Patents by Inventor Mamoru Yaeshima

Mamoru Yaeshima 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: 8143836
    Abstract: A motor controller capable of effectively utilizing electrical energy accumulated in a capacitor and achieving a reduction in capacitance of the capacitor. The motor controller includes a converter that receives an input AC voltage and performs AC-to-DC power conversion thereon, an inverter that receives DC power and performs DC-to-AC conversion thereon, and a capacitor and a charging/discharging control circuit connected in parallel with a DC link between the converter and the inverter. Electrical energy is supplied from the capacitor to the DC link via the charging/discharging control circuit. The charging/discharging control circuit has a circuit for discharging electrical energy accumulated in the capacitor and for stepping up a voltage of the capacitor when discharging the electrical energy.
    Type: Grant
    Filed: February 3, 2009
    Date of Patent: March 27, 2012
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Yuuichi Yamada, Mamoru Yaeshima, Masatomo Shirouzu, Koujirou Sakai
  • Patent number: 7868569
    Abstract: A motor driving apparatus comprises a charge/discharge control circuit for controlling charge to or discharge from a capacitor connected in parallel in a link section between a converter and an inverter, and a current control means for controlling discharge current from the charge/discharge control circuit. The current control means controls discharge current from the charge/discharge control circuit based on input current to the inverter or output current from the converter so that output current from the converter is equal to a prescribed value.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: January 11, 2011
    Assignee: Fanuc Ltd
    Inventors: Yasusuke Iwashita, Mamoru Yaeshima, Yuuichi Yamada, Masatomo Shirouzu, Koujirou Sakai
  • Publication number: 20090237016
    Abstract: A motor controller capable of effectively utilizing electrical energy accumulated in a capacitor and achieving a reduction in capacitance of the capacitor. The motor controller includes a converter that receives an input AC voltage and performs AC-to-DC power conversion thereon, an inverter that receives DC power and performs DC-to-AC conversion thereon, and a capacitor and a charging/discharging control circuit connected in parallel with a DC link between the converter and the inverter. Electrical energy is supplied from the capacitor to the DC link via the charging/discharging control circuit. The charging/discharging control circuit has a circuit for discharging electrical energy accumulated in the capacitor and for stepping up a voltage of the capacitor when discharging the electrical energy.
    Type: Application
    Filed: February 3, 2009
    Publication date: September 24, 2009
    Applicant: FANUC LTD
    Inventors: Yasusuke IWASHITA, Yuuichi Yamada, Mamoru Yaeshima, Masatomo Shirouzu, Koujirou Sakai
  • Publication number: 20090218976
    Abstract: A motor driving apparatus comprises a charge/discharge control circuit for controlling charge to or discharge from a capacitor connected in parallel in a link section between a converter and an inverter, and a current control means for controlling discharge current from the charge/discharge control circuit. The current control means controls discharge current from the charge/discharge control circuit based on input current to the inverter or output current from the converter so that output current from the converter is equal to a prescribed value.
    Type: Application
    Filed: December 23, 2008
    Publication date: September 3, 2009
    Applicant: FANUC LTD
    Inventors: Yasusuke IWASHITA, Mamoru Yaeshima, Yuuichi Yamada, Masatomo Shirouzu, Koujirou Sakai
  • Publication number: 20080150549
    Abstract: A motor insulation deterioration detection device wherein a capacitor provided in a power supply section is utilized as a power supply for motor insulation deterioration detection, with provisions made to be able to detect insulation resistance regardless of the value of the voltage developed across the capacitor. The motor insulation deterioration detection device includes: a first contact which connects one end of the capacitor to ground; a second contact which connects the other end of the capacitor to a motor coil via a detection resistor; a unit which, using the detection resistor, detects a current flowing through a closed circuit formed by the first contact, capacitor, second contact, detection resistor, motor coil, and ground; a unit which detects the voltage developed across the capacitor; and a unit which calculates the insulation resistance value based on the current detection value and the voltage detection value.
