Cooling device for a power converter for a motor vehicle, power converter, electric axle drive, motor vehicle and method for producing a cooling device

Abstract

A cooling device (130) for an electrical circuit for a motor vehicle comprises a cooling channel (200) for conducting a coolant and a first wall (205) of the cooling channel (200) and a second wall (215) of the cooling channel (200). The first wall (205) has a plurality of recesses (210) on a side facing the cooling channel (200). The second wall (215) is arranged opposite the first wall (205) and has a plurality of extensions (220) on a side facing the cooling channel (200). Ends of the extensions (220) facing the first wall (205) are received by the plurality of recesses (210).The cooling device (130) further comprises an inlet (230) arranged on a first side (240) of the cooling device (130) for admitting the coolant into the cooling channel (200) and an outlet (235) arranged on a second side (245) of the cooling device (130) and opposite the inlet (230) for discharging the coolant from the cooling channel (200).

Description

[0001] The present approach relates to a cooling device for a power converter for a motor vehicle, a power converter with a cooling device, an electric axle drive for a motor vehicle, a motor vehicle and a method for producing a cooling device.

[0002] A cooling device may have a cooling channel for guiding a coolant. An inner wall or inner side of the cooling channel is typically flat or planar.

[0003] Against this background, the present approach provides an improved cooling device for a power converter for a motor vehicle, an improved power converter, an improved electric axle drive for a motor vehicle, an improved motor vehicle, and an improved method for producing a cooling device according to the main claims. Advantageous embodiments emerge from the subclaims and the following description.

[0004] Advantageously, the cooling performance of a cooling channel can be improved by providing a so-called pin-fin structure.

[0005] A cooling device for a power converter for a motor vehicle comprises a cooling channel for conducting a coolant. A first wall of the cooling channel has a plurality of recesses on a side facing the cooling channel. A second wall of the cooling channel is arranged opposite the first wall and has a plurality of extensions on a side facing the cooling channel. Ends of the extensions facing the first wall are received by the plurality of recesses. The cooling device further comprises an inlet arranged on a first side of the cooling device for admitting the coolant into the cooling channel and an outlet arranged on a second side of the cooling device and opposite the inlet for discharging the coolant from the cooling channel.

[0006] Heat generated during operation of a power converter, for example from a choke or power electronics, can be dissipated using the cooling device. The opposing walls of the cooling channel are shaped with extensions and recesses to improve heat transfer between a coolant flowing through the cooling channel and the walls. This not only increases the effective area for heat transfer, but also creates turbulence in a coolant flow, which in turn ensures improved heat transfer. The recesses can be holes, recesses, cavities, dimples, or depressions arranged in the first wall. The extensions can be rod-, tube-, or cylinder-like projections protruding from the second wall.A cross-section of at least the ends of the extensions can be smaller than a cross-section of the recesses, so that one end of each of the extensions can be accommodated by an opposite recess.

[0007] The cooling device can be used in a known manner, for example, in connection with a power supply or power electronics. Accordingly, the power converter can be, for example, a DC-DC converter or an inverter. The power converter can be used, for example, in a charging circuit or in a drive train for the motor vehicle. The motor vehicle can be implemented, for example, as a passenger car or truck, as a bus, a commercial vehicle, or as a work machine.

[0008] According to one embodiment, the number of extensions can correspond to the number of recesses. This allows each extension to be accommodated by an associated recess. The extensions and recesses can be arranged across the entire width of the cooling channel. This ensures good heat transfer.

[0009] The projections and recesses can be arranged in a plurality of rows and columns. This allows for a high density of projections. For example, the distance between directly adjacent projections can be smaller than the diameter of the projections.

[0010] The ends of the extensions facing the first wall can each be spaced from the first wall by a gap. This allows gaps to be created between the recesses and the ends of the extensions. This allows the coolant to flow around not only the long sides of the extensions but also the end faces of the extensions facing the first wall.

