Patents by Inventor Naoki Ayai

Naoki Ayai 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: 7468207
    Abstract: A method of manufacturing an oxide superconducting wire which can manufacture the longest possible wire by connecting relatively short wires with each other and is capable of suppressing reduction of a critical current resulting from influence by strain when the wires connected with each other are bent, an oxide superconducting wire, a superconducting coil and a superconducting apparatus are provided. According to the method of manufacturing an oxide superconducting wire by superposing end portions of two oxide superconducting wires with each other thereby bonding the end portions and connecting the oxide superconducting wires with each other, a junction formed by superposing the end portions with each other is so worked as to reduce the quantity of strain on an end of the junction when the two oxide superconducting wires and connected with each other are bent.
    Type: Grant
    Filed: June 9, 2006
    Date of Patent: December 23, 2008
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Naoki Ayai, Ryosuke Hata, Hiromi Takei, Kazuhiko Hayashi, Takeshi Hikata
  • Publication number: 20080020936
    Abstract: A method of producing a material of an oxide superconductor comprises the following steps: (a) in a solution, ionizing a material containing an atom for constituting the oxide superconductor, (b) by removing a solvent by spraying the solution in a first atmosphere, producing a material powder containing the atom for constituting the oxide superconductor, and (c) cooling the material powder in a second atmosphere into which a cooling gas is introduced. In this method, the concentration of carbon dioxide in the second atmosphere is lower than that in the first atmosphere, which contains the removed solvent component. The concentration of nitrogen oxide in the second atmosphere is lower than that in the first atmosphere, which contains the removed solvent component. The concentration of water vapor in the second atmosphere is lower than that in the first atmosphere, which contains the removed solvent component. These specifications enable the method to increase the density and purity of the oxide superconductor.
    Type: Application
    Filed: January 30, 2006
    Publication date: January 24, 2008
    Inventor: Naoki Ayai
  • Publication number: 20070287635
    Abstract: A superconducting wire includes a filament portion which contains a Bi-2223 phase and a sheath portion covering the filament portion. A method for producing the superconducting wire includes a filling step, a drawing step, a rolling step, and a sintering step. The filament portion is absent of the Bi-2223 phase in composition prior to the sintering step.
    Type: Application
    Filed: June 6, 2005
    Publication date: December 13, 2007
    Inventors: Kouhei Yamazaki, Naoki Ayai
  • Patent number: 7293343
    Abstract: A method of manufacturing a superconducting wire is provided. The method is provided with the steps of filling a raw material powder in a metal pipe, the raw material powder being composed of an oxide superconductor or a precursor to become an oxide superconductor through heat treatment; heating the metal pipe filled with the above-described raw material powder to 400° C. or more and 800° C. or less; depressurizing the inside of the above-described heated metal pipe to 100 Pa or less; sealing an opening at an end portion of the metal pipe under the above-described depressurized condition; and subjecting the sealed metal pipe containing the above-described raw material powder to wire drawing, wherein the packing density of the above-described raw material powder is controlled at 10 percent or more and 40 percent or less and, thereby, the degasification of the inside of the metal pipe is adequately performed, so that the critical current density can be increased.
    Type: Grant
    Filed: July 30, 2003
    Date of Patent: November 13, 2007
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Naoki Ayai
  • Patent number: 7162287
    Abstract: This invention relates to an oxide superconducting wire comprising oxide superconducting filaments, a high-density ceramic layer uniformly surrounding each of the filaments, and a silver sheath that directly covers the ceramic layer. The ceramic layer becomes non-superconducting when the filaments are cooled to an operating temperature of oxide superconductors. The oxide superconductors can be isolated by the ceramic that acts as a highly resistive material or an insulator. A high normal resistance is achieved, and thereby AC loss is reduced remarkably.