    Type: Application
    Filed: December 20, 2007
    Publication date: June 26, 2008
    Inventors: Shinichi Horikoshi, Hiroyasu Sato, Akira Hirai, Satoshi Tanabe, Mamoru Yaeshima
  • Publication number: 20080123225
    Abstract: A motor drive apparatus used for an industrial machine, comprising a converter (4) for converting an AC voltage supplied from an external power source to DC voltage, a capacitor bank (7) connected to the output of the converter (4), and a control apparatus (8) stopping the functions of the capacitor bank when detecting an abnormality of the capacitor bank, whereby the safety of the motor drive apparatus when an abnormality occurs in the capacitor bank is secured by building into the capacitor bank a circuit or function for protecting the capacitor bank and motor drive apparatus and whereby electric shock is prevented even when a person mistakenly touches the capacitor bank when the capacitor bank stores a charge.
    Type: Application
    Filed: October 14, 2007
    Publication date: May 29, 2008
    Applicant: FANUC LTD
    Inventors: Shunsuke MATSUBARA, Mamoru YAESHIMA, Yuuichi YAMADA, Shigeki HANYU, Masatomo SHIROUZU
  • Publication number: 20080094022
    Abstract: An insulation-resistance degradation detecting device capable of selecting one of a plurality of motors and detecting its insulation-resistance degradation. A power source unit is connected with a plurality of motor drive amplifiers which drive two motors, individually. The motor is selected by selecting means, and a contactor S1 or S2 is turned on. When a smoothing capacitor C of the power source unit reaches a predetermined voltage after an electromagnetic contactor is turned off, contactors SW1 and SW2 are turned on, whereupon one end of the smoothing capacitor C, contactor SW2, resistors R1 and R2, contactor S1 or S2, coil of the motor, insulation resistor Rx of the motor, grounds G2 and G1, contactor SW1, and the other end of the smoothing capacitor C form a closed circuit. The voltage of the smoothing capacitor C is applied to this closed circuit. A potential difference across the detection resistor R1 is obtained and compared with a reference voltage to detect insulation-resistance degradation.
    Type: Application
    Filed: September 27, 2007
    Publication date: April 24, 2008
    Applicant: FANUC LTD.
    Inventors: Shinichi Horikoshi, Hiroyasu Sato, Akira Hirai, Satoshi Tanabe, Mamoru Yaeshima
  • Patent number: 7256701
    Abstract: A motor driver capable of detecting the insulation deterioration of a motor easily and inexpensively is disclosed. The voltage supplied from an AC power supply (1) is rectified by a first rectifying circuit (D1 to D6) and smoothed by a capacitor (C) in a power supply unit (6). The output voltage of the power supply unit (6) is converted into an AC voltage of a frequency and a motor (M) is driven by a motor drive amplifier (8). Elements (R1, C2, R11, C21) are connected between at least one of the positive electrode (4) and the negative electrode (5) of the output line (4, 5) of the power supply unit (6) and the ground (G2, G4). An insulation deterioration circuit (10, 11, 12) detects at least one of the voltage between the elements and the current flowing through the elements.
    Type: Grant
    Filed: January 4, 2005
    Date of Patent: August 14, 2007
    Assignee: Fanuc Ltd
    Inventors: Shinichi Kono, Shinichi Horikoshi, Masami Kimijima, Mamoru Yaeshima
  • Patent number: 7253639
    Abstract: The drive of the motor is stopped, the electromagnetic switch contacts are switched OFF, and thereafter the first and second contact points are closed to form a closed circuit of the smoothing capacitor, second contact point, first and second resistors, motor coil, ground 1, ground 2, first contact point, and smoothing capacitor. Charging voltage of the smoothing capacitor is applied to the closed circuit. If an insulation resistance of the motor deteriorates, a current flowing through the closed circuit is increased. The increase of the current is detected by means of the potential difference across the first resistor R1 in the closed circuit, to detect insulation resistance deterioration of the motor.
    Type: Grant
    Filed: January 17, 2006
    Date of Patent: August 7, 2007
    Assignee: Fanuc Ltd
    Inventors: Shinichi Horikoshi, Mamoru Yaeshima, Hiroyasu Sato
  • Patent number: 7227323
    Abstract: A motor driving apparatus applicable to various types of motor driving apparatuses and having a power storage section for storing a regenerative current and supplying power to an inverter section at the time of acceleration. The motor driving apparatus further comprises a converter section, a DC link, and an inverter section, thereby driving a motor. Connected to the DC link is the power storage section including a capacitor, a charging circuit, a discharging circuit and a diode. The regenerative current produced at the motor deceleration is stored in the capacitor through the diode. The power stored in the capacitor is outputted to the DC link by turning a switching element of the discharging circuit ON at the motor acceleration. Furthermore, the charging circuit has a boost switching regulator circuit for charging the capacitor to the given upper limit voltage equal to or larger than voltage of the DC link and a current limitation circuit for limiting a charging current to the given upper limit.
