Patents by Inventor Norihisa IWASAKI
Norihisa IWASAKI 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: 20140084741Abstract: A permanent magnet rotating electrical machine includes: a stator including a stator core and a polyphase stator coil incorporated into the stator core; and a rotor including a rotor core and a plurality of permanent magnets which is fixed to the outer peripheral surface of the rotor core, wherein the stator core has a plurality of stator tooth portions forming a slot into which the stator coil is stored, the rotor core is rotatably disposed in opposed relation to the stator, and the stator tooth portion includes at the tip thereof at least one nonmagnetic inner region.Type: ApplicationFiled: August 21, 2013Publication date: March 27, 2014Applicant: Hitachi Automotive Systems, Ltd.Inventors: Norihisa IWASAKI, Masashi KITAMURA, Hiroshi KANAZAWA, Shozo KAWASAKI
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Patent number: 8664902Abstract: Provided is an AC motor in a three-phase unbalanced state such as a claw-teeth type AC motor (108), which is reduced in magnetic flux pulsations and torque pulsations. Among the current command values of individual phases to be intrinsically given to an inverter (106) for feeding three-phase alternating currents of variable voltages/frequencies to the electric motor, a current command of an intermediate phase (a V-phase) having a smaller magnetic resistance of a stator core than those of other phases is subjected to a reducing correction by a correction unit (102) on the basis of the correction amount calculated by a current correction amount calculating unit (103), and the unbalanced three-phase alternating currents are fed to the AC motor (108), so that magnetic flux pulsations of a secondary electric angle and torque pulsations of the same order are reduced.Type: GrantFiled: April 16, 2009Date of Patent: March 4, 2014Assignee: Hitachi, Ltd.Inventors: Norihisa Iwasaki, Junnosuke Nakatsugawa, Yoshitaka Iwaji
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Publication number: 20140009009Abstract: An axial gap rotating-electric machine includes a stator, a rotor arranged via an air gap in the direction of an axis of rotation of a rotating-electric machine with respect to the stator, and a housing configured to accommodate the stator and the rotor, and the stator includes a plurality of stator cores arranged in the circumferential direction, coils configured to wind the peripheries of the respective stator cores, and a resin for molding the plurality of stator cores wound with the coils, and the stator cores each include a protruding portion protruding partly from the coil in the direction of axis of rotation, and a conductive member is provided so as to come into contact with peripheral surfaces of the protruding portions of the stator cores, and grounding is achieved by the conductive member.Type: ApplicationFiled: July 3, 2013Publication date: January 9, 2014Inventors: Kenta DEGUCHI, Hirooki TOKOI, Zhuonan WANG, Norihisa IWASAKI, Yuji ENOMOTO
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Publication number: 20130320795Abstract: The present invention is intended to provide a magnetic gear structure that realizes a magnetic gear that transmits a torque efficiently by reducing eddy currents generated in the interior of magnets. In order to solve the subject described above, in the magnetic gear structure, a structure in which magnets are arranged in the interior of an iron core in an inner rotor portion. Bonded magnets formed by molding, for example, NdFeB powder may be used as the magnets. Since the influence of the eddy current on the side of an outer rotor having a larger pole number is large, a structure in which the magnets are arranged in the interior only of an outer rotor portion having a larger pole number is also applicable. In addition, the magnets to be embedded may be divided into a plurality of pieces. The finer the division of the magnets, the less eddy currents are generated, so that a method of further fining down and assembling the same is also effective.Type: ApplicationFiled: February 21, 2011Publication date: December 5, 2013Applicant: Hitachi, Ltd.Inventors: Yuji Enomoto, Junnosuke Nakatsugawa, Norihisa Iwasaki, Masashi Kitamura
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Patent number: 8575804Abstract: A magnetic gear comprises a first permanent magnet field having a plurality of permanent magnet magnetic poles, a second permanent magnet field having a plurality of permanent magnet magnetic poles, number of poles of which magnet is different from that of the first permanent magnet field, and a modulating magnetic pole arranged between the first permanent magnet field and the second permanent magnet field and having a plurality of pole pieces to modulate the number of poles of the first and second permanent magnet fields. Non-magnetic bars are provided between the plurality of pole pieces. One ends of the non-magnetic bars are fixed to a first non-magnetic end holding member and the other ends of the non-magnetic bars are electrically insulated from and fixed to a second non-magnetic end holding member.Type: GrantFiled: January 19, 2012Date of Patent: November 5, 2013Assignee: Hitachi, Ltd.Inventors: Junnosuke Nakatsugawa, Yuji Enomoto, Hirooki Tokoi, Hiroshi Morita, Norihisa Iwasaki
