Air guide element, air guide assembly and method for cooling stator

Abstract

The invention relates to an air guide element for being movably fastened to an electrical component in an end-side region of an electrical machine comprising at least one stator, said air guide element comprising a rotary element, an impact region and at least two pressure surfaces, the rotational point of the air guide element being located in the region of the rotary element. The air guiding element guides and / or distributes a cooling air flow through the at least two pressure surfaces in order to cool the stator, and when different pressures act on the at least two pressure surfaces, the air guiding element rotates around a rotation point. The invention also relates to an air guide assembly comprising an electrical component and an air guide element. The invention also relates to a method for cooling a stator and to the use of an air guide element and an air guide assembly.

Description

Technical Field

[0001] This invention relates to an air guide element for movably fixing to an electrical component in an end-side region of an electric machine including at least one stator. The air guide element includes a rotating element, an impact region, and at least two pressure surfaces, with a rotation point located within the region of the rotating element. The air guide element guides and / or distributes cooling airflow through the at least two pressure surfaces to cool the stator, wherein the air guide element rotates about the rotation point when different pressures are applied to the at least two pressure surfaces. The invention further relates to an air guide assembly comprising an electrical component and an air guide element. The invention also relates to a method for cooling a stator and the application of an air guide element and an air guide assembly. Background Technology

[0002] Modern fuel cell systems, such as those known from DE102018201162A1, are based on the principle of drawing in air from the surrounding environment, providing the necessary pressure in a turbocharger or compressor, and ultimately supplying it to the fuel cell stack for power generation. For this purpose, a turbocharger capable of operating within a high voltage range is typically used.

[0003] Such turbochargers or compressors are constructed with a stator and a rotor, wherein the stator has a cylindrical stator base with stator windings, a winding head and a stator sleeve, and the rotor is typically constructed as a shaft with a compressor side and, if necessary, a turbine side.

[0004] Such systems are used in a wide range of technological applications and have become increasingly compact in recent years, which means increased packaging density and smaller spacing between charged components due to limited structural space.

[0005] Besides moisture formation and contamination, packaging density and small spacing are factors that can contribute to creepage. Therefore, especially when operating in high-voltage ranges, it is absolutely necessary to ensure that the compressor has sufficiently good electrical insulation.

[0006] Insulating paper provides a relatively simple and cost-effective electrical and mechanical insulation, and it is available in a variety of different implementations on the market. However, common variants, especially in high-voltage applications, do not provide sufficient CTI (Comparative Tracking Index) values ​​according to IEC 60112, which are typically less than 400V.

[0007] Another possibility for electrical insulation is the use of a casting material that can be injected into the cavities of the stator substrate and the regions of the stator windings in an initially liquid state, and then solidified. The casting material can be used in place of insulating paper, but is preferably used in combination with insulating paper. Alternatively, the casting material can be placed throughout the entire stator (so-called complete casting), or it can be used to surround only individual components, as shown, for example, in DE102013223051A1.

[0008] However, while casting materials offer advantages, it is important to note that adequate cooling of the motor is a challenge, especially in fully cast systems.

[0009] Existing systems rely, for example, on openings in the casting material in the form of cooling air channels, as disclosed, for example, in DE102019112551A1. However, it has been shown that manufacturing such cooling air channels in the casting material is relatively time-consuming and requires specially manufactured tooling components. Furthermore, depending on the construction of the cooling air channels, regions with different air pressures, i.e., pressure differentials, may appear in the system, which could lead to deformation of the electrical components.

