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EP0695027A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

Magnetic levitation device

Assignee: KANAGAWA ACADEMY OF SCIENCE AND TECHNOLOGY FOUNDATION
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Filing: 1995-01-24
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Granted: —
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Expires: 2015-01-24
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Abstract

Abstract A ferromagnetic body (21) of a movable part (2) is so disposed as to oppose a high-temperature superconductive body (11) of a fixed part (1), and the high-temperature superconductive body (11) is cooled to a temperature below a critical temperature in a magnetic field to put the same in a superconductive state. The attractive force between the high-temperature superconductive body (11) and the ferromagnetic body (21), produced when the magnetic flux pinned to the high-temperature superconductive body (11) is passed through the ferromagnetic body (21), is utilized as the force holding the movable part (2). Stable levitation can be achieved without control in a non-contact manner by only a combination of the high-temperature superconductive body (11) and ferromagnetic body (21) having such a form that the attractive force weakens when the gap decreases below a predetermined value.

Inventors

  • 👤 Yukio Tsutsui
  • 👤 Toshiro Higuchi

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 03:49
CPC Classifications
F; F16; F16C; F16C32/00; F16C32/04; F16C32/0406; F16C32/0408; F16C32/0436; F16C32/0438; H; H02; H02N; H02N15/00; H02N15/04; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/876; Y10S505/877

