International Superconductivity Technology Center

Railway Technical Research Institute

Nippon Steel Corporation

Kawasaki Jukogyo Kabushiki Kaisha

Tosoh Corporation

Koyo Seiko Company, Ltd.

Shikoku Research Institute Incorporated

Hokuriku Electric Power Company

Shikoku Denryoku Kabushikigaisha

Kawasaki Steel Corporation

Shikoku Electric Power Co., Inc.

Shikoku Denryoku Kabushiki Kaisha

Hiroshi Takaichi

Masato Murakami

Naomichi Sakai

Shoji Tanaka

Naoki Koshizuka

Akihiro Kondoh

Hiroyuki Fujimoto

Ryoichi Takahata

Motoaki Shibayama

Sang-Im Yoo

Takamitsu Higuchi

Shoichi Kagiya

Hiromasa Fukuyama

Satoru Aihara

Naomichi Nakamura

A high critical temperature and high critical current density superconductor is disclosed which contains a metal oxide expressed by the following formula (I):

Superconductor and method of producing same

Superconducting bearing device

A superconducting bearing device comprises an annular permanent magnet portion disposed concentrically with a rotary body in the form of a vertical shaft, and superconductors opposed to the lower end face of the magnet portion and vertically spaced apart therefrom. The permanent magnet portion comprises a disk fixedly mounted on the rotary body, and annular permanent magnets embedded in the disk at a spacing radially of the rotary body. Each of the magnets has upper and lower ends magnetized to polarities opposite to each other, and the adjacent magnets are magnetized to polarities opposite to each other at the upper ends, as well as at the lower ends. The radial spacing between the magnets is optimized in accordance with the radial dimension (width) of the magnets. This improves the device in load capacity and rigidity and prevents the deflection of axis of the rotary body, enabling the bearing device to support the rotary body in a noncontact state with good stability.

A composite magnet comprising a core of R-Ba-Cu-O type bulk superconductor (R denotes rare-earth elements) made by melt process, enclosed around it with normal conductive or superconductive coil, or a composite magnet including a center of normal conductive or superconductive coil, enclosed around it with ring-shaped R-Ba-Cu-O type bulk superconductor (R denotes rare-earth elements) made by melt process is disclosed, which allows easy control of generating magnetic field and gives a relatively strong magnetic field even at a temperature as high as that of liquid nitrogen.

Composite of high-temperature superconductive bulk form with coil magnet

Disclosed is a method of joining Y-based oxide superconductors on joining two or more Y-based oxide superconductors made by melting process under pressure, characterized by incorporating REBa.sub.2 Cu.sub.3 O.sub.7-.delta. (RE=Y, Ho, Er, Tm or Yb), Ag and BaCuO.sub.2 -CuO type composition to the joining interface as an adhesive phase for joining. It becomes possible to easily make a joined material that does not deteriorate the superconductive characteristic at joined interface.

Method of joining Y-based oxide superconductors

A method for producing an REBaCuO oxide superconductor having large magnetic levitation force, where RE is a rare earth element selected from the group consisting of Y, Sm, Eu, Gd, Dy, Ho, Er, and Yb, involves the steps of using a raw material mixture as the starting feed, heating the raw material mixture for partial melting, followed by cooling and solidification, pulverizing and mixing the resulting solid, shaping the resulting mixture into a given shape, placing or embedding nucleates on or in the resulting shape, followed by heating for partial melting, and cooling the resulting partial melt to a substantial temperature at which a superconducting phase starts to form, followed by slow cooling, whereby the superconducting phase is preferentially formed and grown from a nucleation site.

Production of oxide superconductors having large magnetic levitation

To ensure a well-oriented crystal structure, there is provided a process of producing an oxide superconductor of a Y--Ba--Cu--O system with a composition having an atomic ratio Y:Ba:Cu of 1.0-2.0:2.0-2.5:3.0-3.5, the process comprising the steps of: preparing a semimelt including solid and liquid phases and consisting of Y, Ba, Cu and O in the atomic ratio; and solidifying the semimelt to form the oxide superconductor by so controlling a moving speed of a solidification front to have two components of different values in two perpendicularly intersecting directions.

Process of producing oxide superconductor

A superconducting bearing unit compring a permanent magnet mounted to a rotating shaft and a superconducting body mounted on the inner periphery of a housing surrounding the shaft, the superconducting member being adapted to be cooled with the rotating shaft moved upwards until it attains a superconducting condition, so that the rotating shaft is supported in use in a balanced condition between the weight of the rotating shaft, etc. and a pinning force caused by the permanent magnet and the superconducting member.

Superconducting bearing unit and operating method thereof

Growing community of inventors

Tokyo, Japan

Hiroshi Takaichi