Patents by Inventor Junichiro Kozaki

Junichiro Kozaki 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: 9624974
    Abstract: A magnetic bearing device comprises a controller configured to obtain magnetic levitation information of the rotor shaft by AD sampling of current detection signals from the plurality of current sensors and a sum signal obtained by adding the pair of current detection signals relating to the pair of electromagnets, and perform PWM control of the excitation amplifiers based on the magnetic levitation information. The controller performs PWM control so that a length of one of an on-duty period and an off-duty period of the PWM carrier signal is always longer than a predetermined time period based on an attenuation characteristic of a spike noise produced in the electromagnetic current, and performs the AD sampling after the predetermined time period passes from starting timing of one of the on-duty period and the off-duty period.
    Type: Grant
    Filed: January 16, 2014
    Date of Patent: April 18, 2017
    Assignee: Shimadzu Corporation
    Inventors: Junichiro Kozaki, Yoshihiro Nagano
  • Patent number: 9605681
    Abstract: An estimating section detects a signal including counter electromotive voltage information of the motor, and estimating a magnetic pole electric angle and a rotational speed of the motor. A driving current controller repeats generation and cut-off of the driving current supplied from a power supply to the motor via the inverter circuit or regenerated from the motor to the power supply in a low-speed period between a stopped state and a predetermined rotational speed in an accelerating operation at a motor starting time or a decelerating operation at a motor stopping time. The estimating section detects the signal at the cut-off time so as to estimate the magnetic pole electric angle and the rotational speed in the low-speed period.
    Type: Grant
    Filed: March 5, 2014
    Date of Patent: March 28, 2017
    Assignee: Shimadzu Corporation
    Inventor: Junichiro Kozaki
  • Patent number: 9515589
    Abstract: A motor driving device comprises: an inverter having a plurality of switching elements for driving a motor; an arithmetic section for calculating a rotational speed and a magnetic pole electric angle of a motor rotor based on information about a motor phase voltage and information about a motor phase current; a delay correcting section for correcting a phase delay of the magnetic pole electric angle calculated by the arithmetic section so as to generate corrected magnetic pole electric angle; a driving command generating section for generating a sinusoidal wave driving command based on a difference between the rotational speed and a target rotational speed and the corrected magnetic pole electric angle; and a PWM signal generating section for generating a PWM control signal for controlling on/off of the plurality of switching elements based on the sinusoidal wave driving command.
    Type: Grant
    Filed: October 15, 2013
    Date of Patent: December 6, 2016
    Assignee: Shimadzu Corporation
    Inventor: Junichiro Kozaki
  • Patent number: 9506475
    Abstract: An electromagnet has a core with a pair of magnetic poles, a primary coil wound around the core, and a series circuit of a first auxiliary coil wound around the first magnetic pole of the core, a second auxiliary coil wound around the second magnetic pole of the core, and capacitors, and is connected in parallel to the primary coil and the series circuit. The first and the second magnetic poles are each divided into a plurality of split magnetic poles. The first auxiliary coil is composed of a plurality of split auxiliary coils wound around the respective pole in the plurality of split magnetic poles of the first magnetic pole so that the mutual inductance with the primary coil becomes zero. The second auxiliary coil is composed of a plurality of split auxiliary coils wound around the respective pole in a plurality of split magnetic poles of the second magnetic pole so that the mutual inductance with the primary coil becomes zero.
    Type: Grant
    Filed: December 21, 2012
    Date of Patent: November 29, 2016
    Assignee: Shimadzu Corporation
    Inventors: Junichiro Kozaki, Yoshihiro Nagano
  • Patent number: 9353755
    Abstract: A turbomolecular pump device includes: a turbomolecular pump main body; a power unit that drives the turbomolecular pump main body; and a water cooling unit that is provided between the turbomolecular pump main body and the power unit, wherein components provided in a casing of the power unit are classified into an intensive cooling required component that requires intensive cooling, a moderate cooling required component that requires moderate cooling, and a no cooling required component that requires substantially no cooling, the intensive cooling required component is mounted on a first high-conductivity substrate contacting to the water cooling unit, the moderate cooling required component is mounted on a second high heat-conductive substrate contacting to an inner surface of the casing, and the no cooling required component is mounted on a substrate arranged in a space between the first high heat-conductive substrate and the second high heat-conductive substrate.
