Patents by Inventor Junnosuke Nakatsugawa

Junnosuke Nakatsugawa 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).

  • Patent number: 8502425
    Abstract: A totally enclosed motor which includes a rotor disposed inside a housing and a heat of the rotor is transferred to the housing, a stator disposed inside the housing and a heat of the stator is transferred to the housing, and an inner fin which is disposed in the rotor and agitates air inside the housing. The totally enclosed motor is cooled by a forced convection by an outer fan disposed outside the housing, or by a natural convention in the vicinity of an outer surface of the housing, and a shape of the rotor is different between one end side and the other end side of the rotor in an extending direction of a rotary shaft of the rotor.
    Type: Grant
    Filed: January 26, 2011
    Date of Patent: August 6, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Hironori Matsumoto, Atsushi Otake, Hiroshi Morita, Junpei Kusukawa, Kinya Kobayashi, Junnosuke Nakatsugawa
  • Patent number: 8410735
    Abstract: A torque ripple suppression control device for a permanent magnet motor includes a current command conversion unit that outputs a current command value, a position detector that detects a rotational position of the permanent magnet motor, a current detection unit that detects a current at the permanent magnet motor, an induced voltage coefficient setting unit that outputs an information signal related to an induced voltage coefficient for an induced voltage at the permanent magnet motor, a torque ripple suppression operation unit that outputs a current correction command value for the permanent magnet motor, a current control operation unit that outputs a voltage command value based upon addition results obtained by adding together the current command value and the current correction command value and the current detection value, and a power converter that outputs a voltage with which the permanent magnet motor is to be driven.
    Type: Grant
    Filed: January 19, 2011
    Date of Patent: April 2, 2013
    Assignee: Kokusan Denki Co., Ltd.
    Inventors: Kazuaki Tobari, Yoshitaka Iwaji, Junnosuke Nakatsugawa, Rikio Yoshikawa, Masamichi Yagai
  • Patent number: 8362727
    Abstract: A control technology for a synchronous motor for suppressing rotational pulsation caused by variation in individuals without making a control algorithm complex is provided. In a motor drive system which is a control device for a synchronous motor, in order to suppress the pulsation component of N times as high as the AC frequency for driving the synchronous motor, a controller in which the phase property of the disturbance response of the controller with respect to the pulsation frequency is within ±45° is arranged. Therefore, the torque pulsation component generated from distortion in induction voltage or variation between phases is suppressed.
    Type: Grant
    Filed: December 8, 2010
    Date of Patent: January 29, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Yoshitaka Iwaji, Yasuhiko Kokami, Minoru Kurosawa, Junnosuke Nakatsugawa
  • Publication number: 20130002076
    Abstract: 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: Application
    Filed: June 29, 2012
    Publication date: January 3, 2013
    Applicant: HITACHI, LTD.
    Inventors: Norihisa Iwasaki, Yuji Enomoto, Junnosuke Nakatsugawa, Masashi Kitamura, Kinya Kobayashi, Hironori Matsumoto
  • Publication number: 20120194021
    Abstract: 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: Application
    Filed: January 19, 2012
    Publication date: August 2, 2012
    Inventors: Junnosuke Nakatsugawa, Yuji Enomoto, Hirooki Tokoi, Hiroshi Morita, Norihisa Iwasaki
  • Publication number: 20120038301
    Abstract: 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: Application
    Filed: April 16, 2009
    Publication date: February 16, 2012
    Applicant: Hitachi Ltd
    Inventors: Norihisa Iwasaki, Junnosuke Nakatsugawa, Yoshitaka Iwaji
  • Publication number: 20120007528
    Abstract: 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: Application
    Filed: February 26, 2010
    Publication date: January 12, 2012
    Inventors: Junnosuke Nakatsugawa, Yoshitaka Iwaji, Norihisa Iwasaki, Hirokazu Nagura
  • Patent number: 8044618
    Abstract: It is attained by being provided with a motor constant calculation unit for calculating electric constants of a motor, and by correcting setting values of electric constants defined on one of the axes of two orthogonal axes, by a functional expression using a state variable defined on the same axis, and by correcting them by a functional expression using a state variable defined on the other axis.
