Patents by Inventor Yuji Enomoto

Yuji Enomoto 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: 7791244
    Abstract: A multiphase claw-pole type electric rotary machine has two or more phases-stator units. The stator units are arranged phase by phase in an axial direction of the electric rotary machine. Each phase stator unit comprises a pair of complementary-opposed claw pole core blocks and a ring-shaped stator coil sandwiched therebetween. The stator units have structures rotatably adjustable independent of each other in their phase positional relations while maintaining concentricity of them after assembly of the rotary machine before being secured.
    Type: Grant
    Filed: June 15, 2007
    Date of Patent: September 7, 2010
    Assignees: Hitachi Industrial Equipment Systems Co., Ltd., Hitachi Powdered Metals Co., Ltd, Nidec Servo Corporation
    Inventors: Yuji Enomoto, Motoya Ito, Ryoso Masaki, Shoji Ohiwa, Chio Ishihara
  • Patent number: 7750529
    Abstract: A pump is driven by a compact electric motor in which a coil is disposed in a ring form around and along a stator core which has a plurality of claw magnetic poles that extend alternately from both ends of one member of the stator core toward the end of the other member thereof. A stator core can be made from a compressed powder core by molding with resin, with the molded portion able to serve as a partition separating pump and motor units.
    Type: Grant
    Filed: July 18, 2007
    Date of Patent: July 6, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Fumio Tajima, Masashi Kitamura, Yuji Enomoto, Yuji Nomoto, Kenya Takarai
  • Publication number: 20100148611
    Abstract: An armature core includes a core portion formed of a lamination of plural noncrystalline metallic foil bands and resin for bond-fixing the non-crystalline metallic foil bands, wherein the armature core is provided with at least two cut surfaces with respect to the lamination layers. Amorphous metal is used as the iron base of the non-crystalline metallic foil bands. The cut surfaces are perpendicular to the lamination-layers of the non-crystalline foil bands. For the amorphous core, a resin mold is formed. The contact portions between winding wires and amorphous are provided with edge roundness. Further, an axial gap motor using cut cores of amorphous lamination as stator cores is provided.
    Type: Application
    Filed: November 10, 2009
    Publication date: June 17, 2010
    Inventors: Zhuonan Wang, Yuji ENOMOTO, Shigeki MORINAGA, Ryoso MASAKI, Shigeho TANIGAWA, Hiromitsu ITABASHI, Motoya ITO
  • Patent number: 7714466
    Abstract: To realize reduction in vibration and noise while utilizing reluctance torque, a rotating electrical machine includes: a rotor having permanent magnets disposed in a cylindrical surface coaxial with a rotary shaft; and a stator having an annular stator core disposed coaxially with the rotary shaft, and a annular coil for magnetizing the stator core. The stator core has an annular part covering the annular coil, claws disposed at equal intervals in an inner radius surface of the annular part and extending axially, and magnetic gaps formed between neighboring claws. The number of claws is equal to the number of permanent magnets, and magnet flux in a direction orthogonal to a center axis of the magnetic pole of the permanent magnet at right angles in electric angle is larger than magnetic flux in the center axis direction generated between neighboring permanent magnets. Metal interpoles are provided between neighboring permanent magnets.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: May 11, 2010
    Assignees: Hitachi Industrial Equipment Systems Co., Ltd., Hitachi Powdered Metals Co., Ltd., Japan Servo Co., Ltd.
    Inventors: Masashi Kitamura, Fumio Tajima, Shigeru Kakugawa, Yuji Enomoto, Motoya Ito, Ryoso Masaki, Shoji Ohiwa, Chio Ishihara
  • Patent number: 7714475
    Abstract: In a multiple phase claw pole type motor which includes: a plurality of claw poles including a claw portion extending in an axial direction and having a magnetic pole surface facing a rotor in a state of being separated from the rotor by a small gap, a radial yoke portion extending radially outwardly from this claw portion, and an outer peripheral yoke extending from this radial yoke portion in the same direction as the direction of extension of the claw portion; a stator core formed by alternately placing the claw poles in a circumferential direction so that a distal end of each claw portion faces the outer peripheral yoke of an adjacent one of the claw poles; and a stator constructed by sandwiching an annular coil with the adjacent claw poles of this stator core, a multiple phase claw pole type motor characterized in that the claw poles are formed by compacting a magnetic powder and are formed of a magnetic compact having a DC magnetizing property of its flux density becoming 1.
    Type: Grant
    Filed: March 16, 2006
    Date of Patent: May 11, 2010
    Assignees: Hitachi Industrial Equipment Systems Co., Ltd., Hitachi Powdered Metals Co., Ltd., Japan Servo Co., Ltd.
