Modular electrical resistance with a volume configured for the circulation of a cooling fluid

Abstract

The present invention relates to an electrical resistance (1) extending between a first end (2) and a second end (4), comprising a plurality of modules (10) made of an electrically insulating material and a winding (11) wound in turns around the modules (10), each of the modules (10) having an outer peripheral surface (12) and an inner peripheral surface, the modules (10) being arranged side-by-side from the first end (2) to the second end (4) of the electrical resistance (1), thereby defining a volume (44) configured for the circulation of a cooling fluid.

Description

[0001] DESCRIPTION

[0002] Title: Modular electric resistance with volume configured for the circulation of a cooling fluid

[0003] The present invention relates to the field of resistors, and more particularly to the field of resistive power loads.

[0004] Electrical resistors, or resistive dipoles, are devices that allow resistance to the flow of an electric current within an electrical circuit. These electrical resistors include variable electrical resistors, i.e. those whose value is variable. Such a variation results, for example, from mechanical factors, and in particular from an increase or decrease in a dimension of the resistive body.

[0005] Rheostats are variable electrical resistors that are used to vary the ohmic value of a resistive element. These rheostats are sized to withstand a given intensity of the current passing through them, the value of such intensity being adjustable. The intensity is adjusted, for example, by moving a slider along a coil of the rheostat.

[0006] Within rheostats, and more generally within resistive power loads, heat dissipation management is essential. Resistors are therefore generally associated with cooling devices, for example fans which implement a flow of cooling air directed towards the winding.

[0007] However, such cooling means do not allow for optimal management of heat dissipation and may also lead to space constraints. The present invention aims to overcome this drawback by proposing an electrical resistance adaptable to various customer requirements in terms of dimensions, the electrical resistance also having optimized heat dissipation management.

[0008] The main subject of the present invention is thus an electrical resistance extending between a first end and a second end, comprising a plurality of modules made of an electrically insulating material and a winding wound in turns around the modules, each of the modules having an external peripheral surface and an internal peripheral surface, the modules being arranged side by side from the first end to the second end of the electrical resistance, delimiting a volume configured for the circulation of a cooling fluid.

[0009] The electrical resistance according to the invention is formed of several modules made of an electrically insulating material, such modules constituting assembly bricks which form a main body of the electrical resistance. The dimensions of the electrical resistance can therefore easily be adapted to customer requirements, since the addition or removal of modules makes it possible to modify its extension dimension measured from its first end to its second end. The electrical resistance comprises, for example, sixteen modules arranged end to end from one end to the other of the electrical resistance.

[0010] The electrically insulating material is, for example, ceramic or alumina; generally, it is a material with a resistivity greater than or equal to 1 kiloohm per meter.

[0011] Each module is radially delimited by an outer peripheral surface and an inner peripheral surface, both of which have a round shape, a square shape or an ovoid shape, depending on the embodiments. The outer peripheral surfaces constitute an interface between the electrical resistance and a space external to it. The inner peripheral surfaces are radially opposite them and delimit within the electrical resistance a volume configured for the circulation of a cooling fluid, for example pressurized air or water. This volume extends around a virtual line forming a main axis of the electrical resistance.

[0012] A winding is wound around the modules, which corresponds to a resistive wire extending between the first end and the second end of the electrical resistance. The winding is more particularly wound in turns around the modules. This is facilitated in embodiments where the external peripheral surfaces of these modules have a round or ovoid shape. The winding, which heats up when the electric current passes through it, is cooled during the circulation of the cooling fluid. The term "cooling fluid" means any fluid circulating within the electrical resistance and intended to exchange calories for the purpose of cooling it.

[0013] According to an optional characteristic of the invention, the electrical resistance comprises a contact device bearing against the winding and movable between the first end and the second end of the electrical resistance.

[0014] In this embodiment, the electrical resistance is a rheostat. Moving the contact device, for example a slider, along the winding from the first end of the electrical resistance to its second end makes it possible to regulate an intensity of the electric current.

[0015] According to an optional characteristic of the invention, the electrical resistance comprises a metallic element arranged within the volume delimited by the modules, the metallic element being configured to channel the cooling fluid.

[0016] Within the volume delimited by the internal peripheral surfaces of the modules, the cooling fluid is more specifically channeled by a metal element. This metal element, which is for example made of copper or aluminum, improves heat exchange by facilitating the transfer of calories between the winding and the cooling fluid.

[0017] Alternatively, in other embodiments, the volume traveled by the cooling fluid is devoid of any metallic element. The cooling fluid then circulates directly within the volume delimited by the modules, the internal peripheral surfaces of these modules allowing it to be channeled.

[0018] According to an optional characteristic of the invention, the metal element is at least partially pressed against at least one of the internal peripheral surfaces of the modules.

[0019] Preferably, the metal element is pressed against a majority of the internal peripheral surfaces of the modules, or even against the internal peripheral surfaces of all the modules. It is understood that the metal element and the internal peripheral surfaces have complementary shapes. Either the metal element is entirely pressed against the internal peripheral surfaces, or only a portion of this metal element is in contact with these internal peripheral surfaces.

[0020] According to an optional feature of the invention, the metal element is composed of a plurality of modular segments.

[0021] Like the modules forming the body of the electrical resistance, modular segments are parts that can be assembled together to form the metal element. These modular segments are arranged next to each other, end to end from the first end of the electrical resistance to its second end. The presence of modular segments facilitates deformation, in particular the expansion of the metal element during heat exchanges.

[0022] According to an optional characteristic of the invention, the metallic element is a metallic tube.

[0023] According to an optional characteristic of the invention, the metallic element is a metallic blade.

[0024] This blade is a spring blade. Due to its elasticity, the blade is optimally pressed against the modules to ensure heat exchange between them and the cooling fluid. The blade extends from one end of the electrical resistance to the other so as to facilitate a transfer of calories over an entire dimension of the electrical resistance. The blade is either substantially flat or curved.

[0025] According to an optional feature of the invention, at least one of the modular segments is formed of at least two shells.

[0026] This feature corresponds to an alternative embodiment in which the metal element is a metal tube. Preferably, all the modular segments are formed of at least two shells. Each shell has a semi-circular shape, the two shells being joined around the virtual line forming the main axis of the electrical resistance. According to an optional feature of the invention, at least one of the modular segments is formed of an annular portion of metal tube.

[0027] This characteristic corresponds to the embodiment variant in which the metal element is a metal tube. Each modular segment is then a single piece and corresponds to a cut made in a metal tube of annular section.

[0028] According to an optional feature of the invention, at least one of the modular segments is formed of at least two lamellae.

[0029] This characteristic corresponds to an alternative embodiment in which the metal element is a metal blade.

[0030] According to an optional feature of the invention, each modular segment is associated with a module.

[0031] There are at least as many modular segments as there are modules within the electrical resistance. In other words, there is at least one modular segment arranged radially within each module.

[0032] According to an optional characteristic of the invention, at least one of the modular segments has an external face facing the internal peripheral surface of the module and an internal face configured to delimit a circulation conduit for the cooling fluid.

[0033] The outer face of the modular segment has a shape complementary to the inner peripheral surface of the module with which it is associated, i.e. within which it is arranged. When the metal element is a metal tube, the outer face and the inner face of the modular segment are radially opposed. The inner face helps to delimit a circulation duct for the cooling fluid; more particularly, such a circulation duct is formed by the association of the inner faces of the plurality of modular segments of the metal tube of the electrical resistance.

[0034] According to an optional characteristic of the invention, at least one of the modular segments is delimited axially by a first slice and a second slice, the modular segment comprising securing means formed from at least one of the slices.

[0035] The first edge and the second edge are faces of the modular segment that connect its outer face and its inner face. The first edge is for example oriented towards the first end of the electrical resistance, the second edge being oriented towards the second end thereof. At least one of the edges comprises means for securing the modular segments to each other or the modular segments to another element of the electrical resistance. In certain embodiments, the securing means comprise a tab and a recess. The tab corresponds to a portion projecting relative to the edge while the recess corresponds to a removal of material relative to this edge. In other embodiments, the securing means comprise an arm and a hook.

[0036] According to an optional feature of the invention, two adjacent modular segments are held together by cooperation between at least one of their legs and at least one of their respective recesses.

[0037] The legs and recesses of two adjacent modular segments have complementary shapes, so that a leg of a given modular segment fits into a recess of the adjacent, i.e. directly adjacent, modular segment. The legs and recesses therefore constitute a connection between two adjacent modular segments. The modular segments are thus not associated over their entire circumference, but only in the interlocking zones between the legs and the recess, which allows thermal expansion of these modular segments during heat exchange with the coolant.

