Improved cooling electromagnetic device

Abstract

An improved cooling electromagnetic device comprising a magnetic core (10) with at least one electrically conductive winding (20) and at least one slot (11) dividing the magnetic core (10) into several independent magnetic core portions (10'), and at least one cooling structure (30) comprising a heat sink (32) in thermal connection with at least one thermally conductive element (31) comprising a flat wall made of a non-magnetic metal tightly inserted into one of the slots (11) of the magnetic core (10); wherein the cooling structure (30) further comprises cooling channels connected to a cooling circuit, the cooling channels being defined in the heat sink and / or in the part of the at least one thermally conductive element (31) of the cooling structure (30);and the cooling channels comprising several parallel bores (61) and at least one transverse bore (62) intercepting these several parallel bores (61) and connecting them together.;

Description

Title of the invention: Electromagnetic device with improved cooling Technical field

[0001] The present invention relates to an electromagnetic device with improved cooling.

[0002] The electromagnetic device comprises a magnetic core around which an electrically conductive winding is wound. The improved cooling is achieved by at least one cooling structure comprising a thermally conductive element, made of a non-magnetic material, in intimate contact with a heat sink, the thermally conductive element comprising a flat wall inserted by interference fit into a slot in the magnetic core which divides the magnetic core into two independent magnetic core portions. BACKGROUND OF THE INVENTION

[0003] In order to remove heat (produced by generated eddy currents) from the core of the magnetic power group, particularly in the case of power transformers, several approaches have been considered. Examples include increasing the wire size to reduce resistive losses; immersing the transformer in circulating cooling oil; air cooling the transformer windings; increasing the operating frequency of the transformer to reduce windings; and increasing the thermal conductivity of the insulating compound surrounding the transformer windings. However, these solutions negatively impact the size and weight of transformer designs, limiting the use of these applications. Without proper cooling, the efficiency and reliability of these transformers and inductors are significantly reduced.

[0004] Document DE19814896 discloses a high current power transformer comprising a closed cylindrical core made of soft magnetic material with high permeability, high saturation induction and low magnetic losses. This is surrounded by a primary winding and a secondary winding. The core is inside a casing which is then filled with a suitable resin. At least one heat tube (9) for cooling the group is placed in the middle. The heat tube constitutes at least part of the transformer winding.

[0005] Since the contact surface between the conduit and the magnetic core is reduced, it is therefore necessary to circulate a refrigerant fluid in the tube in order to increase the cooling, making this solution more complex and increasing its cost.

[0006] Document US6777835B1 discloses an electrical power cooling technique, and in particular an apparatus for cooling a high power electrical transformer and electric motors by means of a thermally conductive material sandwiched between the layers of turns of a high power transformer and iron core lamination materials, so as to provide a thermal path with low resistance to the environment. The laminations conduct excess heat from the interior to projections outside the windings (and core), the heat then being extracted either by forced air or by the thermally conductive potting compound. This technique offers a considerable reduction in weight and size, as well as a significant increase in power density, while being conducted at a temperature slightly above ambient temperature.In one embodiment, a transformer is made of a material such as laminated iron, ferrite and other core materials, and the transformer is constituted by insulated copper windings wound around the core. Heat is dissipated through the core to a base plate, while thermally conductive lamellae are arranged in predetermined positions between the windings and are preferably made of high modulus flake graphite material, so as to conduct heat according to its fiber orientation, which is unidirectional.

[0007] Document US2004257187 A1 discloses an electromagnetic device, comprising a first tubular magnetic core section; a second tubular magnetic core section spaced apart and in substantially parallel alignment with the first tubular magnetic core section and a primary conductive winding, wherein a first portion of the primary conductive winding is disposed in the first tubular magnetic core section and a second portion of the primary conductive winding is disposed in the second tubular magnetic core section. The magnetic device further comprises heat extraction means with conductive elements, such as cooling fins, in communication with at least a portion of the outer surface of the first tubular magnetic core section and at least a portion of the outer surface of the second tubular magnetic core section.

