EP0221921A1 - Ironless solenoidal magnet. - Google Patents

Ironless solenoidal magnet.

Info

Publication number
EP0221921A1
EP0221921A1 EP86902432A EP86902432A EP0221921A1 EP 0221921 A1 EP0221921 A1 EP 0221921A1 EP 86902432 A EP86902432 A EP 86902432A EP 86902432 A EP86902432 A EP 86902432A EP 0221921 A1 EP0221921 A1 EP 0221921A1
Authority
EP
European Patent Office
Prior art keywords
discs
zones
coil
junctions
overlapping
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP86902432A
Other languages
German (de)
French (fr)
Other versions
EP0221921B1 (en
Inventor
Guy Aubert
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric CGR SA
Original Assignee
Thomson CGR
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thomson CGR filed Critical Thomson CGR
Publication of EP0221921A1 publication Critical patent/EP0221921A1/en
Application granted granted Critical
Publication of EP0221921B1 publication Critical patent/EP0221921B1/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/20—Electromagnets; Actuators including electromagnets without armatures
    • H01F7/202—Electromagnets for high magnetic field strength

Definitions

  • the invention due to the collaboration of the National Service of the Intensive Fields of the CNRS (Director M. AUBERT), relates to a solenoidal magnet, without iron, comprising one or more coils whose technological structure is similar to that of a Bitter coil classic; the invention more particularly relates to improvements making it possible to simplify the manufacture of the coil (s) and to improve the homogeneity of the magnetic field generated by such a type of magnet.
  • Bitter coils are well known for the production of strong magnetic fields.
  • the structure proposed by Bitter is a coil made up of metallic annular discs, split to form as many turns and connected to define a substantially helical winding with flat turns.
  • the stacking of the discs is maintained by a plurality of tie rods.
  • This structure is advantageous because it allows efficient cooling of the magnet by making holes in the discs (and in the insulators separating these discs), these holes being arranged in the same configuration from one disc to another for materialize a set of channels parallel to the axis of the coil, in which circulates a cooling fluid, for example deionized water, kerosene or oil.
  • a cooling fluid for example deionized water, kerosene or oil.
  • the invention provides a magnet consisting of at least one coil derived from this concept and more particularly designed so that the magnetic field generated in a sphere of interest of prescribed radius, the center of which coincides with the center of symmetry of this magnet or very good homogeneity.
  • a preferred field of application of the invention is indeed that of nuclear magnetic resonance imaging (NMR) where it is necessary to have a relatively high magnetic field (0.15 to 1.5 teslas) with very high homogeneity, of the order of 1 to 10 parts per million (pp). ' With a sufficiently long coil, we can obtain a certain homogeneity around the center of symmetry of this coil.
  • NMR nuclear magnetic resonance imaging
  • each insulating disc interposed between the two conductive rings such that it comprises a sector-shaped cutting and clamping the stack of conductive discs and insulating discs between two end plates, by means of the tie rods mentioned above.
  • the electrical contact between two adjacent turns is thus established through the corresponding cutout under the effect of tightening, the construction of the magnet being greatly facilitated.
  • the fact of posing the problem of obtaining a very uniform field from this type of coil (s) leads to recognizing in this arrangement another cause of disturbance of the magnetic field.
  • the variation in current density at each turn in the contact sector is an intrinsic cause of homogeneity.
  • the invention firstly proposes a new type of assembly of the disks which makes it possible to solve this problem.
  • the invention therefore essentially relates to a solenoid magnet of the type comprising at least one coil consisting of a stack, with insulation interposition, of annular conductive discs, each disc having a cutout transforming it into a turn and said turns being connected end to end, characterized in that said discs extend in respective parallel perpendicular planes to the longitudinal axis of said coil, in that said cutting of each disc and a slot, in that the arrangement and the shape of these slots define several zones of overlap of turns between the successive discs, these zones being divided into two groups, and in that the electrical contact between any two adjacent discs is achieved by
  • the above-mentioned slots are
  • the axial component of the current due in previous systems, to the helical shape of the turns, does not exist because each turn extends in a plane.
  • a very “localized” longitudinal current component is created, in parallel to a generator of the coil in the " vicinity of the junction zones between discs. This disturbance can be easily compensated locally by means of longitudinal conductors traversed by currents flowing in opposite directions.
  • the invention makes it possible to solve another problem , namely the need to take into consideration the way in which the current is applied to the magnet.
  • the invention also relates to a soli ⁇ no ⁇ dal magnet according to the preceding definition, characterized in that the or each coil has at least one conduit parallel to said axis, defined by the superposition of holes made in or in the vicinity of zones overlapping longitudinally superimposed, each conduit housing a current return conductor connected between the last turn of an axial end of the magnet and opening at its other axial end to be connected to a terminal of a current supply source continued. If the magnet has several spaced coils, the current return conductors can pass through the spaces between coils inside respective metal tubes, themselves connected to connect said coils in series. This type of coaxial connection structure does not create any field in these spaces.
  • the invention will be better understood and other advantages of it will appear better in the light of the following description of several embodiments implementing its principle, given only by way of example and made with reference to annexed drawings in which:
  • FIG. 1 is a partial view showing a disc of a coil constituting the magnet, the disc being provided with a scalloped slot as defined above;
  • FIG. 2 is a partial section II— II of Figure 1;
  • FIG. 3 is a partial section III— III of Figure 1 j
  • FIG. 1 is a view similar to Figure 1, illustrating a variant
  • FIG. 5 is a partial view illustrating the end of a coil and its connection to a neighboring coil.
  • annular discs 11 constituting a coil entering into the constitution of the magnet.