    Type: Grant
    Filed: June 3, 2004
    Date of Patent: June 5, 2007
    Assignee: Fanuc Ltd
    Inventors: Yuuichi Yamada, Shigeki Hanyu, Mamoru Yaeshima
  • Patent number: 7126300
    Abstract: A first and a second motor drive amplifiers connected to a motor drive power supply include a first and a second memories which store specifications of the amplifiers, respectively. A memory provided in a power supply unit stores an overcurrent detection value for detecting an overcurrent according to the specifications of the respective motor drive amplifiers. A microcontroller reads the specifications from the first and second memories, and integrates overcurrent detection values corresponding to the respective specifications. If a current sensor detects that a current exceeding a reference value calculated based on a set integrated value, the current sensor outputs an overcurrent detection signal.
    Type: Grant
    Filed: May 24, 2004
    Date of Patent: October 24, 2006
    Assignee: Fanuc LTD
    Inventors: Shunsuke Matsubara, Mamoru Yaeshima
  • Patent number: 7106023
    Abstract: The present invention is directed to the provision of a servomotor driving apparatus that feeds energy stored in a power storage part connected with a DC link that connects a rectifier circuit with an inverter circuit so that the energy stored in the power storage part can be reduced. A motor driving apparatus (1) includes: a step-up type DC/DC converter circuit (11) for boosting voltage appearing at an output of the power storage part (C1) connected with a DC link; and a DC/AC conversion circuit (12, 14) for converting the boosted DC electric power into AC electric power and feeding it to an electric power source.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: September 12, 2006
    Assignee: Fanuc LTD
    Inventors: Naoto Ota, Shinichi Kono, Mamoru Yaeshima, Yuuichi Yamada
  • Publication number: 20060158197
    Abstract: The drive of the motor is stopped, the electromagnetic switch contacts are switched OFF, and thereafter the first and second contact points are closed to form a closed circuit of the smoothing capacitor, second contact point, first and second resistors, motor coil, ground 1, ground 2, first contact point, and smoothing capacitor. Charging voltage of the smoothing capacitor is applied to the closed circuit. If an insulation resistance of the motor deteriorates, a current flowing through the closed circuit is increased. The increase of the current is detected by means of the potential difference across the first resistor R1 in the closed circuit, to detect insulation resistance deterioration of the motor.
    Type: Application
    Filed: January 17, 2006
    Publication date: July 20, 2006
    Applicant: FANUC LTD
    Inventors: Shinichi Horikoshi, Mamoru Yaeshima, Hiroyasu Sato
  • Patent number: 7064516
    Abstract: While the motor drive amplifier is not operating, electromagnetic switch contacts are held closed for a predetermined period of time, three-phase power is rectified by a rectifier circuit and a smoothing capacitor is charged. Then, the smoothing capacitor is discharged through a discharging resistor and, when a predetermined voltage is reached, a contact is closed, with the result that a closed circuit is formed by the smoothing capacitor, a detection resistor, a motor coil, motor insulation resistance, and ground. A voltage generating across the detection resistor due to leakage current is detected and compared with a reference value. If the detected voltage exceeds the reference value, an insulation degradation signal is delivered.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: June 20, 2006
    Assignee: Fanuc LTD
    Inventors: Yuuichi Yamada, Naoto Ota, Takashi Harada, Mamoru Yaeshima
  • Patent number: 7042178
    Abstract: A motor driving apparatus including a regeneration control function and a power storage device for accumulating a regenerative current and for supplying an inverter section with electric power during acceleration. The inverter section is connected to a converter section by a DC link to which regeneration start detecting means and the power storage device are connected. When the regeneration start detecting means detects that a voltage at the DC link reaches a regeneration control start voltage, a controller controls switching elements and starts regeneration control. The regenerative current is accumulated in the capacitor through a diode. When a motor is in a power running state, the switching elements are turned on to apply the voltage at the power storage device to the DC link, and the charged power is utilized for motor acceleration.