    Type: Grant
    Filed: March 11, 2010
    Date of Patent: May 31, 2016
    Assignee: SHIMADZU CORPORATION
    Inventors: Yoshihiro Nagano, Masaki Ohfuji, Junichiro Kozaki
  • Patent number: 9347489
    Abstract: A predetermined timing is a timing at which the sampling timing is in a vicinity of a maximum peak position of the carrier wave signal and a timing at which the sampling timing is in a vicinity of a minimum peak position. The demodulation arithmetic section outputs, as the demodulation calculated result, a value d3 calculated with d3=(d1?d2)/2 when a data value of the digital signal sampled in the vicinity of the maximum peak position is denoted by d1 and a data value of the digital signal sampled in the vicinity of the minimum peak position is denoted by d2.
    Type: Grant
    Filed: January 14, 2014
    Date of Patent: May 24, 2016
    Assignee: Shimadzu Corporation
    Inventor: Junichiro Kozaki
  • Patent number: 9065309
    Abstract: A magnetic levitation type vacuum pump includes an electromagnet magnetically levitating a rotor by a magnetic force, an electromagnet driving circuit supplying an electromagnet current including a magnetic levitation control current component and a carrier wave current component having a frequency band higher than the magnetic levitation control current component to the electromagnet coil, a levitated position detecting circuit detecting the carrier wave current component and generating a levitated position signal of the rotor, a magnetic levitation control circuit inputting a current command of the magnetic levitation control current component to the electromagnet driving circuit based on the levitated position signal. The electromagnet coil has a primary coil and a secondary coil connected in parallel with the primary coil.
    Type: Grant
    Filed: November 16, 2012
    Date of Patent: June 23, 2015
    Assignee: SHIMADZU CORPORATION
    Inventors: Junichiro Kozaki, Yoshihiro Nagano, Masaki Ofuji
  • Patent number: 9065369
    Abstract: A motor driving device comprises an inverter, a first arithmetic section, a driving command generating section and a PWM signal generating section. The first arithmetic section calculates a rotational speed and a magnetic pole electrical angle of a motor rotor based on information about a motor phase voltage and information about a motor phase current. The first arithmetic section includes a counter electromotive voltage arithmetic section, a converting section, a second arithmetic section, a third arithmetic section, and a fourth arithmetic section. The first arithmetic section outputs a sum of the magnetic pole phase error and the integrated value as the magnetic pole electrical angle.
    Type: Grant
    Filed: January 15, 2014
    Date of Patent: June 23, 2015
    Assignee: Shimadzu Corporation
    Inventor: Junichiro Kozaki
  • Publication number: 20150050170
    Abstract: A magnetic bearing device comprises a first carrier generation section generating a first carrier signal; a second carrier generation section generating a second carrier signal whose phase differs by (?/2+?) radian from the phase of the first carrier signal; a first demodulation section performing demodulation by sampling the first modulated signal at sampling timing shifted by a phase ? from timing at which the first carrier signal becomes a peak; a second demodulation section performing demodulation by sampling the second modulated signal at sampling timing shifted by a phase (??) from timing at which the second carrier signal becomes a peak; and a controller controlling current in each of the first radial electromagnet and the second radial electromagnet, based on a result of the demodulation by each of the first demodulation section and the second demodulation section.
    Type: Application
    Filed: July 31, 2014
    Publication date: February 19, 2015
    Inventor: Junichiro KOZAKI
  • Publication number: 20140377106
    Abstract: An electromagnet has a core with a pair of magnetic poles, a primary coil wound around the core, and a series circuit of a first auxiliary coil wound around the first magnetic pole of the core, a second auxiliary coil wound around the second magnetic pole of the core, and capacitors, and is connected in parallel to the primary coil and the series circuit. The first and the second magnetic poles are each divided into a plurality of split magnetic poles. The first auxiliary coil is composed of a plurality of split auxiliary coils wound around the respective pole in the plurality of split magnetic poles of the first magnetic pole so that the mutual inductance with the primary coil becomes zero. The second auxiliary coil is composed of a plurality of split auxiliary coils wound around the respective pole in a plurality of split magnetic poles of the second magnetic pole so that the mutual inductance with the primary coil becomes zero.
