Patents by Inventor Hiroyuki Mikami
Hiroyuki Mikami 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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Patent number: 7847456Abstract: A permanent magnet electrical rotating machine having a permanent magnet rotor and a stator, wherein: a plurality of permanent magnets are disposed in a rotor iron core of the permanent magnet rotor along a periphery of the rotor iron core, polarities thereof being alternately changed; a cooling airflow channel is formed between each pair of adjacent opposite poles on the rotor iron core; and the cooling airflow channel has an approximately trapezoidal shape on an outer periphery side of the rotor iron core; and extends from an end on a central side in a radial direction of the approximately trapezoidal shape to a radial center.Type: GrantFiled: April 5, 2010Date of Patent: December 7, 2010Assignee: Hitachi, Ltd.Inventors: Daisuke Kori, Tetsuo Fujigaki, Shuji Aizawa, Motonobu Iizuka, Yasushi Iwai, Hiroyuki Mikami, Mamoru Kimura
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Publication number: 20100231078Abstract: A permanent magnet rotating electric machine has a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof. The rotor core is fixed on a rotary shaft rotating inside the stator, and one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.Type: ApplicationFiled: May 26, 2010Publication date: September 16, 2010Applicant: Hitachi, LTDInventors: Tsukasa TANIGUCHI, Hiroyuki Mikami, Satoshi Kikuchi, Fumio Jiyoraku, Hideyuki Harada
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Publication number: 20100194221Abstract: A permanent magnet electrical rotating machine having a permanent magnet rotor and a stator, wherein: a plurality of permanent magnets are disposed in a rotor iron core of the permanent magnet rotor along a periphery of the rotor iron core, polarities thereof being alternately changed; a cooling airflow channel is formed between each pair of adjacent opposite poles on the rotor iron core; and the cooling airflow channel has an approximately trapezoidal shape on an outer periphery side of the rotor iron core; and extends from an end on a central side in a radial direction of the approximately trapezoidal shape to a radial center.Type: ApplicationFiled: April 5, 2010Publication date: August 5, 2010Inventors: Daisuke KORI, Tetsuo Fujigaki, Shuji Aizawa, Motonobu Iizuka, Yasushi Iwai, Hiroyuki Mikami, Mamoru Kimura
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Patent number: 7768171Abstract: A permanent magnet rotating electric machine has a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof. The rotor core is fixed on a rotary shaft rotating inside the stator, and one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.Type: GrantFiled: July 8, 2008Date of Patent: August 3, 2010Assignee: Hitachi, Ltd.Inventors: Tsukasa Taniguchi, Hiroyuki Mikami, Satoshi Kikuchi, Fumio Jyoraku, Hideyuki Harada
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Publication number: 20100176682Abstract: A permanent magnet type rotary electric machine has a rotor having a rotor core and permanent magnets buried into the rotor core by being incorporated into respective permanent magnet slots. The permanent magnet slot per one pole is divided at least into four slots along an outer circumferential direction in the rotor core, and in respective rest core-portions between adjacent divided permanent magnet slots in the rotor core, a width of a first rest core-portion at the middle of each pole and a width of a second rest core-portion between adjacent poles of different polarities are formed larger than that of the others.Type: ApplicationFiled: January 8, 2010Publication date: July 15, 2010Applicant: HITACHI, LTD.Inventors: Daisuke Kori, Hiroyuki Mikami, Seikichi Masuda, Mamoru Kimura
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Publication number: 20100026008Abstract: 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: ApplicationFiled: July 22, 2009Publication date: February 4, 2010Applicant: HITACHI, LTD.Inventors: Masanori SAWAHATA, Kazuo NISHIHAMA, Hiroyuki MIKAMI, Tetsuo FUJIGAKI, Motonobu IIZUKA, Shuji MIZUTANI
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Publication number: 20090322175Abstract: A rotor is deployed such that the rotor becomes coaxially rotatable with a stator. A shaft is fixed onto the axis of a rotor iron-core. 1-pole constituting magnet slots are deployed into V-character pattern along an outer circumference portion of the rotor iron-core. Permanent magnets are embedded into the magnet slots. For the 1 pole, the 2 pieces of same-polarity permanent magnets are embedded into the V-character pattern. The configuration of each embedded permanent magnet is designed as follows: From the thickness of the permanent-magnet edge portion on the inner-diameter side of the rotor iron-core, which becomes the center of the V-character pattern, the thickness of the permanent magnet gradually increases toward the outer-diameter side of the rotor iron-core, which become the right and left edge portions of the V-character pattern. Simultaneously, curved lines are provided on both edge portions of the permanent magnet.Type: ApplicationFiled: June 22, 2009Publication date: December 31, 2009Applicant: HITACHI, LTD.Inventors: Daisuke KORI, Mamoru KIMURA, Hiroyuki MIKAMI, Seikichi MASUDA, Masayasu FUJIEDA