    Type: Grant
    Filed: December 31, 2003
    Date of Patent: January 9, 2007
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Naoki Ayai
  • Patent number: 7132162
    Abstract: A method of manufacturing an oxide superconducting wire which can manufacture the longest possible wire by connecting relatively short wires with each other and is capable of suppressing reduction of a critical current resulting from influence by strain when the wires connected with each other are bent, an oxide superconducting wire, a superconducting coil and a superconducting apparatus are provided. According to the method of manufacturing an oxide superconducting wire by superposing end portions of two oxide superconducting wires with each other thereby bonding the end portions and connecting the oxide superconducting wires with each other, a junction formed by superposing the end portions with each other is so worked as to reduce the quantity of strain on an end of the junction when the two oxide superconducting wires and connected with each other are bent.
    Type: Grant
    Filed: December 6, 2004
    Date of Patent: November 7, 2006
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Naoki Ayai, Ryosuke Hata, Hiromi Takei, Kazuhiko Hayashi, Takeshi Hikata
  • Publication number: 20060228548
    Abstract: A method of manufacturing an oxide superconducting wire which can manufacture the longest possible wire by connecting relatively short wires with each other and is capable of suppressing reduction of a critical current resulting from influence by strain when the wires connected with each other are bent, an oxide superconducting wire, a superconducting coil and a superconducting apparatus are provided. According to the method of manufacturing an oxide superconducting wire by superposing end portions of two oxide superconducting wires with each other thereby bonding the end portions and connecting the oxide superconducting wires with each other, a junction formed by superposing the end portions with each other is so worked as to reduce the quantity of strain on an end of the junction when the two oxide superconducting wires and connected with each other are bent.
    Type: Application
    Filed: June 9, 2006
    Publication date: October 12, 2006
    Inventors: Naoki Ayai, Ryosuke Hata, Hiromi Takei, Kazuhiko Hayashi, Takeshi Hikata
  • Patent number: 7091423
    Abstract: A superconducting cable has a plurality of superconducting wires wound around a core material (former) in a multilayered manner. The superconducting wires employ a twisted filament type superconducting wire having spiral superconducting filaments and an untwisted filament type superconducting wire having straight superconducting filaments. The layer in which an applied magnetic field is large and of which the low loss effect is expected is formed of twisted filament type superconducting wires, and the other layers are formed using the untwisted filament type superconducting wires; thus the AC loss can be reduced effectively. Thus, in the superconducting cable, the AC loss can be effectively reduced while a degradation of the current characteristics and the increase of cost are suppressed.
    Type: Grant
    Filed: April 7, 2004
    Date of Patent: August 15, 2006
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Hiroyasu Yumura, Naoki Ayai
  • Publication number: 20060057381
    Abstract: A method of manufacturing an oxide superconducting wire which can manufacture the longest possible wire by connecting relatively short wires with each other and is capable of suppressing reduction of a critical current resulting from influence by strain when the wires connected with each other are bent, an oxide superconducting wire, a superconducting coil and a superconducting apparatus are provided. According to the method of manufacturing an oxide superconducting wire by superposing end portions of two oxide superconducting wires with each other thereby bonding the end portions and connecting the oxide superconducting wires with each other, a junction formed by superposing the end portions with each other is so worked as to reduce the quantity of strain on an end of the junction when the two oxide superconducting wires and connected with each other are bent.
    Type: Application
    Filed: December 6, 2004
    Publication date: March 16, 2006
    Inventors: Naoki Ayai, Ryosuke Hata, Hiromi Takei, Kazuhiko Hayashi, Takeshi Hikata
  • Publication number: 20050278939
    Abstract: The present invention provides a method of manufacturing a bismuth based oxide superconducting wire, comprising steps of preparing a raw material powder, and subjecting the raw material powder to plastic working and heat treatment; wherein the raw material powder contains the superconducting phases containing Bi, Pb, Sr, Ca, Cu, and O in a composition ratio of approximately 2:2:1:2 (Bi+Pb):Sr:Ca:Cu, and the non-superconducting phases containing Pb; wherein the composition ratio (Bi+Pb):Sr:Ca:Cu of the raw material powder is approximately 2:2:2:3; and wherein the ratio of the non-superconducting phases to the superconducting phases is 5 wt % or less; or wherein the raw material powder contains orthorhombic superconducting phases containing Bi, Pb, Sr, Ca, Cu, and 0 in a composition ratio of approximately 2:2:1:2 (Bi+Pb):Sr:Ca:Cu; and wherein the composition ratio (Bi+Pb):Sr:Ca:Cu of the raw material powder is approximately 2:2:2:3.
