Patents by Inventor Yuichi Yoshikawa

Yuichi Yoshikawa 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: 20140300235
    Abstract: A rotor of a motor comprises a plurality of magnetic-pole sections including: a plurality of slots which are formed inside of a rotor core; and permanent magnets, at least one of which is inserted into each of the plurality of slots; wherein each of the magnetic-pole sections is formed to correspond to the at least one permanent magnet; and wherein the rotor core includes hollow portions formed by cutting portions of the rotor core which portions are between the magnetic-pole sections which are adjacent in the circumferential direction of the rotor core and are different in polarity such that portions of circumferential end portions of the permanent magnet are exposed, and extending portions each of which is formed in a position corresponding to the hollow portions and extends radially outward from a center portion of the rotor core.
    Type: Application
    Filed: October 26, 2012
    Publication date: October 9, 2014
    Inventors: Yuichi Yoshikawa, Takashi Ogawa
  • Patent number: 8816554
    Abstract: A clutch mechanism moving together with an actuator allows coupling or decoupling an inner rotor to or from a power shaft, thereby controlling a rotation angle. This structure allows a polarity of a magnetic pole of the inner rotor to be the same as that of an opposing magnetic pole of an outer rotor when the motor is driven at a low rpm, so that magnetic fluxes inter-linking with windings can be increased, which results in greater torque. When the motor is driven at a high rpm, the structure allows the polarity of the magnetic pole of the inner rotor to be different from that of the opposing magnetic pole of the outer rotor, so that an amount of leakage flux is increased, and the magnetic fluxes inter-linking with the winding are decreased. As a result, an induction voltage is lowered and a high rpm range is widened.
    Type: Grant
    Filed: March 7, 2011
    Date of Patent: August 26, 2014
    Assignee: Panasonic Corporation
    Inventors: Hu Li, Yuichi Yoshikawa, Hiroshi Murakami, Hideaki Matsuo, Yuichiro Tashiro
  • Publication number: 20140184015
    Abstract: A stator of a motor comprises a stator core including a plurality of plate members stacked together; the stator core including: a yoke of a tubular shape; and teeth each of which includes an extending portion extending inward in a radial direction of the yoke from the yoke and an increased-width portion formed at a tip end of the extending portion so as to have a greater width than the extending portion in a circumferential direction of the yoke; wherein the extending portion has a constant-width portion extending radially in a straight-line shape so as to have a constant circumferential width, a narrower portion having a circumferential width smaller than a circumferential width of the constant-width portion, and a clamp portion for securing the plurality of plate members to each other; and wherein at least a portion of the clamp portion is located in the narrower portion.
    Type: Application
    Filed: July 24, 2012
    Publication date: July 3, 2014
    Applicant: Panasonic Corporation
    Inventors: Takashi Ogawa, Yuichi Yoshikawa, Ikuo Ozaki, Toshiyuki Tamamura, Hirokazu Yamauchi
  • Patent number: 8680737
    Abstract: A stator 3 is provided with a plurality of magnetic poles 3a on the outer circumference thereof, and is configured from a plurality of layers of plate-shaped members. A rotor 4 is rotatably disposed around the stator. The inner circumferential face of the rotor is provided with a magnet 5. The outer circumferential ends of the magnetic poles of the stator are provided with an extended portion that is bent such that at least one plate-shaped member, including an outermost layer, of the plurality of plate-shaped members is substantially parallel to the magnet. When the inner diameter of a bent portion of a plate-shaped member that is the closest to the magnet of the at least one plate-shaped member constituting the extended portion is taken as R1i, and the thickness of the closest plate-shaped member is taken as T1, R1i<T1 is satisfied. Accordingly, it is possible to improve the driving efficiency of an outer rotor-type motor.
    Type: Grant
    Filed: June 30, 2010
    Date of Patent: March 25, 2014
    Assignee: Panasonic Corporation
    Inventors: Hiroaki Kawasaki, Yuichi Yoshikawa, Atsuyoshi Koshiba, Koji Kadowaki, Yasuo Kunishige, Yasuhiro Inoue
  • Patent number: 8664962
    Abstract: The N1(s) turns of a first output winding is divided by a split ratio ? into N1a(s) turns of a lower-layer first output winding and N1b(s) of an upper-layer first output winding. The lower-layer first output winding is continuously wound around all slots as the undermost layer. A second output winding is continuously wound around all slots over the lower-layer first output winding. An upper-layer first output winding is continuously wound around all slots over the second output winding. The split ratio ? is adjusted only in the slots where the detection accuracy decreases. This equalize the contribution of the first output windings and the second output winding to the flux linkage, thereby achieving high angle detection accuracy.