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Patent number: 8513842Abstract: There is disclosed a rotary electromotor including a stator, a stator winding on the stator, a stator frame, a rotator, end covers, and a highly heat-conductive member. The stator has a plurality of magnetic poles. The stator frame supports the stator. The rotator is supported by the stator with a gap therefrom such that the rotator is rotatable. The end covers close opposite ends of the stator frame. The highly heat-conductive member is fixed by a resin material in a space defined inside the stator, the stator frame, and the end covers.Type: GrantFiled: February 24, 2011Date of Patent: August 20, 2013Assignee: Hitachi, Ltd.Inventors: Norihisa Iwasaki, Junnosuke Nakatsugawa, Yuji Enomoto, Masashi Kitamura
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Publication number: 20130002076Abstract: A magnetic gear mechanism including a simplified assembly of a magnetic flux modulating section in the magnetic gear mechanism which improves the strength thereof. In the magnetic flux modulating section of the magnetic gear mechanism, the magnetic flux modulating section being formed of a magnetic member and a non-magnetic member, a piece of the magnetic member and a piece of the non-magnetic member are separately produced. The piece of the magnetic member is sandwiched between circumferential projections provided in pieces of the non-magnetic member, and the magnetic member and the non-magnetic member and bearing holding sections form a structure in which the magnetic member and the non-magnetic member are fitted into the bearing holding sections by using recessed portions provided in the bearing holding sections and axial projections provided in the pieces of the non-magnetic member. This structure simplifies production and improves strength.Type: ApplicationFiled: June 29, 2012Publication date: January 3, 2013Applicant: HITACHI, LTD.Inventors: Norihisa Iwasaki, Yuji Enomoto, Junnosuke Nakatsugawa, Masashi Kitamura, Kinya Kobayashi, Hironori Matsumoto
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Publication number: 20120194021Abstract: A magnetic gear comprises a first permanent magnet field having a plurality of permanent magnet magnetic poles, a second permanent magnet field having a plurality of permanent magnet magnetic poles, number of poles of which magnet is different from that of the first permanent magnet field, and a modulating magnetic pole arranged between the first permanent magnet field and the second permanent magnet field and having a plurality of pole pieces to modulate the number of poles of the first and second permanent magnet fields. Non-magnetic bars are provided between the plurality of pole pieces. One ends of the non-magnetic bars are fixed to a first non-magnetic end holding member and the other ends of the non-magnetic bars are electrically insulated from and fixed to a second non-magnetic end holding member.Type: ApplicationFiled: January 19, 2012Publication date: August 2, 2012Inventors: Junnosuke Nakatsugawa, Yuji Enomoto, Hirooki Tokoi, Hiroshi Morita, Norihisa Iwasaki
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Publication number: 20120038301Abstract: Provided is an AC motor in a three-phase unbalanced state such as a claw-teeth type AC motor (108), which is reduced in magnetic flux pulsations and torque pulsations. Among the current command values of individual phases to be intrinsically given to an inverter (106) for feeding three-phase alternating currents of variable voltages/frequencies to the electric motor, a current command of an intermediate phase (a V-phase) having a smaller magnetic resistance of a stator core than those of other phases is subjected to a reducing correction by a correction unit (102) on the basis of the correction amount calculated by a current correction amount calculating unit (103), and the unbalanced three-phase alternating currents are fed to the AC motor (108), so that magnetic flux pulsations of a secondary electric angle and torque pulsations of the same order are reduced.Type: ApplicationFiled: April 16, 2009Publication date: February 16, 2012Applicant: Hitachi LtdInventors: Norihisa Iwasaki, Junnosuke Nakatsugawa, Yoshitaka Iwaji
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Publication number: 20120007528Abstract: The present invention relates to an AC motor control device and, particularly, to provide an AC control device capable of simply setting a state quantity of an AC motor non-linearly variable, in accordance with the motor driving state and using the setting in motor control, the present invention can be achieved by including a state quantity calculating unit (13, 13a, 13b, 13c) for calculating a state quantity corresponding to a coil interlinkage flux which is an internal quantity of the motor, calculating a setting value of the coil interlinkage flux defined on one axis out of two axes, that is, d and q axes, with a function formula using a current defined on the same one of the axes and a function formula using a state variable defined on the other one of the axes.Type: ApplicationFiled: February 26, 2010Publication date: January 12, 2012Inventors: Junnosuke Nakatsugawa, Yoshitaka Iwaji, Norihisa Iwasaki, Hirokazu Nagura
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Publication number: 20110234028Abstract: There is disclosed a rotary electromotor including a stator, a stator winding on the stator, a stator frame, a rotator, end covers, and a highly heat-conductive member. The stator has a plurality of magnetic poles. The stator frame supports the stator. The rotator is supported by the stator with a gap therefrom such that the rotator is rotatable. The end covers close opposite ends of the stator frame. The highly heat-conductive member is fixed by a resin material in a space defined inside the stator, the stator frame, and the end covers.Type: ApplicationFiled: February 24, 2011Publication date: September 29, 2011Inventors: Norihisa IWASAKI, Junnosuke NAKATSUGAWA, Yuji ENOMOTO, Masashi KITAMURA