Patents by Inventor Sachio Nakayama
Sachio Nakayama 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: 20200382042Abstract: A current detection device (120) including: a current detection unit (200) configured to, on a basis of respective voltage drops of resistance elements (RS1 to RS3) connected in series to lower arm elements of respective phases of a PWM-controlled multiphase inverter (104), detect respective current values of the respective phases; a sum calculation unit (201) configured to calculate an all phase sum of current detection values detected by the current detection unit; a maximum duty phase determination unit (203) configured to determine a phase whose upper arm element is driven at a maximum duty ratio; an output switching unit (204) configured to, when the all phase sum of the current detection values has been determined to be equal to or more than a threshold value, switch a value to be output as a current detection value of a lower arm of the phase whose upper arm element is driven at the maximum duty ratio to a value obtained by inverting a sign of a sum of the current detection values detected in remainingType: ApplicationFiled: March 26, 2019Publication date: December 3, 2020Applicant: NSK LTD.Inventors: Sachio NAKAYAMA, Yuzuru HOSHI
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Patent number: 9604666Abstract: An electric power steering apparatus that protects Zener diodes without impairing steering performances by time-integrating a loss power of the Zener diodes for protecting FETs and gradually limiting a duty ratio with an increase in an integrating loss. The apparatus includes a loss power calculating section that calculates a loss power when a difference between an ignition voltage and an inverter applying voltage is equal to or more than a predetermined voltage; an integrating loss calculating section to calculate an integrating loss of the loss power; a permissible loss calculating section to calculate a permissible loss based on a temperature; a minimum value selecting section to select a minimum value of a loss difference of the permissible loss and the integrating loss; and a limit value calculating section to calculate a limit value of the PWM-signal based on the minimum value of the loss difference and the permissible loss.Type: GrantFiled: March 18, 2013Date of Patent: March 28, 2017Assignee: NSK LTD.Inventors: Sachio Nakayama, Toru Sakaguchi, Yuzuru Hoshi, Shinichi Tanaka, Masanori Shingou
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Publication number: 20160052541Abstract: An electric power steering apparatus that protects Zener diodes without impairing steering performances by time-integrating a loss power of the Zener diodes for protecting FETs and gradually limiting a duty ratio with an increase in an integrating loss. The apparatus includes a loss power calculating section that calculates a loss power when a difference between an ignition voltage and an inverter applying voltage is equal to or more than a predetermined voltage; an integrating loss calculating section to calculate an integrating loss of the loss power; a permissible loss calculating section to calculate a permissible loss based on a temperature; a minimum value selecting section to select a minimum value of a loss difference of the permissible loss and the integrating loss; and a limit value calculating section to calculate a limit value of the PWM-signal based on the minimum value of the loss difference and the permissible loss.Type: ApplicationFiled: March 18, 2013Publication date: February 25, 2016Applicant: NSK LTD.Inventors: Sachio NAKAYAMA, Toru SAKAGUCHI, Yuzuru HOSHI, Shinichi TANAKA, Masanori SHINGOU
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Patent number: 8831832Abstract: A motor control apparatus that is capable of making the whole control system robust not only with respect to motor parameter variations such as the temperature variation and the manufacturing unevenness but also with respect to disturbances while using a cheap and compact one-shunt type current detecting circuit and simultaneously diagnosing an estimation error and an electric power steering apparatus provide with the motor control apparatus.Type: GrantFiled: March 28, 2013Date of Patent: September 9, 2014Assignee: NSK Ltd.Inventors: Yuzuru Hoshi, Toru Sakaguchi, Sachio Nakayama, Masahiro Maeda, Kenji Mori, Yousuke Imamura
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Publication number: 20140156144Abstract: A motor control apparatus that is capable of making the whole control system robust not only with respect to motor parameter variations such as the temperature variation and the manufacturing unevenness but also with respect to disturbances while using a cheap and compact one-shunt type current detecting circuit and simultaneously diagnosing an estimation error and an electric power steering apparatus provide with the motor control apparatus.Type: ApplicationFiled: March 28, 2013Publication date: June 5, 2014Applicant: NSK LTD.Inventors: Yuzuru Hoshi, Toru Sakaguchi, Sachio Nakayama, Masahiro Maeda, Kenji Mori, Yousuke Imamura
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Patent number: 7268459Abstract: The electric power steering apparatus includes a brushless motor as an electric motor. The motor has a rotor and a stator 34. The stator 34 includes: a back core BY; a plurality of teeth TS disposed along the circumference of the back core protruding from the back core BY toward its radial center and forming slots SL therebetween; and an exciting coil 38 wound around each of the teeth TS. Each of the slots SL is filled with a resin material. The back core BY is partially press-fitted into a yoke 21 so that the outer surface of the back core BY comes partially into contact with the inner surface of the yoke 21 along their circumferences.Type: GrantFiled: July 13, 2005Date of Patent: September 11, 2007Assignee: NSK Ltd.Inventors: Takashi Baba, Manabu Okamura, Sachio Nakayama
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Patent number: 7180217Abstract: A motor comprising a motor-wiring bus bar including a plurality of annular ring conductors connecting lead wires of the motor including a stator in which a plurality of stator cores having the lead wires is arranged in a circle or connecting the lead wires and a power line together and a plurality of terminals attached to the ring conductors. The ring conductors are different in diameter and arranged concentrically on a same plane.Type: GrantFiled: January 24, 2005Date of Patent: February 20, 2007Assignee: NSK Ltd.Inventors: Sachio Nakayama, Masaru Wada, Yoshiyuki Watanabe
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Publication number: 20060012262Abstract: The electric power steering apparatus includes a brushless motor as an electric motor. The motor has a rotor and a stator 34. The stator 34 includes: a back core BY; a plurality of teeth TS disposed along the circumference of the back core protruding from the back core BY toward its radial center and forming slots SL therebetween; and an exciting coil 38 wound around each of the teeth TS. Each of the slots SL is filled with a resin material. The back core BY is partially press-fitted into a yoke 21 so that the outer surface of the back core BY comes partially into contact with the inner surface of the yoke 21 along their circumferences.Type: ApplicationFiled: July 13, 2005Publication date: January 19, 2006Applicant: NSK Ltd.Inventors: Takashi Baba, Manabu Okamura, Sachio Nakayama
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Publication number: 20050189828Abstract: A motor comprising a motor-wiring bus bar including a plurality of annular ring conductors connecting lead wires of the motor including a stator in which a plurality of stator cores having the lead wires is arranged in a circle or connecting the lead wires and a power line together and a plurality of terminals attached to the ring conductors. The ring conductors are different in diameter and arranged concentrically on a same plane.Type: ApplicationFiled: January 24, 2005Publication date: September 1, 2005Applicant: NSK LTD.Inventors: Sachio Nakayama, Masaru Wada, Yoshiyuki Watanabe