    Type: Grant
    Filed: January 10, 2012
    Date of Patent: March 4, 2014
    Assignee: Panasonic Corporation
    Inventors: Takashi Ogawa, Yuichi Yoshikawa, Yasuji Echizen, Masahiko Kobayashi, Masaaki Nishiyama
  • Publication number: 20140055001
    Abstract: Provided is a stator of a motor which is capable of reducing a loss generated in a motor and thereby attaining a high-efficient motor, and a motor including the stator.
    Type: Application
    Filed: April 18, 2012
    Publication date: February 27, 2014
    Applicant: PANASONIC CORPORATION
    Inventors: Takashi Ogawa, Yuichi Yoshikawa, Ikuo Ozaki, Toshiyuki Tamamura, Hirokazu Yamauchi
  • Publication number: 20140009031
    Abstract: A motor stator of the invention is provided with a laminated stator core comprising a plurality of core pieces having teeth and linked by intermediate thin-wall portions. The thin-wall portions are bent to form the stator core into an annular shape with two ends of the stator core joined by welding, and slots are formed between adjoining pairs of the teeth. A welded portion of the stator core is not near a center line in a radial direction of any of the slots.
    Type: Application
    Filed: February 2, 2012
    Publication date: January 9, 2014
    Applicant: PANASONIC CORPORATION
    Inventors: Hu Li, Yuichi Yoshikawa, Yukihiro Okada, Minoru Chamura, Tooru Nakamaru, Yasuji Echizen
  • Publication number: 20140001906
    Abstract: A brushless motor capable of high speed rotation by field weakening operation is designed to reduce torque ripple at a maximum load point with current phase advance so that the torque ripple at the maximum load point is 1 to 1.5 times the torque ripple at a low speed load point.
    Type: Application
    Filed: January 25, 2012
    Publication date: January 2, 2014
    Applicant: PANASONIC CORPORATION
    Inventors: Hu Li, Yuichi Yoshikawa, Yuichiro Tashiro, Hideaki Matsuo
  • Publication number: 20130342068
    Abstract: A plurality of protruding portions each having a predetermined width in a circumferential direction are respectively provided at a predetermined interval along an outer periphery of a stator, and through-holes are formed at both ends in the circumferential direction of the protruding portions. A total length of the widths, which the protruding portions respectively have, in the circumferential direction is set equal to or less than 25% of an outer circumference of the stator. With this structure and by virtue of the through-holes, a compressive stress built up in an inner periphery of the stator due to pressing forces imposed on center areas of the protruding portions can be distribute toward the outer periphery of the stator.
    Type: Application
    Filed: February 1, 2012
    Publication date: December 26, 2013
    Applicant: PANASONIC CORPORATION
    Inventors: Takashi Ogawa, Yuichi Yoshikawa, Ikuo Ozaki, Toshiyuki Tamamura, Hirokazu Yamauchi
  • Publication number: 20130342070
    Abstract: Provided is a stator of a motor which is capable of reducing an iron loss generated in a motor and thereby attaining a high-efficient motor. A stator of a motor comprises a yoke of a tubular shape; and teeth each of which includes an extending portion extending inward in a radial direction of the yoke from the yoke and an increased-width portion formed at a tip end of the extending portion so as to have a greater width than the extending portion in a circumferential direction of the yoke; wherein the extending portion has a narrower portion having a smaller width than a remaining portion of the extending portion.
    Type: Application
    Filed: December 6, 2011
    Publication date: December 26, 2013
    Applicant: PANASONIC CORPORATION
    Inventors: Takashi Ogawa, Yuichi Yoshikawa, Ikuo Ozaki, Toshiyuki Tamamura, Hirokazu Yamauchi
  • Patent number: 8604804
    Abstract: The N1(s) turns of an output winding is divided by a split ratio ? into N1a(s) turns of an output winding (1a) and N1b(s) turns of an output winding (1b). The output winding (1a) is continuously wound around all slots as the undermost layer. Output winding 2, which is different in phase by 90 degrees from the output winding (1a), is continuously wound around all the slots over the output winding (1a). An output winding (1b) is continuously wound around all the slots over output winding 2. This equalizes the contribution of the output winding and output winding 2 to the flux linkage, thereby achieving high angle detection accuracy.
