Stationary inductive charging device

Abstract

The present invention relates to a stationary inductive charging device (1) for an inductive vehicle charging system (5) for charging a vehicle battery, comprising an equipment housing (2) having a housing bottom (3) and a housing cover (4) spaced from the housing bottom (3), at least one coil (6) arranged in the equipment housing (2) for generating an alternating electromagnetic field, and power electronics (7) arranged in the equipment housing (2) for supplying energy to the coil (6) and for controlling the driving of the coil (6). In order to efficiently cool the components (10) of the power electronic circuit (7), an air cooling device (11) is provided, the air cooling device (11) having at least one air duct (12) extending into the equipment housing (2) for guiding air, at least one fan (13) arranged in the equipment housing (2) for driving air into the air duct (12), at least one air inlet (14) formed in the equipment housing (2) fluidly connecting the air duct (12) with the surroundings (16) of the inductive charging device (1), and at least one air outlet (15) formed in the equipment housing (2) fluidly connecting the air duct (12) with the surroundings (16). Efficient cooling of the components (10) is achieved because each air duct (12) has a duct wall (17) made of metal, the inner wall surface (18) of the duct wall (17) being exposed to air, and the air duct (12) has at least one heat exchanger area (20) in which the duct wall (17) is thermally coupled to at least one component (10) at its outer wall surface (19).

Description

[Technical field]

[0001] The present invention relates to a stationary inductive charging device for use in an inductive vehicle charging system preferably used to charge the batteries of a battery electric vehicle. The present invention further relates to an inductive vehicle charging system comprising such a stationary inductive charging device.

[0002] Such a vehicle charging system comprises a stationary inductive charging device, which may also be referred to here as a bottom assembly or ground assembly, which is usually stationary, for example located in a parking lot and connected to a power grid, and a mobile inductive charging device, which may also be referred to as a vehicle unit or vehicle assembly, which is arranged in each vehicle, where the mobile inductive charging device is coupled to the vehicle battery in a suitable manner, for example via a corresponding vehicle-side charging device. For charging the battery, the vehicle equipped with the mobile inductive charging device is positioned relative to the stationary inductive charging device, so that electrical energy can be transferred from the stationary inductive charging device to the mobile inductive charging device by means of induction, i.e. via an alternating electromagnetic field. In an inductive vehicle charging system, a charging plug-in connector, which must be plugged into a vehicle-side charging socket, can be dispensed with.

[0003] The stationary inductive charging device has an apparatus housing, which has a housing bottom and a housing cover spaced apart from the housing bottom in the height direction of the inductive charging device. The stationary inductive charging device further has at least one coil, which may also be called a resonator coil, arranged in the apparatus housing and generating an alternating electromagnetic field, and a power electronic circuit arranged in the apparatus housing for supplying energy to the coil and driving and controlling the coil. During operation of the stationary inductive charging device, heat is generated in the components of the power electronic circuit. At this time, a high power output generates a relatively large amount of heat that must be dissipated to avoid damage to the power electronic circuit or to extend the service life of the power electronic circuit.

[0004] In order to remove heat from or cool a power electronic circuit, air cooling devices are known that use fans to generate airflow and guide the airflow to flow around critical components of the power electronic circuit. Thus, the air cooling device uses the airflow for cooling. Such air cooling devices are used, for example, in computers.

[0005] The stationary inductive charging device must be designed to be able to pass over, and therefore must be relatively small in height and sufficiently stable. Shielding of the power electronics is also required, which can enclose the power electronics especially on all sides against the alternating electromagnetic field generated by the coil. This precludes the use of conventional air cooling devices, in which air from the surroundings flows directly around the important components of the power electronics, for heat dissipation.

[0006] The present invention addresses the problem of providing embodiments of a stationary inductive charging device and a vehicle charging system comprising a stationary inductive charging device that feature efficient cooling of the power electronics.

[0007] The above-mentioned object is achieved by the subject matter of the respective independent claims. Advantageous embodiments are the subject matter of the respective dependent claims.

[0008] The invention is based on the general idea that the air cooling device is provided with at least one air duct for guiding air, which extends into the device housing, and which has a duct wall made of metal, the inner wall surface of the duct wall being exposed to an air flow and the outer wall surface of the duct wall being thermally connected to at least one component of the power electronic circuit. During operation of the proposed inductive charging device, heat is thus transferred from the essential components of the power electronic circuit via the outer wall surface to the duct wall and is dissipated by the air flow at the inner wall surface. Since the duct wall is made of metal, it forms a good thermal conductor. In particular, heat is distributed over a large area from the components in the duct wall that are thermally connected locally and approximately point-wise to the outer wall surface to the inner wall surface, which improves the heat transfer to the air. An efficient heat dissipation supports a compact constructional form of the inductive charging device. At the same time, the electromagnetic shielding of the power electronic circuit can be maintained.