    Type: Application
    Filed: December 21, 2012
    Publication date: December 25, 2014
    Inventors: Junichiro Kozaki, Yoshihiro Nagano
  • Publication number: 20140271237
    Abstract: An estimating section detects a signal including counter electromotive voltage information of the motor, and estimating a magnetic pole electric angle and a rotational speed of the motor. A driving current controller repeats generation and cut-off of the driving current supplied from a power supply to the motor via the inverter circuit or regenerated from the motor to the power supply in a low-speed period between a stopped state and a predetermined rotational speed in an accelerating operation at a motor starting time or a decelerating operation at a motor stopping time. The estimating section detects the signal at the cut-off time so as to estimate the magnetic pole electric angle and the rotational speed in the low-speed period.
    Type: Application
    Filed: March 5, 2014
    Publication date: September 18, 2014
    Applicant: SHIMADZU CORPORATION
    Inventor: Junichiro KOZAKI
  • Publication number: 20140219841
    Abstract: A predetermined timing is a timing at which the sampling timing is in a vicinity of a maximum peak position of the carrier wave signal and a timing at which the sampling timing is in a vicinity of a minimum peak position. The demodulation arithmetic section outputs, as the demodulation calculated result, a value d3 calculated with d3=(d1?d2)/2 when a data value of the digital signal sampled in the vicinity of the maximum peak position is denoted by d1 and a data value of the digital signal sampled in the vicinity of the minimum peak position is denoted by d2.
    Type: Application
    Filed: January 14, 2014
    Publication date: August 7, 2014
    Applicant: SHIMADZU CORPORATION
    Inventor: Junichiro KOZAKI
  • Publication number: 20140210385
    Abstract: A motor driving device comprises a first arithmetic section calculating a rotational speed and a magnetic pole electrical angle of a motor rotor, a current command setting section setting a d-axis current command and a q-axis current command in a rotating coordinate dq system based on a difference between the rotational speed and a target rotational speed, a driving command generating section generating a sinusoidal wave driving command based on the d-axis current command, the q-axis current command, the rotational speed and the magnetic pole electrical angle and a PWM signal generating section. When the rotational speed has a positive value indicating a positive rotational state, the current command setting section sets the q-axis current command of acceleration driving, and when the rotational speed has a negative value indicating a reverse rotational state, the current command setting section sets the q-axis current command of deceleration driving.
    Type: Application
    Filed: December 20, 2013
    Publication date: July 31, 2014
    Applicant: SHIMADZU CORPORATION
    Inventor: Junichiro KOZAKI
  • Publication number: 20140212312
    Abstract: A magnetic bearing device comprises a controller configured to obtain magnetic levitation information of the rotor shaft by AD sampling of current detection signals from the plurality of current sensors and a sum signal obtained by adding the pair of current detection signals relating to the pair of electromagnets, and perform PWM control of the excitation amplifiers based on the magnetic levitation information. The controller performs PWM control so that a length of one of an on-duty period and an off-duty period of the PWM carrier signal is always longer than a predetermined time period based on an attenuation characteristic of a spike noise produced in the electromagnetic current, and performs the AD sampling after the predetermined time period passes from starting timing of one of the on-duty period and the off-duty period.
    Type: Application
    Filed: January 16, 2014
    Publication date: July 31, 2014
    Applicant: SHIMADZU CORPORATION
    Inventors: Junichiro KOZAKI, Yoshihiro NAGANO
  • Publication number: 20140203742
    Abstract: A motor driving device comprises an inverter, a first arithmetic section, a driving command generating section and a PWM signal generating section. The first arithmetic section calculates a rotational speed and a magnetic pole electrical angle of a motor rotor based on information about a motor phase voltage and information about a motor phase current. The first arithmetic section includes a counter electromotive voltage arithmetic section, a converting section, a second arithmetic section, a third arithmetic section, and a fourth arithmetic section. The first arithmetic section outputs a sum of the magnetic pole phase error and the integrated value as the magnetic pole electrical angle.