[0011] The ends of the extensions facing the first wall can be soldered to the recesses. This soldering can advantageously bond the extensions to the recesses. This offers the advantage that the first wall, also called secondary cooling, is directly connected to the extensions of the second wall, also called primary cooling. This allows the extensions to be used to dissipate heat from both walls.

[0012] The recesses can all have the same shape or be shaped differently. For example, the recesses can be round or oval. Such shapes are easy to manufacture. Alternatively, the recesses can be angular. The extensions can have a cross-section corresponding to the recesses or differ from the shape of the recesses. For example, the ends of extensions with a round cross-section or the ends of extensions with an oval cross-section can be inserted into round recesses. The flow behavior of the coolant can be influenced by a suitable choice of shapes and their combination.

[0013] The recesses and additionally or alternatively the extensions can be shaped differently in different sections of the cooling channel. This embodiment enables the coolant to be guided in a targeted manner along a desired, intended path through the cooling channel. As a result, certain areas of the walls can be cooled more intensively and other areas less intensively. The recesses can, for example, each have a first shape in a first area of ​​the first wall facing a third side of the cooling device and in a second area of ​​the first wall facing a fourth side of the cooling device opposite the third side. The recesses can have a second shape that differs from the first shape in a third area of ​​the first wall arranged between the first area and the second area.For example, if the recesses arranged on the sides of the first wall are round or circular, and the recesses in the middle of the first wall or in the middle of the cooling channel are oval or oval, this allows for a bypass, i.e., bypassing a central area of ​​the cooling channel. This enables better cooling in the central section of the cooling channel.

[0014] The cooling device can have a circumferential wall arranged between the first wall and the second wall. The cooling channel can be delimited by the circumferential wall and the first wall and the second wall. In addition to the first wall and the second wall, the circumferential wall can advantageously function as a lateral spatial delimiting element of the cooling channel. The outlet and the inlet can each pass through the circumferential wall and be arranged opposite one another. A longitudinal direction of the extensions can be aligned parallel to the circumferential wall.

[0015] The first wall can be formed as part of a housing for a choke or power electronics of the power converter. For example, the first wall can form an upper closure of the housing. This enables direct heat transfer from a heat-emitting component of the power converter to the coolant via the first wall.

[0016] A power converter can comprise the aforementioned cooling device. The power converter can be embodied, for example, as an inverter or a DC / DC converter. In addition to the cooling device, the power converter can comprise a choke or power electronics required for the function of the power converter, which can be accommodated in a housing of the cooling device. This embodiment of the present approach in the form of a power converter also allows the problem underlying the present approach to be solved quickly and efficiently.

[0017] The cooling device is suitable, for example, for an electric axle drive. Such an electric axle drive for a motor vehicle comprises at least one electric machine, a transmission device, and a power converter. The power converter can be designed, for example, as a rectifier or an inverter. Using the power converter, an electrical current required to operate the electric machine can be provided. Using the transmission device, a torque provided by the electric machine can be converted into a drive torque for driving at least one wheel of the motor vehicle. The transmission device can have a gearbox for reducing the speed of the electric machine and optionally a differential.

[0018] Accordingly, a motor vehicle can comprise a power converter or a charging device and, additionally or alternatively, an electric axle drive. This embodiment of the present approach in the form of a motor vehicle also allows the problem underlying the present approach to be solved quickly and efficiently.

[0019] Furthermore, a method for manufacturing a cooling device is presented. The method comprises a step of providing a first wall of a cooling channel and a step of providing a second wall of the cooling channel. The method comprises a step of disposing a soldering material in the recesses and a step of heating the soldering material. Furthermore, the method comprises a step of inserting the ends of the extensions of the second wall into the recesses of the first wall in order to solder the ends of the extensions to the recesses.