[0008] Document US2015155088A1 discloses a heat dissipation structure of a transformer for dissipating heat generated from a core of the transformer, comprising a heat dissipation plate having a bottom plate assembled in a housing of the transformer and an extended plate extending upwardly from the bottom plate. The extended plate has a center plate and a pair of side plates each arranged on an opposite side of the center plate. The pair of side plates are spaced apart from the center plate.

[0009] Document CN113257545A relates to a high-power, high-efficiency, high-frequency transformer comprising an aluminum plate radiator comprising a first aluminum plate, a second aluminum plate and a third aluminum plate arranged one behind the other.

[0010] Document GB2597670A1 relates to the thermal management of an electromagnetic device such as a transformer, comprising a core assembly, windings 204, a primary thermally conductive plate and several secondary thermally conductive plates.

[0011] All of the above documents include a cooling structure on one side of the electromagnetic device, causing uneven cooling of the magnetic core.

[0012] The present invention solves the above-mentioned and other problems. DESCRIPTION OF THE INVENTION

[0013] The present invention relates to an electromagnetic device with improved cooling, as defined in claim 1.

[0014] The recommended electromagnetic device comprises, in a manner known per se from the available state of the art: a magnetic core around which is wound, around a central axis, at least one electrically conductive winding, the magnetic core having at least one slot, parallel to the central axis and dividing the magnetic core into several independent magnetic core portions, and at least one cooling structure each comprising a heat sink in thermal connection with at least one thermally conductive element, each thermally conductive element comprising a flat wall, made of a non-magnetic metal, inserted by press-fitting into one of the slots of the magnetic core in thermal connection with the magnetic core portions.

[0015] The thermal conductive element is an element made of a non-magnetic material, not interfering with the magnetic fields generated at the electromagnetic device during its operation, and having a high conductivity, for example, greater than 120 W / mK, greater than 160 W / mK, or preferably greater than 210 W / mK. Typically, the thermal conductive element will be made of a non-magnetic metal such as aluminum or an aluminum alloy.

[0016] The intimate contact between the thermally conductive element and the at least one dissipation surface of the magnetic core allows heat transfer from the magnetic core, where it is generated when the electromagnetic device is in operation, up to the thermal conductive element.

[0017] Further, the intimate contact between the thermally conductive element and the heat sink allows said heat to be transferred from the thermally conductive element to the heat sink, from which the heat is dissipated.

[0018] The heat sink will also be made of a material with high thermal conductivity, for example, greater than 120 W / mK, greater than 160 W / mK, or preferably greater than 210 W / mK. Typically, the heat sink will be made of a non-magnetic metal such as aluminum or an aluminum alloy.

[0019] Preferably, the heat sink will have a dissipation arrangement in contact with a refrigerant, for example, the surrounding air, but it may also be a refrigerant liquid from a cooling circuit.

[0020] The dissipation arrangement may include, for example, a surface provided with notches, ribs, rods, or any other surface-enlarging arrangement intended to increase the surface area of the heat sink exposed to the refrigerant.

[0021] Thermal bonding means physical contact between the elements which allows heat transfer between them by conduction, or contact by means of an interposed heat transfer means, such as a heat-conducting composition, allowing heat transfer between them by conduction through said heat transfer means.

[0022] There will be a thermal bond, for example, between parts of the same object in a single piece, between two welded components, or between two superimposed surfaces without gaps between them, or between two superimposed surfaces without gaps between them but having a heat-conducting composition interposed so as to fill any irregularities, thus increasing the overall thermal conductivity. The heat-conducting composition is preferably a paste capable of being coated and having a high thermal conductivity, for example, greater than 5 W / mK, greater than 10 W / mK, or preferably greater than 40 W / mK.

[0023] According to the present invention, the thermally conductive element comprises a flat wall inserted by press-fitting into a slot of the magnetic core, said slot dividing the magnetic core into at least two independent magnetic core portions. Preferably, said slot divides the region of the magnetic core surrounded by the electrically conductive winding, so that the at least one thermally conductive element is inserted into said region of the magnetic core surrounded by the electrically conductive winding.