[0010] Therefore, especially when the stator is filled with a casting material for electrical insulation, the need for a system to ensure adequate cooling of the stator in electric machines, particularly air compressors, is significant. A system needs to be found that can be used flexibly and space-efficiently due to limited structural space. Furthermore, the system should be able to counteract pressure differences in electric machines, especially air compressors. Summary of the Invention

[0011] According to the present invention, an air guide element is provided for movably fixing to an electrical component in an end-side region of an electric machine, particularly wherein the electric machine is configured as an air compressor and includes at least one stator as described above. The air guide element according to the invention comprises a rotating element, an impact region, and at least two pressure surfaces, wherein the rotation point of the air guide element is located in the region of the rotating element. According to the invention, the air guide element is designed and configured to guide and / or distribute a cooling airflow K impacting the impact region through the at least two pressure surfaces, thereby cooling the stator. Here, the air guide element rotates about the rotation point when different pressures are applied to the at least two pressure surfaces.

[0012] Therefore, the air guide element according to the invention is a component capable of directing, redirecting, or reversing air in an electrical machine to areas that generate heat and therefore require cooling. Here, the air guide element according to the invention can also divide the cooling flow and guide it to different areas within the electrical machine. Through the rotating element in the air guide element according to the invention, it can also be adapted to different airflows, meaning airflows with different speeds and therefore different acting pressures. Thus, by combining its geometry with the possibility of rotation around a pivot point, the air guide element according to the invention can guide and / or distribute the cooling airflow impacting the impact area via the at least two pressure surfaces, thereby adequately cooling the stator. Here, the air guide element according to the invention does not require an active fan or a rotatable impeller, but can cooperate with these components. Here, the cooling airflow impacting the impact area can originate from a cooling element present in the system, such as a heat exchanger, wherein the air guide element is positioned in the area from which the cooling airflow exits the cooling element.

[0013] In a preferred embodiment of the air guide element according to the invention, the rotating element is configured such that the air guide element itself includes a clearance. A separate fixing element can be received in this clearance, which on the one hand rotatably fixes the air guide element to the electrical component, and on the other hand constitutes the rotation point of the air guide element. Thus, the air guide element can rotate about the fixing element. In an alternative configuration, the fixing element may also be part of the air guide element, wherein the fixing element can then be fixed to the electrical component by screwing or pushing in; however, in which case, after fixing, a clearance is left for the air guide element to rotate about the fixing element.

[0014] In a suitable embodiment, the air guide element according to the invention has a basic triangular shape in cross-section, with an arcuate tip, wherein the arcuate tip opens to two pressure surfaces on both sides. Therefore, when a straight line is drawn through the arcuate tip and the point of rotation of the air guide element, it is preferable to obtain symmetrically formed sides that are mirror images of each other.

[0015] When the motor is not running, is being shut down, is in pause mode, or is in any other conceivable operating state, wherein there is no cooling or only minimal cooling by the cooling element, i.e. there is no cooling airflow or only a very low pressure cooling airflow, the air guide element according to the invention is in a stationary position.

[0016] In this stationary position, the impact zone is substantially perpendicular to the cooling airflow of the impact, meaning that the cooling airflow of the impact is substantially perpendicular to the straight line passing through the arcuate tip and the rotation point of the air guide element (see also...). Figure 4When the cooling airflow K now impacts the impact area and further impacts the at least two pressure surfaces with different pressures, the air guide element distributing the cooling airflow moves out of its rest position. This movement from the rest position does not occur through an active process, but rather the air guide element is rotatably supported around a fixed element about its point of rotation, such that when airflows with different velocities and therefore different pressures impact the pressure surfaces, the air guide element moves clockwise or counterclockwise.

[0017] Once the airflow weakens again or becomes uniform in its velocity, i.e., when substantially the same pressure is applied to the two pressure surfaces, the air guide element according to the invention moves around its point of rotation back to its stationary position.

[0018] To facilitate or accelerate the process of returning the movement to a stationary position, the air guide element according to the invention may, in a preferred configuration, further include at least one receiving element for at least one reset element. Here, the reset element is fixed at its other end to an electrical component and may be constructed, for example, as a mechanical spring, an elastic plastic connector (e.g., rubber), or the like.

[0019] Alternatively or additionally, at least two pressure surfaces of the air guide element may be configured such that when the air guide element moves out of its rest position, the at least two pressure surfaces are blocked by at least one stop, which causes the air guide element to move back to its rest position. Here, at least one stop, or alternatively two stops acting on one pressure surface respectively, is fixed to the electrical component, and the at least two pressure surfaces preferably have an arched shape.