[0020] The present approach is explained in more detail using the attached drawings. They show: Fig. 1 a schematic representation of a motor vehicle according to an embodiment; Fig. 2 a schematic representation of a cooling device according to an embodiment; Fig. 3 a schematic representation of a cooling device according to an embodiment; Fig. 4 a sectional view of a cooling device according to an embodiment; Fig. 5 a schematic representation of a first wall and a housing of a cooling device according to an embodiment; Fig. 6 a schematic representation of a second wall of a cooling device according to an embodiment; Fig. 7 a sectional view of a first wall of a cooling device according to an embodiment; Fig. 8 is a sectional view of a first wall and a second wall of a cooling device according to an embodiment; Fig. 9 is a sectional view of a first wall and a second wall of a cooling device according to an embodiment; and Fig. 10 is a flowchart of an embodiment of a method for manufacturing a cooling device.

[0021] In the following description of preferred embodiments of the present approach, the same or similar reference numerals are used for the elements shown in the various figures and having a similar effect, whereby a repeated description of these elements is omitted.

[0022] Fig. 1 shows a schematic representation of a motor vehicle 100 according to an exemplary embodiment. The motor vehicle 100 has an electric axle drive with an electric machine 105. Electrical energy for operating the electric machine 105 is provided by a power supply device 110, for example a battery. For example, the power supply device 110 provides a direct current, which is converted into an alternating current, for example a three-phase alternating current, using a power converter 115 and supplied to the electric machine 105. A shaft driven by the electric machine 105 is coupled directly or using the transmission device 120 to at least one wheel 125 of the motor vehicle 100. Thus, the motor vehicle 100 can be moved using the electric machine 105.Optionally, the electric axle drive comprises a housing in which the power converter 115, the electric machine 105 and the transmission device 120 are integrated or arranged.

[0023] According to one embodiment, the power converter 115 has a cooling device 130, which is used, for example, to cool a choke 131 and additionally or alternatively a power electronics 132 of the power converter 115.

[0024] According to one embodiment, the motor vehicle 100 has a charging device 135, which includes a corresponding cooling device 130, with which a heat-emitting component, for example, a choke or power electronics of a power converter of the charging device 135, can be cooled. The charging device 135 is used to charge the energy supply device 110 using an external charging station.

[0025] Fig. Figure 2 shows a representation of a cooling device 130 according to an embodiment. The cooling device 130 is shown in a non-assembled state and is, for example, for use in a power converter of the Fig. 1 shown motor vehicle.

[0026] The cooling device 130 comprises a Fig. 2 open cooling channel 200 for guiding a coolant.

[0027] The cooling channel 200 has a first wall 205, which, on a side facing the cooling channel 200, has a plurality of recesses 210 arranged adjacent to one another. According to one embodiment, the recesses 210 are round in shape. Alternatively, the recesses 210 are oval in shape. Alternatively, the recesses 210 have a different cross-section. Recesses 210 with different cross-sectional shapes can also be used.

[0028] The cooling channel 200 also has a second wall 215, which is arranged opposite the first wall 205. The second wall 215 has, on a side facing the cooling channel 200, a plurality of adjacently arranged extensions 220. According to one embodiment, the extensions 220 are designed as rods that protrude at right angles from a surface of the second wall 215. The ends of the extensions 220 facing the first wall 205 in the assembled state of the cooling device 130 can be received by the plurality of recesses 210 or, as in the following Fig. 3. According to one embodiment, a number of projections 220 corresponds to a number of recesses 210. According to the embodiment shown, the recesses 210 and the projections 220 are arranged in an identical pattern, such that each of the projections 220 has a corresponding recess 210.

[0029] In order to assemble the cooling device 130, for example, the extensions 220, also called pins, of the second wall 215, also referred to as cooling plate, are inserted into the recesses 210, also called dimples, of the first wall 205, or in other words into the dimples of the cooling channel 200.

