Patents by Inventor Kohji Maki

Kohji Maki 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: 20040150269
    Abstract: Disclosed herewith a compact linear motor provided with a plurality of magnetic pole teeth and used to increase the thrust force by canceling a magnetic attractive force working between the primary member and the secondary member. The linear motor comprises a primary member and a secondary member. The primary member includes cores formed with a magnetic material and an electromagnetic coil wound on the cores while the secondary member supported so as to be capable of moving relatively with respect to the primary member with a gap therebetween. In the linear motor, the coil that is wound commonly on the cores is also disposed between adjacent magnetic pole teeth.
    Type: Application
    Filed: August 20, 2003
    Publication date: August 5, 2004
    Inventors: Kohji Maki, Houng Joong Kim, Yasuo Morooka, Keijirou Sakai, Hitoshi Shibata, Hideki Shimane, Hisao Tadokoro, Takashi Kobayashi
  • Patent number: 6753627
    Abstract: A linear motor has an armature; a moving member movable relatively to the armature; first and second magnetic pole tooth trains each having magnetic pole teeth magnetically coupled to one of two magnetic poles of the moving element, the first and second magnetic pole tooth trains being separated from each other in a direction substantially perpendicular to a moving direction of the moving member; and third and fourth magnetic pole tooth trains each having magnetic pole teeth magnetically coupled to the other of the two magnetic poles of the moving element, the third and fourth magnetic pole tooth trains being separated from each other in a direction substantially perpendicular to a moving direction of the moving member and the moving member being arranged between the first and second magnetic pole tooth trains and the third and fourth magnetic pole tooth trains.
    Type: Grant
    Filed: October 9, 2001
    Date of Patent: June 22, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Houng Joong Kim, Kohji Maki
  • Publication number: 20040090128
    Abstract: The conventional linear drive apparatus has the problem that in constructing a linear motor of a multiphase structure by connecting a plurality of armature units, the length of the armature becomes longer in proportion to the number of the phases, thus limiting the locations where the apparatus can be installed. The problem is solved by a linear drive apparatus comprising a plurality of armature units 3 formed by a magnetic material on which a conductor coil 4 is disposed, and an armature comprising an arrangement of the armature units 3. The armature units 3 comprise a plurality of opposing portions having opposing magnetic pole teeth. The magnetic pole teeth of adjacent opposing portions are arranged in an interdigitated manner. A secondary member 6 is disposed between magnetic pole teeth of the opposing portions. The armature units 3 comprise the coil 4 arranged on opposite sides thereof in an alternating manner.
    Type: Application
    Filed: August 13, 2003
    Publication date: May 13, 2004
    Inventors: Houng Joong Kim, Kohji Maki, Hisao Tadokoro, Hideki Shimane, Hitoshi Shibata, Keijiro Sakai
  • Publication number: 20040056748
    Abstract: An angle-torque sensor has: a torque detection coil that detects a change in state quantity in a mechanism to detect a relative angle made between input axis and output axis of a torsion bar to be twisted by a torque; an angle detection coil that detects a change in state quantity in a mechanism to detect a rotation angle of a reduction axis which rotates with a rotation being transmitted from the input axis or output axis and being reduced by a reduction mechanism; a torque detection circuit that detects the relative angle from the output of the torque detection coil; and an angle detection circuit that detects the rotation angle from the output of the angle detection coil.
    Type: Application
    Filed: July 31, 2003
    Publication date: March 25, 2004
    Inventors: Ryoso Masaki, Satoru Kaneko, Kohji Maki, Ryoichi Menju
  • Publication number: 20040021373
    Abstract: A drive apparatus overcomes the problems of ensuring accurate mounting of a plurality of armature coils relative to a plurality of magnetic pole position detectors, limitations concerning the location for mounting, and the extension of primary-side length. The drive apparatus comprises a primary side including an arrangement of a plurality of armatures each having a core made of a magnetic material with coil windings. It also comprises a secondary side including a permanent magnet movably supported relative to the armatures via a gap. A magnetic pole position detector is disposed between adjacent armatures.
