Patents by Inventor Seiya Yokoyama

Seiya Yokoyama 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: 8643239
    Abstract: A motor including a rotor and a stator. The rotor includes a rotor core, magnet pole portions, and core pole portions. First magnetic pole portions, which are the magnet pole portions or the core pole portions, each include a first and second opposing parts arranged in an axial direction. Each first opposing part includes an auxiliary groove, and each second opposing part does not include an auxiliary groove. Where M(°) represents an open angle of the first magnetic pole portion, G(°) represents an open angle of the void, and L represents the number of teeth, an angle D1 from a center line in the circumferential direction of the first magnetic pole portion to the side surface in the auxiliary groove that is closer to the center line in the circumferential direction satisfies D1=M/2+G?a×360(°)/L (where a is a natural number).
    Type: Grant
    Filed: July 18, 2011
    Date of Patent: February 4, 2014
    Assignee: Asmo Co., Ltd.
    Inventors: Yoshiaki Takemoto, Shigemasa Kato, Seiya Yokoyama, Keisuke Koide
  • Publication number: 20130313938
    Abstract: A brushless motor includes a first rotor core, a second rotor core, and a field magnet member. The first rotor core includes primary projecting pieces arranged along a circumferential direction at equal intervals. The second rotor core has the same shape as the first rotor core, and includes secondary projecting pieces arranged along the circumferential direction at equal intervals. The secondary projecting pieces are positioned between the primary projecting pieces that are adjacent to one another in the circumferential direction. The field magnet member is arranged between the first rotor core and the second rotor core. The field magnet member is magnetized along an axial direction to generate primary magnetic poles in the primary projecting pieces, and generate secondary magnetic poles in the secondary projecting pieces. A rotor includes the first rotor core, the second rotor core, and the field magnet member.
    Type: Application
    Filed: March 15, 2013
    Publication date: November 28, 2013
    Inventors: Yoji YAMADA, Seiya YOKOYAMA, Yoshiaki TAKEMOTO, Chie MORITA, Koji MIKAMI
  • Patent number: 8536749
    Abstract: A motor having a rotor and a stator is disclosed. The rotor is a consequent-pole rotor having a rotor core, a plurality of magnets, and a plurality of salient poles. The stator includes a stator core and multiphase coils. Each coil is wound about the teeth by distributed winding, in such a manner as to wind two or more consecutive teeth in single winding. The opening degree each of salient pole opposed to the distal ends of the teeth is set greater than or equal to twice the opening angle of the distal end of each tooth.
    Type: Grant
    Filed: October 5, 2010
    Date of Patent: September 17, 2013
    Assignee: ASMO Co., Ltd.
    Inventors: Keisuke Koide, Seiya Yokoyama, Shigemasa Kato, Yoji Yamada, Yoshiaki Takemoto, Shinji Santo
  • Patent number: 8405342
    Abstract: A motor including a stator, a rotor, and a current supply unit. The stator includes a stator core, which has a plurality of teeth, and a plurality of coils, which are wound around the teeth. The rotor includes a plurality of magnets, which function as first magnetic poles, and salient poles, which function as second magnetic poles. Each of the salient poles is arranged between adjacent magnets spaced apart by a clearance from the magnets. When P represents the number of poles in the rotor and S represents the number of coils, a ratio P/S of the pole number P and the coil number S is represented by (4n?2)/3m (where n and m are integers that are greater than or equal to 2). The plurality of coils includes a plurality of coil groups including coils for three phases. The current supply unit executes a different current control for each coil groups.
    Type: Grant
    Filed: September 29, 2010
    Date of Patent: March 26, 2013
    Assignee: Asmo Co., Ltd.
    Inventors: Yoji Yamada, Shinji Santo, Seiya Yokoyama, Yoko Tateishi, Yoshiaki Takemoto, Shigemasa Kato
  • Publication number: 20130045478
    Abstract: This invention provides a method for efficiently detecting DNA methylation. The method for detecting DNA methylation comprises subjecting DNA to bisulfite treatment, subjecting DNA after bisulfite treatment to a first PCR, subjecting the resultant to nested PCR, and subjecting amplified DNA to denaturing gradient gel electrophoresis.
