Air guiding element for detachable fastening to an electrical component, air guiding arrangement, method for producing an air guiding arrangement, and use of the air guiding element

Abstract

The present invention relates to an air guiding element (1) for detachable fastening to an electrical component (2) in the region of an end face of an electrical machine (4) comprising a stator (8), wherein the air guiding element (1) is fixed to the electrical component (2) by at least one limiting element (16) and has an impingement region (12) and at least one deflection region (14, 14'), wherein the air guiding element (1) is designed and configured to guide and / or distribute a cooling air flow (K), which impinges on the impingement region (12), via the at least one deflection region (14, 14'), in such a way that cooling of the stator (8) takes place. The invention further relates to an air guiding arrangement (100) comprising an electrical component (2), an air guiding element (1) and at least one limiting element (16). The invention further relates to a method for producing the air guiding arrangement (100) and to a use of the air guiding element (1).

Description

[0001] R.415072

[0002] - 1 -

[0003] Description

[0004] title

[0005] Air guide element for detachable attachment to an electrical component, air guide arrangement, method for manufacturing an air guide arrangement and use of the air guide element

[0006] Technical field

[0007] The present invention relates to an air guide element for detachable attachment to an electrical component in the region of an end face of an electrical machine comprising a stator, wherein the air guide element is fixed to the electrical component by at least one limiting element and has an impact area and at least one deflection area, wherein the air guide element is designed and configured to guide and / or distribute a cooling airflow that strikes the impact area over the at least one deflection area in such a way as to cool the stator. The invention further relates to an air guide arrangement comprising an electrical component, an air guide element and at least one limiting element. The invention further relates to a method for manufacturing the air guide arrangement and to a use of the air guide element.

[0008] State of the art

[0009] Electric turbomachines are integral to numerous technical applications; for example, they can be designed as turbo compressors and supply a fuel cell system with oxygen. Such fuel cell systems are known to those skilled in the art, for instance, from DE 10 2018 201 162 A1, in which air is drawn in from the environment, pressurized to the necessary pressure in the compressor, and then supplied to the fuel cell stack for power generation.

[0010] The compressors feature a rotor, which is designed as a shaft with a compressor end and, optionally, a turbine end, as well as a stator surrounding the rotor. This stator, in turn, usually has a cylindrical shape. R.415072

[0011] - 2 -

[0012] Stator body with stator windings, formed winding heads and a stator sleeve.

[0013] Especially in turbomachinery, which operates in high voltage ranges and has an increasing packing density with ever smaller distances between current-carrying parts, the requirements for electrical insulation are immense in order to avoid leakage current.

[0014] Standardly, insulating paper is used for electrical and mechanical insulation, but the more cost-effective variants have an insufficient CTI (Comparative Tracking Index) value according to IEC 60112, which is usually less than 400.

[0015] Alternatively or additionally, the individual components of the stator can be encapsulated with an electrically insulating potting compound. The initially liquid potting compound penetrates the cavities of the stator body and the stator windings and then hardens. The potting compound can be used throughout the entire stator or only for the insulation of individual components, as shown, for example, in DE 10 2013 223 051 A1.

[0016] Especially in systems where the potting compound is used as a full encapsulation, adequate cooling of the system must be ensured. Prior art includes the use of recesses in the potting compound to create cooling air channels, as shown, for example, in DE 10 2019 112 551 A1. The disadvantage of such cooling solutions is that the channels in the potting compound are relatively complex to manufacture, which, in addition to costs and time, also requires specially manufactured tooling components.

[0017] Accordingly, there is immense demand for systems that ensure adequate cooling of the stator in an electric machine, particularly in an air compressor, even when it is filled with an encapsulating material for electrical insulation. The system should be flexible in its application and easily integrated into limited installation space. Furthermore, the electrical insulation of the stator should not be adversely affected.

[0018] Disclosure of the invention

[0019] According to the invention, an air guide element for detachable attachment to an electrical component in the area of ​​an end face of an electrical machine is proposed, wherein the electrical machine in preferred R.415072

[0020] - 3 -

[0021] The device is designed as an air compressor. The electric machine comprises at least one stator as described above. The air guide element according to the invention comprises at least one positioning element, an impact area, and at least one deflection area, wherein the at least one positioning element is designed and configured to position the air guide element on an electrical component. According to the invention, the air guide element is fixed to the electrical component by at least one limiting element and is designed and configured to guide and / or distribute a cooling airflow that strikes the impact area over the at least one deflection area in such a way that the stator is cooled.

[0022] According to the invention, an air guide element is understood to be an element that can guide, direct, or even redirect air in a system, particularly in an electric machine, to preferred areas, namely where cooling is required due to the heat generated. Additionally, the air guide element can also divide cooling airflows, allowing the cool air to reach multiple areas where cooling is needed. According to the invention, the air guide element achieves this solely through its geometry and position within the electric machine; in particular, no active fans or rotating impellers are part of the air guide element according to the invention, although interaction with such components is certainly possible. According to the invention, the air guide element is positioned within the electric machine such that a cooling airflow strikes an impact area of ​​the air guide element.The cooling airflow can originate from a cooling element located within the system, such as a heat exchanger, with the air guide element positioned in the area where the cooling airflow departs from the cooling element. From the point of impact, the cooling airflow is guided through at least one deflection area and ultimately enters the stator, specifically the inner wall of the stator body.

