Patents by Inventor Yasuhiko Kitajima

Yasuhiko Kitajima 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).

  • Publication number: 20060091833
    Abstract: A motor drive system includes a multi-output dc power source providing three or more output potentials, and a switching circuit including switching devices connected, respectively, with the output potentials of the multi-output power source. A controller determines a command apply voltage representing a desired voltage to be applied to the motor, and further determines a plurality of command share voltages corresponding to supply voltages of the multi-output dc power source, from the command apply voltage. The controller produces a pulsed voltage by driving the switching devices in accordance with the command share voltages.
    Type: Application
    Filed: October 26, 2005
    Publication date: May 4, 2006
    Inventors: Yasuhiko Kitajima, Kantaro Yoshimoto
  • Patent number: 7034493
    Abstract: A motor control apparatus having a fundamental wave current control circuit that implements feedback control on a fundamental wave component of a motor current in a dq coordinate system rotating in synchronization with the rotation of the motor and a higher harmonic current control circuit that implements feedback control on a higher harmonic components of the motor current in a dhqh coordinate system rotating with a frequency which is an integral multiple of the frequency of the fundamental wave component of the motor current, eliminates the higher harmonic component of the motor current from the control deviation between a fundamental wave current command value and a motor current feedback value.
    Type: Grant
    Filed: April 1, 2004
    Date of Patent: April 25, 2006
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima
  • Patent number: 7030526
    Abstract: An integrated drive motor unit which is integrally constituted of a motor, an inverter and a reducer differential unit arranged in a row, and a frame member. The reducer differential unit is connected to an output shaft of the motor, and distributes torque of the motor to a pair of axles, one of which passes through the inverter. The frame member constitutes a part of the motor and a part of the reducer differential unit, and has a portion surrounding the axle passing through the inverter. The inverter is disposed outside the frame member.
    Type: Grant
    Filed: November 5, 2003
    Date of Patent: April 18, 2006
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Masahiro Tsukamoto, Yuki Nakajima, Toshiro Shinohara, Hiroyuki Kaneko, Yasuhiko Kitajima, Makoto Iwashima, Akihiro Hanamura, Kouichirou Yonekura, Tadayuki Hatsuda, Masakazu Kobayashi, Yutaro Kaneko
  • Publication number: 20060006832
    Abstract: A power conversion system for converting a dc voltage to a pulsed ac voltage includes a dc voltage source providing three or more electric potentials, and a switching circuit arranged to connect one of the potentials selectively to an output terminal. A controller produces a pulsed ac output voltage at the output terminal from the potentials of the dc voltage source by controlling an on time for connecting each of the potentials to the output terminal.
    Type: Application
    Filed: July 6, 2005
    Publication date: January 12, 2006
    Inventors: Yasuhiko Kitajima, Kantaro Yoshimoto, Masanori Yamagiwa, Ryuuta Yamaguchi, Yutaka Tajima, Yasuaki Hayami
  • Patent number: 6940387
    Abstract: A coil-embedded dust core and a method for manufacturing the coil-embedded dust core are provided. The coil-embedded dust core comprises a coil formed from a flat conductor wound in a coil configuration, and a green body consisting of insulating material-coated ferromagnetic metal particles. This results in a coil-embedded dust core more compact in size but with larger inductance. A rectangular wire can be used as the flat conductor. In addition, parts of the coil may function as terminal sections. In this case, the terminal sections of the coil may be formed wider than other part of the coil. The coil-embedded dust core is less prone to joint failures between a coil and terminal sections and to insulation failures of the coil and the terminal section with respect to the magnetic powder. The coil-embedded dust core is more compact while achieving larger inductance.