    Type: Grant
    Filed: April 12, 2011
    Date of Patent: December 10, 2013
    Assignee: Panasonic Corporation
    Inventors: Takashi Ogawa, Yuichi Yoshikawa, Yasuji Echizen, Masahiko Kobayashi, Masaaki Nishiyama
  • Publication number: 20130313934
    Abstract: Provided are a rotor of a motor capable of attaining a high-speed rotation by appropriately dispersing a stress exerted on a flux barrier portion while reducing a leakage of magnetic flux, and a fan driving motor including the rotor. A second inner wall surface is greater than a first inner wall surface in length in a cross-section perpendicular to a rotational axis (C). A side wall surface has a flux barrier wall surface extending from each of both ends of the second inner wall surface in the cross-section perpendicular to the rotational axis (C), the flux barrier wall surface extending outward relative to the second inner wall surface in an extending direction of the second inner wall surface and more distant from an outer edge of a rotor as it goes from the second inner wall surface toward the first inner wall surface in the cross-section perpendicular to the rotational axis (C).
    Type: Application
    Filed: December 6, 2011
    Publication date: November 28, 2013
    Applicant: PANASONIC CORPORATION
    Inventors: Hiroaki Kawasaki, Yuichi Yoshikawa
  • Publication number: 20130313933
    Abstract: Provided are a rotor of a motor capable of attaining a high-speed rotation by appropriately dispersing a stress exerted on a flux barrier portion while reducing a leakage of magnetic flux, and a fan driving motor including the rotor. A second inner wall surface is greater than a first inner wall surface in length in a cross-section perpendicular to a rotational axis (C). A side wall surface has a flux barrier wall surface extending from each of both ends of the second inner wall surface in the cross-section perpendicular to the rotational axis (C), the flux barrier wall surface extending outward relative to the second inner wall surface in an extending direction of the second inner wall surface and more distant from an outer edge of a rotor as it goes from the second inner wall surface toward the first inner wall surface in the cross-section perpendicular to the rotational axis (C).
    Type: Application
    Filed: December 6, 2011
    Publication date: November 28, 2013
    Applicant: PANASONIC CORPORATION
    Inventors: Hiroaki Kawasaki, Yuichi Yoshikawa
  • Publication number: 20130088127
    Abstract: The N1(s) turns of an output winding is divided by a split ratio ? into N1a(s) turns of an output winding (1a) and N1b(s) turns of an output winding (1b). The output winding (1a) is continuously wound around all slots as the undermost layer. Output winding 2, which is different in phase by 90 degrees from the output winding (1a), is continuously wound around all the slots over the output winding (1a). An output winding (1b) is continuously wound around all the slots over output winding 2. This equalizes the contribution of the output winding and output winding 2 to the flux linkage, thereby achieving high angle detection accuracy.
    Type: Application
    Filed: April 12, 2011
    Publication date: April 11, 2013
    Applicant: PANASONIC CORPORATION
    Inventors: Takashi Ogawa, Yuichi Yoshikawa, Yasuji Echizen, Masahiko Kobayashi, Masaaki Nishiyama
  • Patent number: 8410654
    Abstract: A motor comprises a stator having a plurality of magnetic poles disposed at first predetermined intervals along an outer periphery thereof, and a rotor having a permanent magnet with poles magnetized alternately to have different polarities at second predetermined intervals and disposed rotatably around the outer periphery of the stator with a predetermined gap. The magnetic poles of the stator has extended portions formed in a manner to extend from magnetic polar bases into a direction generally parallel to the permanent magnet, and the extended portions are formed of a high-permeability magnetic steel sheet with silicon content less than 3.0 wt-%.
    Type: Grant
    Filed: December 11, 2008
    Date of Patent: April 2, 2013
    Assignee: Panasonic Corporation
    Inventors: Yuichi Yoshikawa, Hiroshi Murakami, Atsuyoshi Koshiba, Koji Kadowaki, Haruki Kato, Yasuo Kunishige
  • Publication number: 20130076195
    Abstract: A motor of this invention comprises a rotor having a permanent magnet, the number of which magnet poles is P, and a stator including M pcs of teeth, the teeth arranged in a circumferential direction in a manner to face the permanent magnet through a spatial gap, wherein the stator includes stator core having the number M of the teeth, and a winding wire wound about each of the tooth, wherein the number P of the magnet poles and the number M of the teeth have a relation defined by formulae (2/3)M<P<(4/3)M, and M?P, and wherein ratio (t1/Ds) of teeth tip width t1 to stator inside diameter Ds is given by a formula 0.18<(t1/Ds)<0.25.