[0009] In particular, the invention proposes that the air cooling device has at least one air duct extending in the device housing for guiding air, at least one fan arranged in the device housing for driving the air in the air duct, at least one air inlet arranged in the device housing for fluidly connecting the air duct with the surroundings of the inductive charging device, and at least one air outlet arranged in the device housing for fluidly connecting the air duct with the surroundings. Furthermore, each air duct has a duct wall made of metal, the inner wall surface of the duct wall being exposed to air. Furthermore, the air duct has at least one heat exchanger area, in which the duct wall is thermally coupled on its outer wall surface opposite to the inner wall surface to at least one component of the power electronic circuit. That is, in each air duct, a heat exchanger area is defined in the duct wall, in which the outer wall surface is thermally coupled to at least one component of the power electronic circuit to be cooled. It is clear that the air cooling device may have a number of air ducts, each of which may have a respective duct wall which may have at least one heat exchanger area, and it is further clear that within each air duct the duct wall may have a number of such heat exchanger areas.

[0010] In an advantageous embodiment, at least in such a heat exchanger region, a heat exchanger structure can be arranged in the air duct, through which air can flow and which is heat-transferably connected to the wall inner surface. The heat exchanger structure is used to transfer heat from the wall inner surface to the air. In particular, such a heat exchanger structure is characterized by a large surface exposed to the air flow. Such a heat exchanger structure can have or be formed, for example, by ribs, lamellae, turbulators. The heat exchanger structure is preferably made of metal. The heat-transferably connection to the wall inner surface can be realized by areal contact, preferably in conjunction with a soldered or welded or adhesive or screwed connection.

[0011] In a preferred development, at least one such heat exchanger structure can have ribs around which the air flows, which can advantageously extend parallel to one another, in which case the ribs extend parallel to a main flow direction, in particular defined by the air duct.

[0012] According to an advantageous embodiment, at least one such heat exchanger structure may have at least one heat transfer tube that releases heat from the inner wall surface. Such a heat transfer tube is generally a heat exchanger that utilizes the enthalpy of vaporization of a medium to allow high heat flow density. The heat transfer tube may be formed as a heat pipe or as a two-phase thermosiphon. In particular, each heat transfer tube may be thermally coupled to the above-mentioned rib.

[0013] According to another embodiment, at least one such heat exchanger structure may have at least one rib, which protrudes from the duct wall on the wall inner surface, which runs parallel to the duct side walls laterally defining the air duct and which is supported on each duct side wall via a number of flat tube blocks. The duct walls define the air duct downwards or upwards, i.e. in the height direction, while each duct side wall defines the air duct in a transverse direction to the height direction. Via the flat tube blocks, each rib is thermally connected to each duct side wall. In particular, a number of flat tube blocks are arranged one after the other in the air flow direction and spaced apart from each other. This results in a cascade arrangement of heat transfer parts. Each flat tube block has a number of flat tubes through which air can flow, which are arranged next to each other in a transverse direction to the air flow direction and are thermally connected to each other. The flat tubes are characterized in that their height is significantly smaller than their width and length. By providing a number of flat tubes in each flat tube block, the surface available for heat transfer to the air is significantly enlarged. For this reason, flat tube blocks of the above-mentioned type can be preferably arranged in areas where components of the power electronics, which are characterized by a particularly high heat dissipation, are thermally connected to the outer wall surface of the duct wall. Furthermore, in this case, each rib can be a solid body or alternatively a tubular hollow body, in particular another flat tube, through which air can flow.

[0014] In the vertical arrangement, each flat tube block may have, in particular, outer flat tubes facing and heat-transferably connected to the duct side walls, and inner flat tubes on the opposite side from the duct side walls and heat-transferably connected to the ribs. If three or more flat tubes are provided inside the flat tube block, at least one central flat tube is disposed between the outer and inner flat tubes and heat-transferably connected to the adjacent flat tubes.

[0015] In the horizontal arrangement, each flat tube block may in particular have an upper flat tube on the side opposite the duct wall, heat-transferably connected to each duct side wall and each rib and / or to a boundary wall located on the side opposite the duct wall, and a lower flat tube facing the duct wall, heat-transferably connected to each rib and each duct side wall and / or to the duct wall. If three or more flat tubes are provided inside the flat tube block, at least one central flat tube is arranged between the upper and lower flat tubes and is heat-transferably connected to the adjacent flat tubes.

[0016] In an advantageous embodiment, the air duct can have, in at least one such heat exchanger area, two duct side walls extending parallel to one another. In this case, the heat exchanger structure arranged in said heat exchanger area can have two of the above-mentioned ribs forming two outer ribs. In this case, one outer rib is supported on one duct side wall via a plurality of such flat tube blocks, while the other outer rib is supported on the other duct side wall via a plurality of such flat tube blocks. This results in a symmetrical structure that allows efficient heat transfer from the duct wall through the ribs and the duct side wall connected to the flat tube blocks to the air.