[0024] In accordance with the above, the magnetic core will be divided into at least two independent magnetic core portions oriented relative to each other, defining a slot between them, and it is proposed that the conductive element thermal comprises at least one portion configured as a flat wall inserted by press fit into said slot of the magnetic core, between the at least two independent magnetic core portions.

[0025] This construction remarkably increases the contact surfaces between the dissipating magnetic core and the thermal conductive element, thus increasing the cooling of the electromagnetic device.

[0026] Preferably, the magnetic core portions are oriented relative to each other by means of corresponding dissipation surfaces, and therefore the slot will be provided between said dissipation surfaces. The thermally conductive element will have two opposite main surfaces, corresponding to the two opposite main surfaces of the flat wall conformation, each of them being in intimate contact with one of said dissipation surfaces.

[0027] The present invention also proposes, in an unknown manner, the following: the cooling structure also comprises cooling channels connected to a cooling circuit, the cooling channels being provided on the heat sink and / or on the portion of the at least one thermally conductive element of the cooling structure; and the cooling channels comprise several parallel bores and at least one transverse bore intersected with said several parallel bores so as to connect them together.

[0028] The cooling channels may be connected to a cooling circuit, preferably comprising a refrigerant pump.

[0029] At least some of the parallel bores may be blind bores provided on the at least one thermally conductive element of the cooling structure. Said blind bores may have an inner wall inserted therein by interference fit, the inner wall longitudinally dividing the blind bore into two channels and defining a connection between these two channels in a lower part of the blind bore.

[0030] At least some of the cooling channels may be provided on the flat wall inserted into the slot, when the latter is sufficiently thick, or may be provided on portions of the thermally conductive elements external to the slot, which constitute external thermally conductive elements, being in thermal connection with the flat wall inserted by tight fitting into the slot.

[0031] It is proposed, for example, to provide cooling channels on bulging portions of the external thermally conductive elements, thicker than the flat wall inserted into the slot of the magnetic core.

[0032] Said bulging portions, which may be configured in the form of a pillar, will be thermally connected to the edges of the flat walls inserted into the slot of the magnetic core either directly or through the interposed external thermal conductive element, also configured as flat walls perpendicular to the flat wall inserted into the slot.

[0033] Optionally, the cooling structure may be divided into two half-parts, superimposed in the direction of the central axis, each half-part comprising a heat sink and a portion of the thermal conductive elements thermally connected to the corresponding heat sink. In this embodiment, the passage of induction currents through the cooling structure will be prevented by means of an air gap, or an electrical insulator, located between the portions of the thermal conductive elements surrounded by the electrically conductive winding and / or between the portions of the cooling structure surrounding the electrically conductive winding.

[0034] According to the above, the cooling structure comprises at least two heat sinks, each being integrated in each half-part of the cooling structure, and the at least one thermal conductive element is divided into at least two independent portions, each portion being in thermal connection with one of the heat sinks.

[0035] The two half-parts of the cooling structure are superimposed in the direction of the central axis, so that the portions of the at least one thermal conductive element of one half-part are separated from the portions of the other half-part by a separation transverse to the direction of the central axis.

[0036] Preferably, the at least one thermally conductive element is inserted into the region of the magnetic core surrounded by the electrically conductive winding, and the cooling structure may also externally surround the magnetic device. In this case, undesirable induction currents may be generated through the cooling structure if it is made of an electrically conductive material, such as aluminum or an aluminum alloy.

[0037] In order to prevent these induction currents, a circular electrical circuit having a region surrounded by the electrically conductive winding is to be avoided. In order to prevent these induction currents, an interruption of the electrical connection between the portions of the at least one thermally conductive element is provided, by means of an air gap or an electrical insulator, in the region of the magnetic core surrounded by the electrically conductive winding.

