peripheral direction in the rotor iron core. The rotor iron core of the permanent magnets is composed of magnetic pole pieces, auxiliary magnetic poles, and a stator yoke, and furthermore has concavities formed on the air gap face of the magnetic pole pieces of the rotor iron core of the permanent magnets, gently tilting from the central part of the magnetic poles to the end thereof. In a permanent magnet rotating electric machine, effects of iron loss are reduced, and an electric car using highly efficient permanent magnet rotating electric machine are realized.Type: GrantFiled: December 15, 2006Date of Patent: April 21, 2009Assignee: Hitachi, Ltd.Inventors: Fumio Tajima, Yutaka Matsunobu, Masashi Kitamura, Noriaki Hino, Takashi Kobayashi, Shigeru Kakugawa, Takashi Yasuhara