  • These are metallic annular discs (typically made of copper or aluminum) stacked with the interposition of insulating sheets 12 of the same shape and connected end to end to form said coil.
  • the sections of FIGS. 2 and 3 show five annular discs l ia, 11b, lie, ld, l ie, mounted in this way.
  • the discs have a structure in accordance with that proposed by Bitter, that is to say that they comprise, in particular, holes 13 according to the same configuration from one disc to the other to overlap and define channels through which a coolant flows.
  • the discs also have holes 1 of larger diameter, overlapping in a similar manner to allow the passage of isolated tie rods 17.
  • the main function of the tie rods (which can also be outside the discs) is to hold the discs 11 and the insulating sheets 12 in a tight stack.
  • the discs are not deformed to become more or less helical portions, but on the contrary extend parallel to each other, in their respective planes, perpendicular to the longitudinal axis of the coil and each disc has a slot 15 which (in the examples described) is a scalloped slot, extending from its outer edge to its inner edge. Furthermore, all the festoon slots are all grouped in the same longitudinal portion of the coil but inverted from one disc to another. Thus, in Figures 1 and •, there is shown one of the slots 15; in solid line while the slot 15. of the adjacent disc is sketched by a dashed line.
  • the electrical contact between any two adjacent discs is made by their junction on a group (a part) of said overlapping zones while the electrical contacts from disc to disc are made by junctions on one or the other group of said overlapping zones, alternately.
  • the overlapping zones at the level of each disk are divided into two groups, zones 16,, 16, on the one hand and I62, 16 ⁇ on the other hand, which will always be used together to make electrical contacts between two neighboring discs.
  • the electrical contacts between discs will be made alternately by their junction on a zone 16. then by their junction on two zones 16_, 16_ and so on.
  • the junctions are established through windows 20 made in the insulating sheets 12.
  • the windows 0 are arranged opposite the overlapping zones selected to establish contact. between two discs considered.
  • the reliability of the contact is improved by a weld 21 with filler metal, said weld having substantially the
  • the insulating sheet • 5 same thickness as the insulating sheet.
  • An indium solder is preferably used. If the insulating sheet is of sufficiently small thickness, the supply (indium may be carried out beforehand by electrolytic deposition on the selected overlapping zones, the welding then consisting in locally heating the Q turns during assembly.
  • the surfaces of the different overlapping zones of the same disc are not equal, they depend both on their even or odd number (thus in the example of FIG. •, the zone 16 ⁇ is necessarily larger) and on the density value of
  • holes 25 are made in the overlap zones (FIG. 1) or in the vicinity of these (FIG. •), these holes being superimposed to define one or more parallel conduits housing each one a current return conductor 26, connected between the last turn of an axial end of the magnet and opening out at the other axial end to which the DC power source is connected.
  • Each conductor 26 is of course isolated inside the conduit which I enclose. The fact of bringing the current to this axial end of the magnet facilitates the connection to the two poles of the supply, this connection being able to be carried out from conductors with coaxial structure not creating disturbance of magnetic field.
  • the current return conductors in the magnet itself can, if they are judiciously arranged, compensate for the local disturbances created at the junctions between discs. Compensation is ensured by taking into account the following parameters: the number of overlapping zones in each disc, their respective surfaces, the number of current return conductors and their locations with respect to the overlapping zones.
  • the general principle to be observed for fixing these different parameters is that each current return conductor must be traversed by a current substantially equal to the current which crosses the overlapping zone or zones (or the fractions of zones) which it influences.
  • Ja figure 1 shows how we have choose the different parameters in the case of an even number of overlapping zones (four in this case). Because the overlapping zones are even in number, the electrical contacts are provided by half of the zones on each passage from one disc to another. So just choose Ja surface of these areas, taking mainly into consideration the change in the current density in the O ring disk for the currents through these contact areas are substantially equal. This is why, in FIG. 1, the surfaces of the zones 16., 16 2 , 16-, 16 ⁇ decrease from the outside towards the inside of the annular disc.
  • the current is equally distributed in each pair of junctions, from disc to disc and compensation can be obtained from as many conductors 26 as there are overlapping zones (four in the example), each conductor passing substantially through the center of all of the overlapping zones longitudinally superimposed.
  • Ja figure ⁇ corresponding to an odd number of overlapping zones, one must take into account both Ja the current density in 7 5 " and the number of overlapping zones brought into play alternately to ensure the passage from one disc to another, since the groups of abovementioned overlapping zones necessarily carry different numbers of such zones.
  • the zone 16 would have a double surface
  • the area of. the area 16 ⁇ is larger than that of each of the areas 16 or 16, but it represents less than twice the surface of the area 16 and more than twice the area of the area 16.
  • two current return conductors 26, 26 can be provided, traversed respectively by substantially Ja half of the return current and arranged between the overlapping zones.
  • the driver 26 thus ensures the compen sation ⁇ current for all of the overlapping areas 16 and a portion of the overlapping areas 16, while I conductor 26, provides current compensation for all of the superimposed areas 16 and the other part of the superimposed areas 16,.
  • the determination of the areas of the overlapping zones that is to say the shape of the festoon slots which delimit them, is within the reach of a person skilled in the art by applying the principles set out above, to the in light of the examples described.
  • FIG. 5 illustrates the connection structure between two coils of the magnet when the latter consists of a number of coils spaced axially from each other.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
  • Electromagnets (AREA)