[0038] In addition or as a variant, the interruption of the circular circuit, in order to avoid induction currents, can be obtained by interrupting the electrical connection between the two half-parts of the cooling structure at the region of the cooling structure not surrounded by the electrically conductive winding. In this case, the induction currents will be prohibited even if the portions of the at least one thermal conductive element surrounded by the electrically conductive winding are electrically connected.

[0039] According to one embodiment of the invention, the flat wall provided on the at least one thermally conductive element is parallel to the central axis around which the at least one electrically conductive winding is wound.

[0040] The at least one thermal conductive element may comprise several parallel thermal conductive elements, dividing the magnetic core at at least two parallel slots.

[0041] Alternatively, the at least one thermal conductive element may comprise one or more parallel thermal conductive elements, dividing the magnetic core at at least two parallel slots, and one or more thermal conductive elements perpendicular to the aforementioned thermal conductive elements, further dividing the magnetic core at at least one additional slot perpendicular to the aforementioned at least two parallel slots.

[0042] Each heat sink may be, for example, a housing accommodating the magnetic core, or a portion of said housing. The outer walls of the housing may, for example, dissipate heat to the surrounding air, which acts as a heat sink.

[0043] The thermal conductive elements may further comprise external thermal conductive elements, made of a non-magnetic metal and being in thermal connection with the heat sink, positioned adjacent to the outside of the magnetic core, in thermal connection with the magnetic core and / or in thermal connection with the flat wall inserted by interference fit into one of the slots of the magnetic core. According to this embodiment, the external thermal conductive element will be in thermal connection with the outside of the magnetic core, directly or via an interposed heat transfer means, which removes heat from the outside of the magnetic core to the heat sink, and / or will be in thermal connection with at least one flat wall inserted by interference fit into a slot of the magnetic core, so as to assist the flat wall in removing heat from the inside of the magnetic core to the heat sink.

[0044] The thermal conductive element and the heat sink may be part of the single monobloc element constituting the cooling structure. Thus, the production thereof is simplified and the heat transfer between the thermal conductive element and the heat sink is improved.

[0045] Each half-part of the cooling structure may, for example, be made of a non-magnetic cast metal, a non-magnetic cast aluminum, or a non-magnetic cast aluminum alloy. Casting each half-part of the cooling structure allows for the creation of customized configurations. capable of increasing heat dissipation and / or reducing manufacturing costs of the electromagnetic device, while making assembly thereof easier and simpler. Preferably, each half-part of the cooling structure will have a shape capable of being manufactured in a two-part mold.

[0046] Alternatively, each half-part of the cooling structure may be made of a non-magnetic extruded metal, a non-magnetic extruded aluminum, or a non-magnetic extruded aluminum alloy that is extruded in a direction perpendicular to the central axis. In this case, the portions of the thermally conductive element of each half-part of the cooling structure will be a flat wall or several flat walls parallel to each other, so as to allow them to be made by extrusion, but the portions of the thermally conductive element of the two half-parts of the cooling structure may be parallel or perpendicular to each other.

[0047] The production of each half-part of the cooling structure by an extrusion process remarkably increases the production rate, while reducing its cost, and allows high dimensional accuracy of the parts obtained. In this case, the cooling structure will have a constant cross-section along its entire length, or a constant cross-section along its entire length, including certain parts thereof removed by milling.

[0048] It is well known that aluminum and many aluminum alloys are non-magnetic materials and have high thermal conductivity.

[0049] According to the present invention, the heat sink is a housing, or a portion of a housing, of the electromagnetic device. In accordance with the above, the electromagnetic device will be housed in a housing, typically a rigid housing intended to protect it, and the heat sink will consist of the entire housing or a portion thereof, the thermally conductive element being arranged in intimate contact with said housing or with a part thereof. The walls of the housing ensuring the dissipation of heat, said walls are therefore part of the cooling structure.

[0050] According to one embodiment of the invention, a thermally conductive composition surrounds the magnetic core and the at least one electrically conductive winding wound around the magnetic core. The thermally conductive composition will also be in intimate contact with one side of the heat sink, so as to transfer heat from the thermally conductive composition to the heat sink, an opposite side of which will preferably remain uncovered to dissipate the heat. When the heat sink is a housing or a portion of a housing of the electromagnetic device, the thermally conductive composition will be contained in said housing, preferably cast therein.