    Type: Application
    Filed: March 24, 2011
    Publication date: March 28, 2013
    Applicant: PANASONIC CORPORATION
    Inventors: Hu Li, Yuichi Yoshikawa, Hiroshi Murakami, Haruhiko Kado, Kiyomi Kawamura
  • Patent number: 8405270
    Abstract: Supposing a straight line joining rotation center O of a rotor and a magnetic pole middle, that is, a middle of permanent magnets (25) to be a d-axis, and a straight line joining rotation center O and an intermediate point of mutually adjacent permanent magnets (25) to be a q-axis, mutually adjacent arcs A1 and A2 are composed such that radius R1 of arc A1 at the d-axis side is larger than radius R2 of arc A2 at the q-axis side, and that, at intersection point ? of mutual arcs A1 and A2, angle ? of tangent u of arc A2 at the q-axis side with respect to tangent t of arc A1 at the d-axis side is set by ?3 degrees???2 degrees.
    Type: Grant
    Filed: March 21, 2008
    Date of Patent: March 26, 2013
    Assignee: Panasonic Corporation
    Inventors: Hu Li, Yuichi Yoshikawa, Hiroshi Murakami, Hiroki Sato
  • Patent number: 8405276
    Abstract: The motor comprises a stator, a rotor, and magnets. The stator has a plurality of magnetic poles circumferentially arranged at first spaced intervals. The rotor is rotatably arranged in a position opposing to the stator. The magnets are arranged at second spaced intervals circumferentially on a surface of the rotor. The stator is formed by laminating plate materials, and a plurality of laminated plate materials at least including outermost layers of a laminated body thereof are bent in a direction substantially parallel to the magnet in order to form extended portions. And, when a magnet opposed area of pole tip portion being closest to a magnet including the extended portion is S, and a sectional area of magnetic pole is A, then area ratio (S/A) fulfills the relation of 4.8>(S/A).
    Type: Grant
    Filed: January 13, 2011
    Date of Patent: March 26, 2013
    Assignee: Panasonic Corporation
    Inventors: Hiroaki Kawasaki, Yuichi Yoshikawa, Atsuyoshi Koshiba, Yasuhiro Inoue, Koji Kadowaki, Yasuo Kunishige
  • Publication number: 20130043864
    Abstract: The N1(s) turns of a first output winding is divided by a split ratio ? into N1a(s) turns of a lower-layer first output winding and N1b(s) of an upper-layer first output winding. The lower-layer first output winding is continuously wound around all slots as the undermost layer. A second output winding is continuously wound around all slots over the lower-layer first output winding. An upper-layer first output winding is continuously wound around all slots over the second output winding. The split ratio ? is adjusted only in the slots where the detection accuracy decreases. This equalize the contribution of the first output windings and the second output winding to the flux linkage, thereby achieving high angle detection accuracy.
    Type: Application
    Filed: January 10, 2012
    Publication date: February 21, 2013
    Applicant: PANASONIC CORPORATION
    Inventors: Takashi Ogawa, Yuichi Yoshikawa, Yasuji Echizen, Masahiko Kobayashi, Masaaki Nishiyama
  • Patent number: 8368278
    Abstract: A motor comprising a stator having a plurality of magnetic poles disposed in a circumferential direction along an outer periphery thereof, a rotor disposed rotatably around the outer periphery of the stator, and a magnet disposed in a circumferential direction along an inner periphery of the rotor. The stator is formed by laminating sheet-like plates. A plurality of the sheet-like plates including an outermost layer of this laminated body comprises a flat portion substantially perpendicular to the magnet, and an extended portion bent to a direction substantially parallel to the magnet. A part of the sheet-like plate having the extended portion disposed to the outermost side is formed into a thickness smaller than thicknesses of the other parts.
    Type: Grant
    Filed: November 12, 2008
    Date of Patent: February 5, 2013
    Assignee: Panasonic Corporation
    Inventors: Yuichi Yoshikawa, Hiroshi Murakami, Atsuyoshi Koshiba, Haruki Kato, Yasuo Kunishige, Koji Kadowaki, Hiroyuki Asai