[0017] In another embodiment, the heat exchanger structure further comprises at least one inner rib, which protrudes from the duct wall on the wall inner surface, extending parallel to the outer ribs and disposed between the outer ribs. Each inner rib likewise radiates heat away from the duct wall and can be supported on one side by a plurality of such flat tube blocks to one of the outer ribs. On the other side, each inner rib can be supported on the other outer rib or another inner rib by a plurality of such flat tube blocks. In particular, three or more inner ribs can be provided, whereby at least one inner rib can be configured to be supported on one side by a plurality of flat tube blocks to an adjacent inner rib. The ribs channelize the air duct in the heat exchanger structure. The ribs and the duct side walls radiate heat away from the duct walls. The flat tube blocks radiate heat away from the duct side walls and the ribs and transfer this heat to the air flow. In this case too, the outer rib and / or each inner rib can be designed as a solid body or as a tubular hollow body, in particular as a separate flat tube, through which air can flow.

[0018] In another embodiment, in the air duct and / or in at least one such heat exchanger structure, a number of pressure supports can be arranged around which air flows, which pressure supports transmit a pressing force extending in the height direction between the duct wall of the air duct and a boundary wall located on the opposite side of the duct wall. The pressure supports can be rod- or column-shaped and can consist of metal. In particular, they can penetrate the duct wall and / or the boundary wall located on the opposite side. The pressure supports serve to stabilize the air duct, so that the device housing remains passable upwards.

[0019] In order to improve the heat transfer from the respective components of the power electronics to be cooled to the duct wall, additional measures may be provided which are alternatively or additionally applied. For example, at least one component of the power electronics may be preloaded by a spring device against the wall outer surface. The preload improves the surface contact and thus the heat transfer. At least one component of the power electronics may be thermally coupled to the wall outer surface by a heat transfer tube. This allows, for example, components with a relatively large distance to the wall outer surface to be efficiently thermally coupled to the wall outer surface. At least one component of the power electronics may be thermally coupled to the wall outer surface by a thermal conductor, for example a thermally conductive film, a thermally conductive pad, a thermally conductive paste or a thermally conductive gel.

[0020] In another embodiment, the duct wall can be formed by a part of a shielding sheet covering the power electronics towards the housing bottom or towards the housing cover. For example, the shielding sheet covers the power electronics towards the housing bottom and, in particular, together with the housing bottom, can define a receiving chamber in which the power electronics is arranged. In particular for this, the housing bottom can be manufactured from metal. Alternatively, the duct wall can be formed by a part of a shielding housing arranged in the device housing and in which the power electronics is arranged. The shielding housing is advantageously made of metal. Forming the duct wall by a shielding sheet or a part of a shielding housing thus makes use of components inside the air cooling device that are present in any case in the inductive charging device. This supports a compact construction and at the same time results in efficient heat transfer. It should be noted here that the respective parts are formed only by a part of the shielding sheet or the shielding housing. That is to say, in order to effect the air guide in the air passage, only a partial area of ​​the shielding sheet or the shielding housing is used to form the duct wall. This allows good utilization of the construction space present inside the device housing.

[0021] In one embodiment, the duct walls can be configured to be adapted to the topology of the power electronics in the height direction. Thus, the air duct has a duct height measured in the height direction, which varies according to the topology of the power electronics in the air flow direction. In the power electronics, high and low components can alternate in the height direction. The adaptation of the duct walls to the topology of the power electronics reduces the distance from the components to the duct walls and facilitates a heat-transferable coupling between the components to be cooled and the duct walls.

[0022] In another embodiment, the air duct has a duct width transverse to the air flow direction, which can vary in the air flow direction, and / or the air has a through-flow cross-sectional area, which can vary in the air flow direction. The through-flow cross-sectional area or duct width of the air duct can form a narrowing in the respective heat exchanger area. In other words, the duct width or through-flow cross-sectional area decreases in the flow direction towards the respective heat exchanger area and increases again behind it. By reducing the duct width or through-flow cross-sectional area, the air flow velocity is increased, which promotes the heat release in the heat exchanger area.

[0023] In another embodiment, the device housing can have a frame structure surrounding it laterally. The frame structure can be ramp-like or wedge-like, in cross section extending parallel to the height direction, to allow the upward passage of the inductive charging device. Advantageously, the frame structure can have at least one inlet area permeable to air, to which the respective air inlets are connected. Furthermore, the frame structure can have at least one outlet area, remote from the inlet area, permeable to air, to which the respective air outlets are connected. The permeability to air can be achieved by a plurality of inlet or outlet openings in the respective frame area. By accommodating the air inlets and air outlets in the frame structure, a relatively long flow path for air can be achieved in each air duct, which promotes effective heat transfer.