[0030] The cooling device 130 also has a circumferential wall 225, which is optionally octagonal in shape with rounded corners. The circumferential wall 225 is arranged between the first wall 205 and the second wall 215. The cooling channel 200 is delimited by the first wall 205 and the second wall 215 and by the circumferential wall 225. An inlet 230 and an outlet 235 opposite the inlet 230 are arranged in the circumferential wall 225. The inlet 230 is arranged on a first side 240 of the cooling device 130 and is used, for example, to let the coolant into the cooling channel 200. The outlet 235 is arranged on a second side 245 of the cooling device 130 and is used, for example, to discharge the coolant from the cooling channel 200.

[0031] According to one embodiment, the first wall 205 and the peripheral wall 225 are formed in one piece.

[0032] When the coolant flows through the cooling channel 200, it must pass through the extensions. This results in improved heat transfer compared to a cooling channel without extensions.

[0033] Fig. 3 shows a schematic representation of a cooling device 130 according to an embodiment. The cooling device 130 is, for example, the one shown in Fig. 2 shown cooling device in an assembled state. To assemble the cooling device 130, for example, the extensions of the second wall 215 were inserted into the recesses of the first wall, or in other words into the recesses of the Fig. 3 closed cooling channel. Edges of the second wall 215 rest on the surrounding wall 225.

[0034] Fig. 4 shows a sectional view of a cooling device 130 according to an embodiment. The cooling device 130 is, for example, the one shown in Fig. 3 shows the assembled cooling device in a sectional view through the inlet 230 and the outlet 235. The ends of the extensions 220 of the second wall 215 are inserted into the recesses of the first wall 205.

[0035] According to one embodiment, the first wall 205 is formed as part of a housing 400 for a choke or power electronics of a power converter. The first wall 205 optionally forms an upper closure of the housing 400. Furthermore, the housing 400 has a circumferential side wall. Optionally, the first wall 204 and the housing 400 are formed as a single piece.

[0036] A side of the first wall 205 facing away from the cooling channel optionally has at least one recess for receiving a portion of a coil winding of a choke. For example, the housing 400 is formed into two chambers for receiving two chokes. In this way, heat generated by the chokes during operation of the power converter can be dissipated via the first wall to the coolant flowing through the cooling channel.

[0037] Fig. 5 shows a schematic representation of a first wall 205 and a housing 400 of a cooling device according to an exemplary embodiment. The first wall 205 is formed, for example, as part of a housing 400. The first wall 205 optionally forms a closure of the housing 400 facing the cooling channel 200.

[0038] The recesses 210 are arranged in a plurality of rows and columns, which, according to one embodiment, extend over a large part of a surface of the first wall 205, for example over at least 70%, at least 80% or at least 90% of the surface of the first wall 205 of the cooling channel 200.

[0039] By way of example only, a number and an arrangement of the recesses 210 correspond to a number and an arrangement of the Fig. 6, so that, for example, each extension can be arranged in its own recess 210 in order to arrange the second wall on the first wall 205.

[0040] According to one embodiment, the recesses 210 extend over a rectangular section of the first wall 205. Optionally, only a section of the first wall 205 facing the inlet 230 and a section of the first wall 205 facing the outlet 235 are each free of recesses 210.

[0041] According to one embodiment, the rows of recesses 210 extend continuously along and parallel to rectilinear sections of the circumferential wall 225 on a third side 500 and a fourth side 510 of the cooling device arranged opposite the third side 500.

[0042] According to one embodiment, the columns of the recesses 210 extend continuously between a section of the circumferential wall 225 arranged on the third side 500 and a section of the circumferential wall 225 arranged on the fourth side 510. According to one embodiment, the recesses 210 are arranged offset from one another in adjacent columns, so that a distance between adjacent recesses 210 in the same column as well as a distance between adjacent recesses 210 in adjacent columns can be kept small.

[0043] For example, the recesses 210 each have a first shape in a first region 505 running along the third side 500 of the cooling device and in a second region 515 facing the fourth side 510 of the cooling device. This first shape of the recesses 210 is, for example, round or circular. In a third region 520 arranged between the first region 505 and the second region 515, the recesses 210 have a second shape that differs from the first shape. This second shape of the recesses 210 is, for example, oval or egg-shaped.