[0038] According to an optional feature of the invention, the electrical resistance comprises a fixing flange arranged at a junction between two adjacent modular segments, the securing means extending at least partially through this fixing flange. The flange is substantially flat. It is made of metal, for example copper. It has a first contact face oriented towards the first end of the electrical resistance and a second contact face oriented towards its second end. The flange is arranged between two adjacent modular segments, and by extension between the two modules associated with these two modular segments. It constitutes an interlayer between the modules and contributes to the mechanical strength of the electrical resistance.In some embodiments, the flange is configured to bring at least one of the modular segments closer to the inner peripheral surface of the module, i.e., to press the modular segments against the modules with which they are associated by rotating.

[0039] Alternatively, a fixing crosspiece is arranged at a junction between two adjacent modules, and advantageously between two adjacent modular segments. The fixing crosspiece, which cooperates with receiving areas provided in the modules, ensures optimal positioning of the modules relative to each other. This ensures that the external peripheral surfaces of the modules are aligned with each other when the contact device is moved.

[0040] Generally speaking, two adjacent modules are mechanically connected by a fixing system, a first example of which is the fixing flange and a second example is the fixing crosspiece.

[0041] According to an optional feature of the invention, the flange has a slot in which the tab is housed.

[0042] In other words, the leg of a given modular segment fits through a slot provided for this purpose in the flange. The modular segment and the flange are held in position relative to each other by a bayonet system which results from an L-shape of the leg.

[0043] According to an optional feature of the invention, each modular segment comprises a plurality of legs having different orientations relative to a central axis of the metal tube. By "different orientations" is meant that the legs extend in planes which form angles of different values ​​with the central axis of the metal tube. These different orientations contribute to the pressing of the modular segment against the module with which it is associated.

[0044] According to an optional feature of the invention, the flange comprises an external wall arranged radially between the external and internal peripheral surfaces of two adjacent modules.

[0045] The outer wall of the flange delimits it radially. The flange thus has an external diameter, in which the external wall is inscribed, one dimension of which is between an internal diameter of a given module in which its internal peripheral surface is inscribed and an external diameter of the module in which its external peripheral surface is inscribed.

[0046] In embodiments where at least a portion of the electrical resistor is covered with a sealing member, the flange allows this sealing member to be retained between the modules. The sealing member is therefore not in contact with the legs of the modular segments or the slots of the flanges. In addition, the sealing member locks the flanges in position to prevent them from rotating.

[0047] According to an optional characteristic of the invention, the metallic element is in one piece from the first to the second end of the electrical resistance.

[0048] This is an alternative embodiment in which the metal element is made of a single piece. A single-piece metal element reduces the machining and assembly operations required to obtain the electrical resistance.

[0049] According to an optional characteristic of the invention, the electrical resistance comprises at least one calorie transfer device which extends at least partly within the volume delimited by the modules.

[0050] The heat transfer device helps improve heat exchange between the cooling fluid on the one hand and the winding on the other. It acts as a drain to recover and / or dissipate heat. This heat transfer device is positioned either directly against the modules or, if necessary, in the space delimited by the metal tube. This heat transfer device corresponds, for example, to a plurality of copper plates arranged in a cross within the metal tube.

[0051] According to an optional characteristic of the invention, at least one opening is provided within the metal blade.

[0052] Such an opening has the effect of facilitating the circulation of the cooling fluid on either side of the blade and thus increasing the exchange of calories within the volume delimited by the modules.

[0053] According to an optional characteristic of the invention, the transfer device comprises a first portion extending radially within at least one module and a second portion in contact with the metal tube.

[0054] The first portion is for example dedicated to the dissipation of calories while the second portion is dedicated to the capture of these calories. The second portion is in physical contact with the internal face of the metal tube. The heat transfer device is for example pressed against the metal tube to receive its heat and transmit it to the cooling fluid.

[0055] According to an optional characteristic of the invention, the electrical resistance comprises a sealing member covering at least the external peripheral surfaces of the modules.

[0056] Such a sealing element is, for example, a layer of cement, enamel or silicone. It allows the electrical resistance to be structured and the external peripheral surfaces to be smoothed for better winding apposition. The sealing element can also be inserted between two adjacent modules, covering the flanges.

[0057] According to an optional characteristic of the invention, at least one of the modules is composed of at least two shells.

[0058] Preferably, all the modules are formed of at least two shells. Each shell has a semicircular shape, the two shells of the same module being joined around the virtual line forming the main axis of the electrical resistance. According to an optional characteristic of the invention, the modules are annular sections.

[0059] Each module is then made from a single piece and has the shape of a closed circle.

[0060] According to an optional characteristic of the invention, at least one cavity is provided between the external peripheral surface and the internal peripheral surface of at least one of the modules, the heat transfer device being arranged at least partially in the cavity.

[0061] It is understood that the cavity is arranged, radially, in a thickness of the module. The cavity has, for example, an upper wall of a shape complementary to the external peripheral surface and a lower wall of a shape complementary to the internal peripheral surface. Each module comprises, for example, eight cavities.

[0062] The cavity constitutes a housing for receiving a heat transfer device; it is understood that the heat transfer device extends at least partly within it.

[0063] According to an optional feature of the invention, the cavity is filled with a sealing member.

[0064] Such filling is carried out, for example, by injection using a syringe, the heat transfer device being inserted into the sealing member after injection.

[0065] According to an optional characteristic of the invention, the electrical resistance has a generally rectilinear shape.

[0066] According to an optional characteristic of the invention, the electrical resistance has a general toroidal shape.

[0067] These are two embodiments of the electrical resistance. In its generally rectilinear form, the modules have edges extending in parallel planes. In its generally toroidal form, at least one of the edges of the modules extends in a plane oblique to a main elongation direction of the module concerned, whether this is curved or rectilinear. In other words, the edge(s) of a given module extend in planes oblique to a central axis of said module, such an axis being able to be formed by a curve or by a rectilinear straight line. The edges of the modules extend for example in planes intersecting such a central axis of the torus, in particular by forming between these two planes an angle of between 20° and 90°. In the case of a rectilinear central axis, an angle formed between this central axis of the module and the plane passing through an edge of said module is between 30° and 80°.

[0068] Electrical resistors with a generally rectilinear shape are easy to manufacture. Electrical resistors with a generally toric shape have the advantage of compactness, with a greater number of turns for reduced packaging.

[0069] According to an optional characteristic of the invention, the general toric shape of the electrical resistance has a square section.

[0070] This square or quasi-square section allows on the one hand to increase the length of the turns of the winding of the electrical resistance, and on the other hand to increase a passage section of the cooling fluid within the electrical resistance. Alternatively, the general toric shape of the electrical resistance is of circular section. The shape of the section of the electrical resistance depends on the round or square shape of the external peripheral surfaces of the modules.

[0071] According to an optional characteristic of the invention, each of the modules has complementary serrations of the adjacent modules.

[0072] Such serrations allow the modules to be angularly coupled and also prevent the winding from jamming at an interface between two adjacent modules. Alternatively, grooves are provided on the outer peripheral surface of the modules, with the winding being housed in the grooves to fix the position of its turns. This prevents contact between one turn of the winding and an adjacent turn.

[0073] According to an optional feature of the invention, the electrical resistance comprises a first end plate associated with the first end and a second end plate associated with the second end. These end plates are for example made of epoxy and are optionally lined with a metal plate each, to which they are secured by screwing.

[0074] According to an optional characteristic of the invention, the electrical resistance comprises at least one holding member, at least one of the modules being held against an adjacent module by the holding member.

[0075] The holding member takes the form of a staple or a hook, for example. It is made up of a straight central portion, curved at both ends to attach to an adjacent module.

[0076] According to an optional characteristic of the invention, the electrical resistance comprises at least one cable extending from the first end to the second end of the electrical resistance passing through the modules.

[0077] The cable is a safety device against violent handling of the electric resistance. It allows the modules to be held together. Preferably, the electric resistance has two cables, each arranged at one end with a diameter of the electric resistance.

[0078] The invention further relates to a method of assembling an electrical resistance as mentioned above, comprising a step of assembling the modules during which the modules are joined end to end and a winding step during which the winding is wound in turns around the modules.

[0079] The assembly process allows obtaining an electrical resistance according to the invention. The assembly step corresponds to the association of the modules with each other. The modules are then surrounded by the winding during the winding step.

[0080] According to an optional characteristic of the invention, the assembly method comprises a step of covering the modules with the sealing member.

[0081] The covering step comprises, for example, a smoothing operation in order to obtain a regular surface to support the winding. According to an optional characteristic of the invention, the assembly step comprises a relative rotation between a modular segment and a flange so as to press the modular segment against a module and to secure the modular segment and the flange along a virtual line forming the axis of the electrical resistance.

[0082] According to an optional characteristic of the invention, during the assembly step each of the modules is assembled to an adjacent module by means of a holding member.