    Type: Grant
    Filed: November 25, 2008
    Date of Patent: October 25, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Junnosuke Nakatsugawa, Yoshitaka Iwaji, Kazuaki Tobari, Kiyoshi Sakamoto
  • Publication number: 20110234028
    Abstract: 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: Application
    Filed: February 24, 2011
    Publication date: September 29, 2011
    Inventors: Norihisa IWASAKI, Junnosuke NAKATSUGAWA, Yuji ENOMOTO, Masashi KITAMURA
  • Publication number: 20110181138
    Abstract: A totally enclosed motor which includes a rotor disposed inside a housing and a heat of the rotor is transferred to the housing, a stator disposed inside the housing and a heat of the stator is transferred to the housing, and an inner fin which is disposed in the rotor and agitates air inside the housing. The totally enclosed motor is cooled by a forced convection by an outer fan disposed outside the housing, or by a natural convention in the vicinity of an outer surface of the housing, and a shape of the rotor is different between one end side and the other end side of the rotor in an extending direction of a rotary shaft of the rotor.
    Type: Application
    Filed: January 26, 2011
    Publication date: July 28, 2011
    Inventors: Hironori MATSUMOTO, Atsushi Otake, Hiroshi Morita, Junpei Kusukawa, Kinya Kobayashi, Junnosuke Nakatsugawa
  • Publication number: 20110175556
    Abstract: A torque ripple suppression control device for a permanent magnet motor includes a current command conversion unit that outputs a current command value, a position detector that detects a rotational position of the permanent magnet motor, a current detection unit that detects a current at the permanent magnet motor, an induced voltage coefficient setting unit that outputs an information signal related to an induced voltage coefficient for an induced voltage at the permanent magnet motor, a torque ripple suppression operation unit that outputs a current correction command value for the permanent magnet motor, a current control operation unit that outputs a voltage command value based upon addition results obtained by adding together the current command value and the current correction command value and the current detection value, and a power converter that outputs a voltage with which the permanent magnet motor is to be driven.
    Type: Application
    Filed: January 19, 2011
    Publication date: July 21, 2011
    Inventors: Kazuaki TOBARI, Yoshitaka Iwaji, Junnosuke Nakatsugawa, Rikio Yoshikawa, Masamichi Yagai
  • Publication number: 20110074324
    Abstract: A control technology for a synchronous motor for suppressing rotational pulsation caused by variation in individuals without making a control algorithm complex is provided. In a motor drive system which is a control device for a synchronous motor, in order to suppress the pulsation component of N times as high as the AC frequency for driving the synchronous motor, a controller in which the phase property of the disturbance response of the controller with respect to the pulsation frequency is within ±45° is arranged. Therefore, the torque pulsation component generated from distortion in induction voltage or variation between phases is suppressed.
    Type: Application
    Filed: December 8, 2010
    Publication date: March 31, 2011
    Applicant: Renesas Electronics Corporation
    Inventors: Yoshitaka Iwaji, Yasuhiko Kokami, Minoru Kurosawa, Junnosuke Nakatsugawa
  • Patent number: 7859209
    Abstract: A control technology for a synchronous motor for suppressing rotational pulsation caused by variation in individuals without making a control algorithm complex is provided. In a motor drive system which is a control device for a synchronous motor, in order to suppress the pulsation component of N times as high as the AC frequency for driving the synchronous motor, a controller in which the phase property of the disturbance response of the controller with respect to the pulsation frequency is within ±45° is arranged. Therefore, the torque pulsation component generated from distortion in induction voltage or variation between phases is suppressed.
    Type: Grant
    Filed: August 23, 2007
    Date of Patent: December 28, 2010
    Assignee: Renesas Electronics Corporation
    Inventors: Yoshitaka Iwaji, Yasuhiko Kokami, Minoru Kurosawa, Junnosuke Nakatsugawa
  • Patent number: 7847500
    Abstract: Control technique of a synchronous motor capable of suppressing rotation pulsation caused by individual difference without complicating control algorithm is provided. A pulsation generator superimposing a pulsation component anticipated in advance to a current command for the synchronous motor and a correction current generator superimposing a correction signal substantially having an average value of zero to the current command are provided in a synchronous motor control device. By this configuration, the correction signal suppressing a distortion component is superimposed to a value of the current command with a simplified control configuration. Torque pulsation is suppressed by determining the correction signal from difference between a detection current and a command current.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: December 7, 2010
    Assignee: Renesas Technology Corporation
    Inventors: Yoshitaka Iwaji, Junnosuke Nakatsugawa, Yasuhiko Kokami, Minoru Kurosawa
  • Patent number: 7825620
    Abstract: A controller and a constant measuring apparatus have a means for supplying a synthesized current, resulting from superimposing an AC current to a DC current, from an inverter and for changing the DC current component of the synthesized current continuously or discontinuously. Accordingly, the controller and constant measuring apparatus can measure inductances, which are electric constants of the AC motor, with high accuracy and can use the measured inductances for control.