    Type: Grant
    Filed: April 2, 2004
    Date of Patent: September 6, 2005
    Assignee: TDK Corporation
    Inventors: Kazuhiko Shibata, Takashi Nagasaka, Junetsu Tamura, Yasuhiko Kitajima, Hideharu Moro, Tsutomu Chou, Tsuneo Suzuki
  • Patent number: 6899270
    Abstract: A noncontact reader/writer is disclosed which performs, at a high speed, a processing of communication, such as read or write, with a plurality of noncontact information carriers such as noncontact IC cards. A transmitting unit transmits signals, such as commands, to the respective kinds of noncontact information carriers. A memory stores information about at least one of the kinds of noncontact information carriers with which the noncontact reader/writer communicated. A control unit decides, based on the stored information, the priority of the kinds of noncontact information carries in the communication processing and performs a communication processing. The stored information includes the kinds of noncontact information carriers or the number of occurences of communication with the respective kinds of noncontact information carriers.
    Type: Grant
    Filed: November 15, 2001
    Date of Patent: May 31, 2005
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Keiichiro Obayashi, Yasuhiko Kitajima, Nobuhiko Fujii
  • Publication number: 20050088136
    Abstract: An inverter supply voltage generator comprises an inverter supply voltage computing unit 10, a voltage converter 11 and a battery 12. The inverter supply voltage generator varies inverter supply voltage Vdc in synchronization with motor-application voltages Vu_pwm, Vv_pwm, and Vw_pwm. Thus, the degree of freedom of the switching operation of a PWM inverter 13 is increased, an inverter loss and the size of the PWM inverter 13 can be reduced, and its efficiency can be enhanced without deteriorating the driving efficiency of an IPM motor 14.
    Type: Application
    Filed: October 25, 2004
    Publication date: April 28, 2005
    Inventor: Yasuhiko Kitajima
  • Patent number: 6861813
    Abstract: Limits are imposed on a fundamental voltage command value calculated at a fundamental current control circuit that controls a fundamental component of a 3-phase AC motor current in a dq-axis coordinate system rotating in synchronization with the rotation of the 3-phase AC motor by using predetermined limit values and limits are imposed on a higher harmonic voltage command value calculated in an orthogonal coordinate system (a higher harmonic coordinate system) rotating at a frequency set to an integral multiple of the frequency of the fundamental component in the 3-phase AC motor current by using a predetermined limit values. The voltage command values resulting from the limit processing are added together and a voltage corresponding to the sum is applied to the AC motor for drive control.
    Type: Grant
    Filed: November 4, 2002
    Date of Patent: March 1, 2005
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima
  • Publication number: 20050034941
    Abstract: A shock absorber has a function of transmitting electric power between sprung and unsprung electrical components. The shock absorber includes a pair of conductive elements. The conductive elements are coupled electrically to each other. One of the conductive elements is attached to the rod of the shock absorber. The other conductive element is mounted within the tube.
    Type: Application
    Filed: August 9, 2004
    Publication date: February 17, 2005
    Inventors: Masahiro Tsukamoto, Yasuhiko Kitajima, Kouichirou Yonekura, Tetsuya Niikuni
  • Publication number: 20040195993
    Abstract: A motor control apparatus having a fundamental wave current control circuit that implements feedback control on a fundamental wave component of a motor current in a dq coordinate system rotating in synchronization with the rotation of the motor and a higher harmonic current control circuit that implements feedback control on a higher harmonic components of the motor current in a dhqh coordinate system rotating with a frequency which is an integral multiple of the frequency of the fundamental wave component of the motor current, eliminates the higher harmonic component of the motor current from the control deviation between a fundamental wave current command value and a motor current feedback value.
    Type: Application
    Filed: April 1, 2004
    Publication date: October 7, 2004
    Applicant: NISSAN MOTOR CO., LTD.
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima
  • Publication number: 20040189431
    Abstract: A coil-embedded dust core and a method for manufacturing the coil-embedded dust core are provided. The coil-embedded dust core comprises a coil formed from a flat conductor wound in a coil configuration, and a green body consisting of insulating material-coated ferromagnetic metal particles. This results in a coil-embedded dust core more compact in size but with larger inductance. A rectangular wire can be used as the flat conductor. In addition, parts of the coil may function as terminal sections. In this case, the terminal sections of the coil may be formed wider than other part of the coil. The coil-embedded dust core is less prone to joint failures between a coil and terminal sections and to insulation failures of the coil and the terminal section with respect to the magnetic powder. The coil-embedded dust core is more compact while achieving larger inductance.