[0024] Furthermore, the frame structure can also be used to accommodate other important elements of the air cooling device. For example, at least one fan can be arranged at each air inlet in each inlet region. Additionally or alternatively, at least one fan can also be arranged at each air outlet in each outlet region. Additionally or alternatively, at least one fan can be arranged at any position in the air duct, for example to provide a good continuity of the air flow, and / or several fans can be arranged in cascade or connected in series, for example to reduce noise emissions to the surroundings. Additionally or alternatively, air filters can also be arranged at each inlet region.

[0025] According to another advantageous embodiment, the air duct can have at least three duct sections interconnected via branching positions, where each branching position splits the incoming air flow into two or more downstream air flows or merges two or more incoming air flows into one downstream air flow, and in particular can be configured such that at least one heat exchanger area is formed in each of these duct sections.

[0026] An inductive vehicle charging system according to the invention, used for charging the batteries of battery electric vehicles, comprises a stationary inductive charging device of the above-mentioned type and a mobile inductive charging device arranged in each vehicle. In a ready-to-operate state, the stationary inductive charging device is fixedly located in or on the ground of the parking lot and is electrically connected to the power grid. The mobile inductive charging device is arranged at the bottom of the vehicle and is electrically connected to a battery charging device arranged in the vehicle, which is further electrically connected to the vehicle battery.

[0027] Important further features and advantages of the invention emerge from the respective dependent claims, the description of the drawings and the corresponding figures based thereon.

[0028] It is clear that the features mentioned above and those further described below can be used not only in the respective described combinations, but also in other combinations or alone, without departing from the scope of the invention. For example, the elements further described below of a higher-level unit, such as a unit, device or apparatus shown separately, may form separate elements or components of the unit or may be integrated regions or sections of this unit, even if shown differently in the figures.

[0029] Preferred embodiments of the present invention are illustrated in the drawings and will be described in detail in the following description, where like reference numbers indicate like or similar or functionally similar elements. [Brief description of the drawings]

[0030] [Figure 1] FIG. 3 is a cross-sectional view according to the section line I in FIG. 2, showing the basic design of a stationary inductive charging device in a greatly simplified manner. [Diagram 2] FIG. 2 is a highly simplified perspective view of the inductive charging device of FIG. 1. [Diagram 3]1, but showing a cross-sectional view of an inductive charging device in another embodiment. [Figure 4] 4 is a perspective view similar to FIG. 2 but showing the inductive charging device of the embodiment of FIG. 3. [Diagram 5] FIG. 2 is an enlarged cross-sectional view of the inductive charging device in the area of ​​the air duct. [Figure 6] FIG. 6 is a cross-sectional view similar to FIG. 5 but showing another embodiment. [Figure 7] FIG. 2 is a highly simplified projection view of an area of ​​the heat exchanger structure exploded.

[0031] According to Figs. 1 to 4, the stationary inductive charging device 1 has a device housing 2, which has a housing bottom 3 and a housing cover 4 spaced apart from the housing bottom 3 in a height direction Z. The housing bottom 3 and the housing cover 4 are configured as flat plates in this example, which extend perpendicular to the height direction Z and therefore parallel to the longitudinal direction X of the inductive charging device 1 and parallel to the transverse direction Y of the inductive charging device 1. The transverse direction Y extends perpendicular to the longitudinal direction X. The height direction Z extends perpendicular to the longitudinal direction X and perpendicular to the transverse direction Y. The respective directions are indicated by arrows in the figures. The observation directions in Figs. 1 and 3 extend perpendicular to the longitudinal direction X. The observation directions in Figs. 2 and 4 extend perpendicular to the height direction Z. The observation directions in Figs. 5 and 6 exemplarily extend perpendicular to the transverse direction Y.

[0032] The stationary inductive charging equipment 1 forms a component of an inductive vehicle charging system 5 used for charging the batteries of battery electric vehicles. The vehicle charging system 5 here further comprises mobile inductive charging equipment, not shown here, fitted to each vehicle.

[0033] The stationary inductive charging device 1 comprises at least one coil 6, which is arranged in a device housing 2 and which generates an alternating electromagnetic field, and which is shown in a highly simplified manner in Figs. 2 and 4. Furthermore, the inductive charging device 1 comprises power electronics 7, which are arranged in the device housing 2, but which are hidden in Figs. 2 and 4. The power electronics 7 are used to supply energy to the coil 6 and to drive and control the coil 6. The power electronics 7 can be connected to a power grid via external terminals 8 in Fig. 2. The power electronics 7 is electrically connected to the coil 6 via internal terminals 9. The power electronics 7 comprises a number of components 10. Some of these components 10 generate heat during the operation of the power electronics 7, which must be dissipated.