[0083] For this purpose, the holding member of a given module cooperates with a cylinder of an adjacent module, the cylinder being inserted into the curved portion of the holding member to make the modules integral.

[0084] According to an optional characteristic of the invention, the assembly method comprises, prior to the assembly step, a step of cutting the modules from a tube of electrically insulating material.

[0085] The cutting step is carried out in a straight tube. The cut is made straight when the general shape of the electrical resistance is rectilinear, and the cut is made at an angle when the electrical resistance is generally toroidal in shape. The modules are therefore rectilinear sections. It is the assembly of the electrical resistance, in combination with the cutting angle, which gives it its general rectilinear shape or its general toroidal shape. Alternatively, the modules can have a general arc-shaped shape.

[0086] A similar cutting step is performed in a metal tube or blade when the metal element of the electrical resistance is composed of a plurality of modular segments.

[0087] Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and examples of embodiment given for informational and non-limiting purposes with reference to the appended drawings on the other hand, in which:

[0088] [Fig. 1] illustrates, schematically, an electrical resistance according to the invention according to a first embodiment; [Fig. 2] illustrates, schematically, an electrical resistance according to the invention according to a second embodiment, in which the modules are sections;

[0089] [Fig. 3] illustrates, schematically, a close-up view of a portion of the electrical resistance of Figure 2, one of the sections having been removed;

[0090] [Fig. 4] illustrates, schematically, a close-up view of a portion of an electrical resistor according to a third embodiment;

[0091] [Fig. 5] illustrates, schematically, an electrical resistance according to the invention, according to a fourth embodiment;

[0092] [Fig. 6] illustrates, schematically, a close-up view of a portion of the electrical resistance of Figure 5;

[0093] [Fig. 7] illustrates, schematically, a cooperation between different modules and different modular segments of the electrical resistance of figure 5;

[0094] [Fig. 8] illustrates, schematically, a cooperation between a flange and a modular segment of the electrical resistance of figure 5;

[0095] [Fig. 9] illustrates, schematically, an electrical resistance according to the invention, according to a fifth embodiment in which the electrical resistance is provided with a metallic element in the form of a metallic blade;

[0096] [Fig. 10] illustrates, schematically, a portion of the electrical resistance of figure 9;

[0097] [Fig. 11] illustrates, schematically, a sectional view of the electrical resistance of figure 9;

[0098] [Fig. 12] illustrates, schematically, an association between a fixing flange and the metal blade of the electrical resistance of figure 9;

[0099] [Fig. 13] illustrates, schematically, an exploded view of the electrical resistance of figure 9;

[0100] [Fig. 14] illustrates, schematically, an electrical resistance according to the invention according to a sixth embodiment; [Fig. 15] illustrates, schematically, a sectional view of a portion of the electrical resistance of figure 14;

[0101] [Fig. 16] illustrates, schematically, a close-up view of a portion of the electrical resistance of Figure 14.

[0102] The features, variants and different embodiments of the invention may be combined with each other in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0103] In the figures, elements common to several figures retain the same reference.

[0104] Figures 1 to 16 thus illustrate, schematically, an electrical resistor 1 according to the invention. The electrical resistor 1 is for example a rheostat. This electrical resistor 1 is represented according to a first embodiment in Figure 1, according to a second embodiment in Figures 2 and 3, according to a third embodiment in Figure 4, according to a fourth embodiment in Figures 5 to 8, according to a fifth embodiment in Figures 9 to 13 and according to a sixth embodiment in Figures 14 to 16. The characteristics described in relation to any one of these embodiments may apply, mutatis mutandis, to one or other of the other embodiments as long as this is not incompatible.

[0105] The electrical resistance 1 has a generally toroidal shape in the figures. However, without departing from the scope of the invention, it is possible to imagine an electrical resistance 1 having a generally rectilinear shape. Depending on the embodiments, the electrical resistance has either a square or polygonal section, as is the case in the embodiment of Figures 9 to 13, or a circular or oval section, as is the case in the embodiments of Figures 1 to 8 and 14 to 16. The electrical resistance 1 extends between a first end 2 and a second end 4, in a completely rectilinear or completely toroidal manner. In the latter case, the torus may comprise at least one rectilinear module or a module curved along an arc of a circle, and advantageously a plurality of rectilinear modules or modules curved along an arc of a circle.Each of these ends 2, 4 is equipped with an end plate 6, 8; there is thus a first end plate 6 arranged at the first end 2 and a second end plate 8 arranged at the second end 4, these end plates 6, 8 being notably visible in figures 1, 5, 9, 14 and 15.

[0106] The electrical resistor 1 being configured for the circulation of a cooling fluid, each of the end plates 6, 8 is connected to a cooling fluid circuit. The first end plate 6 is for example connected to a cooling fluid inlet duct while the second end plate 8 is connected to a cooling fluid discharge duct. Filtration devices, such as grids, may be arranged at an interface between these cooling fluid inlet and discharge ducts on the one hand and the end plates 6, 8 on the other hand in order to prevent the introduction and / or passage of foreign bodies within the electrical resistor 1.

[0107] The electrical resistance 1 is composed of a plurality of modules 10 made of an electrically insulating material, in particular ceramic or alumina. These modules 10, the configurations of which vary according to the embodiments, are arranged side by side, that is to say end to end, from the first end 2 to the second end 4 of the electrical resistance 1. In other words, the modules 10 are assembled one after the other from the first end 2 of the electrical resistance 1 to its second end 4 to form a main body thereof. A winding 11, a portion of which is illustrated in FIGS. 5 and 9, is wound around the modules 10 in the form of turns, this winding 11 being wound from the first end 2 to the second end 4.

[0108] An interface between the electrical resistance 1 and a space external to it corresponds to an external peripheral surface 12 of the modules 10. In other words, the external peripheral surfaces 12 radially delimit the modules 10. These external peripheral surfaces 12 are of substantially round or oval shape for the embodiments shown in Figures 1 to 8 and 14 to 16, and they are of substantially square shape for the embodiment of Figures 9 to 13.

[0109] When the electrical resistance 1 is a rheostat, in the embodiments shown in Figures 1 to 8 and 14 to 16 the external peripheral surfaces 12 have a round or oval shape with the exception of a flat portion 14 formed along the modules from the first end 2 of the electrical resistance 1 to its second end 4, such a flat portion 14 allowing the movement of a contact device of the electrical resistance 1 bearing against the winding 11. The flat portion 14 is visible in Figure 6. It is obtained by machining the modules 10, for example by sanding. Conversely, in the embodiment shown in Figures 9 to 13, the external peripheral surfaces 12 have a square shape; machining is therefore not necessary to provide a portion allowing the movement of a contact device of the electrical resistance 1 bearing against the winding 11.Such a movement is then carried out along one of the four faces of the external peripheral surfaces 12 of the modules 10, this number of four faces resulting from the square shape of the external peripheral surfaces 12. The contact device, not shown in the figures, is movable from the first end 2 to the second end 4 in order to regulate an intensity of the electric current passing through the electrical resistance 1.

[0110] At the interfaces between the end plates 4, 6 and the modules 10, the electrical resistance 1 comprises metal collars, not illustrated in the figures, these metal collars extending around the external peripheral surfaces 12 so as to ensure electrical contacts between the modules 10 and the end plates 4, 6. In certain embodiments, these metal collars are continuous all around the modules 10. In other embodiments, they have a solid portion facing, as the case may be, the flat portion 14 or the face receiving the contact device, and a portion provided with open areas on the other faces of the external peripheral surfaces 12.The solid portion opposite the flat portion 14 or the face receiving the contact device ensures optimal electrical contact with the contact device, while the portion provided with open areas has a securing function which will be discussed later.

[0111] The modules 10 are further delimited by an inner peripheral surface 16, which is radially opposite the outer peripheral surface 12. This inner peripheral surface 16 has a round or square shape depending on the embodiments. A distance measured between the outer peripheral surface 12 and the inner peripheral surface 16 of a given module 10 corresponds to its thickness, such a distance being measured at the right angle of the outer 12 and inner 16 peripheral surfaces. In the fifth embodiment shown in Figures 9 to 13, the inner peripheral surfaces 16 comprise ribs 17. These ribs 17 are outgrowths of the inner peripheral surfaces 16 which extend from the first end 2 to the second end 4 of the electrical resistance 1.

[0112] As mentioned above, the modules 10 have different configurations depending on the embodiments. The modules 10 are thus in the form of shells or half-shells 18 in the first and fifth embodiments, while they are constituted by annular sections 20 in the second, third, fourth and sixth embodiments. It is understood that in the form of half-shells 18 a given module 10 is composed of at least two parts, while in the form of an annular section it is made in a single piece.