[0020] The electrical components used for movable fixation are selected from the stator base, stator sleeve, and / or the cooling elements themselves in suitable configurations of the invention. Here, the air guide element according to the invention is preferably fixed to only one electrical component, but alternatively it can be fixed across two electrical components. This fixation is achieved by fixing elements, either separately or constructed as part of the air guide element, as discussed previously. In suitable embodiments, the fixation by the fixing elements is not only rotatable but also easily detachable, meaning the air guide element can be removed from the electrical components relatively easily.

[0021] The air guide element according to the invention can comprise plastic or metal, particularly plastic or metal. The advantage of the air guide element according to the invention being made of plastic is that it can be mass-produced simply and cost-effectively via injection molding, and additionally, with the selection of a suitable plastic, it also contributes to electrical insulation. Here, plastics having a CTI value >400V according to IEC 60112 are particularly advantageously suitable.

[0022] When the air guide element according to the invention is made of metal, a particularly robust air guide element can be obtained, which has high thermal and mechanical load capacity and is therefore very durable. Aluminum is particularly suitable due to its good thermal conductivity and low weight. Reworking / refinishing the metal air guide element can also be considered, which allows for reuse.

[0023] As mentioned at the beginning, the electric motor also includes a rotor, which is preferably constructed as a shaft and includes a compressor side and, if necessary, a turbine side. According to the invention, the air guide element is preferably mounted on the compressor side, but alternatively it can also be located on the turbine side. In another alternative configuration, air guide elements according to the invention can be mounted on both the compressor side and the turbine side, respectively.

[0024] According to the invention, the air guiding element is preferably part of an electromechanical device, particularly part of an air compressor for supplying compressed air to a fuel cell system. Specifically, the air compressor includes a stator filled with a verguss material (durchzogen), which can include full verguss filling or only partial filling with verguss material as described at the beginning.

[0025] According to the present invention, an air guiding assembly for use in electric machines, particularly air compressors, is also provided, wherein the air guiding assembly includes an air guiding element according to the present invention, particularly the air guiding element as described above, and includes electrical components, particularly a stator base, a stator sleeve, and / or a cooling element. Here, the electrical components have at least one stop and / or are alternatively or additionally connected to the air guiding element according to the present invention via a reset element, particularly via a mechanical spring. Here, the air guiding assembly according to the present invention is designed and configured for: i) The cooling airflow K impacting the impact area is guided and / or distributed by at least two pressure surfaces of the air guide element; and / or ii) Especially when different pressures are applied to at least two pressure surfaces, the air guide element can rotate about the pivot point; and / or iii) In particular, when the pressure acting on at least two pressure surfaces decreases, the air guide element is brought back to the stationary position by at least one stop and / or at least one reset element.

[0026] According to the present invention, pressure reduction is understood herein as the following operating states of the motor in which full-power cooling is not required, such as when the machine is turned on, turned off, or in pause mode.

[0027] All features and configurations already discussed for the air guide element according to the invention can be similarly transferred or applied to the air guide assembly according to the invention.

[0028] Furthermore, according to the present invention, a method for cooling a stator is proposed, comprising the following steps: a) Providing an air guiding assembly, particularly an air guiding assembly according to the present invention, the air guiding assembly comprising: In particular, according to the invention, the air guiding element has a rotating element, an impact region, and at least two pressure surfaces; and Electrical components, especially the stator base, stator sleeve and / or cooling elements, The electrical component includes at least one stop and / or reset element. If the electrical component includes a reset element, the air guide element is connected to the electrical component via the reset element if necessary. b) The cooling airflow K is guided and / or distributed to the impact area by at least two pressure surfaces of the air guiding element; c) When different pressures impact at least two pressure surfaces, the air guide element according to the invention is oriented, in particular, the air guide element is rotated about the point of rotation; d) When the pressure decreases, the air guide element is returned to the stationary position by at least one stop and / or at least one reset element.