    Type: Application
    Filed: April 21, 2011
    Publication date: February 21, 2013
    Applicant: KAGOSHIMA UNIVERSITY
    Inventors: Seiya Yokoyama, Suguru Yonezawa
  • Patent number: 8324779
    Abstract: A motor having a rotor and a stator is disclosed. The rotor is a consequent-pole rotor having a rotor core, a plurality of magnets, and a plurality of salient poles. The stator includes a plurality of teeth. A first auxiliary groove is formed in a surface of each salient pole that is opposed to the teeth. Each first auxiliary groove has first and second side surfaces facing each other in the circumferential direction. The first side surface is closer to a circumferential center of the salient pole than the second side surface. When the angle from the circumferential center line to the first side surface of each salient pole about the axis of the rotor is represented by KC1, the opening angle between the circumferential ends of the distal end of each tooth about the axis is represented by KA, and the opening angle between the circumferential ends of each salient pole about the axis is represented by KB, the following expression is satisfied: KC1=KA?KB/2.
    Type: Grant
    Filed: October 5, 2010
    Date of Patent: December 4, 2012
    Assignee: ASMO Co., Ltd.
    Inventors: Shigemasa Kato, Seiya Yokoyama, Yoji Yamada, Yoshiaki Takemoto, Keisuke Koide, Shinji Santo
  • Patent number: 8319386
    Abstract: A motor having a rotor and a stator is disclosed. A motor having a rotor and as stator is disclosed. The rotor is a consequent-pole rotor having a rotor core, a plurality of magnets, and a plurality of salient poles. The stator includes a plurality of teeth. The stator is arranged to be opposite to the rotor with a gap along the radial direction. The gap between the stator and the rotor is set to satisfy an expression 1<B/A, where A represents the shortest gap distance between the stator and the magnets, and B represents the shortest gap distance between the stator and the salient poles.
    Type: Grant
    Filed: October 5, 2010
    Date of Patent: November 27, 2012
    Assignee: ASMO Co., Ltd.
    Inventors: Yoji Yamada, Seiya Yokoyama, Yoshiaki Takemoto, Shigemasa Kato, Keisuke Koide, Shinji Santo
  • Publication number: 20120248919
    Abstract: A motor in which drive current supplied to a winding is controlled in accordance with a rotational position of a rotor detected from a waveform of an induced voltage between phases. The motor is provided with a stator including 3×n teeth and windings for three phases. A rotor includes a rotor core, an n number of magnets, and an n number of salient poles. The magnets function as one of the magnetic poles, the salient poles function as the other one of the magnetic poles. Each salient pole is spaced apart by a gap from the adjacent ones of the magnets in the circumferential direction. The magnets and gap are arranged inward in the radial direction from the rotor core. An electrical angle between two ends of each magnet is set to be smaller than an electrical angle between two ends of each salient pole.
    Type: Application
    Filed: March 27, 2012
    Publication date: October 4, 2012
    Applicant: ASMO, CO., LTD.
    Inventors: Yoshiaki TAKEMOTO, Toshihiro UCHIDA, Seiya YOKOYAMA, Shigemasa KATO
  • Patent number: 8264113
    Abstract: A brushless motor including a stator having teeth and a rotor having magnetic pole portions is disclosed. The magnetic pole portions are arranged to have the same polarities as each other. The rotor includes gaps that function as magnetic resistance at circumferential ends of each of the magnetic pole portions so that an iron core portion is formed between the circumferentially adjacent magnetic pole portions. Magnetic flux of the magnetic pole portions passes through the iron core portion along the radial direction. The gaps include a first gap located on the leading end of the magnetic pole portion in the rotation direction of the rotor and a second gap located on the trailing end of the magnetic pole portion in the rotation direction of the rotor. The circumferential width of the first gap is set to be greater than the circumferential width of the second gap.
    Type: Grant
    Filed: March 1, 2012
    Date of Patent: September 11, 2012
    Assignee: Asmo Co., Ltd.
    Inventors: Yoshiaki Takemoto, Seiya Yokoyama, Yoji Yamada, Shigemasa Kato
  • Patent number: 8242654
    Abstract: A motor is disclosed that includes a rotor having a consequent-pole structure. The rotor core of the rotor includes a magnetic flux dividing portion at each position that faces one of the magnets. Each magnetic flux dividing portion forcibly divides magnetic flux in the vicinity of the backside of the corresponding magnet to both sides in the circumferential direction.
    Type: Grant
    Filed: May 13, 2010
    Date of Patent: August 14, 2012
    Assignee: Asmo Co., Ltd.