[0044] In other words, the dimples or dimples, i.e. the recesses 210, in a further variant of the approach presented have different shapes, for example recesses 210 arranged laterally on the first wall 205 in a circular shape for a bypass, i.e. for bypassing a central region of the first wall 205, and for example recesses 210 in an oval shape in the middle of the first wall 205 or in the middle of Fig. 5 shown open cooling channel 200 for a better cooling function of the cooling channel 200, and in particular of the first wall 205, which functions as a secondary cooling example. Accordingly, Fig. 5 may alternatively be referred to as a representation of the cooling channel 200 with dimples for secondary cooling.

[0045] Fig. Figure 6 shows a schematic representation of a second wall 215 of a cooling device according to an embodiment. The second wall 215 can be seen in particular at the Fig. 5 to produce an assembled cooling device.

[0046] The extensions 220 are arranged in a plurality of rows and columns, which optionally form a large part of a surface of the second wall 215. Optionally, the extensions 220, also referred to as pin fins, are arranged over a largely rectangular surface of the second wall 215 and form a structure, here a so-called pin fin structure, which is used, for example, for primary cooling. The second wall 215 is also referred to as a cooling plate and functions, for example, as the primary cooling of the cooling device. Optionally, only outer edge regions of the second wall 215 are free of extensions 220 for resting on the surrounding wall.

[0047] Fig. 7 shows a sectional view of a first wall 205 of a cooling device according to one embodiment. The first wall 205 is shown in an XY plane, for example from above, and has the recesses 210. According to one embodiment, the recesses 210 are round. Alternatively, the recesses 210 are oval. In other words, the recesses 210 can also be oval-shaped, which enables a lower pressure loss of the flowing coolant. The extensions 220 of the second wall are at least partially accommodated by the recesses 210. Optionally, the ends of the extensions 220 have an oval cross-section, wherein a longitudinal axis of the oval cross-section is aligned parallel to a longitudinal axis of the cooling channel between the inlet and the outlet. Thus, a gap between the extensions 220 and walls of the recesses 210 is larger transverse to the longitudinal axis of the cooling channel than along the longitudinal axis.

[0048] According to one embodiment, the coolant 700 flows into the recesses 210 and around the extensions 220 arranged in the recesses 210, past the extensions 220, and between the extensions 220. For example, the coolant 700, also referred to as the flow of the coolant 700, flows into a first recess 210, in this first recess 210 in an arcuate flow path around a first extension 220 and past the first extension 220, and out of the first recess 210. For example only, the coolant 700 then flows into a second recess 210, in this second recess 210 in an arcuate flow path around a second extension 220 and past the second extension 220, and out of the second recess 210. According to one embodiment, this process continues with further extensions 220 and recesses 210. In other words, in the dimples, the coolant 700 flows around the pin fins.This leads in particular to a wave flow of the coolant 700 on the in . Fig. 7 illustrated XY plane.

[0049] Fig. 8 shows a sectional view of a first wall 205 and a second wall 215 of a cooling device according to an exemplary embodiment. The first wall 205 and the second wall 215 are shown in an XZ plane, for example, from the perspective of the third side or the fourth side of the cooling device. The first wall 205 has the recesses 210. The extensions 220 of the second wall 215 are at least partially accommodated by the recesses 210. The ends of the extensions 220 facing the first wall 205 are optionally each spaced from the first wall 205 by a gap 800. In this way, the coolant can flow not only along the side walls of the extensions 220, but also along the end faces of the extensions 220 facing the first wall 205.

[0050] In addition, manufacturing-related height tolerances of the extensions can be compensated for by appropriate gaps between the free ends of the extensions 220 and the first wall 205.