    Type: Application
    Filed: July 28, 2003
    Publication date: February 5, 2004
    Inventors: Houng Joong Kim, Kohji Maki, Hisao Tadokoro, Hideki Shimane, Hitoshi Shibata, Keijirou Sakai
  • Patent number: 6623255
    Abstract: A fluid transfer apparatus utilizes a linear motor including a movable element in which magnetic poles are provided at a predetermined pitch along a moving direction, magnetic pole teeth provided in upper and lower portions of the movable element at a predetermined pitch along a moving direction of the movable element and so as to oppose to each other via the movable element, and a coil, wherein adjacent magnetic pole teeth and opposing magnetic pole teeth among the magnetic pole teeth form different poles.
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: September 23, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Kim Houng Joong, Kohji Maki, Taizou Miyazaki, Tomoyuki Hanyu, Ryouichi Naganuma
  • Patent number: 6614137
    Abstract: Leakage of magnetic fluxes passing through the gaps between the magnetic pole teeth of an armature is reduced thereby to reduce a magnetic attraction force between the armature and a mover. A linear motor includes a first member and a second member. The first member is configured with at least a magnetic pole of a first polarity having a first opposed portion and a magnetic pole of a second polarity having a second opposed portion. The second member is held by the first opposed portion, while the second member is held by the second opposed portion and moves relatively. The first member is formed of an iron core and a winding, and the second member is formed of a permanent magnet, a magnetic material, a winding of a single type or a combination of a plurality of types of materials.
    Type: Grant
    Filed: February 26, 2001
    Date of Patent: September 2, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Kim Houng Joong, Kohji Maki, Yoshitaka Iwaji, Taizou Miyazaki, Tomoyuki Hanyu
  • Publication number: 20030155819
    Abstract: In order to reduce load supported by a support mechanism for supporting a movable part so as to prevent the movable part from moving in a horizontal direction when stress is generated thereon in the horizontal direction, there is provided a drive unit including a primary side having a magnetic body around which a coil is wound, and a secondary side having a plurality of permanent magnets, the primary side including magnetic poles and step portions provided on the magnetic poles. The width of each step portion is smaller than the width of each permanent magnet.
    Type: Application
    Filed: August 16, 2002
    Publication date: August 21, 2003
    Inventors: Houng Joong Kim, Kohji Maki, Yasuo Morooka, Isamu Numata, Hisao Tadokoro, Takeo Morimoto, Yasunori Sannohe, Hiroshi Ueno, Hideki Shimane
  • Patent number: 6570274
    Abstract: With an electric motor formed according to a prior art, there is a relatively large amount of magnetic flux leaking between an armature and a secondary, resulting in a problem that an electric current is large but a desired output is small. In addition, since a magnetic attraction acts only in one direction between the armature and the secondary, there is a relatively large load on the support structures of the secondary, causing a distortion in the motor structure and some other disadvantages. In order to solve the above problems, the present invention provides an improved electric motor comprising an armature having a core formed by a magnetic material and having a coil wound around the core; and a secondary disposed within the armature with a clearance formed therebetween and supported to be relatively movable with respect to the armature.
    Type: Grant
    Filed: February 27, 2001
    Date of Patent: May 27, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Houng Joong Kim, Kohji Maki
  • Patent number: 6548919
    Abstract: In a linear motor comprising, a stator, a movable element, and an electromagnetic coil device for magnetizing the movable element or stator, the stator includes at least one pair of magnetic core parts, and at least two pairs of magnetic poles, the magnetic poles of each of the at least two pairs are aligned on an imaginary line perpendicular to the movable direction, magnetic polar directions of the at least two pairs adjacent to each other are opposite to each other, first one of the magnetic poles of each of the at least two pairs faces to a first side surface of the movable element, and second one of the magnetic poles of each of the at least two pairs faces to a second side surface of the movable element opposite to the first side surface in a traverse direction perpendicular to the movable direction.