    Inventors: Yuji Enomoto, Motoya Ito, Kenji Miyata, Chio Ishihara, Ryoso Masaki, Yasuaki Motegi, Kouki Isozaki, Tadashi Sato
  • Patent number: 7701109
    Abstract: It is an object of the present invention to make it possible to easily wind a stator winding, enhance an occupied ratio in a stator core, reduce a winding resistance because there is no coil end, and change a field magnetic flux in accordance with a use. Stator pawl magnetic poles of a stator core extend from both sides in an axial direction alternately at locations opposed to a rotor to form a plurality of magnetic poles. With this stator core, it is only necessary to annularly wind a stator winding. Therefore, it is possible to enhance operability and an occupied ratio, and since there is no coil end, it is possible to reduce winding resistance. Since the rotor is a Randall type rotor having a field winding and a rotor pawl magnetic pole, it is possible to change the field magnetic flux in accordance with a use.
    Type: Grant
    Filed: December 5, 2007
    Date of Patent: April 20, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Toshio Ishikawa, Minoru Yabuki, Hiroshi Kanazawa, Yuji Enomoto, Yoshihisa Ishikawa
  • Patent number: 7692344
    Abstract: In a motor having a pawl-shaped magnetic pole, if a coil is wound like a ring shape so as to be formed, one leader line can be generally drawn out to an external portion from a position close to an outer periphery of a stator, however, the other leader line is drawn out to the external portion from an inner periphery of the stator. Accordingly, the leader line occupies a part of the inner space formed by the stator core, so that there is generated a problem that a space factor of the coil is reduced. Accordingly, an object of the present invention is to improve the space factor of the coil. In order to achieve the object mentioned above, a space passing wirings of a plurality of coils therethrough is provided in a part of the pawl-shaped magnetic pole of the stator core of the stator having the pawl-shaped magnetic pole.
    Type: Grant
    Filed: December 6, 2006
    Date of Patent: April 6, 2010
    Assignee: Hitachi Industrial Equipment Systems Co., Ltd.
    Inventors: Ryoso Masaki, Kazuhide Ebine, Yuji Enomoto, Motoya Ito
  • Patent number: 7649298
    Abstract: A claw teeth type electric rotary machine comprises a stator including an annular core with claws formed from a powder core and an annular coil installed inside the annular core, and a rotor rotatably positioned inside the stator. An inner edge of the annular core is provided with plural claw poles which are protruded at a predetermined interval in a circumferential direction and extended in an axial direction of the annular core so as to alternately meshes with each other. The stator comprises the annular core with claws, the annular coil, and a molded nonmagnetic potting material filled between the annular core with claws and annular coil, so that the annular core with claws and annular coil are integrated with the molded potting non-magnetic material.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: January 19, 2010
    Assignees: Hitachi Industrial Equipment Systems Co., Ltd., Hitachi Powered Metals Co., Ltd., Japan Servo Co., Ltd.
    Inventors: Yuji Enomoto, Motoya Ito, Masashi Kitamura, Ryoso Masaki, Katsuyuki Yamazaki, Shoji Ohiwa, Yasuaki Motegi, Kazuo Asaka, Chio Ishihara
  • Patent number: 7626301
    Abstract: An electric rotating machine having permanent magnets having a rotor having a plurality of permanent magnets, a stator iron core disposed in opposite relation with the rotor, and a stator winding wound around the stator core, wherein the stator core is constituted by a yoke and a plurality of teeth portions disposed to the yoke. The teeth portions are projected towards the inner periphery of the rotor. The teeth portions are made of amorphous magnetic material.
    Type: Grant
    Filed: September 22, 2005
    Date of Patent: December 1, 2009
    Assignees: Japan Servo Co., Ltd., Hitachi Powdered Metals Co., Ltd., Hitachi Industrial Equipment Systems Co., Ltd., Hitachi Metals, Ltd.
    Inventors: Yuji Enomoto, Haruo Koharagi, Motoya Ito, Katsuyuki Yamasaki, Ryoso Masaki, Shoji Ohiwa, Chio Ishihara, Masahiro Mita
  • Patent number: 7605517
    Abstract: A claw pole type rotating electric machine includes first and second claw cores which are disposed on a ring shaped ring yoke portion and a plurality of claw magnetic poles which extend in the axial direction are provided, and stator cores are formed by meshing of the claw magnetic poles with each other, and the stator is formed by holding the ring coils on the outer circumference side of the claw magnetic poles, wherein the first and second claw cores are formed by powder cores, the radial direction thickness of the claw magnetic pole is 2 mm or more, a flat surface is formed perpendicular to the axial direction at the end extending in the axial direction of the claw magnetic pole, a ejection taper in the circumference direction of the claw magnetic pole is formed in the range of 10 degrees or less, and the ratio of the axial direction length of the claw magnetic pole and the axial direction thickness of the ring yoke portion is no more than 5:1.