    Inventors: Yoji Yamada, Seiya Yokoyama, Shigemasa Kato, Yoshiaki Takemoto, Yoko Tateishi
  • Publication number: 20120175987
    Abstract: A brushless motor including a stator having teeth and a rotor having magnetic pole portions is disclosed. The magnetic pole portions are arranged to have the same polarities as each other. The rotor includes gaps that function as magnetic resistance at circumferential ends of each of the magnetic pole portions so that an iron core portion is formed between the circumferentially adjacent magnetic pole portions. Magnetic flux of the magnetic pole portions passes through the iron core portion along the radial direction. The gaps include a first gap located on the leading end of the magnetic pole portion in the rotation direction of the rotor and a second gap located on the trailing end of the magnetic pole portion in the rotation direction of the rotor. The circumferential width of the first gap is set to be greater than the circumferential width of the second gap.
    Type: Application
    Filed: March 1, 2012
    Publication date: July 12, 2012
    Applicant: ASMO CO., LTD.
    Inventors: YOSHIAKI TAKEMOTO, Seiya Yokoyama, Yoji Yamada, Shigemasa Kato
  • Patent number: 8179011
    Abstract: A brushless motor including a stator having teeth and a rotor having magnetic pole portions is disclosed. The magnetic pole portions are arranged to have the same polarities as each other. The rotor includes gaps that function as magnetic resistance at circumferential ends of each of the magnetic pole portions so that an iron core portion is formed between the circumferentially adjacent magnetic pole portions. Magnetic flux of the magnetic pole portions passes through the iron core portion along the radial direction. The gaps include a first gap located on the leading end of the magnetic pole portion in the rotation direction of the rotor and a second gap located on the trailing end of the magnetic pole portion in the rotation direction of the rotor. The circumferential width of the first gap is set to be greater than the circumferential width of the second gap.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: May 15, 2012
    Assignee: ASMO Co., Ltd.
    Inventors: Yoshiaki Takemoto, Seiya Yokoyama, Yoji Yamada, Shigemasa Kato
  • Publication number: 20120019089
    Abstract: A motor including a rotor and a stator. The rotor includes a rotor core, magnet pole portions, and core pole portions. First magnetic pole portions, which are the magnet pole portions or the core pole portions, each include a first and second opposing parts arranged in an axial direction. Each first opposing part includes an auxiliary groove, and each second opposing part does not include an auxiliary groove. Where M (°) represents an open angle of the first magnetic pole portion, G (°) represents an open angle of the void, and L represents the number of teeth, an angle D1 from a center line in the circumferential direction of the first magnetic pole portion to the side surface in the auxiliary groove that is closer to the center line in the circumferential direction satisfies)D1=M/2+G?a×360 (°)/L (where a is a natural number).
    Type: Application
    Filed: July 18, 2011
    Publication date: January 26, 2012
    Applicant: Asmo Co., Ltd.
    Inventors: Yoshiaki Takemoto, Shigemasa Kato, Seiya Yokoyama, Keisuke Koide
  • Publication number: 20120001509
    Abstract: A motor including a stator and a rotor. The stator includes teeth and windings. Each tooth has a distal portion defined by a radially inward side of the stator. The rotor, which is arranged inward in the radial direction from the stator, includes a rotor core, magnets, and salient poles. Each salient pole is separated by a void from the magnet that is adjacent in the circumferential direction. The distal portion of each tooth is longer than a radially outward side of each magnet.
    Type: Application
    Filed: June 24, 2011
    Publication date: January 5, 2012
    Applicant: Asmo Co., Ltd.
    Inventors: Yoji Yamada, Seiya Yokoyama, Keisuke Koide, Yoshiaki Takemoto, Shigemasa Kato, Toshihiro Uchida
  • Patent number: 8084911
    Abstract: A motor including a stator and a rotor is disclosed. The rotor includes a first unit and a second unit. The first unit includes an N-pole first magnet and an S-pole second magnet. The first and the second magnets are alternately arranged along a circumferential direction of the rotor at equal angular intervals to form magnetic pole portions. The second unit includes an N-pole or S-pole third magnet and a salient pole arranged in the rotor core. The salient pole functions as a magnetic pole that differs from the third magnet. The third magnet and the salient pole are alternately arranged along the circumferential direction of the rotor to form magnetic pole portions. The number of magnetic pole portions of the second unit is the same as the number of magnetic pole portions of the first unit. The third magnet and the magnet of the first unit having the same pole as the third magnet are aligned in the axial direction of the rotor.
    Type: Grant
    Filed: October 15, 2009
    Date of Patent: December 27, 2011
    Assignee: Asmo Co., Ltd.
