Patents by Inventor Atsushi Sakawaki

Atsushi Sakawaki 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: 11009070
    Abstract: A magnetic bearing supports an object to be supported in a noncontact manner by means of a composite electromagnetic force of first and second electromagnets. A processor-based controller causes a first current and a second current to be controlled according to the following equations, i 1 = g 0 - ax g 0 ? ( i b + i d ) ( 1 ) i 2 = g 0 + ax g 0 ? ( i b - i d ) ( 2 ) where i1 is the first current flowing to the first electromagnet, i2 is the second current flowing to the second electromagnet, id is a control current, ib is a bias current, g0 is a reference gap length, x is a displacement amount of the object to be supported with respect to a center position, and a is a predetermined correction coefficient.
    Type: Grant
    Filed: June 8, 2018
    Date of Patent: May 18, 2021
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventor: Atsushi Sakawaki
  • Publication number: 20210115929
    Abstract: A drive support unit of a turbo compressor includes at least one bearingless motor. The at least one bearingless motor includes a rotor-stator pair constituted by a rotor and a stator, and is configured to rotationally drive a drive shaft and to support a radial load of the drive shaft in a contactless manner. Accordingly, it is possible to provide a turbo compressor to which a bearingless motor is applied.
    Type: Application
    Filed: May 8, 2018
    Publication date: April 22, 2021
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Yuji NAKAZAWA, Atsushi SAKAWAKI, Hirofumi HIGASHI, Taiichi NOSE, Takaaki ONO, Yusuke IRINO
  • Publication number: 20210108646
    Abstract: A radial load of a drive shaft is supported by only a plurality of bearingless motors. Maximum values of the radial load acting on the plurality of bearingless motors are not uniform. The bearingless motor, the maximum value of the radial load acting on which is the largest, has a greater maximum value of supporting magnetic flux generated to generate an electromagnetic force for supporting the radial load, compared with the bearingless motor, the maximum value of the radial load acting on which is the smallest. This configuration allows a reduction in size of a rotary system including a load and a drive shaft in an electric motor system.
    Type: Application
    Filed: April 27, 2018
    Publication date: April 15, 2021
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Yuji NAKAZAWA, Atsushi SAKAWAKI
  • Patent number: 10895282
    Abstract: A controller performs, in a first mode, a first operation for controlling composite electromagnetic force of electromagnets such that a target member moves within a predetermined moving range, and a second operation for acquiring temperature drift correlation information indicative of a correlation between a reference value and an input-output characteristic of a position sensor, based on the reference value and the input-output characteristic of the position sensor in the first operation. The controller performs, in a second mode, a third operation for controlling the composite electromagnetic force of the electromagnets according to a signal level of a detection signal from the position sensor, and a fourth operation for compensating the input-output characteristic of the position sensor in the third operation, based on the temperature drift correlation information and the reference value in the third operation.
    Type: Grant
    Filed: August 18, 2016
    Date of Patent: January 19, 2021
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Kazuya Hirata, Atsushi Sakawaki
  • Publication number: 20200350804
    Abstract: The stator includes a stator core, a support electric wire formed by one or more conductive wires, and a drive electric wire formed by one or more conductive wires. The stator core includes an annular shaped back yoke and a plurality of teeth on an inner periphery of the back yoke. The support electric wire is disposed so as to pass through a plurality of slots respectively formed between the teeth, and forms a winding portion that generates an electromagnetic force for supporting the rotor in a non-contact manner by being energized. The drive electric wire is disposed so as to pass through the plurality of slots, and forms a winding portion that generates an electromagnetic force for rotating the rotor by being energized. A cross-sectional area per conductive wire of the support electric wire differs from a cross-sectional area per conductive wire of the drive electric wire.
    Type: Application
    Filed: October 25, 2018
    Publication date: November 5, 2020
    Inventors: Takaaki ONO, Yusuke IRINO, Tatsuya TONARI, Yuji NAKAZAWA, Keiji AOTA, Atsushi SAKAWAKI
  • Publication number: 20200292293
    Abstract: Disclosed is a method for calibrating at least one gap sensor, the at least one gap sensor being provided on a magnetic bearing supporting a floating body in a non-contact manner by an electromagnetic force, the at least one gap sensor being configured to detect a gap between the floating body and a reference object that serves as a positional reference for position control of the floating body. The method includes: constructing a transformation formula for transforming an output of the at least one gap sensor into the gap using three or more constraints that are set as conditions for associating the gap with the output of the at least one gap sensor.
