Patents by Inventor Yoshifumi Kuwano
Yoshifumi Kuwano 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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Patent number: 11496027Abstract: A motor case has a first case portion and a second case portion coupled to the first case portion. The stator has a stator core and an insulator fixed to the stator core. The insulator has a tubular portion having an outer circumferential surface and a polygonal shape in the cross-sectional view, and on the outer circumferential surface, insulator flat portions lined up in a circumferential direction. The first case portion includes: three or more core supports which project inward in the radial direction from an inner circumferential surface of a circumferential wall of the first case portion, come into contact with the core outer-circumferential surface, and are disposed at intervals from each other in the circumferential direction; and at least one first detent which is in contact with or is disposed to come into contact with the insulator flat portion.Type: GrantFiled: September 26, 2019Date of Patent: November 8, 2022Assignee: NIDEC SERVO CORPORATIONInventors: Toru Kobayashi, Yoshifumi Kuwano
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Publication number: 20200106348Abstract: A motor case has a first case portion and a second case portion coupled to the first case portion. The stator has a stator core and an insulator fixed to the stator core. The insulator has a tubular portion having an outer circumferential surface and a polygonal shape in the cross-sectional view, and on the outer circumferential surface, insulator flat portions lined up in a circumferential direction. The first case portion includes: three or more core supports which project inward in the radial direction from an inner circumferential surface of a circumferential wall of the first case portion, come into contact with the core outer-circumferential surface, and are disposed at intervals from each other in the circumferential direction; and at least one first detent which is in contact with or is disposed to come into contact with the insulator flat portion.Type: ApplicationFiled: September 26, 2019Publication date: April 2, 2020Applicant: NIDEC SERVO CORPORATIONInventors: Toru KOBAYASHI, Yoshifumi KUWANO
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Patent number: 7728543Abstract: A stepping motor controlling device according to the present invention includes lead angle computing means which computes a lead angle according to the load torque current deviation of the stepping motor, adding means which adds an angle command to the lead angle to determine a winding exciting angle and voltage applying means which applies a voltage according to the winding exciting angle to the stepping motor.Type: GrantFiled: March 15, 2007Date of Patent: June 1, 2010Assignee: Japan Servo Co., Ltd.Inventors: Akio Takemori, Yoshifumi Kuwano, Hiroaki Taka, Yoshitaka Iwaji
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Publication number: 20070216335Abstract: A stepping motor controlling device according to the present invention includes lead angle computing means which computes a lead angle according to the load torque current deviation of the stepping motor, adding means which adds an angle command to the lead angle to determine a winding exciting angle and voltage applying means which applies a voltage according to the winding exciting angle to the stepping motor.Type: ApplicationFiled: March 15, 2007Publication date: September 20, 2007Inventors: Akio Takemori, Yoshifumi Kuwano, Hiroaki Taka, Yoshitaka Iwaji
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Patent number: 7088072Abstract: A stepping motor control system according to the present invention includes a counting mechanism for counting the number of steps of the pulse train command, a latch mechanism for holding a counting value of the counting mechanism with a latch signal and finding a position command, a reference signal generating mechanism for generating the latch signal and a reference clock signal, a first calculating mechanism for calculating a pulse spacing of the pulse train command with the reference clock signal, and a second calculating mechanism for calculating a time interval from generation of the pulse train command to generation of the latch signal with the reference clock signal. In the stepping motor control system, the position command is corrected using command pulse spacing information calculated by the first calculating mechanism and time difference information calculated by the second calculating mechanism.Type: GrantFiled: October 27, 2005Date of Patent: August 8, 2006Assignee: Japan Servo Co., Ltd.Inventors: Yoshifumi Kuwano, Hiroaki Taka, Akio Takemori