    Inventors: Yoshiaki Takemoto, Seiya Yokoyama, Yoji Yamada, Shigemasa Kato, Yoko Tateishi
  • Publication number: 20110309707
    Abstract: There is provided a motor including a rotor and a stator arranged outside the rotor in the radial direction. The rotor includes a rotor core, a plurality of magnets arranged at equal intervals in the circumferential direction of the rotor core and functioning as one magnetic pole, and salient poles integrated with the rotor core, each arranged between adjacent magnets and at a distance from the magnets. The salient poles function as the other magnetic pole. A stator has a stator core having a plurality of teeth extending in the radial direction of the stator and arranged at equal intervals in the circumferential direction, and multi-phase coils attached to the teeth. The plurality of salient poles are arranged to have center portions arranged at equal intervals in the circumferential direction, and each have an outer surface extending in the circumferential direction in a range of a predetermined opening angle having an axis of the rotor as a center.
    Type: Application
    Filed: June 14, 2011
    Publication date: December 22, 2011
    Applicant: Asmo Co., Ltd.
    Inventors: Shigemasa Kato, Seiya Yokoyama, Yoji Yamada, Keisuke Koide, Yoshiaki Takemoto, Shinji Santo
  • Publication number: 20110204833
    Abstract: A controller for use with a motor including a stator, around which three-phase coils are wound, and a rotor, which includes a magnet functioning as a first magnetic pole and a salient pole of a core functioning as a second magnetic pole. The controller supplies the three-phase coils with excitation currents having a predetermined phase difference from one another to drive and rotate the rotor. The controller includes a current adjustment unit that adjusts a fundamental wave current using high-order currents for third order and ninth order components in a q-axis to reduce torque ripple. The excitation current is generated based on the fundamental wave current adjusted by the current adjustment unit.
    Type: Application
    Filed: February 16, 2011
    Publication date: August 25, 2011
    Applicant: ASMO CO., LTD
    Inventors: Shinji SANTO, Seiya YOKOYAMA, Yoji YAMADA, Yoshiaki TAKEMOTO, Shigemasa KATO, Kenta GOTO
  • Publication number: 20110193440
    Abstract: A motor having a rotor and a stator is disclosed. A motor having a rotor and as stator is disclosed. The rotor is a consequent-pole rotor having a rotor core, a plurality of magnets, and a plurality of salient poles. The stator includes a plurality of teeth. The stator is arranged to be opposite to the rotor with a gap along the radial direction. The gap between the stator and the rotor is set to satisfy an expression 1<B/A, where A represents the shortest gap distance between the stator and the magnets, and B represents the shortest gap distance between the stator and the salient poles.
    Type: Application
    Filed: October 5, 2010
    Publication date: August 11, 2011
    Applicant: ASMO CO., LTD.
    Inventors: YOJI YAMADA, SEIYA YOKOYAMA, YOSHIAKI TAKEMOTO, SHIGEMASA KATO, KEISUKE KOIDE, SHINJI SANTO
  • Publication number: 20110181230
    Abstract: A motor including a stator, a rotor, and a current supply unit. The stator includes a stator core, which has a plurality of teeth, and a plurality of coils, which are wound around the teeth. The rotor includes a plurality of magnets, which function as first magnetic poles, and salient poles, which function as second magnetic poles. Each of the salient poles is arranged between adjacent magnets spaced apart by a clearance from the magnets. When P represents the number of poles in the rotor and S represents the number of coils, a ratio P/S of the pole number P and the coil number S is represented by (4n?2)/3m (where n and m are integers that are greater than or equal to 2). The plurality of coils includes a plurality of coil groups including coils for three phases. The current supply unit executes a different current control for each coil groups.
    Type: Application
    Filed: September 29, 2010
    Publication date: July 28, 2011
    Applicant: ASMO CO., LTD.
    Inventors: Yoji Yamada, Shinji Santo, Seiya Yokoyama, Yoko Tateishi, Yoshiaki Takemoto, Shigemasa Kato
  • Publication number: 20110148240
    Abstract: A motor having a rotor and a stator is disclosed. The rotor is a consequent-pole rotor having a rotor core, a plurality of magnets, and a plurality of salient poles. The stator includes a stator core and multiphase coils. Each coil is wound about the teeth by distributed winding, in such a manner as to wind two or more consecutive teeth in single winding. The opening degree each of salient pole opposed to the distal ends of the teeth is set greater than or equal to twice the opening angle of the distal end of each tooth.
    Type: Application
    Filed: October 5, 2010
    Publication date: June 23, 2011
    Applicant: ASMO CO., LTD.
    Inventors: Keisuke Koide, Seiya Yokoyama, Shigemasa Kato, Yoji Yamada, Yoshiaki Takemoto, Shinji Santo