Abstract

Structure de raccordement des disques d'une bobine de Bitter. Selon l'invention, les disques comportent chacun une découpe en forme de fente (15), par exemple ondulée de façon à définir d'un disque à l'autre des zones de chevauchement de spire (16) réparties en deux groupes et les liaisons électriques sont assurées par des jonctions desdites zones de chevauchement d'un groupe ou de l'autre, alternativement d'un disque à l'autre. Application à l'imagerie par RMN.Connection structure of the discs of a Bitter coil. According to the invention, the discs each comprise a slot-shaped cutout (15), for example corrugated so as to define, from one disc to the other, areas of overlap of turns (16) divided into two groups and the connections electrical connections are provided by the junctions of said overlapping zones of one group or the other, alternately from one disc to another. Application to NMR imaging.

Description

AIMANT SOLENOIDAL SANS FER SOLENOIDAL MAGNET WITHOUT IRON
L'invention, due à la collaboration du Service National des Champs Intenses du CNRS (Directeur M. AUBERT), concerne un aimant solénoïdal, sans fer, comportant une ou plusieurs bobines dont la structure technologique est voisine de celle d'une bobine de Bitter classique ; l'invention a plus particulièrement pour objet des perfectionnements permettant de simplifier la fabrication de la ou les bobines et cf améliorer l'homogénéité du champ magnétique engendré par un tel type d'aimant.The invention, due to the collaboration of the National Service of the Intensive Fields of the CNRS (Director M. AUBERT), relates to a solenoidal magnet, without iron, comprising one or more coils whose technological structure is similar to that of a Bitter coil classic; the invention more particularly relates to improvements making it possible to simplify the manufacture of the coil (s) and to improve the homogeneity of the magnetic field generated by such a type of magnet.
Les bobines de Bitter sont bien connues pour la production de champs magnétiques intenses. En théorie, la structure proposée par Bitter est une bobine constituée de disques annulaires métalliques, fendus pour former autant de spires et raccordés pour définir un enroulement sensiblement hélicoïdal à spires plates. L'empilement des disques est maintenu par une pluralité de tirants. Cette struc¬ ture est avantageuse car elle permet un refroidissement efficace de l'aimant en pratiquant des trous dans les disques (et dans les isolants séparant ces disques), ces trous étant disposés suivant une même configuration d'un disque à l'autre pour matérialiser un ensemble de canaux parallèles à l'axe de la bobine, dans lesquels circule un fluide de refroidissement, par exemple de l'eau désionisée, du kérozène ou de l'huile.Bitter coils are well known for the production of strong magnetic fields. In theory, the structure proposed by Bitter is a coil made up of metallic annular discs, split to form as many turns and connected to define a substantially helical winding with flat turns. The stacking of the discs is maintained by a plurality of tie rods. This structure is advantageous because it allows efficient cooling of the magnet by making holes in the discs (and in the insulators separating these discs), these holes being arranged in the same configuration from one disc to another for materialize a set of channels parallel to the axis of the coil, in which circulates a cooling fluid, for example deionized water, kerosene or oil.
L'invention propose un aimant constitué d'au moins une bobine dérivée de ce concept et plus particulièrement conçu pour que le champ magnétique engendré dans une sphère d'intérêt de rayon prescrit, dont le centre est confondu avec le centre de symétrie de cet aimant soit d'une très bonne homogénéité. Un domaine d'ap¬ plication privilégié de l'invention est en effet celui de l'imagerie par Résonance Magnétique Nucléaire (RMN) où il est nécessaire de disposer d'un champ magnétique relativement élevé (0,15 à 1,5 teslas) avec une très grande homogénéité, de l'ordre de 1 à 10 parties par million (pp ).' Avec une bobine suffisamment longue, on peut obtenir une certaine homogénéité autour du centre de symétrie de cette bobine. Cette homogénéité sera plus facilement atteinte et avec une structure plus compacte soit en faisant varier l'épaisseur des disques le long de l'axe de l'aimant soit en alignant plusieurs bobines de Bitter le long d'un axe commun, les longueurs des bobines et leurs espacements étant choisis pour réaliser l'homogénéité requise. Ces solutions font l'objet d'autres demandes de brevet déposées par la Demanderesse. Les perfectionnements selon l'in¬ vention s'appliquent aussi bien à un aimant à bobine unique qu'à un aimant à plusieurs bobines alignées, accolées ou espacées.The invention provides a magnet consisting of at least one coil derived from this concept and more particularly designed so that the magnetic field generated in a sphere of interest of prescribed radius, the center of which coincides with the center of symmetry of this magnet or very good homogeneity. A preferred field of application of the invention is indeed that of nuclear magnetic resonance imaging (NMR) where it is necessary to have a relatively high magnetic field (0.15 to 1.5 teslas) with very high homogeneity, of the order of 1 to 10 parts per million (pp). ' With a sufficiently long coil, we can obtain a certain homogeneity around the center of symmetry of this coil. This homogeneity will be more easily achieved and with a more compact structure either by varying the thickness of the discs along the axis of the magnet or by aligning several coils of Bitter along a common axis, the lengths of the coils. and their spacings being chosen to achieve the required homogeneity. These solutions are the subject of other patent applications filed by the Applicant. The improvements according to the invention apply both to a magnet with a single coil and to a magnet with several coils aligned, contiguous or spaced.
Il peut en effet subsister d'autres causes structurelles d'inho- mogénéîté du champ magnétique engendré ou des causes de pertur¬ bation de ce champ magnétique.There may indeed remain other structural causes of inhomogeneity of the magnetic field generated or causes of disturbance of this magnetic field.
Ainsi, selon un mode de réalisation actuellement très répandu de l'aimant de Bitter, le raccordement de d'eux spires adjacentes est simplement obtenu en conformant chaque disque d'isolant, intercalé entre les deux anneaux conducteurs, de façon qu'il comporte une découpe en forme de secteur et en serrant l'empilement de disques conducteurs et de disques isolants entre deux plateaux d'extrémité, au moyen des tirants mentionnés ci-dessus. Le contact électrique entre deux spires adjacentes est ainsi établi au travers de la découpe correspondante sous l'effet du serrage, la construction de l'aimant en étant grandement facilité. Cependant, le fait de se poser le problème d'obtenir un champ très uniforme à partir de bobine(s) de ce genre conduit à reconnaître dans cet agencement une autre cause de perturbation du champ magnétique. En effet, la variation de densité de courant à chaque tour dans le secteur de contact est une cause intrinsèque cPinhomogénéïté.Thus, in one embodiment currently widespread magnet Bitter, the connection of them adjacent turns is simply achieved by shaping each insulating disc interposed between the two conductive rings, such that it comprises a sector-shaped cutting and clamping the stack of conductive discs and insulating discs between two end plates, by means of the tie rods mentioned above. The electrical contact between two adjacent turns is thus established through the corresponding cutout under the effect of tightening, the construction of the magnet being greatly facilitated. However, the fact of posing the problem of obtaining a very uniform field from this type of coil (s) leads to recognizing in this arrangement another cause of disturbance of the magnetic field. In fact, the variation in current density at each turn in the contact sector is an intrinsic cause of homogeneity.