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Patent number: 7053584Abstract: Disclosed is a driving device for a motor such as a stepping motor etc. for controlling an angle and a speed of the motor, wherein the driving device comprises exciting current detectors for detecting exciting currents of motor windings of the motor, an exciting current amplitude computation means for computing an exciting current amplitude value or the square of the exciting current amplitude value from exciting current detection values detected by the exciting current detectors, and a voltage impression unit for impressing voltages at values corresponding to a deviation value of the exciting current amplitude value and the current amplitude command or a deviation value of the square of the exciting current amplitude value and the square of the current amplitude command to the motor windings.Type: GrantFiled: October 1, 2003Date of Patent: May 30, 2006Assignee: Japan Servo.Co., Ltd.Inventors: Hiroaki Taka, Yoshifumi Kuwano, Akio Takemori, Yukinari Takahashi
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Publication number: 20060091843Abstract: A stepping motor control system according to the present invention includes a counting mechanism for counting the number of steps of the pulse train command, a latch mechanism for holding a counting value of the counting mechanism with a latch signal and finding a position command, a reference signal generating mechanism for generating the latch signal and a reference clock signal, a first calculating mechanism for calculating a pulse spacing of the pulse train command with the reference clock signal, and a second calculating mechanism for calculating a time interval from generation of the pulse train command to generation of the latch signal with the reference clock signal. In the stepping motor control system, the position command is corrected using command pulse spacing information calculated by the first calculating mechanism and time difference information calculated by the second calculating mechanism.Type: ApplicationFiled: October 27, 2005Publication date: May 4, 2006Inventors: Yoshifumi Kuwano, Hiroaki Taka, Akio Takemori
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Patent number: 7023165Abstract: A stepping motor control apparatus in accordance with the present invention comprises: a current detection unit that detects phase currents flowing into a stepping motor; an equivalent model-of-motor arithmetic unit that includes a coefficient multiplication block which performs multiplication using a coefficient ka?=Ts/? as a multiplier, a coefficient multiplication block which performs multiplication using a coefficient kb?=?/(Ts+?) as a multiplier, and a coefficient multiplication block which performs multiplication using a coefficient kg?=I0/E0 as a multiplier, and that calculates an estimated angle of excitation; a current control unit that controls an exciting current on the basis of the estimated angle of excitation, an angle command, and the phase currents detected by the current detection unit; and a variable voltage inverter that applies phase voltages to phase windings included in the stepping motor according to outputs of the current control unit.Type: GrantFiled: March 31, 2005Date of Patent: April 4, 2006Assignee: Japan Servo Co., Ltd.Inventors: Yoshifumi Kuwano, Hiroaki Taka, Akio Takemori
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Patent number: 7019484Abstract: A stepping motor driver according to the present invention includes a torque component current calculating means for calculating a torque component current from phase currents and a rotor rotation angle, an absolute value converting means for obtaining an absolute value of the torque component current, a high speed-response judging means adapted for outputting a first control signal when a speed deviation between a command speed and a rotor speed is not more than a reference level, and outputting a second control signal when the speed deviation exceeds the reference level, and a current command outputting means adapted for outputting a current command according to the absolute value of the torque component current when the first control signal is outputted, and outputting a maximum current command value as the current command when the second control signal is outputted.Type: GrantFiled: March 29, 2005Date of Patent: March 28, 2006Assignee: Japan Servo Co., Ltd.Inventors: Akio Takemori, Yoshifumi Kuwano, Hiroaki Taka
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Publication number: 20050218858Abstract: A stepping motor driver according to the present invention includes a torque component current calculating means for calculating a torque component current from phase currents and a rotor rotation angle, an absolute value converting means for obtaining an absolute value of the torque component current, a high speed-response judging means adapted for outputting a first control signal when a speed deviation between a command speed and a rotor speed is not more than a reference level, and outputting a second control signal when the speed deviation exceeds the reference level, and a current command outputting means adapted for outputting a current command according to the absolute value of the torque component current when the first control signal is outputted, and outputting a maximum current command value as the current command when the second control signal is outputted.Type: ApplicationFiled: March 29, 2005Publication date: October 6, 2005Inventors: Akio Takemori, Yoshifumi Kuwano, Hiroaki Taka