    Type: Application
    Filed: April 2, 2004
    Publication date: September 30, 2004
    Applicant: TDK Corporation
    Inventors: Kazuhiko Shibata, Takashi Nagasaka, Junetsu Tamura, Yasuhiko Kitajima, Hideharu Moro, Tsutomu Chou, Tsuneo Suzuki
  • Publication number: 20040189114
    Abstract: A power converter that is arranged in series with a motor to form a unitary structure through which an output shaft extends is provided with a plurality of coolers and a power semiconductor module mounted on a cooling surface of at least one of the plurality of coolers to supply electric power to a motor. Each of the plurality of coolers is disposed along an extending direction radially extending from an output shaft to be perpendicular to the output shaft. The cooling surface is provided along such an extending direction.
    Type: Application
    Filed: February 18, 2004
    Publication date: September 30, 2004
    Applicant: NISSAN MOTOR CO., LTD.
    Inventors: Makoto Iwashima, Akihiro Hanamura, Masanori Yamagiwa, Yasuhiko Kitajima
  • Patent number: 6791445
    Abstract: A coil-embedded dust core and a method for manufacturing the coil-embedded dust core are provided. The coil-embedded dust core comprises a coil formed from a flat conductor wound in a coil configuration, and a green body consisting of insulating material-coated ferromagnetic metal particles. This results in a coil-embedded dust core more compact in size but with larger inductance. A rectangular wire can be used as the flat conductor. In addition, parts of the coil may function as terminal sections. In this case, the terminal sections of the coil may be formed wider than other part of the coil. The coil-embedded dust core is less prone to joint failures between a coil and terminal sections and to insulation failures of the coil and the terminal section with respect to the magnetic powder. The coil-embedded dust core is more compact while achieving larger inductance.
    Type: Grant
    Filed: February 19, 2002
    Date of Patent: September 14, 2004
    Assignee: TDK Corporation
    Inventors: Kazuhiko Shibata, Takashi Nagasaka, Junetsu Tamura, Yasuhiko Kitajima, Hideharu Moro, Tsutomu Chou, Tsuneo Suzuki
  • Publication number: 20040174239
    Abstract: A coil-embedded dust core and a method for manufacturing the coil-embedded dust core are provided. The coil-embedded dust core comprises a coil formed from a flat conductor wound in a coil configuration, and a green body consisting of insulating material-coated ferromagnetic metal particles. This results in a coil-embedded dust core more compact in size but with larger inductance. A rectangular wire can be used as the flat conductor. In addition, parts of the coil may function as terminal sections. In this case, the terminal sections of the coil may be formed wider than other part of the coil. The coil-embedded dust core is less prone to joint failures between a coil and terminal sections and to insulation failures of the coil and the terminal section with respect to the magnetic powder. The coil-embedded dust core is more compact while achieving larger inductance.
    Type: Application
    Filed: March 19, 2004
    Publication date: September 9, 2004
    Applicant: TDK CORPORATION
    Inventors: Kazuhiko Shibata, Takashi Nagasaka, Junetsu Tamura, Yasuhiko Kitajima, Hideharu Moro, Tsutomu Chou, Tsuneo Suzuki
  • Publication number: 20040163409
    Abstract: A drive unit for an electric vehicle is comprised of a motor, an inverter which supplies alternating current electric power to the motor, a speed reducer which is connected to the motor, and a cooling system which cools the motor, the inverter and the speed reducer. The speed reducer reduces a revolution speed of a mechanical output of the motor. The cooling system comprises a heat exchanger at which first refrigerant for receiving heat of at least one of the motor and the inverter receives heat of second refrigerant for receiving heat of at least one of the motor and the speed reducer.
    Type: Application
    Filed: February 25, 2004
    Publication date: August 26, 2004
    Applicant: NISSAN MOTOR CO., LTD.