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Publication number: 20090267428Abstract: A rotating electrical machine includes: a rotor comprising a rotor core and a field winding wound round the rotor core; and a stator comprising a stator core and a stator winding wound round the stator core. The stator is arranged in opposition to the rotor with a predetermined spacing therebetween. the stator core is formed by punching a split piece, which comprises teeth for insertion of the stator winding thereinto and a core back on an outer periphery thereof, from a magnetic steel sheet, and laminating a plurality of those circular configurations in an axial direction, in which a plurality of the split pieces are arranged in a circle in a circumferential direction. The stator core has magnetic steel sheets, which are different in magnetic permeability in a diametrical direction, laminated at an axial end region of and in an axial central region of the stator core.Type: ApplicationFiled: April 23, 2009Publication date: October 29, 2009Inventors: Akihito NAKAHARA, Hiroyuki Mikami, Kazumasa Ide, Kazuhiko Takahashi, Kenichi Hattori
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Publication number: 20090200885Abstract: The present invention provides a permanent magnet that a fluorine compound is formed on the surfaces of Fe-based magnetic particles, and a recoil permeability is determined in a range of 1.05 to 1.30 by controlling an iron concentration in the fluorine compound to a range of 1 to 50% to reduce a loss due to magnetization rotation, thereby remedying reduction of a residual magnetic flux density and degradation of steady-state characteristics.Type: ApplicationFiled: December 23, 2008Publication date: August 13, 2009Inventors: Satoshi Kikuchi, Yuuichi Satsuu, Matahiro Komuro, Hiroyuki Mikami, Akeshi Takahashi
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Publication number: 20090160285Abstract: A self-starting type permanent magnet synchronous motor comprises a stator and a rotor. The rotor comprises a rotor core having a plurality of slots provided in an outer periphery thereof and a cage winding comprising conductive bars embedded in the slots and conductive end rings that short-circuit the conductive bars on both end faces of the bars in an axial direction thereof. The rotor core comprises at least one magnet insertion hole arranged on an inner peripheral side from the slots, and at least one permanent magnet embedded in the at least one magnet insertion hole. When a pole center axis is denoted as a d-axis and an axis deviating from the pole center axis by an electrical angle 90° is denoted as a q-axis, a flux content generated by the cage winding during start-up becomes maximal in the vicinity of and on one of the d-axis and the q-axis.Type: ApplicationFiled: December 17, 2008Publication date: June 25, 2009Inventors: Satoshi Kikuchi, Hiroyuki Mikami, Akeshi Takahashi, Tomio Yoshikawa, Keiji Tanaka, Masashi Miyake, Baiying Huang, Masaru Ohtahara, Kenji Tojo, Hideyuki Kumakura
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Publication number: 20090096317Abstract: There is provided a rotating machine including a stator and a rotor, in which the inner side surface (facing the stator) of the axial end structures of the stator is provided with grooves filled with an electrically nonconductive material.Type: ApplicationFiled: October 14, 2008Publication date: April 16, 2009Inventors: Manabu Sasaki, Hiroyuki Mikami, Tadaharu Kishibe
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PERMANENT MAGNET ROTATING ELECTRICAL MACHINE AND PERMANENT MAGNET ROTATING ELECTRICAL MACHINE SYSTEM
Publication number: 20090015090Abstract: Movement of magnets due to centrifugal force is restricted. In a permanent magnet rotating electrical machine 100 having a stator 1 and a rotor core 5 provided with a plurality of permanent magnets 3 inserted in an outer circumferential portion of the rotor 5, each permanent magnet 3 has inclined surfaces on the outer circumferential side of the rotor 2 and the thinnest portions of the inclined surfaces are adjacent to permanent magnets of the opposite polarity. Further, each magnet 3 has a convex-shaped cross section and is divided into two magnet segments 3, 3. A magnetic pole bridge 15 is formed at the boundary of the permanent magnet segments 3, 3. Thus, movement of the permanent magnet segments 3, 3 due to centrifugal force is firmly restricted, and the peeling off of the rotor core 5 and the permanent magnet segments 3, 3 from each other is prevented.Type: ApplicationFiled: July 10, 2008Publication date: January 15, 2009Inventors: Mamoru Kimura, Daisuke Kori, Hiroyuki Mikami, Seikichi Masuda, Masayasu Fujieda -
Publication number: 20080278017Abstract: A permanent magnet rotating electric machine has a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof. The rotor core is fixed on a rotary shaft rotating inside the stator, and one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.Type: ApplicationFiled: July 8, 2008Publication date: November 13, 2008Applicant: Hitachi, LTDInventors: Tsukasa TANIGUCHI, Hiroyuki Mikami, Satoshi Kikuchi, Fumio Jyoraku, Hideyuki Harada
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Publication number: 20080238237Abstract: An induction machine has a stator and rotor. The stator comprises teeth and slots and stator winding disposed in the slots. The rotor comprises a rotor core having teeth and slots and a rotor-conductor disposed in the rotor slots. Both of the stator core and rotor core are made of laminated steel sheets, and the teeth and slots made of steel sheets are formed by etching.Type: ApplicationFiled: February 6, 2008Publication date: October 2, 2008Inventors: Kazuo Nishihama, Teruyoshi Abe, Yoshihisa Ishikawa, Hiroyuki Mikami