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Publication number: 20050218859Abstract: A stepping motor control apparatus in accordance with the present invention comprises: a current detection unit that detects phase currents flowing into a stepping motor; an equivalent model-of-motor arithmetic unit that includes a coefficient multiplication block which performs multiplication using a coefficient ka?=Ts/? as a multiplier, a coefficient multiplication block which performs multiplication using a coefficient kb?=?/(Ts+?) as a multiplier, and a coefficient multiplication block which performs multiplication using a coefficient kg?=I0/E0 as a multiplier, and that calculates an estimated angle of excitation; a current control unit that controls an exciting current on the basis of the estimated angle of excitation, an angle command, and the phase currents detected by the current detection unit; and a variable voltage inverter that applies phase voltages to phase windings included in the stepping motor according to outputs of the current control unit.Type: ApplicationFiled: March 31, 2005Publication date: October 6, 2005Inventors: Yoshifumi Kuwano, Hiroaki Taka, Akio Takemori
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Patent number: 6946814Abstract: A stepping motor driver comprises: an excitation angle generating means which generates an excitation angle from an external command pulse; a current control means which controls exciting currents for a stepping motor according to the excitation angle and a current command; a current detection means which detects phase currents of the stepping motor; an angle detection means which detects a rotor rotation angle of the stepping motor; a torque component current calculating means which calculates a torque component current from the phase currents and the rotor rotation angle; an absolute converting means which obtains the absolute value of the torque component current; and a current command output means which outputs the current command depending on the absolute value of the torque component current.Type: GrantFiled: September 17, 2004Date of Patent: September 20, 2005Assignee: Japan Servo Co., Ltd.Inventors: Akio Takemori, Yoshifumi Kuwano, Yukinari Takahashi, Hiroaki Taka
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Patent number: 6897633Abstract: A stepping motor driver which drives a stepping motor for position and speed control. The stepping motor driver comprises: a current control means which outputs values corresponding to applied voltages; current sensors which detect phase currents; and a magnetic pole position estimation unit which uses the values corresponding to applied voltages and detected phase current values as outputs of the current sensors to obtain a magnetic pole position estimate. The magnetic pole position estimation unit calculates a magnetic pole position estimate from speed electromotive force estimates or from differences between phase currents at zero speed and detected phase current values.Type: GrantFiled: March 9, 2004Date of Patent: May 24, 2005Assignee: Japan Servo Co., Ltd.Inventors: Yoshifumi Kuwano, Akio Takemori, Hiroaki Taka, Yasuo Matsuda, Yoshihiro Okumatsu, Atsuo Kawamura, Yukinari Takahashi
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Publication number: 20050062451Abstract: A stepping motor driver comprises: an excitation angle generating means which generates an excitation angle from an external command pulse; a current control means which controls exciting currents for a stepping motor according to the excitation angle and a current command; a current detection means which detects phase currents of the stepping motor; an angle detection means which detects a rotor rotation angle of the stepping motor; a torque component current calculating means which calculates a torque component current from the phase currents and the rotor rotation angle; an absolute converting means which obtains the absolute value of the torque component current; and a current command output means which outputs the current command depending on the absolute value of the torque component current.Type: ApplicationFiled: September 17, 2004Publication date: March 24, 2005Inventors: Akio Takemori, Yoshifumi Kuwano, Yukinari Takahashi, Hiroaki Taka