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 104 words
A magnetic suspension apparatus in which a movable part faces a stationary part with a predetermined gap therebetween to suspend said movable part by a magnetic action in a non-contacting manner, wherein at least one superconductor is provided on one of said stationary and movable parts, said superconductor having at least one region in which magnetic flux is pinned by cooling the region to a temperature below a critical temperature in a magnetic field, and at least one ferromagnetic material is provided on the other of said stationary and movable parts such that the flux pinned in said superconductor passes through said ferromagnetic material.
Claim 2
Dependent Claim 36 words
A magnetic suspension apparatus according to Claim 1, wherein said ferromagnetic member has a surface facing said superconductor, and the area of the surface is smaller than the area of the pinning region of said superconductor.
Claim 3
Dependent Claim 36 words
A magnetic suspension apparatus according to Claim 1 or 2, wherein said ferromagnetic member has a bypass to bypass a magnetic flux of said superconductor from said pinning area to an end portion of said superconductor.
Claim 4
Dependent Claim 54 words
A magnetic suspension apparatus according to any one of Claims 1 through 3, wherein a tip portion of said ferromagnetic member which faces said superconductor is disposed at a position shifted from the pinning region of said superconductor, in a direction perpendicular to the direction of said gap, within a range facing said superconductor.
Claim 5
Dependent Claim 46 words
A magnetic suspension apparatus according to any one of Claims 1 through 4, wherein at least one of said superconductor and said ferromagnetic member is provided with a magnetic member on the side opposite to the side facing said gap to form a closed magnetic circuit.
Claim 6
Dependent Claim 37 words
A magnetic suspension apparatus according to any one of Claims 1 through 5, wherein said superconductor is provided with a permanent magnet or an electromagnet for biasing on the side opposite to the side facing said gap.
Claim 7
Dependent Claim 28 words
A magnetic suspension apparatus according to Claim 6, wherein said permanent magnet or said electromagnet is also used to form a region where said magnetic flux is pinned.
Claim 8
Dependent Claim 25 words
A magnetic suspension apparatus according to Claim 7, wherein the amount of said pinned magnetic flux is adjusted by adjusting exciting current of said electromagnet.
Claim 9
Dependent Claim 36 words
A magnetic suspension apparatus according to any one of Claims 1 through 8, wherein said superconductor is formed as a stationary part while said ferromagnetic member is formed as a movable part which is rotatably arranged.
Claim 10
Dependent Claim 130 words
A magnetic suspension apparatus according to Claim 9, wherein said movable part is formed by a ferromagnetic member which has a circular plate portion fixed to a rotary shaft and a cylindrical portion which is coaxially extended from the periphery of said circular plate portion and is fixed thereto, and said stationary part includes at least two block-shaped superconductors which face the end surface of said cylindrical portion and each of which is provided with a surface facing the end surface and having a size greater than the thickness of the cylindrical portion of said ferromagnetic member, and a circular magnetic member having a diameter roughly equal to the diameter of said cylindrical portion is fixed to said block-shaped superconductors on the side opposite to the side facing the gap.
Claim 11
Dependent Claim 46 words
A magnetic suspension apparatus according to Claim 10, wherein said stationary part includes a plurality of block-shaped permanent magnets which are disposed between said block-shaped superconductors and said circular magnetic member such that the magnetic poles of said permanent magnets are alternately directed in opposite directions.
Claim 12
Dependent Claim 144 words
A magnetic suspension apparatus according to Claim 9, wherein said movable part is formed by a ferromagnetic member which has a rotary shaft and a larger diameter portion formed at a part of the rotary shaft, and said stationary part includes a circular superconductor which is disposed at a position facing an end surface of said rotary shaft and has a diameter larger than the diameter of said end surface and an annular superconductor which faces an outer circumferential surface of the larger diameter portion of said rotary shaft, said circular superconductor is fixed to a bottom surface of a cup-shaped magnetic member through the side of said circular superconductor which is opposite to the side facing the gap, and said annular superconductor is fixed to an inner circumferential surface of said cup-shaped magnetic member through the outer circumferential surface of said annular superconductor.
Claim 13
Dependent Claim 87 words
A magnetic suspension apparatus according to Claim 12, wherein said stationary part includes a cylindrical permanent magnet which is disposed between said circular superconductor and the bottom surface of said cup-shaped magnetic member, which has a diameter smaller than the diameter of said superconductor and which is polarized in the axial direction, and an annular permanent magnet which is disposed between the outer circumferential surface of said annular superconductor and the inner circumferential surface of said cup-shaped magnetic member and which is polarized in the radial direction.
Claim 14
Dependent Claim 88 words
A magnetic suspension apparatus according to Claim 9, wherein said movable part is formed by a ferromagnetic member having a rotary shaft and at least two circular plates which are coaxially fixed to the rotary shaft with a predetermined axial space therebetween, and said stationary part is formed by two annular superconductors which are disposed to surround the circular plates of said ferromagnetic member with respective gaps and which have a width in the axial direction greater than the width of the circular plates of said ferromagnetic member.
Claim 15
Dependent Claim 62 words
A magnetic suspension apparatus according to Claim 14, wherein said stationary part includes at least four permanent magnets which are polarized in the radial direction and are disposed on the outer circumferential surface of said annular superconductor such that the magnetic poles of said permanent magnets are alternately directed in opposite directions, and an annular magnetic member disposed outside said permanent magnets.
Claim 16
Dependent Claim 55 words
A magnetic suspension apparatus according to any one of Claims 1 through 8, wherein said ferromagnetic member is formed as an elongated stationary part while said superconductor is formed as a movable part, and wherein drive means is added to one of said ferromagnetic member and said super conductor for linear movement by electromagnetic induction.
Claim 17
Dependent Claim 60 words
A magnetic suspension apparatus according to Claim 16, wherein said stationary part is formed by a ferromagnetic member having a C-like cross section and provided with two tips, and said movable part is formed by a rectangular parallelepipedonal superconductor which has a width greater than the distance between the two tips of said ferromagnetic member and which faces the tips.
Claim 18
Dependent Claim 60 words
A magnetic suspension apparatus according to Claim 17, wherein said movable part includes two block-shaped permanent magnets which are fixed to the side of said superconductor opposite to the side facing the gap, with spacing, such that different poles of said permanent magnets face the gap, and a magnetic member which connects the free ends of said two permanent magnets.
Claim 19
Dependent Claim 85 words
A magnetic suspension apparatus according to Claim 16, wherein said stationary part is formed by an elongated magnetic member and at least four elongated ferromagnetic members each of which has a rectangular cross section having a width smaller than the width of said magnetic member and which are arranged in the widthwise direction at a constant pitch, and said movable part is formed by a rectangular parallelepipedonal superconductor which has a width greater than the distance between two ferromagnetic members provided at both outer sides.
Claim 20
Dependent Claim 74 words
A magnetic suspension apparatus according to Claim 19, wherein said movable part includes two rectangular parallelepipedonal permanent magnets which have poles facing the gap and which are fixed to the side of said superconductor opposite to the side facing the gap along the longitudinal direction of said stationary part such that different poles of said permanent magnets face the gap, and a magnetic member which connects the free ends of said two permanent magnets.

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