[0029] Furthermore, according to the invention, the application of the air guiding element and / or the air guiding assembly according to the invention for cooling the stator of an electric machine is proposed, wherein the stator particularly relates to a stator filled with casting material and is part of an air compressor, which is particularly used to provide compressed air for a fuel cell system.

[0030] Advantages of the present invention By means of the air guide element according to the invention being movably and particularly rotatably fixed to the electrical components in the end-side region of the electric machine, especially the air compressor, the stator, which may be filled with casting material, can be adequately cooled without the need for special manufacturing methods to introduce the casting material.

[0031] Furthermore, it can flexibly respond to different air pressures in the system, especially those that may occur when the electric machine switches from one operating state to another. Therefore, these pressure differences can be avoided from affecting electrical components, thus preventing their deformation.

[0032] The air guide element according to the invention can be installed in a space-saving manner, and depending on the material, it can either be mass-produced cost-effectively or constructed robustly with high thermal and mechanical load capacity.

[0033] Since the air guide element according to the invention can be configured to move rather than be rigid, and moves approximately with the system rather than against it as required, noise generation can be greatly reduced. Attached Figure Description

[0034] The embodiments of the present invention will be described in detail with reference to the accompanying drawings and the following description.

[0035] The attached diagram shows: Figure 1 A schematic side view, a front view, and a perspective view of the air guiding element according to the present invention are shown; Figure 2 A schematic cross-sectional view of an air guiding assembly according to the present invention is shown; Figure 3 A schematic cross-sectional view of the installed air guide element according to the invention is shown; and Figure 4 A schematic perspective view of the air guiding element or air guiding assembly according to the invention, already installed, is shown.

[0036] In the following description of embodiments of the invention, the same or similar elements are denoted by the same reference numerals, and in some cases, repeated descriptions of these elements are omitted. The drawings are only schematic representations of the subject matter of the invention. Detailed Implementation

[0037] Figure 1A side view of the air guide element 1 according to the invention is shown on the upper left, a front view of the corresponding element is shown on the right, wherein the front side is the side facing the electrical component 2 (not shown here) with the air guide element 1 installed, and a perspective view of the air guide element 1 according to the invention is shown below. The air guide element 1 according to the invention here has a generally triangular basic shape in cross-section with an arcuate tip, wherein the arcuate tip forms an impact region 12, which has two pressure surfaces 14 and 14' on both sides. A rotating element 10 (not fully shown here) is formed in the variant shown here by a recess 18 in the air guide element 1, which is designed and configured to receive a fixing element 20 (not shown here). In the embodiment shown here, the air guide element 1 according to the invention further includes a receiving element 24 configured to receive a reset element 26, which is in particular in the form of a mechanical spring (not shown here), wherein the reset element 26 itself is fixed to the electrical component 2 (not shown here) and is used to move the air guide element 1 according to the invention back to a rest position 22 (not shown here).

[0038] Figure 2 A schematic cross-sectional view of an air guide assembly 100 according to the present invention is shown, the air guide assembly including, for example, such as Figure 1 The air guide element 1 is shown. The electrical device 4 is configured here as an air compressor 6 and includes a stator 8 having a stator base 30, a stator sleeve 32, and a cooling element 34, wherein the stator base 30 is filled with a casting material 44. Furthermore, the air compressor 6 has a rotor 36 configured as a shaft 38 with a compressor side 40 and a turbine side 42. On the compressor side 40, in the illustrated embodiment of the air guide assembly 100 according to the invention, the air guide element 1 according to the invention is movably mounted on an electrical component 2, which is here formed by the stator sleeve 32.

[0039] For clarity, the individual elements of air guide element 1 are shown in... Figure 2 Although not shown in the figure, it can be seen that the cooling airflow K flows from the cooling element 34 through the impact area 12 of the air guide element 1 and the two pressure surfaces 14 and 14' (not shown here) to the inner wall of the stator base 30.