    Inventors: Yuki Nakajima, Masahiro Tsukamoto, Masakazu Kobayashi, Yutaro Kaneko, Hiroyuki Kaneko, Toshiro Shinohara, Makoto Iwashima, Yasuhiko Kitajima, Akihiro Hanamura, Kouichirou Yonekura, Tadayuki Hatsuda
  • Patent number: 6768280
    Abstract: A motor control apparatus includes a fundamental wave current control system that controls a fundamental wave component of a motor current in an orthogonal coordinate system and a higher harmonic current control system that controls a higher harmonic component contained in the motor current in an orthogonal coordinate system. In the motor control apparatus, it is judged whether an output voltage from the power conversion device is in a saturated state, and a current control gain for the higher harmonic current control system is reduced if it is judged that the output voltage is in the saturated state.
    Type: Grant
    Filed: June 26, 2002
    Date of Patent: July 27, 2004
    Assignee: Nissan Motor Co., Ltd.
    Inventor: Yasuhiko Kitajima
  • Publication number: 20040108778
    Abstract: An integrated drive motor unit which is integrally constituted of a motor, an inverter and a reducer differential unit arranged in a row, and a frame member. The reducer differential unit is connected to an output shaft of the motor, and distributes torque of the motor to a pair of axles, one of which passes through the inverter. The frame member constitutes a part of the motor and a part of the reducer differential unit, and has a portion surrounding the axle passing through the inverter. The inverter is disposed outside the frame member.
    Type: Application
    Filed: November 5, 2003
    Publication date: June 10, 2004
    Applicant: NISSAN MOTOR CO., LTD.
    Inventors: Masahiro Tsukamoto, Yuki Nakajima, Toshiro Shinohara, Hiroyuki Kaneko, Yasuhiko Kitajima, Makoto Iwashima, Akihiro Hanamura, Kouichirou Yonekura, Tadayuki Hatsuda, Masakazu Kobayashi, Yutaro Kaneko
  • Publication number: 20040098270
    Abstract: A noncontact reader/writer is disclosed which performs, at a high speed, a processing of communication, such as read or write, with a plurality of noncontact information carriers such as noncontact IC cards. A transmitting unit transmits signals, such as commands, to the respective kinds of noncontact information carriers. A memory stores information about at least one of the kinds of noncontact information carriers with which the noncontact reader/writer communicated. A control unit decides, based on the stored information, the priority of the kinds of noncontact information carries in the communication processing and performs a communication processing. The stored information includes the kinds of noncontact information carriers or the number of occurences of communication with the respective kinds of noncontact information carriers.
    Type: Application
    Filed: December 18, 2002
    Publication date: May 20, 2004
    Inventors: Keichiro Obayashi, Yasuhiko Kitajima, Nobuhiko Fujii
  • Patent number: 6727675
    Abstract: A motor control apparatus comprises a fundamental current control device that controls a fundamental current in a 3-phase AC motor in an orthogonal coordinate system constituted of a d-axis and a q-axis rotating in synchronization with the rotation of the 3-phase AC motor, a higher harmonic current control device that controls a higher harmonic current in the motor in an orthogonal coordinate system constituted of a dh-axis and a qh-axis rotating at a frequency that is an integral multiple of the frequency of the fundamental component of the current flowing to the motor, an estimating device that estimates the level of the harmonic speed electromotive force in the motor in the dhqh-axis coordinate system and a compensating device that compensates the harmonic speed electromotive force estimated by the estimating device.
    Type: Grant
    Filed: August 28, 2002
    Date of Patent: April 27, 2004
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima
  • Patent number: 6674262
    Abstract: A motor control apparatus comprises a fundamental current command value determining device that determines a fundamental current command value for a motor current based upon at least a torque command value for an AC motor, a higher harmonics current command value determining device that determines a higher harmonics current command value for the motor current and a current control device that controls the current flowing to the AC motor based upon the fundamental current command value and the higher harmonics current command value.
    Type: Grant
    Filed: November 7, 2001
    Date of Patent: January 6, 2004
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Yasuhiko Kitajima, Masahiro Tsukamoto, Kouichirou Yonekura, Kantaro Yoshimoto