[0051] Preferably, the thermally conductive composition comprises a mixture of a silicone resin and at least one first filler or a silicone resin and a first filler including a natural mineral filler. Optionally, the thermally conductive composition further comprises a second filler including aluminum hydroxide.

[0052] According to an additional embodiment, the magnetic core may further comprise a magnetic gap, perpendicular to the slot, intended to increase the magnetic performance of the magnetic core, said gap entirely dividing each of the independent magnetic core portions into two independent sections.

[0053] The magnetic core may comprise, for example, a central region of prismatic or cylindrical shape elongated in a direction parallel to the central axis, the at least one electrically conductive winding being wound around said central region. Said central region of the magnetic core will be divided by the slot.

[0054] Optionally, the magnetic core further comprises an armature region surrounding a central opening, the central region of the magnetic core being arranged in said central opening, connected to the armature region of both ends and dividing the central opening in two. Said armature region of the magnetic core will also be divided by the slot.

[0055] The at least one electrically conductive winding may be wound around a coil interposed between the at least one electrically conductive winding and the magnetic core.

[0056] It will be understood that references to geometric position, such as parallel, perpendicular, tangent, etc., allow for deviations of up to plus or minus 5° from the theoretical position defined by these terms.

[0057] It will also be understood that over any given range of values, it is possible that the limit values are not optimal, and adaptations of the invention would possibly be required in order for these limit values to be applicable, such adaptations being within the reach of those skilled in the art. BRIEF DESCRIPTION OF THE FIGURES

[0058] The above and other advantages and features will be better understood from the following detailed description of one embodiment with reference to the accompanying drawings, which should be taken for illustrative and non-limiting purposes, in which:

[0059] [Fig.l] shows an exploded perspective view of the electromagnetic device according to an embodiment in which the cooling structure comprises a heat sink, and a thermal conductive element having two flat walls perpendicular to each other and inserted into two perpendicular slots of the magnetic core, as well as two bulges, in the form of parallel pillars to the central axis, attached to the ends of one of the flat walls, the cooling structure comprising cooling channels passing through the heat sink and passing through said pillars, so as to generate active cooling of the cooling structure.

[0060] [Fig.2] shows a perspective view of the electromagnetic device shown in [Fig.l], in which the magnetic core is divided by a slot, parallel to the central axis, and a gap perpendicular to said central axis, the cooling structure and the conductive composition not being visible in this figure.

[0061] [Fig. 3] shows an exploded perspective view of the electromagnetic device according to an alternative embodiment similar to that shown in [Fig. 1], in which the cooling structure comprises two half-parts, the lower half-part being equal to that described in [Fig. 1], and the upper half-part comprising an additional heat sink and two mutually perpendicular flat walls, the upper half-part being devoid of cooling channels.

[0062] Figures 4 and 5 show a vertical cross-section of the thermal conductive element shown in [Fig.3] coplanar with the central axis, representing the exploded view in [Fig.4] and the assembled view in [Fig.5].

[0063] [Fig. 6] shows an exploded perspective view of the electromagnetic device according to an alternative embodiment similar to that shown in [Fig.3], wherein each half-portion of the cooling structure has a flat wall, and wherein the lower half-portion of the cooling structure comprises, at the four corner regions surrounding the magnetic core, four bulges of the thermal conductive element in the form of pillars parallel to the central axis, said pillars being thermally connected to the ends of said flat wall by an interposed external thermal conductive element configured in the form of a flat wall perpendicular to the flat wall inserted in the slot of the magnetic core, and wherein this lower half-portion further comprises cooling channels passing through the heat sink and passing through said pillars, so as to generate active cooling of the cooling structure.

[0064] Detailed description of the invention and particular embodiments

[0065] The present invention relates to an electromagnetic device comprising a magnetic core (10), having an electrically conductive winding (20) wound around a central axis (X) surrounding the magnetic core (10) or a portion thereof, and a cooling structure (30) in intimate contact with the magnetic core (10).