[0113] The modules 10 are in the form of two half-shells 18 in the first embodiment illustrated in FIG. 1. Each module 10 more particularly comprises a first half-shell 18A arranged along an internal periphery of the toroidal electrical resistance 1, and a second half-shell 18B arranged along an external periphery of the toroidal electrical resistance 1, the shapes of the first half-shell 18A and the second half-shell 18B being complementary to facilitate their association with each other. The first half-shell 18A and the second half-shell 18B are thus joined along a virtual line corresponding to a main axis of the electrical resistance 1.The first half-shell 18A and the other half-shells 18 arranged along the internal periphery of the electrical resistance 1 form an internal subassembly of half-shells 18, while the second half-shell 18B and the other half-shells 18 arranged along the external periphery of this electrical resistance 1 form an external subassembly of half-shells 18. The internal and external subassemblies here comprise nine half-shells 18 each, or eighteen half-shells 18 for the electrical resistance 1 taken as a whole.

[0114] The half-shells 18 are associated with each other by means of articulation means 22. Such articulation means 22 are configured to cause a half-shell 18 of the internal subassembly to cooperate with a half-shell 18 of the external subassembly on the one hand, for example the first half-shell 18A with the second half-shell 18B, and to cause the half-shells 18 of the internal subassembly to cooperate with each other and the half-shells 18 of the external subassembly with each other on the other hand. The articulation means 22 here comprise a system of locking teeth associated with pins, the locking teeth being for example carried by the half-shells 18 of the internal subassembly and being arranged in abutment against the pins which are carried by the half-shells 18 of the external subassembly.

[0115] Similarly, in the fifth embodiment illustrated in Figures 9 to 13, each module 10 is in the form of two half-shells 18. These half-shells 18 are opposite each other along a plane of symmetry of the electrical resistance 1 substantially perpendicular to a main elongation plane of each of the end plates 6, 8. Each module 10 thus comprises a first half-shell 18A arranged on a first side of this plane of symmetry and a second half-shell 18B arranged on a second side of the plane of symmetry. The shapes of the first half-shell 18A and the second half-shell 18B are complementary so as to facilitate their association with each other. The electrical resistance 1 has, in this fifth embodiment, four modules 10 each corresponding to a quarter of a torus, i.e. eight half-shells 18 in total. In this fifth embodiment, each half-shell 18 comprises two ribs 17, namely an internal rib and an external rib.These two internal and external ribs 17 are arranged in a staggered pattern within a given half-shell 18, such that the internal rib 17 extends beyond the half-shell 18 at one of its ends towards a half-shell 18 which is adjacent to it and the external rib 17 extends beyond the given half-shell 18 at the other of its ends, towards another half-shell 18 which is also adjacent to it.

[0116] In this fifth embodiment, the face of the modules 10 dedicated to the movement of the contact device is for example the largest face of the first half-shells 18A. Thus, the contact device moves along the winding between the internal diameter of the electrical resistance 1 and its external diameter.

[0117] In a different manner, the modules 10 are annular sections 22 for the second, third, fourth and sixth embodiments. According to certain exemplary embodiments, sixteen annular sections are necessary to form the electrical resistance 1; it would however be possible, without departing from the scope of the invention, to envisage electrical resistances 1 comprising a different number of annular sections 22.

[0118] These annular sections 22 are assembled to each other using at least one holding member 24. The holding member 24 makes it possible to secure a given module 10 to the module 10 which is adjacent to it. With the exception of the modules 10 arranged against the end plates 6, 8, each module 10 comprises two holding members 24 to secure it to the modules 10 which are arranged on either side of it.

[0119] The holding member 24 is shown in Figures 3 and 4, a holding member 24 being visible outside the module 10 in Figure 3 while a holding member 24 is visible within a module 10 in each of Figure 3 and Figure 4. The holding member 24 here corresponds to a hook, comprising a straight portion and two curved portions at each of its ends. The straight portion of the holding member 24 extends through the thickness of the module 10, that is to say between its external peripheral surface 12 and its internal peripheral surface 16. This straight portion extends between a first edge 26 and a second edge 28 of the module 10 which correspond to its faces arranged opposite the adjacent modules 10, such edges being arranged in intersecting planes with respect to an axis of the torus. More particularly, the holding member 24 extends in a chamber 30 provided within the module 10 from its first edge 26 to its second edge 28.The chamber 30 of a given module 10 is arranged opposite the chamber 30 of the module(s) 10 which are adjacent to it, the set of chambers 30 of all the modules 10 forming a channel extending from the first end 2 to the second end 4 of the electrical resistance 1. Each chamber 30 of a given module 10 is further dimensioned to receive two holding members 24, namely where appropriate the one which connects the given module 10 to the module 10 which is directly to its right and the one which connects it to the module 10 which is directly to its left.

[0120] The holding member 24 of a given module 10 works in cooperation with a retention member 32 of the adjacent module 10, such a retention member 32 being for example a cylinder intended to be housed in the curved portion of the holding member 24. The curved portion of the holding member 24 engages the retention member 32, then this retention member 32 is positioned in a receiving housing 34 provided for this purpose on the edge 26, 28 of the module 10. A rim of the receiving housing 34 prevents the retention member 32 from coming out of this receiving housing 34. The module 10 having the holding member 24 and the module 10 having the retention member 32 with which the holding member 24 cooperates are held relative to each other due to the tension exerted by the holding member 24.In other words, once the retaining member 32 is in a predetermined position within its receiving housing 32, it puts the holding member 24 under tension and makes the modules 10 integral by forcing them against each other.

[0121] In addition to the holding members 24, the assembly of the modules 10 to each other can be solidified by the presence of at least one safety device. This safety device is for example a cable 36 extending within a conduit 38 formed in the thickness of the modules 10 from the first end 2 of the electrical resistance 1 to its second end 4. The cable 36 is visible in Figures 6 and 7, while the conduit 38 is shown in Figures 3, 4, 6 and 7. The electrical resistance 1 comprises for example two cables 36, extending respectively along its internal periphery and along its external periphery. The two conduits 38 receiving these cables 36 are arranged substantially equidistant from the chamber 30 within which the holding member 24 extends.

[0122] In order to facilitate the assembly of the modules 10, each module 10 has serrations 40 illustrated in figures 2, 3, 4, 9 and 13. These serrations 40 can be triangular in shape as is the case in figures 2 to 4, or even more complex in shape as in figure 9. The serrations 40 are complementary to the serrations 40 of the adjacent modules 10, which allows them to be fitted together angularly. In the case of the fifth embodiment illustrated in figure 9, the complex shape of the serrations 40 also allows the modules 10 to be held relative to each other once they are fitted together.

[0123] At the junction between two adjacent modules 10, that is to say at the level of the serrations 40, these modules 10 have a reduction in section; thus, the thickness of the modules 10, measured between the external peripheral surface 12 and the internal peripheral surface 16, is less at the level of the serrations 40 in comparison with a central portion of the modules 10 at a distance from these serrations 40. In other words, the electrical resistance 1 has shoulders bordering each of the modules 10 along their edges 26, 28, so as to form grooves at the level of the serrations 40.

[0124] The serrations 40 also make it possible to prevent the winding 11 from getting stuck between two neighboring modules 10, by avoiding straight junction lines into which a turn could sink. The serrations 40 are particularly useful for this purpose when the winding 11 is a round-section wire. Alternatively, the winding 11 may be a flat ribbon, wound flat against the modules 10 of the electrical resistance 1.

[0125] Although the serration is described in connection with a particular embodiment, the serration 40 provided on the edge of at least one of the modules is a feature applicable to any of the embodiments and all of the features and effects described above in connection with the serration are transferable to any of these embodiments.

[0126] In certain embodiments, the winding 11 is held in position by covering the modules 10 with a sealing member, for example cement, which makes it possible to smooth at least the external peripheral surfaces 12 of the modules 10. In order in particular to retain this sealing member around the modules 10, the half-shells 18 of the first embodiment have edges 42 extending in line with the external peripheral surfaces 12.

[0127] According to the invention, the modules 10 delimit a volume 44 configured for the circulation of the cooling fluid, which depending on the embodiments may be air or water. More specifically, such a volume 44 is delimited by the internal peripheral surfaces 16 of the modules 10, their assembly forming a circulation conduit for the cooling fluid. The volume 44 thus extends around the virtual line which forms the main axis of the electrical resistance 1.

[0128] According to the embodiments, either the cooling fluid circulates directly within the volume 44 by being channeled by the internal peripheral portions 16 of the modules 10, or this cooling fluid is channeled by a metallic element arranged within the volume 44. In the second embodiment of FIG. 4, the electrical resistance 1 is devoid of a metallic element; in the fifth embodiment of FIGS. 9 to 13 and in the sixth embodiment of FIGS. 14 to 16 the metallic element takes the form of a metallic blade 80; in the other three embodiments, the metallic element takes the form of a metallic tube 46. In other words, in the presence of a metallic element, it takes either the form of a metallic blade 80, or the form of a metallic tube 46, the latter being in particular continuous.