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Patent number: 6850027Abstract: The stepping motor driver comprises an inverter for feeding stepped currents to windings of a stepping motor, a position detector for obtaining a detected angle of a rotor of the stepping motor and a current controller for controlling the inverter. In a d-q rotational coordinate system in which the d-axis is in the direction of the magnetic flux of the rotor and the q-axis is in the direction perpendicular to the d-axis, an excitation angle for a winding is determined from a d-axis component and a q-axis component of a command current to the winding, a lead angle control signal is computed from the excitation angle, and a phase of an applied voltage to the stepping motor is controlled using the lead angle control signal.Type: GrantFiled: March 18, 2003Date of Patent: February 1, 2005Assignee: Japan Servo Co., Ltd.Inventors: Yoshifumi Kuwano, Akio Takemori, Yasuo Matsuda, Yoshihiro Okumatsu, Atsuo Kawamura
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Patent number: 6850026Abstract: The stepping motor driver comprises an angle computing element that receives rotor position detection signals from an encoder and calculates a detected angle representing the rotational angle of the rotor, and a lead angle controller that generates a corrected command angle based on the difference between a command angle given from outside and the detected angle. The lead angle controller calculates an angle deviation that is the difference between the command angle and the detected angle, compares the angle deviation with a predetermined value, outputs the command angle as the corrected command angle if the angle deviation is less than the predetermined value, and outputs a value obtained by adding an approximated lead angle to the detected angle as the corrected command angle if the angle deviation is greater than, or equal to, the predetermined value, and the phase of voltage applied to the motor is controlled according to the corrected command angle.Type: GrantFiled: March 6, 2003Date of Patent: February 1, 2005Assignee: Japan Servo Co., Ltd.Inventors: Akio Takemori, Yoshifumi Kuwano, Yukinari Takahashi, Hiroaki Taka
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Publication number: 20040178763Abstract: A stepping motor driver which drives a stepping motor for position and speed control. The stepping motor driver comprises: a current control means which outputs values corresponding to applied voltages; current sensors which detect phase currents; and a magnetic pole position estimation unit which uses the values corresponding to applied voltages and detected phase current values as outputs of the current sensors to obtain a magnetic pole position estimate. The magnetic pole position estimation unit calculates a magnetic pole position estimate from speed electromotive force estimates or from differences between phase currents at zero speed and detected phase current values.Type: ApplicationFiled: March 9, 2004Publication date: September 16, 2004Inventors: Yoshifumi Kuwano, Akio Takemori, Hiroaki Taka, Yasuo Matsuda, Yoshihiro Okumatsu, Atsuo Kawamura, Yukinari Takahashi
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Patent number: 6747433Abstract: The controller comprises current sensors for detecting motor currents, an inverter containing a current control means for feeding currents to motor windings, a coordinate transformer that transforms the motor currents in a fixed coordinates system into currents in a first rotational coordinates system, and an angle calculator that transforms a command pulse into a command angle. A second rotational coordinates system composed of a dp axis and a qp axis perpendicular to the dp axis is determined from the command angle. A command current on the dp axis is set to be a value corresponding to a motor current amplitude and another command current on the qp axis is set to be zero. The motor current is projected on the dp and qp axes and controlled so as to make the components on the dp and qp axes coincide with the respective command currents on the dp and qp axes.Type: GrantFiled: September 25, 2002Date of Patent: June 8, 2004Assignee: Japan Servo Co., Ltd.Inventors: Yoshifumi Kuwano, Yukinari Takahashi, Akio Takemori
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Publication number: 20040066164Abstract: Disclosed is a driving device for a motor such as a stepping motor etc. for controlling an angle and a speed of the motor, wherein the driving device comprises exciting current detectors for detecting exciting currents of motor windings of the motor, an exciting current amplitude computation means for computing an exciting current amplitude value or the square of the exciting current amplitude value from exciting current detection values detected by the exciting current detectors, and a voltage impression unit for impressing voltages at values corresponding to a deviation value of the exciting current amplitude value and the current amplitude command or a deviation value of the square of the exciting current amplitude value and the square of the current amplitude command to the motor windings.Type: ApplicationFiled: October 1, 2003Publication date: April 8, 2004Inventors: Hiroaki Taka, Yoshifumi Kuwano, Akio Takemori, Yukinari Takahashi
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Patent number: D927423Type: GrantFiled: March 12, 2019Date of Patent: August 10, 2021Assignee: NIDEC SERVO CORPORATIONInventors: Toru Kobayashi, Yoshifumi Kuwano