    Type: Grant
    Filed: September 27, 2006
    Date of Patent: October 20, 2009
    Assignees: Hitachi Industrial Equipment Systems Co., Ltd., Hitachi Powered Metals Co., Ltd., Japan Servo Co., Ltd.
    Inventors: Yuji Enomoto, Motoya Ito, Shoji Ohiwa, Ryozo Masaki, Chio Ishihara
  • Patent number: 7592734
    Abstract: A three-phase permanent magnet brushless motor comprises a stator having three-phase windings, and a rotor having a permanent magnet with a plurality of poles for serving as a field magnet. The stator comprises a stator core which includes a powder core that is compacted at a high density in at least teeth thereof. A combination of the number of magnetic poles of the rotor with the number of slots of the stator satisfies a condition that a least common multiple of the number of slots and the number of magnetic poles is 60 or more in a region in which the number of magnetic poles is 16 or less, and the number of slots is 12 or less. The powder core is made by compacting magnetic powders to have a green density of 7.5 g/cm3 or higher.
    Type: Grant
    Filed: August 17, 2006
    Date of Patent: September 22, 2009
    Assignees: Hitachi Industrial Equipment System Co., Ltd., Japan Servo Co., Ltd., Hitachi Powered Metals Co., Ltd.
    Inventors: Yuji Enomoto, Akeshi Takahashi, Motoya Ito, Ryoso Masaki, Katsuyuki Yamazaki, Masahide Yamazaki, Masashi Kitamura, Chio Ishihara, Kazuo Asaka, Shoji Ohiwa, Yasuaki Motegi
  • Publication number: 20090189471
    Abstract: A spindle motor having a stator and a rotor includes: a stator core provided in the stator having salient-poles; a stator coil arranged between the salient-poles; a rotor; and a permanent magnet provided in the rotor. The stator core includes a stack of steel sheets whose salient-poles are formed by etching. The permanent magnet includes a ferromagnetic material consisting mainly of iron. The ferromagnetic material has formed in laminae on a surface thereof a layer of a fluorine compound containing an alkali element, an alkaline earth element or a rare earth element formed in laminae. Near an interface between the ferromagnetic material and the layer of the fluorine compound, iron exists in the layer of the fluorine compound such that a basic crystal structure of the fluorine compound is not changed and the fluorine compound containing the iron exists in the layer of the fluorine compound.
    Type: Application
    Filed: July 29, 2008
    Publication date: July 30, 2009
    Applicant: Hitachi, Ltd.
    Inventors: Hisato Amano, Yuji Enomoto, Matahiro Komuro, Yuichi Satsu, Fumio Tajima
  • Publication number: 20090108713
    Abstract: An outer rotor type hybrid stepping motor includes a stator, a rotor, a magnet disposed axially in the stator or the rotor, a stator core disposed inwardly from a gap between the stator and rotor, and a stator winding on the stator core. The rotor is disposed outside the gap. The magnet has an axial cross sectional area A. The residual magnetic flux density of the magnet is Br, and a total of magnetic fluxes exiting axially from the surface is A×Br. A gap average magnetic flux density, determined by dividing A×Br by the top cross sectional area small teeth poles on the rotor is Bg; pitch of the teeth is ?; and tooth width is Tw. Average magnetic flux density Bg, tooth pitch ?, and tooth width Tw are determined by the equation K=1/(?×Bg×Tw/?), with the coefficient k in a range of 0.56-0.66 (1/T).
    Type: Application
    Filed: October 29, 2008
    Publication date: April 30, 2009
    Applicant: Japan Servo Co. Ltd.
    Inventors: Yuji ENOMOTO, Kenji Miyata, Yasuaki Motegi, Shoji Ohiwa
  • Publication number: 20090102314
    Abstract: A rotating electrical machine includes: a stator that includes two stator stages each constituted with a plurality of claw poles extending toward opposite sides along an axial direction at alternate positions and a ring-shaped core back that forms a magnetic path between the claw poles, the two stator stages being stacked over along the axial direction; a stator winding formed by winding a coil in a ring shape and disposed in a space enclosed by the claw poles and the core back at each of the stator stages; and a rotor rotatably disposed at a position facing the claw poles of the stator, and: stator windings corresponding to a plurality of phases are disposed together at least at one of the two stator stages.
    Type: Application
    Filed: August 22, 2008
    Publication date: April 23, 2009
    Applicant: Hitachi, Ltd.
    Inventors: Kenji Miyata, Yoshihisa Ishikawa, Motoya Ito, Yuji Enomoto, Takayuki Koyama
  • Publication number: 20090001843
    Abstract: A rotating electrical machine includes: a claw pole stator constituted with a stator core that includes a plurality of claw poles and a stator coil wound inside the stator core; and a rotor rotatably disposed at a position facing opposite the claw poles. The stator core is constituted of split blocks each corresponding to at least one of magnetic pole pairs each made up with two claw poles assuming different magnetic polarities when an electric current is supplied to the stator coil.