[0034] The inductive charging device 1 further comprises an air cooling device 11 for cooling the components 10 of the power electronics 7. For this purpose, the air cooling device 11 has at least one air duct 12 for guiding air, which extends into or is arranged in the device housing 2. The air cooling device 11 further comprises at least one fan 13 for driving air in the air duct 12, which is arranged in the device housing 2, at least one air inlet 14 and at least one air outlet 15. The air inlet 14 is fluidly connected to the surroundings 16 of the inductive charging device 1. The air outlet 15 is likewise fluidly connected to the surroundings 16. During operation of the air cooling device 11, each fan 13 generates an air flow, which is indicated by an arrow in Fig. 2, Fig. 4 and Fig. 5. In this case, air is drawn in from the surroundings 16 and reaches into the air duct 12 through the air inlet 14. In the air duct 12, the air is guided to the air outlet 15, from where it flows out again into the surroundings 16.

[0035] Here, the air duct 12 has a duct wall 17 made of metal. The duct wall 17 has an inner wall surface 18 exposed to the air and an outer wall surface 19 opposite the inner wall surface 18. At least one heat exchanger area 20 is formed in the air duct 12. In the example of Figs. 1 to 4, several heat exchanger areas 20 are provided, which are partially shown in Figs. 1 to 4 by bent brackets. Each heat exchanger area 20 can advantageously extend over the entire width of the air passage 12. Furthermore, the heat exchanger area 20 extends only over a longitudinal part of the air duct 12. The length and width of the air duct 12 relate to the main flow direction of the air in the air duct 12. The duct length therefore extends in the flow direction, whereas the duct width extends transversely to the flow direction. 2, the air duct 12 extends approximately parallel to the transverse direction Y of the inductive charging device 1, so that in this case the duct width extends in the transverse direction Y, whereas the duct width extends in the longitudinal direction X. The duct height extends parallel to the height direction Z.

[0036] In the example of Figures 1 to 4, a number of such heat exchanger areas 20 are formed in each air duct 12, which are partially shown by hatching in Figures 2 and 4.

[0037] In the heat exchanger area 20, the wall outer surface 19 of the duct wall 17 is connected to at least one component 10 of the power electronic circuit 7 in a heat-transferable manner. In this way, heat generated by each component 10 during operation of the power electronic circuit 7 can be introduced into the duct wall 17 via the wall outer surface 19, so that the heat is distributed over a large area within the duct wall 17. The air flow can absorb and release the heat at the wall inner surface 18.

[0038] In at least one such heat exchanger region 20, a heat exchanger structure 21 may be disposed within the air duct 12 and on the inner wall surface 18. Each heat exchanger structure 21 is passable by air and is heat transferably coupled to the inner wall surface 18. Thus, heat may be transferred from the inner wall surface 18 of the duct wall 17 to the heat exchanger structure 21, and heat may be released to the air as it flows through the heat exchanger structure 21.

[0039] According to figures 5 and 6, such a heat exchanger structure 21 can have a number of ribs 22 which are thermally connected to the duct wall 17 and around which air can flow. For the purpose, the ribs 22 run parallel to one another and in the longitudinal direction of the air duct 12. In the example of figure 5, the air duct 12 runs below the respective components 10 to be cooled. In the example of figure 6, the air duct 12 runs above the respective components 10 to be cooled.

[0040] According to the embodiment shown in Fig. 6, at least one such heat exchanger structure 21 can comprise at least one heat transfer tube 23. In this case, each heat transfer tube 23 can be formed as a heat pipe or as a two-phase thermosiphon. Furthermore, in the example of Fig. 6, the above-mentioned ribs 22 are also provided. Each heat transfer tube 23 is here heat-transferably connected to the duct wall 17 and to at least one of the ribs 22 here, so that the heat transfer tube can transfer heat from the duct wall 17 to the respective rib 22. Release of heat to the air then takes place via the rib 22.

[0041] In the example of FIG. 7, the air duct 12 is reproduced only in the heat exchanger area 20, in which another heat exchanger structure 21 is provided. In said heat exchanger area 20, the air duct 12 has two duct side walls 24 extending parallel to one another, which laterally, i.e. in width, delimit the air duct 12. Furthermore, the heat exchanger structure 21 shown here comprises at least one rib 25, which protrudes from the duct wall 17 at the wall inner surface 18 and penetrates into the air duct 12. Each rib 25 in this case extends parallel to the respective duct side wall 24. Furthermore, each rib 25 is supported on the respective adjacent duct side wall 24 via at least one flat tube block 26, in particular via several flat tube blocks 26. In the example of FIG. 7, each rib 25 is supported on the respective adjacent duct side wall 24 via three such flat tube blocks 26, respectively. It is clear here that more or less flat tube blocks 26 can also be used in this case, which are then arranged one behind the other and spaced apart from one another in the air flow direction between each rib 25 and the adjacent duct side wall 24.