[0129] The metal element is for example made of copper, aluminum, beryllium or an alloy of these metals. This metal element extends at least from the first end 2 of the electrical resistance 1 to its second end 4, or even beyond these. It is connected to the cooling fluid inlet duct and to the cooling fluid outlet duct mentioned above, in order to ensure the circulation of the cooling fluid towards the electrical resistance 1 and away from it. The metal element is pressed, at least partially, against at least one of the internal peripheral surfaces 16 of the modules 10; preferably, the metal tube 46 is pressed against all the internal peripheral surfaces 16 of the electrical resistance 1, so that it matches at least some of the internal contours of the modules 10.

[0130] Among the embodiments in which the electrical resistance 1 is equipped with a metal element, there are variants in which this metal element is in one piece from the first end 2 to the second end 4 of the electrical resistance 1, and other variants in which the metal element results from an assembly of several parts, that is to say that it is composed of a plurality of modular segments 48, 88. The metal element is in one piece for the first and second embodiments corresponding respectively to figures 1 as well as 2 and 3, while it is formed of several modular segments 48 in the fourth embodiment illustrated in figures 5 to 8, in the fifth embodiment shown in figures 9 to 13 and in the sixth embodiment shown in figures 14 to 16.

[0131] For embodiments where the metal element is in one piece, the management of its thermal expansion during heat exchanges with the cooling fluid is carried out either by insertion within the electrical resistance 1 of a spring effect device, or by connection of this metal tube 46 to only one of the end plates 6, 8.

[0132] In the embodiments for which the metal element comprises several modular segments 48, 88, the thermal expansion is managed in the same way by a spring effect device or even by spacing the modular segments 48 by a distance corresponding substantially to the expected expansion.

[0133] The fourth embodiment will now be described in more detail in relation to figures 5 to 8. In the electrical resistance 1 visible in these figures, each modular segment 48 of the metal tube 46 is associated with a module 10; there is thus an equal number of modular segments 48 and modules 10, i.e. sixteen modular segments 48.

[0134] Each modular segment 48 is here formed of several shells; more particularly, each modular segment 48 is composed of two half-shells 49, such half-shells 49 being particularly visible in the sectional view of FIG. 7. However, still within the scope of the invention, modular segments 48 could be designed formed of a single annular portion of metal tube 46, an annular portion then being associated with a module 10.

[0135] A modular segment 48 comprises an external face 50 and an internal face 52. Its external face 50 is opposite the internal peripheral surface 16 of the module 10 with which it is associated. The external face 50 has a shape complementary to this internal peripheral surface 46, so as to be pressed against it. The internal face 52 is radially opposite the external face 50; it is configured to be in contact with the cooling fluid, the assembly of the internal faces 52 of each of the modules 10 from the first end 2 to the second end 4 of the electrical resistance 1 making it possible to delimit a conduit for circulation of the cooling fluid all along the electrical resistance 1.

[0136] The external 50 and internal 52 faces of a given modular segment 48 are connected to each other by slices 54, 56, namely a first slice 54 and a second slice 56, which axially delimit the modular segment 48. The first slice 54 of the modular segment 48 is arranged in the vicinity of the first edge 26 of the module 10 with which it is associated, while its second slice 56 is arranged in the vicinity of the second edge 28 thereof.

[0137] As is particularly visible in Figures 7 and 8, each modular segment 48 includes securing means. As part of these securing means, each modular segment 48 has at least one tab 58 and at least one recess 60 which are both formed from one of its edges 54, 56. In the embodiment illustrated here, each modular segment 48 comprises four tabs 58 and four recesses 60 formed from its first edge 54, as well as four tabs 58 and four recesses 60 formed from its second edge 56. The tabs 58 of the same edge 54, 56 have different orientations relative to a central axis of the metal tube 46, such a central axis being coincident with the virtual line which forms the axis of the electrical resistance 1. The tab 58 has an L-shape, particularly visible in FIG. 7, and the recess 60 has a substantially rectangular shape.The tab 58 and the recess 60 have complementary shapes; it is understood that the tab 58 of a given modular segment 48 is configured to fit within the recess 60 of an adjacent modular segment 48. These complementary shapes of the tabs 58 and the recesses 60 of the modular segments 48 make it possible to hold them together. Such an assembly, which therefore corresponds to a connection of the modular segments 48 in point zones rather than all along their edges 54, 56, facilitates the thermal expansion of the metal tube 46.

[0138] The electrical resistance 1 comprises, in the fourth embodiment, at least one fixing flange 62. The flange 62 here has an annular shape; it is particularly visible in Figure 8. It is made of metal, so as to ensure thermal conduction between the modular segments 48. The flange 62 is annular in shape and is substantially flat; it extends radially between an external wall 64 and an internal wall 66, this internal wall 66 being its wall which is closest to the central axis of the metal tube 46.

[0139] The flange 62 is disposed between two adjacent modular segments 48, such that it constitutes an interlayer between the modular segments 48. The flange 62 extends axially between a first contact face disposed against the second edge 56 of a given modular segment 48 and a second contact face disposed against the first edge 54 of the adjacent modular segment 48. The flange 62 further extends between two adjacent modules 10, such that its first contact face is attached to the second edge 28 of a given module 10 while its second contact face is against the first edge 26 of the adjacent module 10.

[0140] The flange 62 is dimensioned so that its outer wall 64 is arranged radially between the outer peripheral surfaces 12 and the inner peripheral surfaces 16 of two adjacent modules 10, as can be seen in particular in FIG. 7. It is understood from the above that a circumference of the outer wall 64 of the flange 62 is greater than a circumference of the inner peripheral surface 16 of the module 10, T1, but less than a circumference of the outer peripheral surface 12 of this module 10. The circumference of the outer wall 64 of the flange 62 is also greater than both a circumference of the outer face 50 of the modular segment 48 and a circumference of its inner face 52.

[0141] The flange 62 being arranged between two modular segments 48, a solid flange 62 would constitute a physical obstacle to the connection of these modular segments 48. There is therefore provided in the flange 62 at least one slot 68 to allow the connection between the two modular segments 48 arranged on either side of this flange 62. As can be seen in particular in FIG. 8, the flange 62 here comprises eight slots 68, i.e. four slots 68 intended to receive the four tabs 58 of each of the two modular segments 48 between which it is arranged. It is understood that the tab 58 of a modular segment 48 extends through the flange 62 by being housed through one of its slots 68.

[0142] The relative positions of the modular segment 48 and the flange 62 are locked by a rotation of the flange 62, this rotation causing the modular segment 48 to move closer to the internal peripheral surface 16 of the module 10 with which it is associated. Such locking between the modular segment 48 and the flange 62 is facilitated by the L-shape of the tab 58, this L-shape allowing a bayonet-type fixing within the slot 68. The different orientations between the tabs 58 of the same modular segment 48 also contribute to the pressing of the modular segment 48 against the module 10.

[0143] A sealing member such as that mentioned above can be arranged in a space 68 delimited by the external wall 64 of the flange 62, and the edges 26, 28 of the modules 10 which frame it. The sealing member then allows the flange 62 to be held in position relative to the modules 10, by preventing it from rotating as long as it is correctly positioned within the electrical resistance 1.

[0144] The metallic element of the fifth embodiment will now be described in relation to Figures 9 to 13. As mentioned previously, in this fifth embodiment the electrical resistance 1 is of generally toroidal shape. The electrical resistance 1 is thus inscribed in a circle which defines its overall axis of extension. It is also noted that at least one of the modules, and advantageously all the modules, of this embodiment illustrated in Figures 9 to 13 extends along an arc of a circle. Each module is thus a portion of a curve.

[0145] Here, the metal element is here in the form of at least one metal blade 80 with spring effect. More particularly, the metal element comprises two metal blades 80 with an internal blade 80A facing the internal diameter of the electrical resistance 1 and an external blade 80B facing its external diameter. Each blade 80 extends from the first end 2 of the electrical resistance 1 to its second end 4, that is to say from the first end plate 6 to the second end plate 8.

[0146] The blade 80 has a general arc-shaped form, which follows the general toric shape of the electrical resistance 1. The blade 80 comprises a central zone 82 surrounded by two peripheral zones 84, these zones all three extending from the first end 2 to the second end 4 of the electrical resistance 1. The central zone 82 and the peripheral zones 84 are illustrated in particular in FIGS. 10 to 12.

[0147] A body of the blade 80 extends in two intersecting planes, so that the central zone 82 is closer to the internal diameter of the electrical resistance 1 than the two peripheral zones 84. As is particularly visible in FIG. 11, there is an angle between a plane in which the first peripheral zone 84 mainly extends and a plane in which the second peripheral zone 84 mainly extends, such an angle being for example between 70° and 85°.