    Type: Application
    Filed: September 29, 2017
    Publication date: September 17, 2020
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventor: Atsushi SAKAWAKI
  • Patent number: 10767890
    Abstract: A drive shaft rotates a load. A drive support rotates the drive shaft and supports a radial load of the drive shaft in a non-contact manner, by an electromagnetic force generated by the flow of a current within a predetermined current range through the drive support. A control section controls an operation of the load based on a magnetic flux margin degree expressed by the difference between a total magnetic flux amount generated at the drive support and a predetermined limit of the total magnetic flux amount for the drive support. The total magnetic flux amount includes driving magnetic flux and the supporting magnetic flux in a predetermined operation region of the load. The driving magnetic flux is generated at the drive support for rotating the drive shaft. The supporting magnetic flux is generated at the drive support for supporting a radial load of the drive shaft.
    Type: Grant
    Filed: May 8, 2018
    Date of Patent: September 8, 2020
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Yuji Nakazawa, Atsushi Sakawaki
  • Publication number: 20200096220
    Abstract: A drive shaft rotates a load. A drive support rotates the drive shaft and supports a radial load of the drive shaft in a non-contact manner, by an electromagnetic force generated by the flow of a current within a predetermined current range through the drive support. A control section controls an operation of the load based on a magnetic flux margin degree expressed by the difference between a total magnetic flux amount generated at the drive support and a predetermined limit of the total magnetic flux amount for the drive support. The total magnetic flux amount includes driving magnetic flux and the supporting magnetic flux in a predetermined operation region of the load. The driving magnetic flux is generated at the drive support for rotating the drive shaft. The supporting magnetic flux is generated at the drive support for supporting a radial load of the drive shaft.
    Type: Application
    Filed: May 8, 2018
    Publication date: March 26, 2020
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Yuji NAKAZAWA, Atsushi SAKAWAKI
  • Publication number: 20190203767
    Abstract: A controller performs, in a first mode, a first operation for controlling composite electromagnetic force of electromagnets such that a target member moves within a predetermined moving range, and a second operation for acquiring temperature drift correlation information indicative of a correlation between a reference value and an input-output characteristic of a position sensor, based on the reference value and the input-output characteristic of the position sensor in the first operation. The controller performs, in a second mode, a third operation for controlling the composite electromagnetic force of the electromagnets according to a signal level of a detection signal from the position sensor, and a fourth operation for compensating the input-output characteristic of the position sensor in the third operation, based on the temperature drift correlation information and the reference value in the third operation.
    Type: Application
    Filed: August 18, 2016
    Publication date: July 4, 2019
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Kazuya HIRATA, Atsushi SAKAWAKI
  • Publication number: 20190170151
    Abstract: A magnetic bearing device includes a magnetic bearing including a plurality of electromagnets, a displacement sensor configured to output an output signal in accordance with a displacement of a shaft, and a controller configured to control the electromagnets. The controller compensates for a change in levels of the output signal, the change occurring in accordance with a change in ambient temperature around the displacement sensor, based on one or more reference values correlating with the change in levels of the output signal. The one or more reference values are detected for use in controlling the rotary electric machine, a fluid machine system including the rotary electric machine, or an apparatus including the fluid machine system.
    Type: Application
    Filed: August 18, 2016
    Publication date: June 6, 2019
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Atsushi SAKAWAKI, Kazuya HIRATA
  • Publication number: 20180291957
    Abstract: A magnetic bearing supports an object to be supported in a noncontact manner by means of a composite electromagnetic force of first and second electromagnets. A processor-based controller causes a first current and a second current to be controlled according to the following equations, i 1 = g 0 - ax g 0 ? ( i b + i d ) ( 1 ) i 2 = g 0 + ax g 0 ? ( i b - i d ) ( 2 ) where i1 is the first current flowing to the first electromagnet, i2 is the second current flowing to the second electromagnet, id is a control current, ib is a bias current, g0 is a reference gap length, x is a displacement amount of the object to be supported with respect to a center position, and a is a predetermined correction coefficient.
    Type: Application
    Filed: June 8, 2018
    Publication date: October 11, 2018
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventor: Atsushi SAKAWAKI
  • Publication number: 20170234364
    Abstract: A magnetic bearing includes a controller dividing a control region in two regions based on an individual difference between electromagnets regarding a correlation between two or more parameters among a current flowing through the electromagnets, a number of flux linkages, a gap width, magnetic energy, magnetic co-energy, electromagnetic force, and a parameter derived using these parameters. In a first control region with a small individual difference, the controller uses a control model common for all of the electromagnets. In a second control region with a large individual difference, the controller performs position control of a drive shaft using control models provided one for each of the electromagnets or one for each of a predetermined number of electromagnet groups.
    Type: Application
    Filed: August 31, 2015
    Publication date: August 17, 2017
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Atsushi SAKAWAKI, Yuji NAKAZAWA
  • Publication number: 20170234363
    Abstract: In a state where part of a plurality of electromagnets (27) is controlled based on a control model built in advanced for a first control region (A1), and where position control of a drive shaft (13) is performed by controlling one or a group of the electromagnets (27) in a second control region (A2), an electromagnetic force of the electromagnets (27) controlled within the second control region (A2) is calculated based on an electromagnetic force of the electromagnets (27) controlled within the first control region (A1).