[0042] Each flat tube block 26 has a number of flat tubes 27 through which air can flow, which are arranged side by side transversely to the air flow direction and are heat-transferably connected to one another. In the example of FIG. 7, each flat tube block 26 has three such flat tubes 27. Each flat tube block 26 has an outer flat tube 27 facing each duct side wall 24, which is heat-transferably connected to each duct side wall 24. Furthermore, each flat tube block 26 has an inner flat tube 27 on the side opposite each side wall 24, which is heat-transferably connected to a rib 25 adjacent to each end wall 24. In contrast to these, a third flat tube 27 forms a central flat tube 27, which is heat-transferably connected to the other two flat tubes, i.e., the inner flat tube 27 and the outer flat tube 27. For the thermally conductive connection of the flat tubes 27 with each other and with the duct side walls 24 and the ribs 25, a special heat conductor 48, such as a heat conductive pad, can be used.

[0043] Two ribs 25 supported on the two duct side walls 24 via flat tube blocks 26 form outer ribs 25 between which at least one further rib 28, hereinafter referred to as inner rib 28, can be arranged. In the example of FIG. 7, two such inner ribs 28 are provided. Each inner rib 28 is arranged on the wall inner surface 18 and protrudes from the duct wall 17. Moreover, each inner rib 28 extends parallel to the outer rib 25. Each inner rib 28 is supported on the one hand via at least one flat tube block 26, preferably via several flat tube blocks 26, on one of the outer ribs 25. On the other hand, the inner ribs 28 shown here are supported to each other via at least one flat tube block 26, preferably via several flat tube blocks 26. In the example of FIG. 7, the inner ribs 28 are dimensioned shorter than the outer ribs 25 in relation to the duct length. In another embodiment, the inner ribs 28 may be sized to be the same length as the outer ribs 25 or larger than the outer ribs 25. In the example of Figure 7, the inner ribs 28 are sized larger in the duct width than the outer ribs 25. In another embodiment, the inner ribs 28 may be sized to be the same length as the outer ribs 25 or smaller in the duct width than the outer ribs 25.

[0044] The air duct 12 can be provided with a number of pressure supports 29 in the heat exchanger area 20, in particular inside the heat exchanger structure 21 and / or outside the heat exchanger area 20, according to Fig. 7. The pressure supports 29, around which air can flow, can transmit a pressing force acting in the horizontal direction Z, so that the air duct 12 is relieved by said pressing force. In particular, the pressure supports 29 can transmit said pressing force between the duct wall 17 and a boundary wall 30, which is located on the opposite side to said duct wall 17 and is not shown in Fig. 7 but is shown in broken lines in Figs. 1 and 3. In Fig. 5, the boundary wall 30 here is formed by a lower plate 31, which can in particular form the housing bottom 3. In Fig. 6, the boundary wall 30 here is formed by an upper cover plate 32.

[0045] 1, 3, 5 and 6, in at least one component 10, a thermal conductor 33 may be used to improve the thermally conductive coupling with the wall exterior surface 19. Each thermal conductor 33 may be a thermally conductive film, a thermally conductive paste, a thermally conductive gel or a thermally conductive pad.

[0046] In the example of Fig. 3, by way of example, it is shown that at least one component 10, hereinafter designated 10', is preloaded against the wall outer surface 19 by means of a spring device 34. This also improves the heat transfer to the wall outer surface 19. Furthermore, Fig. 3 shows, purely by way of example, how at least one further component 10, hereinafter designated 10'', is heat-transferably coupled to the wall inner surface 19 by means of a heat transfer tube 35. Functionally, said heat transfer tube 35 has the same structure as the heat transfer tube 23 described with reference to Fig. 6.

[0047] According to figures 1 to 7, the duct wall 17 can be formed by a section of a shielding plate 36. In the example of figures 1 to 4 and 6, the shielding plate 36 covers the power electronics 7 towards the housing bottom 3. In the example of figure 5, the shielding plate 36 covers the power electronics 7 towards the housing cover 4. Alternatively, the duct wall 17 can also be formed by a section of a shielding housing 37 which is arranged in the device housing 2 and in which the power electronics 7 are arranged. In the example of figures 1 to 4, the shielding housing 37 is formed by the shielding plate 36 and the housing bottom 3. Each section forming the duct wall 17 is dimensioned smaller transversely to the flow direction than the corresponding shielding plate 36 or the corresponding shielding housing 37.

[0048] As can be seen from Figures 1 and 3, the duct wall 17 can be configured to follow the topology of the power electronics 7 in the height direction Z. As a result, the air duct 12 has a duct height 46 measured in the height direction Z, which duct height 46 varies in the air flow direction 47. The duct height 46 is shown in Figures 1 and 3. The flow direction 47 is shown in Figures 1 to 4. It can be seen in Figures 1 and 3 that the air flow direction 47 runs from left to right and that the duct height 46 varies from left to right.