    Type: Grant
    Filed: August 14, 2007
    Date of Patent: November 2, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Junnosuke Nakatsugawa, Yoshitaka Iwaji, Kazuaki Tobari
  • Publication number: 20090140674
    Abstract: It is attained by being provided with a motor constant calculation unit for calculating electric constants of a motor, and by correcting setting values of electric constants defined on one of the axes of two orthogonal axes, by a functional expression using a state variable defined on the same axis, and by correcting them by a functional expression using a state variable defined on the other axis.
    Type: Application
    Filed: November 25, 2008
    Publication date: June 4, 2009
    Inventors: Junnosuke NAKATSUGAWA, Yoshitaka Iwaji, Kazuaki Tobari, Kiyoshi Sakamoto
  • Publication number: 20080143288
    Abstract: Control technique of a synchronous motor capable of suppressing rotation pulsation caused by individual difference without complicating control algorithm is provided. A pulsation generator superimposing a pulsation component anticipated in advance to a current command for the synchronous motor and a correction current generator superimposing a correction signal substantially having an average value of zero to the current command are provided in a synchronous motor control device. By this configuration, the correction signal suppressing a distortion component is superimposed to a value of the current command with a simplified control configuration. Torque pulsation is suppressed by determining the correction signal from difference between a detection current and a command current.
    Type: Application
    Filed: December 12, 2007
    Publication date: June 19, 2008
    Applicant: Renesas Technology Corp.,
    Inventors: Yoshitaka Iwaji, Junnosuke Nakatsugawa, Yasuhiko Kokami, Minoru Kurosawa
  • Publication number: 20080079378
    Abstract: A controller and a constant measuring apparatus have a means for supplying a synthesized current, resulting from superimposing an AC current to a DC current, from an inverter and for changing the DC current component of the synthesized current continuously or discontinuously. Accordingly, the controller and constant measuring apparatus can measure inductances, which are electric constants of the AC motor, with high accuracy and can use the measured inductances for control.
    Type: Application
    Filed: August 14, 2007
    Publication date: April 3, 2008
    Inventors: JUNNOSUKE NAKATSUGAWA, Yoshitaka Iwaji, Kazuaki Tobari
  • Publication number: 20080061726
    Abstract: A control technology for a synchronous motor for suppressing rotational pulsation caused by variation in individuals without making a control algorithm complex is provided. In a motor drive system which is a control device for a synchronous motor, in order to suppress the pulsation component of N times as high as the AC frequency for driving the synchronous motor, a controller in which the phase property of the disturbance response of the controller with respect to the pulsation frequency is within ±45° is arranged. Therefore, the torque pulsation component generated from distortion in induction voltage or variation between phases is suppressed.
    Type: Application
    Filed: August 23, 2007
    Publication date: March 13, 2008
    Applicants: Hitachi, Ltd., Renesas Technology Corp.
    Inventors: Yoshitaka Iwaji, Yasuhiko Kokami, Minoru Kurosawa, Junnosuke Nakatsugawa
  • Publication number: 20070285044
    Abstract: A control apparatus and a semiconductor apparatus of AC motors capable of reducing torque ripple with a comparatively simple circuit corresponding to a high withstand voltage and capable of driving a motor at high efficiency even when the rotational speed or load has changed. The control apparatus detects first phase signals fixed in relative phase to induced voltages of the motor and current polarity signals, recognizes phase differences between them, generates second phase signals so as to make the phase differences approach zero to drive the motor at high efficiency, generates modulation wave signals having quasi-sinusoidal waveforms or trapezoidal waveforms on the basis of the second phase signals, compares the modulation wave signals with a carrier wave signal, and conducts PWM control on an inverter.
    Type: Application
    Filed: April 12, 2007
    Publication date: December 13, 2007
    Applicant: Hitachi, Ltd.
    Inventors: Junnosuke Nakatsugawa, Tsuyoshi Tanaka, Kenji Sakurai, Tunehiro Endo