[0040] Figure 3 A schematic cross-sectional view of an air guide element 1 according to the invention is shown, which is installed in an electric motor 4, particularly an air compressor 6, in the view shown.

[0041] The air guide element 1 according to the invention is rotatably mounted on the electrical component 2 (in the form of stator sleeve 32) in the end-side region of the electric motor 4 and includes a rotating element 10, which is formed by a recess 18 and a fixing element 20 in the air guide element 1 according to the invention. The fixing element 20 here constitutes the rotation point 16 of the air guide element 1. The air guide element 1 according to the invention further includes an impact region 12 and two pressure surfaces 14 and 14' (only 14 is visible in the view). According to the invention, the cooling airflow K leaving the cooling element 34 impacts the impact region 12 and is guided and / or distributed through the two pressure surfaces 14 and 14' to cool the stator 8, wherein the air guide element 1 rotates about the rotation point 16 when different pressures p1 and p2 act on at least two pressure surfaces 14 and 14' (not shown here). The stator 8 includes components already designed for... Figure 2 The components that have been discussed.

[0042] In order to move the air guide element 1 according to the invention back to the rest position 22 (not shown here), the air guide element includes a receiving element 24 for a reset element 26, which is symbolically shown above in the figure and is constructed as a mechanical spring.

[0043] Figure 4 Again, a schematic perspective view is shown, which has been targeted Figure 3 The air guide assembly 100 according to the invention discussed herein, or the air guide element 1 according to the invention already installed. The air guide element 1 according to the invention is movably fixed to the stator sleeve 32 and, in the illustrated variant, is in a rest position 22. This means that the impact region 12 is substantially perpendicular to the impacting cooling airflow K, meaning that the impacting cooling airflow K is perpendicular to the straight line passing through the impact region 12 and the rotation point 16. When the cooling airflow K impacts the impact region 12 and impacts at least two pressure surfaces 14 and 14' with different pressures p1 and p2, the air guide element 1 moves out of the rest position 22. Here, it moves out of the rest position 22 by rotational movement about the rotation point 16, which is formed by the fixing element 20.

[0044] In the illustrated embodiment, the air guide element 1 according to the invention includes a receiving element 24 for a reset element 26, which is configured as a mechanical spring and is used to move the air guide element 1 back to the rest position 22. Furthermore, the stator sleeve 32 has a stop 28 configured to block the pressure surface 14 when the air guide element 1 moves out of the rest position 22, and to bring the air guide element 1 back to the rest position 22.

[0045] This invention is not limited to the embodiments described herein and the aspects highlighted therein. Rather, various modifications are possible within the scope indicated in the specification, which are within the capabilities of those skilled in the art.

Claims

1. An air guiding element (1). The air guide element is designed to be movably fixed to the electrical component (2) in the end-side region of the electrical machine (4), in particular of the air compressor (6), wherein The electric machine (4) includes at least one stator (8). The air guiding element includes a rotating element (10), an impact region (12), and at least two pressure surfaces (14, 14'). The rotation point (16) of the air guide element (1) is located in the region of the rotating element (10). The air guide element (1) is designed and configured to guide and / or distribute cooling airflow K impacting the impact region (12) through the at least two pressure surfaces (14, 14') to cool the stator (8), wherein the air guide element (1) rotates about the rotation point (16) when different pressures (p1, p2) are applied to the at least two pressure surfaces (14, 14').

2. The air guiding element (1) according to claim 1. wherein The rotating element (10) includes a gap (18) in the air guide element (1), the gap being designed and configured to receive a fixing element (20) such that the air guide element (1) can rotate around the fixing element (20), wherein the fixing element (20) constitutes the rotation point (16) of the air guide element (1).

3. The air guiding element (1) according to claim 1 or 2. wherein When guiding and / or distributing the cooling airflow K, especially when different pressures (p1, p2) impact the at least two pressure surfaces (14, 14'), the air guiding element (1) can move out of the rest position (22).