L'invention propose en premier lieu un nouveau type d'as¬ semblage des disques permettant de résoudre ce problème.The invention firstly proposes a new type of assembly of the disks which makes it possible to solve this problem.
Dans cet esprit, l'invention concerne donc essentiellement un aimant solénoïdal du type comprenant au moins une bobine cons- tituée d'un empilement, avec interposition d'isolant, de disques annulaires conducteurs, chaque disque comportant une découpe le transformant en spire et lesdites spires étant connectées bout à bout, caractérisé en ce que lesdits disques s'étendent dans des plans parallèles respectifs perpendiculaires à l'axe longitudinal de ladite bobine, en ce que ladite découpe de chaque disque et une fente, en ce que la disposition et la forme de ces fentes définissent plusieurs zones de chevauchement de spires entre les disques successifs, ces zones étant partagées en deux groupes, et en ce que le contact électrique entre deux disques adjacents quelconques est réalisé parIn this spirit, the invention therefore essentially relates to a solenoid magnet of the type comprising at least one coil consisting of a stack, with insulation interposition, of annular conductive discs, each disc having a cutout transforming it into a turn and said turns being connected end to end, characterized in that said discs extend in respective parallel perpendicular planes to the longitudinal axis of said coil, in that said cutting of each disc and a slot, in that the arrangement and the shape of these slots define several zones of overlap of turns between the successive discs, these zones being divided into two groups, and in that the electrical contact between any two adjacent discs is achieved by
10 leur jonction sur un groupe desdites zones de chevauchement tandis que les contacts électriques de disque en disque sont réalisés par des jonctions sur l'un ou l'autre groupe desdites zones de chevau¬ chement, alternativement.10 their junction on a group of said overlapping zones while the electrical contacts from disc to disc are made by junctions on one or the other group of said overlapping areas, alternately.
Selon un mode de réalisation possible, les fentes précitées sontAccording to one possible embodiment, the above-mentioned slots are
15 des fentes en festons (ondulées ou en dents de scie ou analogue) et elles sont inversées d'un disque à l'autre par rapport à un plan passant par l'axe de la bobine, pour définir lesdites zones de chevauchement.15 festoon slots (wavy or sawtooth or the like) and they are reversed from one disc to another with respect to a plane passing through the axis of the coil, to define said areas of overlap.
La structure définie ci-dessus affecte peu la configuration deThe structure defined above has little effect on the configuration of
20 la densité de courant aux jonctions entre spires voisines. Notam¬ ment, l'augmentation de l'épaisseur de conducteur au niveau des jonctions entre spires est compensée par la diminution de la surface de ces mêmes jonctions. On peut donc considérer que la densité de20 the current density at the junctions between neighboring turns. In particular, the increase in the thickness of the conductor at the junctions between turns is compensated by the decrease in the surface of these same junctions. We can therefore consider that the density of
2_ courant ne varie pas sur un tour complet. D'autre part, la distri¬ bution radiale de courant subit naturellement une perturbation au niveau de chaque jonction entre deux spires adjacentes, mais ces perturbations se compensent d'une spire à l'autre. Toutes ces parti¬ cularités font qu'une bobine ainsi construite présente peu de causes2_ current does not vary over a full revolution. On the other hand, the radial current distribution naturally undergoes a disturbance at each junction between two adjacent turns, but these disturbances are compensated for from one turn to another. All these particularities mean that a coil thus constructed presents few causes
,0 intrinsèques d'inhomogénéïté du champ magnétique axial engendré., 0 intrinsic inhomogeneities of the generated axial magnetic field.
En outre, la composante axiale du courant, due dans les systèmes antérieurs, a la forme hélicoïdale des spires, n'existe pas du fait que chaque spire s'étend dans un plan. Il se crée au contraire une composante longitudinale de courant très "localisée", parallèlement à une génératrice de la bobine au "voisinage des zones de jonction entre disques. Cette perturbation peut être facilement compensée localement au moyen de conducteurs longitudinaux parcourus par des courants circulant en sens contraire. Dans cet esprit, l'invention permet de résoudre un autre problème, à savoir la nécessité de prendre en considération la façon dont le courant est appliqué à l'aimant. En effet, si on établit classiquement la liaison entre la source d'alimentation et l'aimant au moyen de deux conducteurs respectivement connectés aux extrémités axiales de l'aimant, des perturbations de champ magnétique engendrées par ces conducteurs peuvent dégrader l'homogénéïté du champ dans la sphère d'intérêt précitée. Si on ramène le courant au moyen de conducteurs longitu¬ dinaux judicieusement placés au voisinage des jonctions entre dis¬ ques, on réalise d'une part la compensation souhaitée et d'autre part on ramène le courant vers l'extrémité axiale de l'aimant à laquelle il a été injecté, sans créer de boucle susceptible de perturber l'homo¬ généïté du champ magnétique délivré. Ceci permet de raccorder la source de courant à une même extrémité axiale de l'aimant, au moyen de conducteurs à structure coaxiale.In addition, the axial component of the current, due in previous systems, to the helical shape of the turns, does not exist because each turn extends in a plane. On the contrary, a very "localized" longitudinal current component is created, in parallel to a generator of the coil in the " vicinity of the junction zones between discs. This disturbance can be easily compensated locally by means of longitudinal conductors traversed by currents flowing in opposite directions. In this spirit, the invention makes it possible to solve another problem , namely the need to take into consideration the way in which the current is applied to the magnet. Indeed, if one classically establishes the connection between the power source and the magnet by means of two conductors respectively connected to the axial ends of the magnet, magnetic field disturbances generated by these conductors can degrade the homogeneity of the field in the aforementioned sphere of interest. If the current is brought back by means of longitudinal conductors judiciously placed in the vicinity of the junctions between dis¬ ques, we realize on the one hand the desired compensation and on the other hand we bring the current to the end axially of the magnet at which it was injected, without creating loop may disrupt the homo¬ geneity of the supplied magnetic field. This makes it possible to connect the current source to the same axial end of the magnet, by means of conductors with coaxial structure.