[0148] The blade 80 is at least partially in contact with the modules 10; more particularly, for a given module 10, one face of one of the peripheral zones 84 is in contact with one of the ribs 17 present on the internal peripheral surface 16 of the first half-shell 18A and one face of the other peripheral zone 82 is in contact with the rib 17 present on the second complementary half-shell 18B. The heat exchanges between the cooling fluid on the one hand and the modules 10 on the other hand, which take place through the blade 18, thus take place along the two peripheral portions. The blade 80 being a spring-effect blade, it generates pressure against these ribs 17. The central zone 82 is arranged between the rib 17 of the first half-shell 18A and the rib 17 of the second half-shell 18B, without being in contact with them. Within the central zone 82 is formed at least one opening 86, here a plurality of openings 86.The opening 86 here has a rectangular shape; it facilitates the circulation of the cooling fluid on either side of the blade 80.

[0149] Depending on the embodiments, either the blade 80 is made in one piece, or it comprises a plurality of modular segments. In the fifth embodiment, these modular segments take the form of lamellae 88. These lamellae 88 are pieces of the blade 80 which are arranged end to end from the first end 2 to the second end 4 of the electrical resistance 1. For a given blade 80, a lamella 88 is associated with a module 10; in the presence of two blades 80 within the volume 44, there are therefore two lamellae 88 per module 10, with a shorter lamella 88 arranged opposite the internal diameter of the electrical resistance 1 and a longer lamella 88 arranged opposite its external diameter. The electrical resistance 1 thus comprises eight lamellae 88. In addition to the lamellae 88 arranged within the modules 10, the electrical resistance may comprise additional lamellae which are of a reduced size compared to the lamellae 88.These additional lamellae, not visible in the figures, form a connection between on the one hand the lamellae 88 and on the other hand either the cooling fluid inlet duct or the cooling fluid outlet duct, the additional lamellae passing for this purpose through the end plates 6, 8 which are connected to these cooling fluid inlet and outlet ducts.

[0150] Each strip 88 of the blade 80 extends between a first edge 54 directed towards the first end 2 of the electrical resistance 1 and a second edge 56 directed towards the second end 4 of this electrical resistance 1. The first edge 54 and the second edge 56 of each strip 88 are equipped with securing means, particularly visible in figures 12 and 13. Such securing means participate in associating the strip 88 either with an adjacent strip 88, or with an additional strip at the end plates 6, 8.Thus, the slats 88 associated with modules 10 adjoining the end plates 6, 8 have securing means oriented towards an additional slat at one of their longitudinal ends and securing means oriented towards a slat 88 adjoining the other of their edges 54, 56, while the slats 88 associated with modules 10 arranged at a distance from the end plates 6, 8 comprise securing means oriented towards slats 88 adjoining their two edges 54, 56.

[0151] The securing means comprise more precisely at least one substantially flat arm 92 and a hook 94, with for example an arm 92 arranged on the first edge 54 and a hook 94 arranged on the second edge 56 of the strip 88. Each strip 88 here comprises two arms 92 and two hooks 94 distributed between the two edges 54, 56, with one arm 92 and one hook 94 for each peripheral zone 84. The arm 92 is similar to the tab 58 of the fourth embodiment.

[0152] In order to facilitate assembly between two adjacent strips 88 or between a strip 88 and an additional strip, in the fifth embodiment the electrical resistance 1 comprises at least one fixing flange 62. The electrical resistance 1 more specifically has a fixing flange 62 at each edge 54, 56 of the strips 88; in other words, a fixing flange 62 is interposed between the bodies of two adjacent strips 88. As a result, at least a portion of the fixing flanges 62 is arranged opposite the serrations 40 at the junction between the modules 10. As is particularly visible in FIG. 10, the securing means extend at least partially through the fixing flange 62.

[0153] The fixing flange 62 is generally square in shape when the cross-section of the electrical resistance 1 is square, as is the case in the fifth embodiment. It is substantially flat and extends mainly in a plane perpendicular to the virtual line forming the axis of the electrical resistance 1. The fixing flange 62 participates in connecting two strips 88 on the one hand, and in connecting these strips 88 to the modules 10 on the other hand. For this purpose, the fixing flange 62 comprises at least one retention finger 98 which extends in the plane perpendicular to the virtual line forming the axis of the electrical resistance 1. This retention finger 98 cooperates with the arm 92 and the hook 94 of the blades 88, the hook 94 being in abutment against the retention finger 98. Each fixing flange 62 here comprises four retention fingers 98, that is to say two retention fingers 98 for the internal blade 80A and two retention fingers 98 for the external blade 80B.The blade 80 being a spring-effect blade, it presses on the fixing flange 62 to press it against the modules 10 and as such participates in holding the electrical resistance 1. Cooperation between a blade 88 and two fixing flanges 62 is illustrated in figure 12, arrows illustrating the cooperation between the means for securing the blade 88 and the retention fingers 98 of the fixing flanges 62.

[0154] The electrical resistance 1 according to the invention will now be described according to a sixth embodiment illustrated in Figures 14 to 16. The electrical resistance 1 is here formed for example by six modules 10 arranged side by side from the first end 2 to the second end 4. The modules 10 extend between the two end plates 6, 8, which are here connected to each other outside the modules 10 by a metal structure 96.

[0155] Each module 10 here contains a plurality of metal elements in the form of folded metal blades 80 which participate in channeling the cooling fluid. As these metal blades 80, the electrical resistance 1 here comprises at least one slide 100 and a gutter 102 for each module 10. More precisely, the electrical resistance 1 has a single slide 100 and two gutters 102 for each module 10. A modular segment of the metal element is thus formed by an assembly comprising the slide 100 and the two gutters 102.

[0156] The slide 100 is a profile which is notably shown in Figure 16. It has a “U” shape, which is composed of a bottom 104 bordered by two arms 106, only one of these arms 106 being visible in Figure 16. The two arms 106 extend mainly in substantially parallel planes. The two arms 106 also extend mainly in planes substantially perpendicular to the bottom 104.

[0157] Free ends of the arms 106, which correspond to their ends furthest from the bottom 104, are pressed against the internal peripheral surface 16 of the module 10 over an entire longitudinal dimension of the slide 100. Such contact between the free ends of the arms 106 and the internal peripheral surface 16 of the module 10 makes it possible to promote heat transfers between these elements. The “U” shape of the slide 100 also makes it easier to channel the cooling fluid, which thus circulates in particular within a space delimited by the bottom 104, the two arms 106 and a half-internal peripheral surface 16 of the module 10.

[0158] At each longitudinal end of the slide 100, that is to say at the level of each edge or slice 54, 56 of a given modular segment, a notch 108 is formed in the bottom 104. This notch 108, which is visible in FIG. 16, has a shape complementary to a free end of a fixing crosspiece 110, the latter making it possible to ensure the mechanical connection between the different modules 10 and between the different modular segments and which will be described subsequently.

[0159] The bottom 104 is also pierced with at least one orifice which allows the passage of a fixing means 112, for example a screw or a rivet. This fixing means 112 makes it possible to secure the slide 100 to the gutters 102 as well as to secure the gutters 102 to each other.

[0160] Each gutter 102 has an “L” shape, with a contact wall 114 which extends substantially parallel to the bottom 104 of the slide 100 and a free wall 116 which extends along a plane intersecting the contact wall 114. Between them, the contact wall 114 and the free wall 116 form for example an obtuse angle.

[0161] The contact walls 114 of the two gutters 102 are superimposed on each other, so that one of the contact walls 114 is arranged between the other contact wall 114 and the bottom 104 of the slide 100. The contact wall 114 which is arranged between the other contact wall 114 and the bottom 104 of the slide 100 is also pressed against this bottom 104. Thus, the fixing means 112 passes through both the bottom 104 of the slide 100 and the contact wall 114 of each of the gutters 102.

[0162] When the two gutters 102 are assembled to each other, they have a section, when viewed perpendicular to the main elongation direction of the module 10, which is U-shaped. Indeed, the two gutters 102 are assembled in such a way that their free walls 116 are opposite each other on either side of the superposition formed by the two contact walls 114. It is understood from the above that the cooling fluid is channeled, in addition to the “U” shape of the slide 100, by the “U” shape resulting from the superposition of the two gutters 102.The cooling fluid is finally channeled on the one hand into a space delimited at least by the internal periphery 16 of the module 10 and by one of the arms 106 of the slide 102 and the free wall 116 of one of the gutters 102, and on the other hand into a space delimited at least by the internal periphery 16 of the module 10 and by the other arm 106 of the slide 102 and the free wall 116 of the other gutter 102.

[0163] Similar to the notches 108 of the slides 100, notches 118 are provided at each longitudinal end of the free walls 116 of the gutters 102, so as to cooperate with the fixing crosspiece 110.