    Type: Grant
    Filed: February 27, 2001
    Date of Patent: April 15, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Kohji Maki, Kim Houng Joong, Hiroshi Katayama, Kenji Miyata
  • Patent number: 6548920
    Abstract: A linear motor and a method of producing the linear motor are provided to reduce a leak magnetic flux flowing between an armature and a moving element to reduce a one-direction magnetic attraction force generated between the armature and the moving element. The linear motor includes the armature having a core formed of a magnetic body and a winding wound around the core, and the moving element supported so as for the moving element to move relatively to the armature via a gap, magnetic pole teeth disposed above and below the moving element, disposed at predetermined pitches along a moving direction of the moving element and disposed opposite to each other via the moving element, and a winding for exciting the magnetic pole teeth such that adjacent and opposite magnetic pole teeth have different magnetic poles, and the moving element is reciprocated relatively to the armature by exciting the winding according to a predetermined control circuit.
    Type: Grant
    Filed: March 2, 2001
    Date of Patent: April 15, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Kim Houng Joong, Hiromitsu Seino, Ryouichi Naganuma, Hiroshi Toyoda, Kohji Maki
  • Patent number: 6541880
    Abstract: There is provided a linear motor, having an armature and a needle with magnetism, in which the armature has at least a magnetic pole of a first polarity having a first opposed part and another magnetic pole of a second polarity having a second opposed part; the needle is held by the first opposed part, and is further held by the second opposed part; and a distribution of magnetism of the needle according to a position in the movable direction thereof. In this way, a leak of a magnetic flux from pole teeth passing between the pole teeth of the armature is decreased to increase a thrust and braking force of the needle, which is thereby enabled to generate a greater or smaller thrust in a specific section or sections than the thrust during usual linear movement.
    Type: Grant
    Filed: February 27, 2001
    Date of Patent: April 1, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Takashi Okada, Kim Houng Joong, Kazuo Tahara, Kohji Maki, Kouki Yamamoto, Miyoshi Takahashi, Kenji Miyata, Ryoichi Takahata
  • Publication number: 20030059320
    Abstract: A fluid transfer apparatus utilizes a linear motor including a movable element in which magnetic poles are provided at a predetermined pitch along a moving direction, magnetic pole teeth provided in upper and lower portions of the movable element at a predetermined pitch along a moving direction of the movable element and so as to oppose to each other via the movable element, and a coil, wherein adjacent magnetic pole teeth and opposing magnetic pole teeth among the magnetic pole teeth form different poles.
    Type: Application
    Filed: February 26, 2001
    Publication date: March 27, 2003
    Inventors: Houng Joong Kim, Kohji Maki, Taizou Miyazaki, Tomoyuki Hanyu, Ryouichi Naganuma
  • Publication number: 20020183946
    Abstract: An electromagnetic field analyzing method and an electromagnetic field analyzer and system for analyzer electromagnetic fields created in a rotary machine. An electromagnetic field is analyzed in a total analysis space of a rotary machine including a stator space containing a stator and a rotor space containing a rotor to determine a boundary field between the stator space and the rotor space.
    Type: Application
    Filed: July 12, 2002
    Publication date: December 5, 2002
    Inventors: Kenji Miyata, Hideshi Fukumoto, Akiyoshi Komura, Kohji Maki
  • Publication number: 20020175584
    Abstract: A permanent magnet type rotating electrical machine capable of reducing core loss due to armature reaction magnetic flux and making an effective use of reactance torque. A permanent magnet type rotating electrical machine comprising a first rotor core containing a permanent magnet and a second rotor core having a flux barrier without magnet, wherein a concave portion is provided between poles in the vicinity of outer surface the rotor core containing the permanent magnet and the length of the gap in the magnetic path on the q-axis side is increased to ensure easy passage of the magnetic path of the armature reaction magnetic flux on the reluctance torque rotor side, whereby a permanent magnet type rotating electrical machine delivering a large output can be obtained by making an effective use of reluctance torque.
    Type: Application
    Filed: October 4, 2001
    Publication date: November 28, 2002
    Inventors: Haruo Koharagi, Shinichi Wakui, Mamoru Kimura, Satoshi Kikuchi, Ryoichi Takahata, Kohji Maki, Kazuo Tahara, Kenji Miyata, Masashi Kitamura, Miyoshi Takahashi
  • Publication number: 20020175583
    Abstract: A permanent magnet type rotating electrical machine capable of reducing core loss due to armature reaction magnetic flux and making an effective use of reluctance torque. A permanent magnet type rotating electrical machine comprising a first rotor core equipped with a permanent magnet stored in a permanent magnet insertion hole, and a second rotor core having a reluctance magnetic circuit, wherein a concave portion is provided between poles in the vicinity of the outer surface of the first rotor core, and a flux barrier constituting the reluctance magnetic circuit of the second rotor core is arranged in a form different from the magnet insertion hole, whereby the magnetic path of the armature reaction magnetic flux is defined, and a permanent magnet type rotating electrical machine delivering a large output is obtained by making an effective use of reluctance torque.