    Type: Application
    Filed: June 19, 2008
    Publication date: January 1, 2009
    Applicant: Hitachi, Ltd.
    Inventors: Yuji Enomoto, Yoshihisa Ishikawa, Motoya Ito, Hiroshi Kanazawa, Kenji Miyata, Takahiro Makiyama, Takayuki Koyama
  • Publication number: 20080315702
    Abstract: An alternator for vehicle includes a stator that outputs an AC voltage and a rotor that includes a field coil and a rotor core. The stator includes a plurality of phase stators that are disposed side-by-side along the rotational axis and individually output AC voltages. The phase stators include an even number of stator tabs alternately extending from one outer side of a phase stator coil toward another outer side of the phase stator coil and extending from the other outer side toward the one outer side along the rotational axis. The rotor includes a field coil and a rotor core at which an even number of rotor tabs are formed along the circumferential direction so as to alternately extend from one outer side of the field coil toward another outer side of the field coil along the rotational axis and extend from the other outer side toward the one outer side along the rotational axis. A phase stator core at each phase stator is formed by laminating a plurality of magnetic sheets.
    Type: Application
    Filed: June 18, 2008
    Publication date: December 25, 2008
    Applicant: Hitachi, Ltd.
    Inventors: Toshio Ishikawa, Minoru Yabuki, Yoshihisa Ishikawa, Yuji Enomoto
  • Patent number: 7446441
    Abstract: An outer rotor type hybrid stepping motor including a stator, a rotor, a magnet disposed axially in either the stator or rotor, a stator core disposed inward from a gap formed between the stator and rotor, the rotor disposed outside the gap, and a stator winding wound around the stator core. The outer rotor type hybrid stepping motor has a cross-sectional area A in the axial direction of the magnet, a gap portion diameter D, a lamination thickness of the stator core in the axial direction L and a residual magnetic flux density of the magnet Br. The lamination thickness of the stator core in the axial direction L and the residual magnetic flux density Br are determined according to the equation D×L/A=k×Br with the condition that coefficient k is kept in a range of 0.56-0.66(1/T). The resulting optimized design parameters for L and Br provide a reduction in size of the outer rotor type hybrid stepping motor, a high output and a high resolution.
    Type: Grant
    Filed: August 19, 2004
    Date of Patent: November 4, 2008
    Assignee: Japan Servo Co., Ltd.
    Inventors: Yuji Enomoto, Kenji Miyata, Yasuaki Motegi, Shoji Ohiwa
  • Publication number: 20080267807
    Abstract: A core rod for forming a cylindrical green compact having an axial protrusion or a radial step portion or dent portion on an inner surface of the cylindrical member by powder compaction, wherein: the core rod is provided with a step portion protruding in a radial direction at least a part on an outer surface thereof; the core rod is divided into two parts, an upper core and a lower core, on a plane that is flush with an upper surface of the step portion; and the upper core and lower core are mechanically joined with fastening members or bonded with an adhesive on a plane along which the core rod is divided.
    Type: Application
    Filed: April 25, 2008
    Publication date: October 30, 2008
    Inventors: Kinya KOBAYASHI, Hideaki NAGASHIMA, Shuuichi ISHIZAWA, Yuji ENOMOTO, Tomoaki ARAKAWA, Jiro SHIMA, Chio ISHIHARA
  • Publication number: 20080224574
    Abstract: A stepping motor comprising: a stator iron core with a plurality of salient poles each having a small tooth at the tip thereof and stator coils each disposed between the salient poles; a rotor core with a plurality of teeth in the faces opposite to the stator; and permanent magnets sandwiched by the rotor cores in an axial direction, wherein the stator iron core and the rotor core are formed by laminated steel plates. The salient poles of the stator iron cores of the steel plates and small teeth are shaped by etching, and a thickness of the steel plates is 0.05 to 0.30 mm.
    Type: Application
    Filed: January 24, 2008
    Publication date: September 18, 2008
    Inventors: Yuji Enomoto, Yoshihisa Ishikawa, Teruyoshi Abe
  • Patent number: D572660
    Type: Grant
    Filed: April 14, 2006
    Date of Patent: July 8, 2008
    Assignees: Hitachi Industrial Equipment Systems Co., Ltd., Japan Servo Co., Ltd., Hitachi Powdered Metals Co., Ltd.
    Inventors: Yuji Enomoto, Motoya Ito, Kazumasa Ide, Masashi Kitamura, Ryoso Masaki, Katsuyuki Yamazaki, Shoji Ohiwa, Yasuaki Motegi, Kazuo Asaka, Chio Ishihara