    Type: Application
    Filed: June 14, 2004
    Publication date: December 22, 2005
    Inventor: Naoki Ayai
  • Publication number: 20050172478
    Abstract: A method of manufacturing a superconducting wire is provided. The method is provided with the steps of filling a raw material powder in a metal pipe, the raw material powder being composed of an oxide superconductor or a precursor to become an oxide superconductor through heat treatment; heating the metal pipe filled with the above-described raw material powder to 400° C. or more and 800° C. or less; depressurizing the inside of the above-described heated metal pipe to 100 Pa or less; sealing an opening at an end portion of the metal pipe under the above-described depressurized condition; and subjecting the sealed metal pipe containing the above-described raw material powder to wire drawing, wherein the packing density of the above-described raw material powder is controlled at 10 percent or more and 40 percent or less and, thereby, the degasification of the inside of the metal pipe is adequately performed, so that the critical current density can be increased.
    Type: Application
    Filed: July 30, 2003
    Publication date: August 11, 2005
    Inventor: Naoki Ayai
  • Patent number: 6844064
    Abstract: A method of manufacturing an oxide superconducting wire which can manufacture the longest possible wire by connecting relatively short wires with each other and is capable of suppressing reduction of a critical current resulting from influence by strain when the wires connected with each other are bent, an oxide superconducting wire, a superconducting coil and a superconducting apparatus are provided. According to the method of manufacturing an oxide superconducting wire by superposing end portions of two oxide superconducting wires (1, 2) with each other thereby bonding the end portions and connecting the oxide superconducting wires with each other, a junction (L) formed by superposing the end portions with each other is so worked as to reduce the quantity of strain on an end of the junction (L) when the two oxide superconducting wires (1) and (2) connected with each other are bent.
    Type: Grant
    Filed: November 1, 2000
    Date of Patent: January 18, 2005
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Naoki Ayai, Ryosuke Hata, Hiromi Takei, Kazuhiko Hayashi, Takeshi Hikata
  • Patent number: 6828508
    Abstract: A high temperature oxide superconducting wire is provided which is capable of preventing metal located on the outer periphery of the superconducting wire from diffusing into a superconductor to achieve restriction of reduction in the critical current density. The high temperature oxide superconducting wire includes a high temperature oxide superconductor 1, a sheathing body 2 formed of material containing silver for coating the high temperature oxide superconductor 1, a heat-resistant oxide ceramic material 3 for coating the sheathing body 2, and a coating body 4 which is inactive relative to the heat-resistant oxide ceramic material 3 in a high temperature oxidative atmosphere.
    Type: Grant
    Filed: June 28, 2001
    Date of Patent: December 7, 2004
    Assignees: Sumitomo Electric Industries, Ltd.
    Inventors: Naoki Ayai, Munetsugu Ueyama, Kazuhiko Hayashi, Hiroshi Maeda, Mitsunori Sato
  • Publication number: 20040200637
    Abstract: A superconducting cable has a plurality of superconducting wires wound around a core material (former) in a multilayered manner. The superconducting wires employ a twisted filament type superconducting wire having spiral superconducting filaments and an untwisted filament type superconducting wire having straight superconducting filaments. The layer in which an applied magnetic field is large and of which the low loss effect is expected is formed of twisted filament type superconducting wires, and the other layers are formed using the untwisted filament type superconducting wires; thus the AC loss can be reduced effectively. Thus, in the superconducting cable, the AC loss can be effectively reduced while a degradation of the current characteristics and the increase of cost are suppressed.