Dans cet esprit, l'invention concerne aussi un aimant solé¬ noïdal selon la définition qui précède, caractérisé en ce que la ou chaque bobine comporte au moins un conduit parallèle audit axe, défini par la superposition de trous pratiqués dans ou au voisinage de zones de chevauchement superposées longitudinalement, chaque conduit abritant un conducteur de retour de courant connecté entre la dernière spire d'une extrémité axiale de l'aimant et débouchant à son autre extrémité axiale pour être connecté à une borne d'une source d'alimentation en courant continu. Si l'aimant comporte plusieurs bobines espacées, les conducteurs de retour de courant peuvent traverser les espaces entre bobines à l'intérieur de tubes métalliques respectifs, eux-mêmes connectés pour relier lesdites bobines en série. Ce type de structure coaxiale de raccordement ne crée aucun champ dans ces espaces. L'invention sera , mieux comprise et d'autres avantages de celle-ci apparaîtront mieux à la lumière de la description qui va suivre de plusieurs modes de réalisation mettant en oeuvre son principe, donnée uniquement à titre d'exemple et faite en référence aux dessins annexés dans lesquels :In this spirit, the invention also relates to a solé¬ noïdal magnet according to the preceding definition, characterized in that the or each coil has at least one conduit parallel to said axis, defined by the superposition of holes made in or in the vicinity of zones overlapping longitudinally superimposed, each conduit housing a current return conductor connected between the last turn of an axial end of the magnet and opening at its other axial end to be connected to a terminal of a current supply source continued. If the magnet has several spaced coils, the current return conductors can pass through the spaces between coils inside respective metal tubes, themselves connected to connect said coils in series. This type of coaxial connection structure does not create any field in these spaces. The invention will be better understood and other advantages of it will appear better in the light of the following description of several embodiments implementing its principle, given only by way of example and made with reference to annexed drawings in which:
- la figure 1 est une vue partielle montrant un disque d'une bobine constituant l'aimant, le disque étant pourvu d'une fente en festons selon la définition qui précède ;- Figure 1 is a partial view showing a disc of a coil constituting the magnet, the disc being provided with a scalloped slot as defined above;
- la figure 2 est une coupe partielle II— II de la figure 1 ;- Figure 2 is a partial section II— II of Figure 1;
- la figure 3 est une coupe partielle III— III de la figure 1 j- Figure 3 is a partial section III— III of Figure 1 j
- la figure • est une vue analogue à la figure 1, illustrant une variante ;- Figure • is a view similar to Figure 1, illustrating a variant;
- la figure 5 est une vue partielle illustrant l'extrémité d'une bobine et son raccordement à une bobine voisine. ,. En se reportant aux dessins, on a représenté partiellement des disques annulaires 11 constituant une bobine entrant dans la cons¬ titution de l'aimant. Il s'agit de disques annulaires métalliques (typiquement en cuivre ou en aluminium) empilés avec interposition de feuilles isolantes 12 de même forme et raccordés bout à bout pour constituer ladite bobine. Les coupes des figures 2 et 3 montrent cinq disques annulaires l ia, 11b, lie, l ld, l ie, montés de cette façon. Comme mentionné ci-dessus, on utilise plusieurs bobines de tce genre, alignées axialement, accolées ou espacées les unes des autres, pour réaliser un aimant délivrant un champ magnétique à _ haute homogénéité dans un volume interne donné. Selon l'exemple décrit, les disques ont une structure conforme à celle proposée par Bitter, c'est-à-dire qu'ils comportent- notamment des trous 13 selon une même configuration d'un disque à l'autre pour se superposer et définir des canaux traversés par un fluide de refroidissement. Eventuellement, les disques comportent aussi des trous 1 de plus 0 grand diamètre, se superposant de façon analogue pour permettre le passage de tirants 17 isolés. Les tirants (qui peuvent aussi être à l'extérieur des disques) ont pour principale fonction de maintenir les disques 11 et les feuilles isolantes 12 en un empilement serré. Selon l'invention, les disques ne sont pas déformés pour devenir des portions plus ou moins hélicoïdales, mais ils s'étendent au contraire parallèlement les uns aux autres, dans leurs plans res¬ pectifs, perpendiculairement à l'axe longitudinal de la bobine et chaque disque comporte une fente 15 qui (dans les exemples décrits) est une fente en festons, s'étendant de son bord externe à son bord interne. Par ailleurs, toutes les fentes en festons sont toutes regroupées dans une même portion longitudinale de la bobine mais inversées d'un disque à l'autre. Ainsi, sur les figures 1 et • , on a représenté l'une des fentes 15; en trait plein tandis que la fente 15. du disque adjacent est esquissée par une ligne en trait interrompu. On voit que, de par la nature des fentes d'une part et leur inversion d'un disque à l'autre d'autre part, des zones de chevauchement de spires 16 sont définies entre deux fentes juxtaposées, le nombre de zones de chevauchement dépend ici du nombre d'ondulations de la fente en festons. Ainsi dans l'exemple de la figure 1, quatre zones de chevauchement sont définies entre deux disques adjacents quel¬ conques alors que dans l'exemple de la figure , on n'en compte que trois. Il apparaît clairement que les zones de chevauchement entre spires constituent autant de zones de contact possibles pour rac¬ corder les spires bout à bout en vue de définir la bobine. Selon une autre caractéristique importante de l'invention, le contact élec¬ trique entre deux disques adjacents quelconques est réalisé par leur jonction sur un groupe (une partie) desdites zones de chevauchement tandis que les contacts électriques de disque en disque sont réalisés par des jonctions sur l'un ou l'autre groupe desdites zones de chevauchement, alternativement.- Figure 5 is a partial view illustrating the end of a coil and its connection to a neighboring coil. ,. Referring to the drawings, there is partially shown annular discs 11 constituting a coil entering into the constitution of the magnet. These are metallic annular discs (typically made of copper or aluminum) stacked with the interposition of insulating sheets 12 of the same shape and connected end to end to form said coil. The sections of FIGS. 2 and 3 show five annular discs l ia, 11b, lie, ld, l ie, mounted in this way. As mentioned above, use is more coils of t such axially aligned side by side or spaced apart from each other to realize a magnet providing a magnetic field with high homogeneity _ in a given internal volume. According to the example described, the discs have a structure in accordance with that proposed by Bitter, that is to say that they comprise, in particular, holes 13 according to the same configuration from one disc to the other to overlap and define channels through which a coolant flows. Optionally, the discs also have holes 1 of larger diameter, overlapping in a similar manner to allow the passage of isolated tie rods 17. The main function of the tie rods (which can also be outside the discs) is to hold the discs 11 and the insulating sheets 12 in a tight stack. According to the invention, the discs are not deformed to become more or less helical portions, but on the contrary extend parallel to each other, in their respective planes, perpendicular to the longitudinal axis of the coil and each disc has a slot 15 which (in the examples described) is a scalloped slot, extending from its outer edge to its inner edge. Furthermore, all the festoon slots are all grouped in the same longitudinal portion of the coil but inverted from one disc to another. Thus, in Figures 1 and •, there is shown one of the slots 15; in solid line while the slot 15. of the adjacent disc is sketched by a dashed line. It can be seen that, by the nature of the slots on the one hand and their inversion from one disc to the other on the other hand, areas of overlapping of turns 16 are defined between two juxtaposed slots, the number of areas of overlapping here depends on the number of undulations of the scalloped slot. Thus, in the example in FIG. 1, four overlapping zones are defined between two adjacent discs which are conical, whereas in the example in the figure, there are only three. It clearly appears that the overlapping zones between turns constitute as many possible contact zones for connecting the turns end to end in order to define the coil. According to another important characteristic of the invention, the electrical contact between any two adjacent discs is made by their junction on a group (a part) of said overlapping zones while the electrical contacts from disc to disc are made by junctions on one or the other group of said overlapping zones, alternately.