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Publication number: 20080238235Abstract: A self-starting permanent magnet synchronous motor which demonstrates satisfactory acceleration performance even at a reduced supply voltage or with an increased load torque, and a compressor using the same. The motor comprises a stator having a stator winding and a rotor having a cage winding and a permanent magnet on the rotor core. The torque component generated by the cage winding is maximal at 1 in the slip range of 0 to 1.Type: ApplicationFiled: January 25, 2008Publication date: October 2, 2008Inventors: Akeshi TAKAHASHI, Satoshi Kikuchi, Hiroyuki Mikami, Kazuo Nishihama, Tomio Yoshikawa, Baiying Huang
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Patent number: 7417348Abstract: In the prior art in which permanent magnets are regularly arranged over the whole circumference of a rotor core, a satisfactory magnetic flux distribution is hard to obtain, and the cogging torque and the distortion factor of the induced electromotive force waveform are large, whereby characteristics of a rotating electric machine are poor. Also, because the permanent magnets are arranged over the whole circumference, a large number of permanent magnets are required and cost reduction is difficult. A permanent magnet rotating electric-machine of the invention comprises a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof, the rotor core being fixed on a rotary shaft rotating inside the stator, and in which one magnetic pole is constituted by each group of three or more of the magnets.Type: GrantFiled: August 8, 2003Date of Patent: August 26, 2008Assignee: Hitachi, Ltd.Inventors: Tsukasa Taniguchi, Hiroyuki Mikami, Satoshi Kikuchi, Fumio Jyoraku, Hideyuki Harada
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Publication number: 20080129129Abstract: A permanent magnet electrical rotating machine having a permanent magnet rotor and a stator, wherein: a plurality of permanent magnets are disposed in a rotor iron core of the permanent magnet rotor along a periphery of the rotor iron core, polarities thereof being alternately changed; a cooling airflow channel is formed between each pair of adjacent opposite poles on the rotor iron core; and the cooling airflow channel has an approximately trapezoidal shape on an outer periphery side of the rotor iron core; and extends from an end on a central side in a radial direction of the approximately trapezoidal shape to a radial center.Type: ApplicationFiled: November 21, 2007Publication date: June 5, 2008Inventors: Daisuke Kori, Tetsuo Fujigaki, Shuji Aizawa, Motonobu Iizuka, Yasushi Iwai, Hiroyuki Mikami, Mamoru Kimura
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Publication number: 20060103251Abstract: In the prior art in which permanent magnets are regularly arranged over the whole circumference of a rotor core, a satisfactory magnetic flux distribution is hard to obtain, and the cogging torque and the distortion factor of the induced electromotive force waveform are large, whereby characteristics of a rotating electric machine are poor. Also, because the permanent magnets are arranged over the whole circumference, a large number of permanent magnets are required and cost reduction is difficult. A permanent magnet rotating electric-machine of the invention comprises a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof, the rotor core being fixed on a rotary shaft rotating inside the stator, and in which one magnetic pole is constituted by each group of three or more of the magnets.Type: ApplicationFiled: August 8, 2003Publication date: May 18, 2006Applicant: Hitachi, LtdInventors: Tsukasa Taniguchi, Hiroyuki Mikami, Satoshi Kikuchi, Fumio Jyoraku, Hideyuki Harada
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Patent number: 6791389Abstract: According to the present invention, a variable delay circuit includes a delay circuit unit group, a control unit and an offset delay amount memory group. The delay circuit unit group includes a plurality of delay circuit units, and the plurality of delay circuit units includes two paths having different delay amounts. The offset delay amount memory group includes a plurality of offset delay amount memories, and offset delay amounts corresponding to delay amounts of the first paths of the corresponding delay circuit units are set in the plurality of offset delay amount memories. The control unit includes a plurality of subtracting units, and the plurality of subtracting units select paths of the delay circuit units through which an input signal may pass by using a delay setting value and offset delay amounts. It is possible to reduce volume of the circuit and remove a table since the path is selected by calculation.Type: GrantFiled: November 27, 2002Date of Patent: September 14, 2004Assignee: Advantest CorporationInventors: Hiroyuki Mikami, Yasutaka Tsuruki
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Patent number: 6657350Abstract: A permanent magnet type rotating electrical machine characterized by reduced vibration and noise, or improved efficiency. In a permanent magnet type rotating electrical machine comprising a stator 10 provided with concentrated winding and a rotor with permanent magnets 24 embedded in the rotor core 21, induced voltage waveform is improved by formation of two grooves or holes (flux barriers) extending in the axial direction for each magnetic pole on the bridge 25 of the core between the permanent magnet insertion hole 23 and the outer surface of rotor 20 in such a way that they are placed at an equally spaced interval over the entire circumference of the rotor 20.Type: GrantFiled: September 26, 2001Date of Patent: December 2, 2003Assignee: Hitachi, Ltd.Inventors: Mamoru Kimura, Haruo Koharagi, Hiroyuki Mikami, Miyoshi Takahashi