    Type: Application
    Filed: August 31, 2015
    Publication date: August 17, 2017
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventor: Atsushi SAKAWAKI
  • Patent number: 9689398
    Abstract: A magnetic bearing body supports a rotating shaft using a combined electromagnetic force of a pair of control electromagnets without contact. A controller detects a control index value based on a first coil current passed through a coil of a first control electromagnet of the pair of control electromagnets which generates an electromagnetic force in the same direction as that of a load exerted on the rotating shaft, the control index value being an index of the degree of margin for error in control depending on a value of the first coil current. And the controller controls a middle value of a pair of coil currents passed through the respective corresponding coils of the pair of control electromagnets so that the control index value approaches a predetermined target index value.
    Type: Grant
    Filed: December 19, 2012
    Date of Patent: June 27, 2017
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventors: Atsushi Sakawaki, Yuji Nakazawa, Yusuke Irino, Naoya Yamashita
  • Patent number: 9660499
    Abstract: A stator is provided which exerts a combined electromagnetic force of a plurality of electromagnets on a drive shaft having a fluctuating load. A controller is provided which controls a current difference between a first coil current passed through a coil of the electromagnet generating an electromagnetic force in a direction opposite to that of the load and a second coil current passed through a coil of the electromagnet generating an electromagnetic force in the same direction as that of the load to perform a position control on the drive shaft. The controller adjusts the second coil current to reduce an average value of the second coil current.
    Type: Grant
    Filed: May 29, 2012
    Date of Patent: May 23, 2017
    Assignee: Daikin Industries, Ltd.
    Inventors: Atsushi Sakawaki, Yuji Nakazawa, Yusuke Irino, Naoya Yamashita
  • Publication number: 20140363321
    Abstract: A magnetic bearing body supports a rotating shaft using a combined electromagnetic force of a pair of control electromagnets without contact. A controller detects a control index value based on a first coil current passed through a coil of a first control electromagnet of the pair of control electromagnets which generates an electromagnetic force in the same direction as that of a load exerted on the rotating shaft, the control index value being an index of the degree of margin for error in control depending on a value of the first coil current. And the controller controls a middle value of a pair of coil currents passed through the respective corresponding coils of the pair of control electromagnets so that the control index value approaches a predetermined target index value.
    Type: Application
    Filed: December 19, 2012
    Publication date: December 11, 2014
    Inventors: Atsushi Sakawaki, Yuji Nakazawa, Yusuke Irino, Naoya Yamashita
  • Publication number: 20140234139
    Abstract: A stator is provided which exerts a combined electromagnetic force of a plurality of electromagnets on a drive shaft having a fluctuating load. A controller is provided which controls a current difference between a first coil current passed through a coil of the electromagnet generating an electromagnetic force in a direction opposite to that of the load and a second coil current passed through a coil of the electromagnet generating an electromagnetic force in the same direction as that of the load to perform a position control on the drive shaft. The controller adjusts the second coil current to reduce an average value of the second coil current.
    Type: Application
    Filed: May 29, 2012
    Publication date: August 21, 2014
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Atsushi Sakawaki, Yuji Nakazawa, Yusuke Irino, Naoya Yamashita
  • Publication number: 20070033029
    Abstract: A noise cancellation helmet includes a noise detecting unit which detects noise in a helmet body, a sound outputting unit which outputs a control sound for canceling the detected noise, a control signal generating unit which processes an output signal of the noise detecting unit through computation to generate a control signal for the control sound and applies the control signal to the sound outputting unit, an utterance detecting unit which detects utterance of a wearer, an utterance absent period gain adjusting unit which adjusts a gain of the control signal generating unit in an utterance absent period, an utterance absent period gain storing unit which stores a gain set by the utterance absent period gain adjusting unit immediately before the detection of the utterance, and an utterance present period gain adjusting unit which adjusts the gain of the control signal generating unit on the basis of the gain stored in the utterance absent period gain storing unit in an utterance present period.
    Type: Application
    Filed: May 24, 2006
    Publication date: February 8, 2007
    Applicant: YAMAHA HATSUDOKI KABUSHIKI KAISHA
    Inventor: Atsushi SAKAWAKI
  • Publication number: 20050117754
    Abstract: An active noise cancellation helmet includes a detection unit which detects noise in a helmet body, and a sound outputting unit which outputs a sound for canceling the noise detected by the detection unit. A control signal is generated by processing an output signal of the detection unit through computation. The control signal is amplified by an amplification unit, and applied to the sound outputting unit. A ratio of sound pressures in different frequency ranges is determined on the basis of the output signal of the detection unit. A gain of the amplification unit is adjusted on the basis of the sound pressure ratio so as to approximate a spectrum of the output signal of the detection unit to a predetermined target spectrum.
    Type: Application
    Filed: November 26, 2004
    Publication date: June 2, 2005
    Inventor: Atsushi Sakawaki