[0049] As can be seen from Figures 2 and 4, the air duct 12 can be advantageously configured with a passage width that varies in the air flow direction 47 and / or a flowable cross-sectional area that varies in the air flow direction 47. For example, starting from the air inlet 14, the passage width and the flowable cross-sectional area first decrease, then become approximately constant in the region of the heat exchanger structure 21 and then increase again up to the air outlet 15. It should be noted that the passage width and / or the flowable cross-sectional area of ​​the air duct 12 form a narrowing in at least one heat exchanger region 20.

[0050] According to Figs. 1 to 4, the device housing 2 can have a frame structure 38 surrounding the device housing 2 at the sides. The frame structure 38 extends around the device housing 2 and closes it around the height direction Z. Here, the frame structure 38 can have at least one inlet area 39 that is permeable to air, which is connected to each air inlet 14 so that it can guide air. For this purpose, the inlet area 39 can be perforated, i.e. it can have a number of inlet openings. The frame structure 38 can further have at least one outlet area 40 that is spaced apart from the inlet area 39 and is configured to be permeable to air. Each outlet area 40 is also connected to each outlet 15 so that it can guide air. The air permeability of the outlet area 40 can be achieved by perforations or by a number of outlet openings. In the example of Fig. 2, only one inlet area 39 and only one outlet area 40 are provided. In the example of FIG. 4, only one inlet region 39 and only two outlet regions 40 are provided.

[0051] According to figures 1 to 4, at least one fan 13 can be arranged in the inlet region 38, whereas according to figures 2 and 4, five fans 13 are arranged in parallel in the inlet region 39, here purely by way of example. According to figures 1 and 2, another fan 13 can also be arranged in the outlet region 40. According to figure 2, three fans 13 are arranged in parallel here. In contrast, in the embodiment shown in figures 3 and 4, no fan is arranged in each outlet region 40. Instead, in the example of figures 3 and 4, an air filter 41 is arranged in the inlet region 39, which avoids contamination of each fan 13, the air duct 12 and the heat exchanger structure 21.

[0052] In the embodiment of Fig. 2, the air duct 12 is consistently configured to connect the air inlet 14 to the air outlet 15. In contrast to the embodiment of Fig. 4, the air duct 12 comprises a branching position 42, whereby the air duct 12 has three duct sections 43, 44, 45 fluidly connected to each other via the branching position 42. The first duct section 43 leads from the air inlet 14 to the branching position 42. The second duct section 44 leads from the branching position 42 to the first air outlet 15. The third duct section 45 leads from the branching position 42 to the second air outlet 15. In this case, the branching position 42 divides the incoming air flow into two downstream air flows.

Claims

1. A stationary inductive charging device (1) for an inductive vehicle charging system (5) for charging the batteries of a battery electric vehicle, comprising: a device housing (2) having a housing bottom (3) and a housing cover (4) spaced apart from the housing bottom (3) in a height direction (Z) of the inductive charging device (1); At least one coil (6) arranged in the device housing (2) for generating an alternating electromagnetic field; a power electronic circuit (7) arranged in the device housing (2) for supplying energy to the coil (6) and for controlling the coil (6); an air cooling device (11) for cooling the components (10) of the power electronic circuit (7); Equipped with The air cooling device (11) has at least one air duct (12) extending into the device housing (2) for guiding air, at least one fan (13) arranged in the device housing (2) for driving air into the air duct (12), at least one air inlet (14) formed in the device housing (2) and fluidly connecting the air duct (12) with the surroundings (16) of the inductive charging device (1), and at least one air outlet (15) formed in the device housing (2) and fluidly connecting the air duct (12) with the surroundings (16), Each of the air ducts (12) has a duct wall (17) made of metal, and an inner wall surface (18) of the duct wall (17) is exposed to air; The air duct (12) has at least one heat exchanger area (20), in which the duct wall (17) is thermally coupled to at least one component (10) of the power electronic circuit (7) on an outer wall surface (19) opposite the inner wall surface (18). Stationary inductive charging device (1).

2. a heat exchanger structure (21) is arranged on the wall inner surface (18) of the air duct (12) at least in the heat exchanger region (20), the heat exchanger structure (21) being air-permeable and heat-transferably connected to the duct wall (17); An inductive charging device (1) according to claim 1.

3. At least one of the heat exchanger structures (21) has ribs (22) around which air flows. An inductive charging device (1) according to claim 2.

4. At least one of the heat exchanger structures (21) has at least one heat transfer tube (23) that dissipates heat from the duct wall (17). An inductive charging device (1) according to claim 2 or 3.

5. At least one of the heat exchanger structures (21) has at least one rib (25) that protrudes from the duct wall (17) on the wall inner surface (18), the duct wall (17) extending parallel to duct side walls (24) that laterally define the air duct (12) and supported by each duct side wall (24) via at least one flat tube block (26); Each flat tube block (26) has a plurality of flat tubes (27) through which air can flow, the plurality of flat tubes (27) being arranged side by side in a direction transverse to the air flow direction and being connected to each other so as to be capable of transferring heat therethrough; Each flat tube block (26) is thermally coupled to each duct side wall (24) and each rib (25). An inductive charging device (1) according to claim 2 or 3.