A ce titre, dans l'exemple des figures 1 à 3 où les zones de chevauchement sont en nombre pair (quatre), lesdites zones sont alternativement utilisées (radialement) pour réaliser les contacts électriques précités. Autrement dit, les zones de chevauchement au niveau de chaque disque sont partagées en deux groupes, les zones 16, , 16, d'une part et I62, 16^ d'autre part, qui seront toujours utilisées ensemble pour réaliser les contacts électriques entre deux disques voisins. Dans l'exemple particulier de la figure où les zones de chevauchement sont au nombre de trois 16 , 16 , 16 pour chaque disque (la zone 16. étant située entre les zones 16 et 16 ), les contacts électriques entre disques se feront alternativement par leur jonction sur une zone 16. puis par leur jonction sur deux zones 16_, 16_ et ainsi de suite.As such, in the example of FIGS. 1 to 3 where the overlapping zones are in even number (four), said zones are alternately used (radially) to make the abovementioned electrical contacts. In other words, the overlapping zones at the level of each disk are divided into two groups, zones 16,, 16, on the one hand and I62, 16 ^ on the other hand, which will always be used together to make electrical contacts between two neighboring discs. In the particular example in the figure where there are three overlapping zones 16, 16, 16 for each disc (zone 16. being located between zones 16 and 16), the electrical contacts between discs will be made alternately by their junction on a zone 16. then by their junction on two zones 16_, 16_ and so on.
Comme le montrent les figures 2 et 3 concernant le mode de réalisation de la figure 1, les jonctions sont établies à travers des fenêtres 20 pratiquées dans les feuilles isolantes 12. Les fenêtres 0 sont agencées en regard des zones de chevauchement sélectionnées pour établir le contact entre deux disques considérés. Avanta¬ geusement, la fiabilité du contact est améliorée par une soudure 21 avec métal d'apport, ladite soudure présentant sensiblement laAs shown in FIGS. 2 and 3 concerning the embodiment of FIG. 1, the junctions are established through windows 20 made in the insulating sheets 12. The windows 0 are arranged opposite the overlapping zones selected to establish contact. between two discs considered. Advantageously, the reliability of the contact is improved by a weld 21 with filler metal, said weld having substantially the
• 5 même épaisseur que la feuille isolante. On utilisera de préférence une soudure à l'indium. Si la feuille isolante est d'épaisseur suffisam¬ ment faible, l'apport ( indium pourra être effectué préalablement par dépôt électrolytique sur les zones de chevauchement sélec¬ tionnées, la soudure consistant alors à réchauffer localement les Q spires en cours d'assemblage.• 5 same thickness as the insulating sheet. An indium solder is preferably used. If the insulating sheet is of sufficiently small thickness, the supply (indium may be carried out beforehand by electrolytic deposition on the selected overlapping zones, the welding then consisting in locally heating the Q turns during assembly.
Les surfaces des différentes zones de chevauchement d'un même disque ne sont pas égales, elles dépendent à la fois de leur nombre pair ou impair (ainsi dans l'exemple de la figure • , la zone 16^ est nécessairement plus grande) et de la valeur de la densité deThe surfaces of the different overlapping zones of the same disc are not equal, they depend both on their even or odd number (thus in the example of FIG. •, the zone 16 ^ is necessarily larger) and on the density value of
25 courant au voisinage desdites zones. Cette particularité est surtout importante lorsque le système de retour de courant qui va être décrit ci-dessous est mis en oeuvre en vue de compenser les perturbations locales de champ dues* à l'existence de composantes longitudinales de courant (voir les flèches des figures 2 et 325 current in the vicinity of said zones. This feature is especially important when the current feedback system which will be described below is implemented in order to compensate for local field disturbances due * to the existence of longitudinal current components (see the arrows in Figures 2 and 3
30 symbolisant le trajet du courant) aux passages entre disques ad¬ jacents. En effet, selon un autre aspect de l'invention, des trous 25 sont pratiqués dans les zones de chevauchement (figure 1) ou au voisinage de celles-ci (figure • ), ces trous étant superposés pour définir un ou plusieurs conduits parallèles abritant chacun un con- ducteur 26 de retour de courant, connecté entre la dernière spire d'une extrémité axiale de l'aimant et débouchant à l'autre extrémité axiale à laquelle se trouve connectée la source d'alimentation en courant continu. Chaque conducteur 26 est bien entendu isolé à l'intérieur du conduit qui Je renferme. Le fait de ramener le courant à cette extrémité axiale de J'aimant facilite le raccordement aux deux pôles de l'alimentation, ce raccordement pouvant être effectué à partir de conducteurs à structure coaxiale ne créant pas de perturbation de champ magnétique. Par ailleurs, comme mentionné précédemment, les conducteurs de retour de courant dans l'aimant même peuvent, s'ils sont judicieusement disposés, assurer la com¬ pensation des perturbations locales créées aux jonctions entre disques. La compensation est assurée en prenant en compte les paramètres suivants : le nombre de zones de chevauchement dans chaque disque, leurs surfaces respectives, Je nombre de conducteurs de retour de courant et leurs emplacements par rapport aux zones de chevauchement. Le principe général à respecter pour fixer ces différents paramètres est que chaque conducteur de retour de courant doit être parcouru par un courant sensiblement égal au courant qui traverse la ou les zones de chevauchement (ou les fractions de zones) qu'il influence. Or, pour des raisons de sim¬ plicité, tous les conducteurs de retour de courant sont connectés en parallèle à l'extrémité axiale de l'aimant opposée à celle ou se trouve raccordée la source d'alimentation ; ils sont donc parcourus par des fractions sensiblement égales du courant total circulant dans l'aimant. Il faut donc que les zones de chevauchement homologues (où les fractions de telles zones) "compensées" par les conducteurs de retour de courant soient parcourues par des courants égaux. Or, on rappelle que dans une bobine à disques annulaires, la densité de courant dans la largeur de la partie annulaire n'est pas uniforme radialement, mais varie en -z , R étant la distance d'un point considéré à l'axe longitudinal de la bobine. Pour tenir compte de ce fait, on peut faire varier en conséquence les surfaces des zones de chevauchement. L'exemple de Ja figure 1 montre comment on a choisi les différents paramètres dans le cas d'un nombre pair de zones de chevauchement (quatre en l'occurence). Du fait que les zones de chevauchement sont en nombre pair, Jes contacts élec¬ triques sont assurés par la moitié des zones à chaque passage d'un disque à l'autre. Il suffit donc de choisir Ja surface de ces zones en prenant essentiellement en considération la variation de la densité de courant en Ô dans le disque annulaire pour que les courants qui traversent ces zones de contact soient sensiblement égaux. C'est pourquoi, sur la figure 1, les surfaces des zones 16. , 162, 16-, 16^ décroissent de l'extérieur vers l'intérieur du disque annulaire. Dès lors que Jes surfaces sont correctement choisies, Je courant se répartit également dans chaque paire de jonctions, de disque en disque et on peut obtenir la