    Type: Grant
    Filed: June 3, 2004
    Date of Patent: May 9, 2006
    Assignee: Fanuc LTD
    Inventors: Yuuichi Yamada, Shigeki Hanyu, Mamoru Yaeshima
  • Publication number: 20060066283
    Abstract: The present invention is directed to the provision of a servomotor driving apparatus that feeds energy stored in a power storage part connected with a DC link that connects a rectifier circuit with an inverter circuit so that the energy stored in the power storage part can be reduced. A motor driving apparatus (1) includes: a step-up type DC/DC converter circuit (11) for boosting voltage appearing at an output of the power storage part (C1) connected with a DC link; and a DC/AC conversion circuit (12, 14) for converting the boosted DC electric power into AC electric power and feeding it to an electric power source.
    Type: Application
    Filed: September 26, 2005
    Publication date: March 30, 2006
    Applicant: FANUC LTD
    Inventors: Naoto Ota, Shinichi Kono, Mamoru Yaeshima, Yuuichi Yamada
  • Publication number: 20050151503
    Abstract: In an inverter comprising a converter circuit that converts an alternating current into a direct current and an inverter circuit that inverts the direct current into the alternating current, supply of energy from a voltage smoothing capacitor to a load or recovery of energy from the load is facilitated without the necessity of increasing the capacitance of the voltage smoothing capacitor interposed between the converter circuit and inverter circuit. In the converter circuit, before the supply of energy to the load is started, the voltage on a dc link is raised. Before collection of energy from the load is started, the voltage on the dc link is lowered.
    Type: Application
    Filed: January 14, 2005
    Publication date: July 14, 2005
    Applicant: FANUC LTD.
    Inventors: Mamoru Yaeshima, Shigeki Hanyu, Hideki Kagami, Yuuichi Yamada
  • Publication number: 20050151658
    Abstract: A motor driver capable of detecting the insulation deterioration of a motor easily and inexpensively is disclosed. The voltage supplied from an AC power supply (1) is rectified by a first rectifying circuit (D1 to D6) and smoothed by a capacitor (C) in a power supply unit (6). The output voltage of the power supply unit (6) is converted into an AC voltage of a frequency and a motor (M) is driven by a motor drive amplifier (8). Elements (R1, C2, R11, C21) are connected between at least one of the positive electrode (4) and the negative electrode (5) of the output line (4, 5) of the power supply unit (6) and the ground (G2, G4). An insulation deterioration circuit (10, 11, 12) detects at least one of the voltage between the elements and the current flowing through the elements.
    Type: Application
    Filed: January 4, 2005
    Publication date: July 14, 2005
    Applicant: FANUC LTD
    Inventors: Shinichi Kono, Shinichi Horikoshi, Masami Kimijima, Mamoru Yaeshima
  • Publication number: 20050068000
    Abstract: While the motor drive amplifier is not operating, electromagnetic switch contacts are held closed for a predetermined period of time, three-phase power is rectified by a rectifier circuit and a smoothing capacitor is charged. Then, the smoothing capacitor is discharged through a discharging resistor and, when a predetermined voltage is reached, a contact is closed, with the result that a closed circuit is formed by the smoothing capacitor, a detection resistor, a motor coil, motor insulation resistance, and ground. A voltage generating across the detection resistor due to leakage current is detected and compared with a reference value. If the detected voltage exceeds the reference value, an insulation degradation signal is delivered.
    Type: Application
    Filed: September 30, 2004
    Publication date: March 31, 2005
    Applicant: FANUC LTD
    Inventors: Yuuichi Yamada, Naoto Ota, Takashi Harada, Mamoru Yaeshima
  • Publication number: 20040257029
    Abstract: A motor driving apparatus capable of predicting motor insulation deterioration at low costs. When a motor drive amplifier is not in operation, a relay contact K1 is turned on or closed to form a closed circuit of a motor housing grounded at G2, a motor coil, resistors R1, R2, the relay contact K1, diodes D4, D5, D6, an AC power source, and a ground point G1. A voltage of the AC power source to ground is applied to the closed circuit. When the insulation resistance of the motor is high, a small current flows through the closed circuit, so that potential difference across the resistor R1 is small. If the motor insulation is deteriorated, a leakage current increases. If potential difference across the resistor R1 exceeds a reference voltage determined by a Zener diode, an output signal is output from a comparator, a signal is output from a photocoupler, and the decrease in insulation resistance is indicated on an indicator of a control unit.
    Type: Application
    Filed: June 18, 2004
    Publication date: December 23, 2004
    Applicant: FANUC LTD
    Inventors: Keiji Sakamoto, Naoto Ota, Takashi Harada, Mamoru Yaeshima