[0164] In the sixth embodiment, the contact between the free ends of the arms 106 of the slide 100 is ensured using a spring element 120. This spring element 120 extends from one edge 54, 56 to the other of the modular segment. The spring element 120 has a bent central portion 122 which is arranged between two flared portions 124. One of the flared portions 124 is arranged at the first edge 54 of the modular segment while the other flared portion 124 is arranged at the second edge 56 of the modular segment. The central portion 122 bears against the contact wall 114 of one of the gutters 102; thus, when, due to the spring effect of the spring element 120, the central portion 122 pushes against the contact wall 144, this thrust force is transmitted to the slide 100 which is then pressed against the internal peripheral surface 16 of the module 10. According to an exemplary embodiment, the spring element 120 is a spring blade.The stress generated by the spring element 120 may result from a bend in the central portion 122.

[0165] At the junction between two modular segments, the fixing crosspiece 110 makes it possible to secure the different elements forming the electrical resistance 1. The fixing crosspiece 110 comprises four branches 126 which are arranged at right angles to each other and which meet at a central point 128. The fixing crosspiece 110 is thus, for example, a cross, for example with branches of identical length. The notch 108 of the slide 100 cooperates with one of the branches 126, while the notches 118 of the gutters 102 each cooperate with a branch 126 adjoining the branch 126 which cooperates with the notch 108. The last of the four branches 126 does not cooperate with the slide 100 and the gutters 102 but its free end is housed in a receiving zone 32.

[0166] One of the flared portions 124 of the spring element 120 cooperates with the fixing crosspiece 110 at its central point 128. More precisely, and as is particularly visible in FIG. 16, the central point 128 of the fixing crosspiece 110 is crossed by a fixing element 130 which also crosses the flared portion 124. The fixing element 130 is for example an assembly formed of at least one bolt formed of a screw and a nut, possibly with a lock nut.

[0167] The fixing crosspiece 110 helps to ensure the connection between two adjoining modules 10. It thus constitutes an alternative to the fixing flange 62 of the fourth embodiment and forms a fixing system between two adjacent modules 10. The fixing crosspiece 110 is arranged between two adjacent modules 10.

[0168] In order to avoid creating too large a spacing between two adjacent modules 10 due to the presence of the fixing crosspiece 110, reception zones 132 for the free ends of the branches 126 of the fixing crosspiece 110 are provided within the modules 10. These reception zones 132 are recesses made on the one hand radially from the internal peripheral surface 26 in the direction of the external peripheral surface 12, and on the other hand axially from the edges 26, 28 of the modules. These reception zones are each a notch provided in the module.

[0169] Thus, the fixing crosspiece 110 extends axially between a first contact face at least partially embedded in the second edge 28 of a given module 10 and a second contact face at least partially embedded in the first edge 26 of the adjacent module 10, said contact face forming a bottom of the notch.

[0170] The fixing crosspiece 110 is dimensioned so that free ends of its branches 126 extend radially between the external peripheral surfaces 12 and the internal peripheral surfaces 16 of two adjacent modules 10. It is understood from the above that a circumference of the fixing crosspiece 110 passing through the free ends of its four branches 126 is strictly greater than a circumference of the internal peripheral surface 16 of the module 10, but strictly less than a circumference of the external peripheral surface 12 of this module 10.

[0171] The metal structure 96 connecting the two end plates 6, 8 of the electrical resistance 1 according to the sixth embodiment will now be described in relation to FIG. 14. The metal structure 96 joins the first end 2 of the electrical resistance 1 and its second end 4; in other words, the metal structure 96 forms a mechanical connection between the two ends 2, 4 of the electrical resistance 1.

[0172] In addition to the connection between the two end plates 6, 8, the metal structure 96 also provides a connection with the cooling fluid inlet duct and the cooling fluid outlet duct to which the end plates 6, 8 are connected.

[0173] The coolant inlet and outlet conduits, like the metal structure 96, are electrically insulated with respect to the metal element which, in this sixth embodiment, is formed in particular by the slides 100 and the gutters 102. To do this, the electrical resistance according to the invention may comprise an electrical insulation device, the latter being able to take the form of at least one insulating plate 134 interposed between the fixing crosspiece 110 closest to one of the end plates 6, 8 and this end plate 6, 8. The electrical resistance 1 may further comprise another insulating plate 134 between the end plate 6, 8 and the coolant circulation conduit. This insulating plate 134 extends, for example, in a plane perpendicular to an axis of the coolant circulation conduit. The insulating plate 134 is, for example, made of mica or epoxy.It should be noted that the fixing elements, here screws, which pass through the end plates are also surrounded by an electrically insulating element, for example mica rings. Similarly, the electrical resistance 1 may comprise cover plates 136 which make it possible to reinforce the connection between the metal structure 96 and the rest of the electrical resistance 1, these cover plates 136 also being made of an electrically insulating material.

[0174] According to the invention, the electrical resistance 1 comprises at least one heat transfer device 70 intended to improve the heat exchanges between the winding 11 and the cooling fluid. This heat transfer device 70 extends at least partly within the volume 44 delimited by the modules 10; it is, depending on the embodiments, either partially arranged within this volume 44 and partially arranged in the thickness of the module 10, or arranged in its entirety within the volume 44.

[0175] In the fifth embodiment illustrated in Figures 9 to 13, the heat transfer device 70 corresponds to the bodies of the lamellae 88 which form the modular segments of the metal blade 80. In the sixth embodiment presented in Figures 14 to 16, the heat transfer device 70 comprises in particular the slides 100 and the gutters 102 which form the modular segments of the metal element.

[0176] In the second embodiment shown in Figure 3 and in the fourth embodiment illustrated in Figures 6 to 8, the electrical resistance 1 comprises, as its calorie transfer device 70, at least one fin 72 arranged within the metal tube 46. This fin 72 is for example a metal plate, in particular a copper plate, which is arranged radially in the metal tube 46. The fins 72 are four in number and are substantially straight in the second embodiment, while they are eight in number and are curved in the fourth embodiment.In this fourth embodiment, the fins 72 comprise a first portion 72A extending radially within the metal tube 46 towards the central axis thereof, and a second portion 72B curved so as to be in contact with the metal tube 46 and more specifically in contact with its internal face 52 in order to improve heat exchanges.

[0177] In the second embodiment visible in Figure 3, the electrical resistance 1 also comprises, as part of the heat transfer device 70, at least one folded flank 74. This folded flank 74 has a first segment 74A in contact with the metal tube 46 and more particularly its external face 50, as well as a second segment 74B arranged in the thickness of the module 10. The second segment 74B is more precisely arranged in a cavity 76 formed in the thickness of the module 10 between its external peripheral surface 12 and its internal peripheral surface 16. The first segment 74A is pressed against the metal tube 46 and the second segment 74B is pressed against a wall of the cavity 76, the folded flank 74 being compressed in order to be inserted into the cavity 76. The module 10 here comprises eight cavities 76, with four cavities 76 formed from its first edge 26 and four cavities 76 formed from its second edge 28.Each cavity 76 is configured to house the second segment 74B of a folded flank 74, so that each module 10 is associated with eight folded flanks 74. The cavities 76 are arranged within the module 10 between the chambers 30 intended to receive the holding members 24 and the conduits 36 dedicated to the cables 36 also participating in holding the modules 10 relative to each other.

[0178] For the third embodiment illustrated in Figure 4, the calorie transfer device 70 takes the form of at least one tab 78. The tab 78 comprises a first substantially planar part 78A which extends radially within the volume 44 delimited by the internal peripheral surfaces 16 of the modules 10, as well as a second corrugated part 78B which extends within a cavity 76 formed to receive it in the thickness of the module 10. In this third embodiment, the calorie transfer device 70 comprises eight tabs 78 arranged regularly within the module 8.

[0179] A method of assembling the electrical resistor 1 will now be described. This assembly method begins with a step of cutting the modules 10 from a tube of electrically insulating material. The resulting modules 10 have parallel edges 26, 28 if the electrical resistor 1 has a generally rectilinear shape, or edges 26, 28 extending in intersecting planes if it has a generally toroidal shape. For the fourth embodiment, the assembly method also comprises a step of cutting the modular segments 48 from a metal tube or blade; in the same way as for the modules 10, the modular segments 48 have, in the case of a metal tube 46, parallel edges 54, 56 if the electrical resistor 1 has a generally rectilinear shape, while they have edges 54, 56 extending in intersecting planes if its general shape is toroidal.

[0180] After the step of cutting the modules 10, the assembly method comprises a step of assembling these modules 10. This assembly step corresponds to a step of assembling the modules 10 to each other. For the first, second, fourth, fifth and sixth embodiments, it further comprises a sub-step of assembling the modules 10 to the metal element, i.e. to the metal tube 46 or to the metal blade 80.