compensation à partir d'autant de conducteurs 26 qu'il y a de zones de chevauchement (quatre dans l'exemple), chaque conducteur passant sensiblement au centre de toutes les zones de chevauchement superposées longitudinalement. Dans l'exemple de Ja figure Ψ, correspondant à un nombre impair de zones de chevauchement, on doit tenir compte à Ja fois de la densité de courant en 75» et du nombre de zones de chevauchement mises en jeu alternativement pour assurer le passage d'un disque à l'autre, puisque les groupes de zones de chevauchement précitées com¬ portent nécessairement des nombres différents de telles zones. Ainsi, dans le cas spécifique de la figure , si la densité de courant était constante radialement, Ja zone 16, aurait une surface double30 symbolizing the path of the current) at the passages between adjacent disks. In fact, according to another aspect of the invention, holes 25 are made in the overlap zones (FIG. 1) or in the vicinity of these (FIG. •), these holes being superimposed to define one or more parallel conduits housing each one a current return conductor 26, connected between the last turn of an axial end of the magnet and opening out at the other axial end to which the DC power source is connected. Each conductor 26 is of course isolated inside the conduit which I enclose. The fact of bringing the current to this axial end of the magnet facilitates the connection to the two poles of the supply, this connection being able to be carried out from conductors with coaxial structure not creating disturbance of magnetic field. Furthermore, as mentioned above, the current return conductors in the magnet itself can, if they are judiciously arranged, compensate for the local disturbances created at the junctions between discs. Compensation is ensured by taking into account the following parameters: the number of overlapping zones in each disc, their respective surfaces, the number of current return conductors and their locations with respect to the overlapping zones. The general principle to be observed for fixing these different parameters is that each current return conductor must be traversed by a current substantially equal to the current which crosses the overlapping zone or zones (or the fractions of zones) which it influences. However, for reasons of simplicity, all the current return conductors are connected in parallel to the axial end of the magnet opposite to that where the power source is connected; they are therefore traversed by substantially equal fractions of the total current flowing in the magnet. It is therefore necessary that the homologous overlapping zones (where the fractions of such zones) "compensated" by the current return conductors are traversed by equal currents. However, it is recalled that in a coil with annular discs, the current density in the width of the annular part is not uniform radially, but varies in -z, R being the distance from a point considered to the longitudinal axis of the coil. To take this fact into account, the surfaces of the overlapping zones can be varied accordingly. The example of Ja figure 1 shows how we have choose the different parameters in the case of an even number of overlapping zones (four in this case). Because the overlapping zones are even in number, the electrical contacts are provided by half of the zones on each passage from one disc to another. So just choose Ja surface of these areas, taking mainly into consideration the change in the current density in the O ring disk for the currents through these contact areas are substantially equal. This is why, in FIG. 1, the surfaces of the zones 16., 16 2 , 16-, 16 ^ decrease from the outside towards the inside of the annular disc. As soon as the surfaces are correctly chosen, the current is equally distributed in each pair of junctions, from disc to disc and compensation can be obtained from as many conductors 26 as there are overlapping zones (four in the example), each conductor passing substantially through the center of all of the overlapping zones longitudinally superimposed. In the example of Ja figure Ψ, corresponding to an odd number of overlapping zones, one must take into account both Ja the current density in 7 5 " and the number of overlapping zones brought into play alternately to ensure the passage from one disc to another, since the groups of abovementioned overlapping zones necessarily carry different numbers of such zones. Thus, in the specific case of the figure, if the current density were radially constant, the zone 16 would have a double surface
D de celle de chacune des zones 16 ou 16 . Pour tenir compte de la j a c densité de courant en ^ , la surface de . la zone 16^ est plus grande que celle de chacune des zones 16 ou 16, , mais elle représente moins du double de la surface de la zone 16 et plus du double de la a surface de la zone 16 . Dans ce cas, on peut prévoir deux conduc¬ teurs de retour de courant 26 , 26, , parcourus respectivement par sensiblement Ja moitié du courant de retour et disposés entre les zones de chevauchement. Le conducteur 26 assure ainsi la compen¬ sation de courant pour la totalité des zones superposées 16 et une partie des zones superposées 16, tandis que Je conducteur 26, assure la compensation de courant pour la totalité des zones superposées 16 et l'autre partie des zones superposées 16, . La détermination des surfaces des zones de chevauchement, c'est-à-dire de la forme des fentes en festons qui les délimitent, est à Ja portée de J'homme du métier en mettant en application Jes principes énoncés ci-dessus, à la lumière des exemples décrits.D of that of each of zones 16 or 16. To take account of the j ac current density in ^, the area of. the area 16 ^ is larger than that of each of the areas 16 or 16, but it represents less than twice the surface of the area 16 and more than twice the area of the area 16. In this case, two current return conductors 26, 26 can be provided, traversed respectively by substantially Ja half of the return current and arranged between the overlapping zones. The driver 26 thus ensures the compen sation ¬ current for all of the overlapping areas 16 and a portion of the overlapping areas 16, while I conductor 26, provides current compensation for all of the superimposed areas 16 and the other part of the superimposed areas 16,. The determination of the areas of the overlapping zones, that is to say the shape of the festoon slots which delimit them, is within the reach of a person skilled in the art by applying the principles set out above, to the in light of the examples described.
La figure 5 illustre la structure de raccordement entre deux bobines de l'aimant lorsque celui-ci est constitué d'un certain nombre de bobines espacées axialement les unes des autres. LesFIG. 5 illustrates the connection structure between two coils of the magnet when the latter consists of a number of coils spaced axially from each other. The
10 quatre conducteurs 26 émergent de la dernière spire de la bobine et chacun d'eux traverse l'espace entre les deux bobines à l'intérieur d'un tube métallique 30 soudé à chacune de ses extrémités à la spire terminale de la bobine correspondante. L'ensemble de ces tubes assure ainsi le branchement en série des bobines. Des courants i c sensiblement égaux circulent ainsi en sens contraires dans les tubes 30 et Jes conducteurs de retour de courant 25 et ces structures de raccordement ne créent pas de champ magnétique dans les espaces entre les bobines. 10 four conductors 26 emerge from the last turn of the coil and each of them crosses the space between the two coils inside a metal tube 30 welded at each of its ends to the end turn of the corresponding coil. All of these tubes thus ensure the series connection of the coils. Substantially equal currents i c thus flow in opposite directions in the tubes 30 and the current return conductors 25 and these connection structures do not create a magnetic field in the spaces between the coils.