4. The air guiding element (1) according to at least one of the preceding claims. The air guiding element further comprises at least one receiving element (24) for at least one reset element (26), in particular a mechanical spring, wherein The at least one reset element (26) is fixed to the electrical component (2), wherein the at least one reset element (26) is constructed and configured to move the air guide element (1) back to the stationary position (22).

5. The air guiding element (1) according to at least one of the preceding claims. in, The at least two pressure surfaces (14, 14') of the air guide element (1) are configured such that when the air guide element (1) moves out of the rest position (22), the at least two pressure surfaces (14, 14') are blocked by at least one stop (28), which causes the air guide element (1) to move back to the rest position (22), wherein the at least one stop (28) is fixed to the electrical component (2).

6. The air guiding element (1) according to at least one of the preceding claims. in, The electrical component (2) used for fixing is selected from the stator base (30), stator sleeve (32) and / or cooling element (34).

7. The air guiding element (1) according to at least one of the preceding claims. in, The air guiding element (1) may be made of plastic or metal.

8. The air guiding element (1) according to at least one of the preceding claims. in, The electric machine (4), especially the air compressor (6), also includes a rotor (36) configured as a shaft (38) with a compressor side (40) and / or a turbine side (42). The air guide element (1) is installed on the compressor side (40) and / or the turbine side (42).

9. The air guiding element (1) according to at least one of the preceding claims. in, The electric machine (4) is configured as an air compressor (6) for providing compressed air to the fuel cell system, and in particular as an air compressor (6) comprising a stator (8) filled with castable material (44).

10. An air guiding assembly (100) in an electric machine (4), particularly in an air compressor (6), the air guiding assembly comprising: Air guiding element (1), especially the air guiding element according to at least one of claims 1 to 9; Electrical components (2), especially stator base (30), stator sleeve (32) and / or cooling elements (34). The electrical component (2) includes at least one stop (28) and / or at least one reset element (26). The air guide element (1) is connected to the electrical component (2) via a reset element (26) when necessary. The air guide assembly (100) is designed and configured to: i) The cooling airflow K is guided and / or distributed to the impact region (12) by at least two pressure surfaces (14, 14') of the air guide element (1); and / or ii) Especially when different pressures (p1, p2) are applied to the at least two pressure surfaces (14, 14'), the air guide element (1) is able to rotate about the rotation point (16); and / or iii) In particular, when the pressure (p1, p2) acting on the at least two pressure surfaces (14, 14') decreases, the air guide element (1) is brought back to the rest position (22) by the at least one stop (28) and / or the at least one reset element (26).

11. A method for cooling a stator (8), comprising the following steps: a) Providing an air guiding assembly (100), particularly the air guiding assembly according to claim 10, the air guiding assembly comprising: An air guide element (1) having a rotating element (10), an impact region (12), and at least two pressure surfaces (14, 14'), the air guide element being particularly an air guide element (1) according to at least one of claims 1 to 9; and Electrical components (2), especially stator base (30), stator sleeve (32) and / or cooling elements (34). The electrical component (2) includes at least one stop (28) and / or at least one reset element (26). The air guide element (1) is connected to the electrical component (2) via a reset element (26) when necessary. b) The cooling airflow K is guided and / or distributed to the impact region (12) by at least two pressure surfaces (14, 14') of the air guiding element (1); c) When different pressures (p1, p2) impact the at least two pressure surfaces (14, 14'), orient the air guide element (1), in particular, rotate the air guide element (1) about the rotation point (16); d) When the pressure (p1, p2) decreases, the air guide element (1) is returned to the rest position (22) by the at least one stop (28) and / or the at least one reset element (26).

12. An application of an air guide element (1) according to at least one of claims 1 to 9 and / or an air guide assembly (100) according to claim 10 for cooling a stator (8) of an electric motor (4), the stator being in particular a stator (8) filled with casting material (44) as part of an air compressor (6), the air compressor being used in particular to provide compressed air for a fuel cell system.

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