    Type: Application
    Filed: April 7, 2004
    Publication date: October 14, 2004
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Hiroyasu Yumura, Naoki Ayai
  • Patent number: 6777376
    Abstract: In order to provide a superconducting wire that has a high critical current value, has no defects such as bulges, and has high mechanical strength, an oxide superconducting material (1) is covered, and ceramic particles or fibers (3) are buried in the surface of a covering (2) made of metal
    Type: Grant
    Filed: October 10, 2000
    Date of Patent: August 17, 2004
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Tetsuyuki Kaneko, Munetsugu Ueyama, Akira Mikumo, Naoki Ayai, Shin-ichi Kobayasi
  • Publication number: 20040157746
    Abstract: This invention relates to an oxide superconducting wire comprising oxide superconducting filaments, a high-density ceramic layer uniformly surrounding each of the filaments, and a silver sheath that directly covers the ceramic layer. The ceramic layer becomes non-superconducting when the filaments are cooled to an operating temperature of oxide superconductors. The oxide superconductors can be isolated by the ceramic that acts as a highly resistive material or an insulator. A high normal resistance is achieved, and thereby AC loss is reduced remarkably.
    Type: Application
    Filed: December 31, 2003
    Publication date: August 12, 2004
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventor: Naoki Ayai
  • Publication number: 20030127492
    Abstract: An oxide superconducting wire is provided which allows an insulating layer to be formed without deteriorating the superconducting properties. An oxide superconducting wire includes oxide superconducting filaments 1, a matrix 2, a covering layer 3, and an insulating layer 4. The matrix 2 is placed so as to enclose the oxide superconducting filaments 1 and is made of silver. The covering layer 3 is placed so as to enclose the matrix 2, contains silver and manganese, and has a thickness of 10 &mgr;m to 50 &mgr;m. The insulating layer 4 is placed so as to enclose the covering layer 3.
    Type: Application
    Filed: December 19, 2002
    Publication date: July 10, 2003
    Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.
    Inventors: Naoki Ayai, Nobuhiro Saga, Kazuhiko Hayashi
  • Patent number: 6555504
    Abstract: An oxide superconducting wire includes oxide superconducting filaments 1, a matrix 2, a covering layer 3, and an insulating layer 4. The matrix 2 is placed so as to enclose the oxide superconducting filaments 1 and is made of silver. The covering layer 3 is placed so as to enclose the matrix 2, contains silver and manganese, and has a thickness of 10 &mgr;m to 50 &mgr;m. The insulating layer 4 is placed so as to enclose the covering layer 3.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: April 29, 2003
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Naoki Ayai, Nobuhiro Saga, Kazuhiko Hayashi
  • Patent number: 6546614
    Abstract: The diameter of a first metal tube charged with raw material powder is reduced for obtaining an elementary wire. A plurality of such elementary wires are charged into a second metal tube, which in turn is reduced in diameter for obtaining a round first wire having a plurality of first filaments. The first wire is uniaxially compressed thereby obtaining a tape-like second wire having a plurality of second filaments. The second wire is heat treated thereby obtaining an oxide superconducting wire including a plurality of superconductor filaments. The maximum grain size of the raw material powder is smaller than the minor diameter of the first or second filaments.
    Type: Grant
    Filed: August 3, 2001
    Date of Patent: April 15, 2003
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Tetsuyuki Kaneko, Naoki Ayai, Jun Fujikami, Shinichi Kobayashi
  • Patent number: 6493925
    Abstract: Powder including at least a superconducting phase is degassed (step S1). After the powder is filled in a silver pipe (step S2), the silver pipe is degassed at a high temperature (step S3). After a plurality of single-core wires are inserted into another silver pipe to attain a multi-core structure, the silver pipe is degassed at a high temperature (step S5). The silver pipe is sealed under a reduced pressure (step S6). Therefore, even when a multi-core superconducting wire is manufactured, a manufacturing method of a superconducting wire capable of preventing swelling of the wire caused by a residual gaseous component can be obtained.
    Type: Grant
    Filed: September 19, 2000
    Date of Patent: December 17, 2002
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Tetsuyuki Kaneko, Munetsugu Ueyama, Akira Mikumo, Naoki Ayai, Shin-ichi Kobayashi