[0051] The coolant 700 flows or streams, for example, in the recesses 210 and in the gaps 800 under the extensions 220 and past the extensions 220, whereby the coolant 700 cools the first wall 205, also called secondary cooling. The coolant 700 also flows between the extensions 220, whereby the coolant 700 cools the second wall 215, also called primary cooling. For example, the coolant 700, also referred to as the flow of the coolant 700, flows in the form of an input of the coolant 700, also called input coolant 700, into a first recess of the recesses 210, in this first recess 210 in a first gap 800 in an arcuate flow path under a first extension of the extensions 220 and past the first extension 220, and out of the first recess 210.For example only, the coolant 700 then flows into a second recess of the recesses 210, in this second recess 210 in a second gap 800 in an arcuate flow path under a second extension of the extensions 220 and past the second extension 220, and out of the second recess 210. According to one embodiment, this process continues with further extensions 220 and recesses 210. In other words, a portion of the coolant 700 flows through a pin-fin structure, i.e., through a structure of the extensions 220, and cools a primary side, i.e., the second wall 215.Another part of the coolant 700 flows into the dimples, i.e. into the recesses 210, and in the form of an output of the coolant 700, also called output coolant 700, (again) out of the recesses 210, thus cooling a secondary side, i.e. the first wall 205, and thereby, for example, additionally improves the primary cooling, i.e. cooling of the second wall 215, by increased turbulence, i.e. movement, of the coolant 700. This leads in particular to a wave flow of the coolant 700 on the in . Fig. 8 illustrated XZ plane.

[0052] Fig. 9 shows a sectional view of a first wall 205 and a second wall 215 of a cooling device according to an embodiment. For example only, the first wall 205 and the second wall 215 are the Fig. 8. The ends of the extensions 220 facing the first wall 205 are soldered to the recesses 210, so that, for example, a soldering material 900 is located in each of the gaps 800 between the extensions 220 and the recesses 210. Due to the recesses 210, the soldering material 900 cannot flow away during heating, thus keeping the cooling channel clean.

[0053] In other words, in the exemplary embodiment shown, the extensions 200 designed as pin fins are soldered into the recesses 210 designed as dimples, and the recesses 210 function, for example, as holders for the soldering material 900. The extensions 200 are thus inserted into the soldering material 900 and are thereby very well connected to the recesses 210. Thus, according to such a variant, the secondary cooling, i.e. the cooling of the first wall 205, has the same or similar pin fin structure as the primary cooling, i.e. the cooling of the second wall 215.

[0054] Fig. 10 shows a flowchart of an embodiment of a method 1000 for producing a cooling device, as described by way of example with reference to the preceding figures.

[0055] The method 1000 comprises a step 1005 of providing a first wall and a second wall of a cooling channel. The first wall has a plurality of recesses on a side facing the cooling channel. The second wall has a plurality of extensions on a side facing the cooling channel.

[0056] In a step 1010 of the arrangement, a solder material is arranged in the recesses and heated in a step 1015.

[0057] In step 1020, the ends of the extensions of the second wall are inserted into the recesses of the first wall and thus into the heated solder material. As the solder material subsequently cools, the ends of the extensions are soldered to the recesses. Alternatively, steps 1015 and 1020 can also be performed in reverse order or simultaneously.

[0058] In other words, the projections are soldered into the recesses, and the recesses act as holders for the solder material. The projections are inserted into the solder material and thus bond very tightly to the recesses. Thus, the secondary cooling, i.e., the cooling of the first wall, has the same or similar pin-fin structure as the primary cooling, i.e., the cooling of the second wall.

[0059] As shown in the preceding figures, the recesses in the first wall of the cooling device enable advantageous choke cooling and an advantageous cooling concept, exemplified for a choke of a rectifier, such as a HVHV DCDC GaN. The described approach can be used, for example, in conjunction with an inverter, a DC / DC converter, or for a charging device in the form of an onboard charger. Reference symbol 100 motor vehicles 105 electric machine 110 Energy supply facility 115 power converters 120 Gearbox 125 bike 130 Cooling device 131 Throttle 132 Power electronics 135 Charging device 200 cooling channel 205 first wall 210 recess 215 second wall 220 extension 225 surrounding wall 230 entrance 235 Outlet 240 first side of the cooling device 245 second side of the cooling device 400 housings 500 third side of the cooling device 505 first area of ​​the first wall 510 fourth side of the cooling device 515 second area of ​​the first wall 520 third area of ​​the first wall 700 coolant 800 gap 805 Heat 900 soldering material 1000 Method for manufacturing a cooling device 1005 Deployment Step 1010 Step of arranging 1015 Heating step 1020 step of arranging

