Patents by Inventor Yoshiaki Takemoto

Yoshiaki Takemoto 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).

  • 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
  • Publication number: 20110140562
    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: Application
    Filed: October 5, 2010
    Publication date: June 16, 2011
    Applicant: ASMO CO., LTD.
    Inventors: Shigemasa Kato, Seiya Yokoyama, Yoji Yamada, Yoshiaki Takemoto, Keisuke Koide, Shinji Santo
  • Publication number: 20100308680
    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: Application
    Filed: May 13, 2010
    Publication date: December 9, 2010
    Applicant: ASMO CO., LTD.
    Inventors: Yoji YAMADA, Seiya YOKOYAMA, Shigemasa KATO, Yoshiaki TAKEMOTO, Yoko TATEISHI
  • Publication number: 20100301695
    Abstract: A motor includes a rotor and a stator. The rotor includes a plurality of magnets, which function as first magnetic poles, and salient poles, which function as second magnetic poles. A ratio X1:X2 of a quantity X1 of magnetic pole portions of the rotor, which is the sum of the quantity of the magnets and the quantity of the salient poles, and the quantity X2 of slots is 2n:3n (n being a natural number). The sum of a magnetic pole occupying angle ?1 of the magnet and a magnetic pole occupying angle ?2 of the salient pole is 360°. The magnetic pole occupying angle ?1 is set in a range of 180°<?1?230°.
    Type: Application
    Filed: April 1, 2010
    Publication date: December 2, 2010
    Applicant: ASMO CO., LTD.
    Inventors: Yoji YAMADA, Seiya YOKOYAMA, Shigemasa KATO, Yoshiaki TAKEMOTO, Yoko TATEISHI
  • Patent number: 7772735
    Abstract: A plurality of magnets are arranged in accommodating holes each extending in a radial direction. A rotor core is provided with an extension portion in a circumferential direction extending further outward in the circumferential direction with respect to the magnet from at least one of a radially outer end and a radially inner end in the accommodating hole, and a radial regulating portion regulating a movement of the magnet in the radial direction. The radial regulating portion extends in the radial direction so as to correspond to a center in the circumferential direction of the accommodating hole. The dimension in the circumferential direction of a portion of the radial regulating portion that is brought into contact with the magnet is smaller than the dimension in the circumferential direction of the magnet.
    Type: Grant
    Filed: April 17, 2007
    Date of Patent: August 10, 2010
    Assignee: ASMO Co., Ltd.
    Inventors: Hideaki Nishiura, Seiya Yokoyama, Yoshiaki Takemoto
  • Publication number: 20100148612
    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: December 15, 2009
    Publication date: June 17, 2010
    Applicant: ASMO CO., LTD.
    Inventors: YOSHIAKI TAKEMOTO, Seiya Yokoyama, Yoji Yamada, Shigemasa Kato
  • Publication number: 20100133939
    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: Application
    Filed: October 15, 2009
    Publication date: June 3, 2010
    Applicant: ASMO CO., LTD.
    Inventors: Yoshiaki Takemoto, Seiya Yokoyama, Yoji Yamada, Shigemasa Kato, Yoko Tateishi
  • Publication number: 20070252469
    Abstract: A plurality of magnets are arranged in accommodating holes each extending in a radial direction. A rotor core is provided with an extension portion in a circumferential direction extending further outward in the circumferential direction with respect to the magnet from at least one of a radially outer end and a radially inner end in the accommodating hole, and a radial regulating portion regulating a movement of the magnet in the radial direction. The radial regulating portion extends in the radial direction so as to correspond to a center in the circumferential direction of the accommodating hole. The dimension in the circumferential direction of a portion of the radial regulating portion that is brought into contact with the magnet is smaller than the dimension in the circumferential direction of the magnet.
    Type: Application
    Filed: April 17, 2007
    Publication date: November 1, 2007
    Applicant: ASMO CO., LTD.
    Inventors: Hideaki NISHIURA, Seiya YOKOYAMA, Yoshiaki Takemoto