[0066] The magnetic core (10) is composed of several independent magnetic core portions (10'), oriented relative to each other by means of surfaces of corresponding dissipation parallel to the central axis (X), so as to provide a slot (11) between them.

[0067] The magnetic core (10) may also be divided by a gap (12) perpendicular to the central axis, in order to improve the magnetic performance of the device.

[0068] For example, in the embodiment shown in [Fig.3], the magnetic core comprises two slots (11) parallel to the central axis (X) and perpendicular to each other, and a gap (12) perpendicular to the central axis, dividing the magnetic core (10) into eight magnetic core portions (10').

[0069] The non-magnetic thermally conductive element (31) may comprise cooling channels connected to a cooling circuit, which preferably comprise a coolant pump. Optionally, the cooling channels may also be provided at the heat sink.

[0070] At least some of the cooling channels may be provided on the flat wall inserted into the slot (11), when the latter is sufficiently thick, or may be provided on external thermally conductive elements in thermal connection with the flat wall inserted by tight fitting into the slot (11).

[0071] It is proposed, for example, to provide cooling channels on bulging portions of the external thermally conductive elements, thicker than the flat wall inserted into the slot (11) of the magnetic core (10).

[0072] Said bulging portions, which may be configured in the form of a pillar, will be thermally connected to the edges of the flat walls inserted in the slot of the magnetic core (10) either directly or via the interposed external thermal conductive element, also configured in the form of flat walls perpendicular to the flat wall inserted in the slot (11).

[0073] The cooling channels may comprise several parallel bores (61) and at least one transverse bore (62) intersected with said several parallel bores (61) so as to connect them together.

[0074] Preferably, at least some of the parallel bores (61) are blind bores, typically parallel to the central axis (X), provided on the portion of the at least one thermally conductive element (31) of at least one of the half-parts of the cooling structure (30). Each blind bore will have an inner wall (63) inserted by press-fitting therein and connected to a cover attached to the open end of each blind bore, for example by threading, so that the inner wall (63) longitudinally divides the blind bore into two channels and defines a connection between these two channels in a lower part of the blind bore, thus generating a cooling effect over the entire length of the blind bore.

[0075] Typically, the internal wall (63) is shorter than the blind hole in which it is inserted, or it has a transverse opening at its distal end, so as to create on each blind hole said two parallel channels, one being connected to a segment of the transverse hole and the other being connected to the other segment of the transverse hole, so as to force the refrigerant fluid towards the lower part of each blind hole.

[0076] According to one embodiment, the blind bores pass through the heat sink (32), having an open end on a side of the heat sink (32) opposite the side of the heat sink connected to the thermal conductive element (31). These parallel bores (61) are aligned and intersected, at a region adjacent to the open end thereof, by a transverse bore (62) which, in this embodiment, is coplanar and perpendicular to the parallel bores (61), said transverse bore passing entirely through the heat sink (32) connected thereto.

[0077] The cooling structure (30) may comprise two half-parts superimposed in the direction of the central axis, each half-part comprising a heat sink (32) in thermal connection with a portion of the thermal conductive element (31). Preferably, each half-part of the cooling structure is a single-piece metal element made from cast iron or extrusion or assembled by welding.

[0078] One or both half-portions of the cooling structure may comprise cooling channels. For example, even if in the embodiments shown in Figures 3 and 6 the cooling circuit is present only on the lower half-portion of the cooling structure, the two half-portions may have similar or symmetrical configurations comprising cooling channels.

[0079] The portion of the thermal conductive element (31) inserted by press fit into the slot (11) is configured as a flat wall, being in intimate contact with the dissipation surfaces of each of the independent magnetic core portions (10'), i.e., with each major surface of the flat wall being in intimate contact with one of the dissipation surfaces.