Claims

REVENDICATIONS
1. Aimant solénoïdal du type comprenant au moins une bobine constituée d'un empilement, avec interposition d'isolant, de disques annulaires conducteurs, chaque disque (11) comportant une découpe le transformant en spire et lesdites spires étant connectées bout à bout, caractérisé en ce que Jesdits disques s'étendent dans des plans parallèles respectifs perpendiculaires à l'axe longitudinal de ladite bobine, en ce que ladite découpe de chaque disque est une fente (15), en ce que la disposition et la forme de ces fentes définissent plusieurs zones de chevauchement de spires (16) entre les disques successifs, ces zones étant partagées en deux groupes (16. , 16-- 16_,1 , et en ce que le contact électrique entre deux disques adjacents quelconques est réalisé par leur jonction (21) sur un groupe desdites zones de chevauchement tandis que les contacts électriques de disque en disque sont réalisés par des jonctions sur l'un ou l'autre groupe desdites zones de chevauchement, alternativement.1. Solenoidal magnet of the type comprising at least one coil consisting of a stack, with insulation interposition, of annular conducting discs, each disc (11) comprising a cutout transforming it into a turn and said turns being connected end to end, characterized in that said discs extend in respective parallel planes perpendicular to the longitudinal axis of said coil, in that said cutout of each disc is a slot (15), in that the arrangement and the shape of these slots define several overlapping zones of turns (16) between the successive disks, these zones being divided into two groups (16., 16-- 16_, 1, and in that the electrical contact between any two adjacent disks is achieved by their junction ( 21) on a group of said overlapping zones while the electrical contacts from disk to disk are produced by junctions on one or the other group of said overlapping zones t, alternatively.
2. Aimant solénoïdal selon la revendication 1, caractérisé en ce que lesdites jonctions (21) sont établies à travers des fenêtres (20) pratiquées dans des isolants (12) intercalés entre lesdits disques, lesdites fenêtres étant disposées en regard des zones de chevau¬ chement sélectionnées.2. Solenoid magnet according to claim 1, characterized in that said junctions (21) are established through windows (20) formed in insulators (12) interposed between said discs, said windows being arranged opposite the overlapping zones selected.
3. Aimant solénoïdal selon la revendication 1 ou 2, caractérisé en ce que les jonctions (21) desdites: zones de chevauchement sélectionnées entre disques sont des jonctions soudées. k. Aimant solénoïdal selon la revendication 3, caractérisé par des jonctions soudées avec apport d'indium.3. Solenoid magnet according to claim 1 or 2, characterized in that the junctions (21) of said : selected overlap zones between discs are welded junctions. k. Solenoid magnet according to Claim 3, characterized by welded junctions with the addition of indium.
5. Aimant solénoïdal selon l'une des revendications précé¬ dentes, caractérisé en ce que la ou chaque bobine comporte au moins un conduit parallèle audit axe, défini par la superposition de trous (25) pratiqués dans ou au voisinage de zones de chevauchement superposées longitudinalement, chaque conduit abritant un con¬ ducteur de retour de courant (26) connecté entre la dernière spire d'une extrémité axiale de l'aimant et débouchant à son autre extrémité axiale pour être connecté à une borne d'une source d'alimentation en courant continu.5. Solenoid magnet according to one of the preceding claims, characterized in that the or each coil has at least one duct parallel to said axis, defined by the superimposition of holes (25) formed in or in the vicinity of overlapping overlapping zones longitudinally, each conduit housing a current return conductor (26) connected between the last turn from one axial end of the magnet and opening at its other axial end to be connected to a terminal of a DC power source.
6. Aimant solénoïdal selon l'une des revendications précé¬ dentes, caractérisé en ce que, de façon connue "en soi, la ou lesdites bobines sont des bobines de Bitter comportant notamment des canaux de circulation de fluide de refroidissement, s'étendant longi- tudinalement, et des tirants de serrage de l'empilement desdits disques. 6. Solenoid magnet according to one of the preceding claims, characterized in that, in a known manner "per se, the said coil or coils are Bitter coils comprising in particular cooling fluid circulation channels, extending along - tudinally, and tightening tie rods of the stack of said discs.
EP86902432A 1985-05-10 1986-04-22 Ironless solenoidal magnet Expired EP0221921B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8507152 1985-05-10
FR8507152A FR2581761B1 (en) 1985-05-10 1985-05-10 SOLENOIDAL MAGNET WITHOUT IRON

Publications (2)

Publication Number Publication Date
EP0221921A1 true EP0221921A1 (en) 1987-05-20
EP0221921B1 EP0221921B1 (en) 1989-11-02

Family

ID=9319176

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86902432A Expired EP0221921B1 (en) 1985-05-10 1986-04-22 Ironless solenoidal magnet

Country Status (5)

Country Link
US (1) US4745387A (en)
EP (1) EP0221921B1 (en)
DE (1) DE3666743D1 (en)
FR (1) FR2581761B1 (en)
WO (1) WO1986006870A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01226125A (en) * 1988-03-07 1989-09-08 Kanazawa Univ Stratified eddy current type coil for alternate current strong magnetic field
JPH0245902A (en) * 1988-08-08 1990-02-15 Kanazawa Univ Stratified eddy current type coil for strong ac magnetic field
CN114743754B (en) * 2022-04-08 2023-04-25 电子科技大学 Low-power-consumption compact normal-temperature bit type strong magnet

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1494887A (en) * 1966-08-02 1967-09-15 Fives Lille Cail Electric coils and method of manufacturing such coils
FR1600511A (en) * 1968-12-02 1970-07-27
GB8334374D0 (en) * 1983-12-23 1984-02-01 Picker Int Ltd Coil arrangements
JPS60227403A (en) * 1984-04-26 1985-11-12 Yokogawa Hokushin Electric Corp Coil for generating magnetic field

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO8606870A1 *

Also Published As

Publication number Publication date
FR2581761B1 (en) 1987-06-12
FR2581761A1 (en) 1986-11-14
US4745387A (en) 1988-05-17
EP0221921B1 (en) 1989-11-02
WO1986006870A1 (en) 1986-11-20
DE3666743D1 (en) 1989-12-07

Similar Documents

Publication Publication Date Title
FR2786334A1 (en) ALTERNATIVE GENERATOR STATOR FOR USE IN A VEHICLE AND MANUFACTURING METHOD THEREOF
EP4038728A1 (en) Electrical winding for a rotary electric machine
EP0600759B1 (en) Linear electromagnetic induction machine with an optimised magnetic-flux distribution and application
WO1983001541A1 (en) Synchronous electric machine with superconductor inducer
EP0203952B1 (en) Ironless solenoidal magnet
EP0221921B1 (en) Ironless solenoidal magnet
FR2570228A1 (en) Rotating electric motor with a permanent rotor magnet
EP0215832B1 (en) Solenoidal magnet with high homogeneity magnetic field
EP0099274B1 (en) Transformer, particularly a tension reducer for electric welding equipment
EP0221920B1 (en) Solenoidal magnet with high magnetic field homogeneity
WO1986005625A1 (en) Solenoidal magnet with annular discs of the bitter type
EP0215043B1 (en) Method for making a coil of a solenoidal magnet
FR3028110A1 (en) STATOR FOR AN ALTERNATOR OR ELECTRIC MACHINE
FR3087934A1 (en) METHOD FOR ASSEMBLING AN ELECTRICAL CABLE WITH REDUCED SKIN EFFECT AND CORRESPONDING ELECTRICAL CABLE
WO2018083409A1 (en) High-voltage electrical transformer with insulating housing
FR2545293A1 (en) Linear induction electromagnetic machine
EP2422580B1 (en) Heating device with a power inductor, power inductor and oven with such an equipment
FR2731295A1 (en) Ignition coil for vehicle using permanent magnet in magnetic circuit
CH364028A (en) Multipolar inductor element for rotating electric machine
FR3098048A1 (en) Electric winding for a rotating electric machine
EP3991274A1 (en) Electrical winding for a rotating electrical machine
WO2020260260A1 (en) Electrical winding for a rotary electric machine
FR2843649A1 (en) Transformer coil for producing high flux densities, has end of conductor of primary winding connected to main body of coil, closing current path
BE672938A (en)
FR2856838A1 (en) Medium/high frequency transformer-rectifier for electrical power supply device, has secondary windings directly connected to input collector and connected to output collector via diodes, such that they are parallel to load circuit

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19861227

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE GB NL

17Q First examination report despatched

Effective date: 19890201

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: GENERAL ELECTRIC CGR SA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE GB NL

REF Corresponds to:

Ref document number: 3666743

Country of ref document: DE

Date of ref document: 19891207

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19900328

Year of fee payment: 5

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19900331

Year of fee payment: 5

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19900430

Year of fee payment: 5

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19910422

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19911101

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19920201