[0181] In the context of the sixth embodiment, the step of assembling the modules 10 comprises a sub-step of assembling the slide 100 to the gutters 102, so as to form the metal element. The slide 100 and the gutters 102 are secured to each other using the fixing means 112 which pass through them. Once secured, the slide 100 and the gutters 102 are inserted within a given module 10, penetrating its internal volume through one or other of the edges 26, 28 of the modules 10, then the spring element 120 is also arranged within the module 10. The fixing crosspieces 110 are inserted into the receiving zones 132 formed in the edges 26, 28 of the modules 10.If necessary, a sealing member may be previously deposited within these reception zones 132 and / or on the edge of the module formed by the edge 26, 28, in order to improve the mechanical maintenance of the electrical resistance 1 and to perfect its sealing with respect to the cooling fluid.

[0182] The complementarity of shapes between the notch 108 of the slide 100 and the notches 118 of the gutters 102 on the one hand and the branches 126 of the fixing crosspiece 110 on the other hand makes it possible to ensure their correct positioning. The spring element 120 is then secured to the fixing crosspiece 110 by means of the fixing element 130. During the assembly step, the modules 10 are arranged side by side, if necessary around the metal tube 46 or the metal blade 80, and are secured at their serrations 40 or more generally at their edges 26, 28. The sub-step of assembling the modules 10 to the metal element is characterized, when this metal element is in the form of modular segments 48 as is the case in the fourth, fifth and sixth embodiments, by the at least partial pressing of a given modular segment 48 against the internal peripheral surface 16 of the module 10 with which it is associated.For the metal tube 46, such plating results from the rotation of a flange 62 relative to the modular segment 48, as explained above. For the metal blade 80 of the fifth embodiment, the plating occurs along a rib 17 forming a projection within an internal peripheral surface 16. For the metal element of the sixth embodiment, which corresponds to the assembly formed by the slide 100 and the gutters 102, the plating is permitted thanks to the spring element 120 which presses, at its central portion 122, on the gutters 102 which themselves press on the slide 100, the latter coming into contact with the internal peripheral surface 16 of the corresponding module 10.

[0183] The assembly step further comprises a sub-step of positioning the at least one calorie transfer device 70, such a positioning sub-step being prior to the assembly of the modules 10 with each other. This calorie transfer device 70 can be positioned within the metal tube 46.

[0184] Alternatively or additionally, and in particular within the framework of the second embodiment of the electrical resistance 1, the cavity 76 intended to receive this calorie transfer device 70 is filled with a sealing member, by injection by syringe for example, then the calorie transfer device 70 is inserted within the sealing member in a compressed form in order to be optimally pressed against the cavity 76 when it is released.

[0185] Once the calorie transfer device 70 is in position, the modules 10 are joined end to end. For this purpose, the modules 10 cooperate by means of their articulation means 22 in the first embodiment, or by means of their holding members 24 as described previously in relation to the fourth embodiment or fixing crosspieces 110 as detailed in relation to the sixth embodiment. Each module 10 is thus assembled to at least one adjacent module 10, and possibly to one of the end plates 6, 8.

[0186] Once the modules 10 have been assembled, the assembly method continues in certain embodiments with a step of covering these modules 10 with the sealing member. The sealing member is deposited in a layer around the external peripheral surfaces 12 of the modules 10, as well as in the space 68 delimited by a flange 62 and two adjacent modules 10 for the fourth embodiment. The covering step may comprise a smoothing sub-step, in order to obtain a surface of the electrical resistance 1 suitable for receiving the winding 11.

[0187] The assembly method ends with a winding step during which this winding 11 is wound in turns around the modules 10, or even around the sealing member if necessary. The winding 11 has a binding effect around the modules 10, holding their half-shells 18 in position when these modules 10 are not in one piece. A new covering step can take place to cover the winding 11 with a new layer of sealing member. As mentioned previously, in certain embodiments the modules 10 have grooves at the level of their serrations 40. The sealing member then penetrates into the grooves and makes it possible to secure the adjoining modules 10 to each other so as to reinforce the assembly of the electrical resistance 1.Either the modules 10 have grooves on the entirety of their external peripheral surfaces 12, or the external peripheral surfaces 12 are devoid of grooves both on their face which receives the contact device and the face which is opposite it or even these external peripheral surfaces 12 are devoid of grooves on the flat portion 14 provided for the movement of this contact device. In addition, at the interfaces between the modules 10 and the end plates 4, 6, the sealing member is inserted, within the portion provided with open zones of the metal collars which ensure the electrical contacts between the modules 10 and the end plates 4, 6. The sealing member, by crossing these open zones, thus reaches the grooves which it fills.

[0188] The present invention thus proposes a modular electrical resistance for which the management of heat dissipation is facilitated by the presence of a volume configured for the circulation of a cooling fluid within the electrical resistance.

[0189] The present invention cannot, however, be limited to the means and configurations described and illustrated here and it also extends to any equivalent means and configuration as well as to any technically effective combination of such means.

Claims

CLAIMS 1. Electrical resistance (1) having a generally toroidal shape, extending between a first end (2) and a second end (4), comprising a plurality of modules (10) made of an electrically insulating material and a winding (11) wound in turns around the modules (10), each of the modules (10) having an external peripheral surface (12) and an internal peripheral surface (16), the modules (10) being arranged side by side from the first end (2) to the second end (4) of the electrical resistance (1) delimiting a volume (44) configured for the circulation of a cooling fluid.

2. Electrical resistance (1) according to claim 1, comprising a contact device bearing against the winding (11) and movable between the first end (2) and the second end (4) of the electrical resistance (1).

3. Electrical resistance (1) according to any one of claims 1 or 2, comprising a metallic element (46, 80) arranged within the volume (44) delimited by the modules (10), the metallic element (46, 80) being configured to channel the cooling fluid.

4. Electrical resistance (1) according to claim 3, in which the metallic element (46, 80) is at least partially pressed against at least one of the internal peripheral surfaces (16) of the modules (10).

5. Electrical resistance (1) according to any one of claims 1 to 4 in combination with claim 3, wherein the metallic element (46, 80) is composed of a plurality of modular segments (48, 88).

6. Electrical resistance (1) according to any one of claims 1 to 5 in combination with claim 3, in which the metallic element (46, 80) is a metallic tube (46).

7. Electrical resistance (1) according to claim 3, in which the metallic element (46, 80) is a metallic blade (80, 80A, 80B).

8. Electrical resistance (1) according to claim 3, in which the metallic element (46, 80) is formed by an assembly comprising at least one slide (100) and at least two gutters (102).

9. Electrical resistance (1) according to any one of claims 1 to 8 in combination with claim 5, in which each modular segment (48) is associated with a module (10).

10. Electrical resistance (1) according to claim 9, in which at least one of the modular segments (48) is delimited axially by a first slice (54) and a second slice (56), the modular segment (48) comprising securing means (58, 60, 92, 94) formed from at least one of the slices (54, 56).

11. Electrical resistance (1) according to any one of claims 1 to 10, comprising a fixing system which mechanically connects two adjacent modules (10).

12. Electrical resistance (1) according to claim 11 in combination with claim 5, in which the fixing system comprises a fixing flange (62) arranged at a junction between two adjacent modular segments (48, 88), the securing means extending at least partially through this fixing flange (62).

13. Electrical resistance (1) according to claim 11, in which the fixing system comprises a fixing crosspiece (110) arranged at a junction between two adjacent modules (10).

14. Electrical resistance (1) according to any one of claims 1 to 13 in combination with claim 7, in which at least one opening (86) is provided within the metal blade (80, 80A, 80B).

15. Electrical resistor (1) according to any one of claims 3 or 4, in which the metallic element (46, 80) is in one piece from the first to the second end (4) of the electrical resistor (1).

16. Electrical resistance (1) according to any one of claims 1 to 15, comprising at least one calorie transfer device (70) which extends at least partly within the volume (44) delimited by the modules (10).

17. Electrical resistance (1) according to any one of claims 1 to 16, in which at least one of the modules (10) is composed of at least two shells (18).

18. Electrical resistance (1) according to any one of claims 1 to 16, in which the modules (10) are annular sections (20).

19. Electrical resistance (1) according to any one of claims 1 to 18, in which the general toric shape of the electrical resistance (1) is of square section.

20. Electrical resistance (1) according to any one of claims 1 to 19, in which at least one of the modules (10) has serrations (40) complementary to an adjacent module (10).

21. Electrical resistance (1) according to any one of claims 1 to 20, comprising a first end plate (6) associated with the first end (2) and a second end plate (8) associated with the second end (4).

22. Method for assembling an electrical resistance (1) according to any one of claims 1 to 21, comprising a step of assembling the modules (10) during which the modules (10) are joined end to end and a winding step during which the winding (11) is wound in turns around the modules (10).

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