[0080] The non-magnetic thermally conductive element (31) of the two half-parts of the cooling structure is interrupted by an air gap, or by an electrical insulator, so as to avoid electrical contact between the two half-parts of the cooling structure through the portion inserted into the magnetic core (10) and surrounded by the electrically conductive winding (20).

[0081] According to the embodiment shown in [Fig.2], each half-part of the heat sink (32) is configured as a partially open housing upper, forming a portion of a housing intended for the electromagnetic device, in the center of which stands the flat wall, perpendicular to the base of said housing, said flat wall constituting a portion of the non-magnetic thermally conductive element (31) inserted in the core.

[0082] In this embodiment, the electromagnetic device comprises two symmetrical cooling structures, each defining a half portion of the housing, such that, when the electromagnetic device is assembled, the combination of the two heat sinks (32) forms a housing that fully encloses the electromagnetic device.

[0083] According to this first embodiment, said housing is filled with a thermally conductive composition (40) in which the magnetic core (10) and the electrically conductive winding (20) are embedded, so as to further increase the thermal transmission of heat also through said thermally conductive composition (40) from the magnetic core (10) to the heat sink (32).

[0084] In the second embodiment, each half-part of the cooling structure comprises a heat sink (32) defining only a base plate or a top plate, which may form part of a housing after assembly of additional walls, or it may be a simple base plate or top plate intended to support all the components of the electromagnetic device and to facilitate the fixing of the latter on a support, for example, using screws which are inserted into through holes provided on said base plate and top plate.

[0085] Said plate may also comprise, on only two sides thereof, side walls parallel to the thermal conductive element, the side walls providing a more secure housing than the base plate alone and being able to come from the same material as the flat wall by an extrusion process.

[0086] According to the second embodiment, the thermally conductive composition (40) is cast and then allowed to harden between the heat sinks of the cooling structure (30).

[0087] Optionally, each half-part of the cooling structure comprises at least one flat wall and two side walls parallel to said at least one flat wall, the flat wall and the side walls of one half-part being perpendicular to the flat wall and the side walls of the other half-part, so that the device is entirely enclosed by the two side walls of one half-part and the other two side walls of the other half-part while being framed by four side walls and two heat sinks, while each half-part is produced economically and easily by extrusion.

[0088] According to a preferred embodiment, the magnetic core has a central region, elongated in the direction of the central axis (X), housed in a central opening of an armature region and connected by its ends to said armature region. The electrically conductive winding (20) is wound around the central region, for example, on a coil 50 interposed between the electrically conductive winding (20) and the central region of the magnetic core (10).

[0089] The central region may have a cylindrical or prismatic shape such as a cube-like shape.

[0090] Although in both embodiments the slot (11) vertically divides the central region as well as the armature region in two, in the first embodiment the slot (11) transversely divides the armature region into two C-shaped portions, and in the second embodiment the slot (11) longitudinally divides the armature region into two thinner armatures, each half-portion of the thermal conductive element having an E-shape for insertion not only into the central region of the magnetic core, but also between the thinner armatures. In this case, each half-portion of the thermal conductive element (31) will have an upper edge, remote from the heat sink (32) connected thereto, having an E-shaped profile defining a central projection inserted into the central region of the magnetic core, and two lateral projections inserted into the armature region of the magnetic core at a distance from the central region.This embodiment is visible in Figures 4 and 5.

[0091] In both embodiments, the gap (12) horizontally divides the central region and the reinforcement region in two.

Claims

Claims

1. An electromagnetic device with improved cooling comprising: a magnetic core (10) around which is wound, around a central axis (X), at least one electrically conductive winding (20), the magnetic core (10) having at least one slot (11), parallel to the central axis (X) and dividing the magnetic core (10) into several independent magnetic core portions (10'), and at least one cooling structure (30) each comprising a heat sink (32) in thermal connection with at least one thermally conductive element (31), each thermally conductive element (31) comprising a flat wall, made of a non-magnetic metal, inserted by press-fitting into one of the slots (11) of the magnetic core (10) in thermal connection with the magnetic core portions (10');characterized in that the cooling structure (30) also comprises cooling channels connected to a cooling circuit, the cooling channels being arranged on the heat sink and / or on a portion of the at least one thermally conductive element (31) of the cooling structure (30); and the cooling channels comprising several parallel bores (61) and at least one transverse bore (62) intersected with said several parallel bores (61) so as to connect them together.;

2. An electromagnetic device according to claim 1, wherein at least some of the parallel bores (61) are blind bores provided on the at least one thermally conductive element (31) of the cooling structure (30) and have an inner wall (63) inserted by press fit therein, the inner wall (63) longitudinally dividing the blind bore into two channels and defining a connection between these two channels in a lower part of the blind bore.