    Type: Application
    Filed: January 15, 2014
    Publication date: July 24, 2014
    Applicant: SHIMADZU CORPORATION
    Inventor: Junichiro KOZAKI
  • Publication number: 20140112801
    Abstract: A motor driving device comprises: an inverter having a plurality of switching elements for driving a motor; an arithmetic section for calculating a rotational speed and a magnetic pole electric angle of a motor rotor based on information about a motor phase voltage and information about a motor phase current; a delay correcting section for correcting a phase delay of the magnetic pole electric angle calculated by the arithmetic section so as to generate corrected magnetic pole electric angle; a driving command generating section for generating a sinusoidal wave driving command based on a difference between the rotational speed and a target rotational speed and the corrected magnetic pole electric angle; and a PWM signal generating section for generating a PWM control signal for controlling on/off of the plurality of switching elements based on the sinusoidal wave driving command.
    Type: Application
    Filed: October 15, 2013
    Publication date: April 24, 2014
    Applicant: Shimadzu Corporation
    Inventor: Junichiro KOZAKI
  • Patent number: 8628309
    Abstract: A turbomolecular pump having a pump main unit having, at least, a rotary vein provided on a rotor, a static vein for working in cooperation with the rotary vein to perform a vacuum exhaust, and a motor for driving the rotor, comprising: a controlling device that includes a motor driving circuit for converting into thermal energy, in a regenerative braking resistance, the regenerative electric current that is produced at the time of regeneratively driving the motor; and a cooling device for cooling the controlling device. A rod-shape heating resistive element is used as the regenerative braking resistance, where this resistive heating element is routed along the inner peripheral surface of an end portion 14a of the controlling device case that contacts the cooling device.
    Type: Grant
    Filed: March 30, 2010
    Date of Patent: January 14, 2014
    Assignee: Shimadzu Corporation
    Inventors: Yoshihiro Nagano, Junichiro Kozaki
  • Patent number: 8613604
    Abstract: The provision of the components requiring cooling on top of the cooling mechanism enables the cooling efficiency to be increased. Furthermore, a case of a control device is attached to the cooling mechanism whereon the components requiring cooling are disposed. The cooling mechanism fulfills the role of the contact surface of the case of the control device with the turbomolecular pump main unit, where the case does not have a case panel on the contact surface with the turbomolecular pump main unit. The cooling mechanism fulfills the role of one surface of the case for the control device, where the cooling mechanism is structured integrally with the control device. Additionally, the turbomolecular pump main unit, the cooling mechanism, and the control device are structured integrally by the turbomolecular pump main unit and the cooling mechanism being in contact.
    Type: Grant
    Filed: March 18, 2010
    Date of Patent: December 24, 2013
    Assignee: Shimadzu Corporation
    Inventors: Yoshihiro Nagano, Toshiki Yamaguchi, Takuto Onishi, Masaki Ohfuji, Junichiro Kozaki
  • Patent number: 8480379
    Abstract: A condensation sensor is provided within a power supply device that is provided integratedly with a vacuum pump main unit. When the condensation sensor detects condensation within the power supply device, a CPU closes a cooling water valve. This stops the flow of cooling water that flows through the interior of the power supply device, through a cooling water duct.
    Type: Grant
    Filed: August 5, 2010
    Date of Patent: July 9, 2013
    Assignee: Shimadzu Corporation
    Inventors: Nobuhiko Moriyama, Yoshihiro Nagano, Junichiro Kozaki
  • Publication number: 20120321442
    Abstract: A turbomolecular pump device includes: a turbomolecular pump main body; a power unit that drives the turbomolecular pump main body; and a water cooling unit that is provided between the turbomolecular pump main body and the power unit, wherein components provided in a casing of the power unit are classified into an intensive cooling required component that requires intensive cooling, a moderate cooling required component that requires moderate cooling, and a no cooling required component that requires substantially no cooling, the intensive cooling required component is mounted on a first high-conductivity substrate contacting to the water cooling unit, the moderate cooling required component is mounted on a second high heat-conductive substrate contacting to an inner surface of the casing, and the no cooling required component is mounted on a substrate arranged in a space between the first high heat-conductive substrate and the second high heat-conductive substrate.
    Type: Application
    Filed: March 11, 2010
    Publication date: December 20, 2012
    Applicant: SHIMADZU CORPORATION
    Inventors: Yoshihiro Nagano, Masaki Ohfuji, Junichiro Kozaki