    Type: Application
    Filed: October 4, 2001
    Publication date: November 28, 2002
    Inventors: Satoshi Kikuchi, Haruo Koharagi, Shinichi Wakui, Mamoru Kimura, Ryoichi Takahata, Kohji Maki, Kazuo Tahara, Kenji Miyata, Masashi Kitamura, Miyoshi Takahashi
  • Publication number: 20020117934
    Abstract: A vehicular alternator is provided which can effectively utilize the magnetic flux of a permanent magnet disposed between claw-type magnetic poles and can improve an output of the alternator. The vehicular alternator comprises a rotor and a stator constituted by coiling stator windings over a stator core, the rotor comprising a pair of claw-type magnetic poles arranged in an opposed relation, a permanent magnet disposed between adjacent two of a plurality of claws provided on the pair of claw-type magnetic poles, and field windings coiled radially inward of the plurality of claws. Each of the plurality of claws of the rotor is formed to have a shape coming into contact with the whole of a magnetic pole surface of the permanent magnet.
    Type: Application
    Filed: August 30, 2001
    Publication date: August 29, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Hiroshi Kanazawa, Kenji Miyata, Kaoru Kawabata, Kohji Maki, Kazuo Tahara, Susumu Sasaki, Ryoichi Takahata
  • Patent number: 6434491
    Abstract: A method of analyzing electromagnetic fields created in a rotary machine and an analyzer. The method and analyzer provide for an electromagnetic field in a total analysis space of a rotary machine including a stator space containing a stator and a rotor space containing a rotor to be analyzed to determined a boundary field between the stator space and the rotor space. The boundary field in a direction of rotation in modes is expanded and the modes obtained by expansion are converted into rotating magnetic field components. using the rotating magnetic field components as boundary conditions for a boundary between the stator space and the rotor space, an electromagnetic field in the stator space is analyzed and an electromagnetic field in the rotor space is analyzed.
    Type: Grant
    Filed: January 28, 2000
    Date of Patent: August 13, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Kenji Miyata, Hideshi Fukumoto, Akiyoshi Komura, Kohji Maki
  • Publication number: 20020070612
    Abstract: A linear motor has an armature; a moving member movable relatively to the armature; first and second magnetic pole tooth trains each having magnetic pole teeth magnetically coupled to one of two magnetic poles of the moving element, the first and second magnetic pole tooth trains being separated from each other in a direction substantially perpendicular to a moving direction of the moving member; and third and fourth magnetic pole tooth trains each having magnetic pole teeth magnetically coupled to the other of the two magnetic poles of the moving element, the third and fourth magnetic pole tooth trains being separated from each other in a direction substantially perpendicular to a moving direction of the moving member and the moving member being arranged between the first and second magnetic pole tooth trains and the third and fourth magnetic pole tooth trains.
    Type: Application
    Filed: October 9, 2001
    Publication date: June 13, 2002
    Applicant: Hitachi Ltd.
    Inventors: Kim Houng Joong, Kohji Maki
  • Publication number: 20020053833
    Abstract: With an electric motor formed according to a prior art, there is a relatively large amount of magnetic flux leaking between an armature and a secondary, resulting in a problem that an electric current is large but a desired output is small. In addition, since a magnetic attraction acts only in one direction between the armature and the secondary, there is a relatively large load on the support structures of the secondary, causing a distortion in the motor structure and some other disadvantages. In order to solve the above problems, the present invention provides an improved electric motor comprising an armature having a core formed by a magnetic material and having a coil wound around the core; and a secondary disposed within the armature with a clearance formed therebetween and supported to be relatively movable with respect to the armature.
    Type: Application
    Filed: February 27, 2001
    Publication date: May 9, 2002
    Inventors: Houng Joong Kim, Kohji Maki