3. Electromagnetic device according to claim 1 or 2, wherein the at least one thermal conductive element (31) is several parallel and / or perpendicular thermal conductive elements (31).

4. An electromagnetic device according to claim 2 or 3, wherein at least some of the cooling channels are provided on the flat wall inserted by press fit into the slot (11), or are provided on portions of the thermally conductive elements external to the slot (11), which constitute external thermally conductive elements, being in thermal connection with the flat wall inserted by press fit into the slot (11).

5. Electromagnetic device according to any one of the preceding claims, in which each heat sink (32) is a housing accommodating at least in part the magnetic core (10), or a portion of said housing.

6. An electromagnetic device according to any preceding claim, wherein the thermally conductive elements (31) further comprise at least one external thermally conductive element adjacent to, and in thermal connection with, the exterior of the magnetic core (10), the external thermally conductive element being made of a non-magnetic metal and being in thermal connection with the heat sink (32), and / or with the flat wall inserted by interference fit into one of the slots of the magnetic core.

7. An electromagnetic device according to any preceding claim, wherein the heat sink (32) and the thermally conductive member (31) thermally connected thereto constitute a single-piece member made of cast metal, cast aluminum or cast aluminum alloy, or a single-piece member made of extruded metal, extruded aluminum or extruded aluminum alloy which is extruded in a direction perpendicular to the central axis (X).

8. An electromagnetic device according to any preceding claim, wherein the cooling structure (30) is divided into two half-parts, superimposed in the direction of the central axis (X), each half-part comprising a heat sink (32) and a portion of the thermal conductive elements (31) thermally connected to the corresponding heat sink (32), and the passage of induction currents through the cooling structure (30) is prevented by means of an air gap, or an electrical insulator, located between the portions of the thermal conductive elements (31) surrounded by the winding electrically conductive (20) and / or between the portions of the cooling structure (30) surrounding the electrically conductive winding (20).

9. An electromagnetic device according to claim 8, wherein each half-part of the cooling structure (30) is a single-piece element made of extruded metal, extruded aluminum or extruded aluminum alloy which is extruded in a direction perpendicular to the central axis (X), the flat wall of one half-part being perpendicular to the flat wall of the other half-part.

10. An electromagnetic device according to claim 9, wherein each half-part of the cooling structure further comprises two side walls, parallel to the flat wall, adjacent to an outer side of the magnetic core (10).

11. An electromagnetic device according to any preceding claim, wherein the magnetic core (10) and the at least one electrically conductive winding (20) are embedded in a thermally conductive composition (40), the thermally conductive composition (40) being in thermal contact with each heat sink (32).

12. An electromagnetic device according to claim 11, wherein the thermally conductive composition comprises: a mixture of a silicone resin and at least one first filler or a silicone resin and a first filler including a natural mineral filler; or a mixture of a silicone resin and at least one first filler or a silicone resin and a first filler including a natural mineral filler and a second filler including aluminum hydroxide.

13. An electromagnetic device according to any preceding claim, wherein the magnetic core further comprises a magnetic gap (12), perpendicular to the central axis (X), intended to increase the magnetic performance of the magnetic core (10), said gap (12) entirely dividing each of the independent magnetic core portions (10') into two independent sections.

14. An electromagnetic device according to any preceding claim, wherein the at least one electrically conductive winding (20) is wound around a coil (50) interposed between the at least one electrically conductive winding (20) and the magnetic core (10).

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