6. Each flat tube block (26) has an outer flat tube (27) facing each duct side wall (24) and heat-transferably connected to the duct side wall (24), and an inner flat tube (27) on the opposite side from each duct side wall (24) and heat-transferably connected to each rib (25). An inductive charging device (1) according to claim 5.

7. The air duct (12) has, in at least one of the heat exchanger regions (20), two duct side walls (24) extending parallel to each other; The heat exchanger structure (21) arranged in the heat exchanger area (20) has two ribs (25) forming two outer ribs (25), one of which is supported on one duct side wall (24) via at least one of the flat tube blocks (26), while the other outer rib (25) is supported on the other duct side wall (24) via at least one of the flat tube blocks (26). An inductive charging device (1) according to claim 5.

8. The heat exchanger structure (21) further comprises at least one inner rib (28) protruding from the duct wall (17) on the wall inner surface (18), the duct wall (17) extending parallel to the outer ribs (25) and being disposed between the outer ribs (25); Each of the inner ribs (28) is supported on one of the outer ribs (25) via at least one of the flat tube blocks (26) on the one hand, and on another outer rib (25) or another inner rib (28) via at least one of the flat tube blocks (26) on the other hand. An inductive charging device (1) according to claim 7.

9. The flat tube blocks (26) are arranged one behind the other in the air flow direction and spaced apart from each other. An inductive charging device (1) according to claim 5.

10. In the air duct (12) and / or in the at least one heat exchanger structure (21), a plurality of pressure supports (29) are arranged around which air can flow, and which transmit a pressure force extending in a height direction (Z) between the duct wall (17) of the air duct (12) and a boundary wall (30) located on the opposite side of the duct wall (17). An inductive charging device (1) according to claim 1 or 2.

11. At least one component (10, 10') of the power electronic circuit (7) is preloaded against the wall outer surface (19) by a spring device (34). An inductive charging device (1) according to claim 1 or 2.

12. At least one component (10, 10'') of the power electronic circuit (7) is thermally coupled to the wall outer surface (19) via a heat transfer tube (35). An inductive charging device (1) according to claim 1 or 2.

13. At least one component (10) of the power electronic circuit (7) is thermally coupled to the wall outer surface (19) by a thermal conductor (33). An inductive charging device (1) according to claim 1 or 2.

14. the duct wall (17) is formed by a portion of a shielding lamella (36) covering the power electronic circuit (7) towards the housing bottom (3) or towards the housing cover (4), or the duct wall (17) is formed by a portion of a shielding housing (37) arranged in the device housing (2) and in which the power electronic circuit (7) is arranged; An inductive charging device (1) according to claim 1 or 2.

15. the duct walls (17) are adapted in the height direction (Z) to the topology of the power electronics (7), so that the air duct (12) has a duct height (46) measured in the height direction (Z), which duct height (46) varies in the air flow direction (47); An inductive charging device (1) according to claim 1 or 2.

16. the air duct (12) has a duct width transverse to the air flow direction (47), the duct width varying in the air flow direction (47), and / or a cross-sectional area through which air can flow, the cross-sectional area varying in the air flow direction (47); the duct width and / or the cross-sectional area of ​​the air duct (12) forms a narrow section in at least one of the heat exchanger regions (20); An inductive charging device (1) according to claim 1 or 2.

17. The device housing (2) has a frame structure (38) that laterally surrounds the device housing (2), the framework (38) has at least one inlet area (39) permeable to air, to which each air inlet (14) is connected; The framework (38) has at least one outlet area (40) separate from the inlet area (39) and permeable to air, to which each air outlet (15) is connected. An inductive charging device (1) according to claim 1 or 2.

18. At least one fan (13) is arranged for each air inlet (14) in each inlet region (39); and / or At least one fan (13) is arranged for each air outlet (15) in each outlet region (40); and / or At least one fan (13) is arranged in said air duct (12) between each air inlet (14) and each air outlet (15); and / or An air filter (41) is arranged in each inlet area (39); 18. An inductive charging device (1) according to claim 17.

19. The air duct (12) has at least three duct sections (43, 44, 45) interconnected via branching points (42) for splitting an incoming air flow into at least two discharge air flows or for joining at least two incoming air flows into a downstream air flow. An inductive charging device (1) according to claim 1 or 2.

20. At least one heat exchanger region (20) is formed in each of the three duct sections (43, 44, 45). An inductive charging device (1) according to claim 1 or 2.

21. An inductive vehicle charging system (5) for charging a battery of a battery electric vehicle, comprising: A stationary inductive charging device (1) according to claim 1 or 2; a mobile inductive charging device located in or on a vehicle; An inductive vehicle charging system (5) comprising:

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