Claims

[1] Cooling device (130) for a power converter (115) for a motor vehicle (100), wherein the cooling device (130) has a cooling channel (200) for guiding a coolant (700) and the following features: a first wall (205) of the cooling channel (200), the first wall (205) having a plurality of recesses (210) on a side facing the cooling channel (200); a second wall (215) of the cooling channel (200), wherein the second wall (215) is arranged opposite the first wall (205) and has a plurality of extensions (220) on a side facing the cooling channel (200), wherein ends of the extensions (220) facing the first wall (205) are received by the plurality of recesses (210); and an inlet (230) arranged on a first side (240) of the cooling device (130) for admitting the coolant (700) into the cooling channel (200) and an outlet (235) arranged on a second side (245) of the cooling device (130) and opposite the inlet (230) for discharging the coolant (700) from the cooling channel (200). [2] Cooling device (130) according to claim 1, wherein a number of the extensions (220) corresponds to a number of the recesses (210). [3] Cooling device (130) according to one of the preceding claims, wherein the extensions (220) and the recesses (210) are arranged in a plurality of rows and columns. [4] Cooling device (130) according to one of the preceding claims, wherein the ends of the extensions (220) facing the first wall (205) are each spaced from the first wall (205) by a gap (800). [5] Cooling device (130) according to one of the preceding claims, wherein the ends of the extensions (220) facing the first wall (205) are soldered to the recesses (210). [6] Cooling device (130) according to one of the preceding claims, wherein the recesses (210) are round or oval in shape. [7] Cooling device (130) according to one of the preceding claims, wherein the recesses (210) in a first region (505) of the first wall (205) facing a third side (500) of the cooling device (130) and in a second region (515) of the first wall (205) facing a fourth side (510) of the cooling device (130) opposite the third side (500) each have a first shape, and wherein the recesses (210) in a third region (520) of the first wall (205) arranged between the first region (505) and the second region (515) have a second shape different from the first shape. [8] Cooling device (130) according to one of the preceding claims, wherein the cooling device (130) has a circumferential wall (225) arranged between the first wall (205) and the second wall (215), wherein the cooling channel (200) is delimited by the circumferential wall (225) and the first wall (205) and the second wall (215), and wherein the inlet (230) and the outlet (235) are each arranged adjacent to the circumferential wall (225) and opposite one another. [9] Cooling device (130) according to one of the preceding claims, wherein the first wall (205) is formed as part of a housing (400) for a choke (131) or for power electronics (132) of the power converter (115). [10] Power converter (115) with a cooling device (130) according to claim 9 and with a choke (131) or power electronics (132) arranged in the housing (400). [11] Electric axle drive for a motor vehicle (100), wherein the electric axle drive comprises at least one electric machine (105), a transmission device (120) and a power converter (115) according to claim 10. [12] Motor vehicle (100) with a power converter (115) according to claim 10 and / or an electric axle drive according to claim 11. [13] Method (1000) for manufacturing a cooling device (130), the method (1000) comprising the following steps: Providing (1005) a first wall (205) and a second wall (215) of a cooling channel (200), wherein the first wall (205) has a plurality of recesses (210) on a side facing the cooling channel (200), and wherein the second wall (215) has a plurality of extensions (220) on a side facing the cooling channel (200); Arranging (1010) a soldering material (900) in the recesses (210); heating (1015) the soldering material; and Inserting (1020) the ends of the extensions (220) of the second wall (215) into the recesses (210) of the first wall (205) in order to solder the ends of the extensions to the recesses.

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