[0023] In suitable embodiments, the electrical component for mounting is selected from a stator base body, a stator sleeve, and / or the cooling element itself. Preferably, the air guide element is attached to only one component, but in alternative embodiments, it can also be mounted across two components. R.415072 provides a mounting solution.

[0024] - 4 - The air guide element according to the invention comprises at least one positioning element, wherein in embodiments in which the air guide element is attached to exactly one component, one positioning element is sufficient. In suitable embodiments, the positioning element is designed as a raised portion in the air guide element, which can be inserted into a recess in the electrical component. The positioning element primarily serves the purpose of positioning the air guide element, i.e., attaching it at a specific point, but in some embodiments it can also provide for fixation, meaning a secure attachment. In both cases, the attachment via the positioning element is a detachable attachment, meaning that the air guide element can be easily removed from the electrical component.

[0025] In suitable embodiments of the air guide element according to the invention, it additionally comprises at least one snap-in element, which serves for the fixed, but releasable, attachment of the air guide element. The snap-in element can be designed as an insertion element projecting from the air guide element, with the electrical component accordingly having a recess or a receiving element. The releasable connection is then achieved by snapping, clicking, or the like, the common snap-in systems being familiar to those skilled in the art. A magnetic connection is also possible, provided that the snap-in element and the recess comprise magnetic materials. Snap-in elements designed in this way enable a particularly cost-effective fixed attachment of the air guide element according to the invention.

[0026] The limiting element serves to hold the air guide element in its position, particularly in embodiments where no snap-in element is present. According to the invention, this is achieved by exerting pressure on the side of the air guide element that does not face the electrical component. In preferred embodiments, this pressure is exerted by the housing of the electric machine itself; in this case, the limiting element is the housing of the machine, with the air guide element essentially being clamped between the electrical component for mounting and the housing. Using the housing as the limiting element thus has the advantage that no additional element is required, but rather the existing components of the electric machine are utilized, making installation cost-effective and time-saving. R.415072

[0027] - 5 -

[0028] In a preferred embodiment, the air guide element according to the invention comprises or is made of plastic. On the one hand, such an air guide element can be manufactured relatively easily and cost-effectively using injection molding; on the other hand, this can also contribute to electrical insulation when suitable plastics are selected. Plastics with a CTI value according to IEC 60112 of > 400 V are particularly well suited for this purpose.

[0029] In an alternative, but no less preferred, embodiment, the air guide element according to the invention comprises or is made of metal. Aluminum has proven particularly suitable due to its good thermal conductivity and low weight. In such embodiments, the air guide element is particularly robust, meaning that it withstands high thermal and mechanical loads and has a long service life. In suitable embodiments, the air guide element according to the invention can also be refurbished and reused, for example, in the event of a defect in the electric motor.

[0030] The electric machine also includes a rotor, as described above. In preferred embodiments, this rotor is designed as a shaft and comprises a compressor side and, optionally, a turbine side. In preferred configurations, the air guide element is attached to the compressor side, but alternatively, it can also be attached to the turbine side. In a further alternative embodiment, an air guide element according to the invention can be attached to both the compressor side and the turbine side.

[0031] In preferred embodiments of the air guide element according to the invention, this element is part of an electric machine designed as an air compressor for supplying compressed air to a fuel cell system. In particular, the air compressor comprises a stator through which a potting material is encased, which may be a full encasement or only a partial encasement with potting material, as described above.

[0032] According to the invention, an air guide arrangement in an electric machine, in particular in an air compressor, is further proposed, wherein this includes an electrical component, in particular a stator base body, an R.415072

[0033] - 6 -

[0034] The air guide assembly comprises a stator sleeve and / or a cooling element, as well as an air guide element according to the invention, in particular as described above, and at least one limiting element. In the air guide assembly according to the invention, the air guide element according to the invention is arranged between the electrical component and the limiting element such that, when guiding and / or distributing a cooling airflow over the at least one deflection area into the stator, the air guide element according to the invention is positioned essentially without movement and noise generation is avoided.

[0035] According to the invention, "positioned essentially without movement" means that, in the case of only one positioning element without an additional locking element, the air guide element may exhibit a certain natural vibration due to the cooling airflow passing over the at least one deflection area, but the pressure of the limiting element prevents any noticeable movements, such as rotations around the positioning element. In the case of two positioning elements, i.e., two contact points on the electrical component(s), this natural vibration is further reduced. In embodiments with an additional locking element, the natural vibration of the air guide element is virtually non-existent.

[0036] Because the air guide element according to the invention vibrates almost imperceptibly, no noise is generated when the air guide arrangement according to the invention is used for cooling the stator.

[0037] Furthermore, according to the invention, a method for manufacturing an air guidance arrangement, in particular an air guidance arrangement according to the invention, is proposed, wherein the air guidance element in this embodiment does not include a snap-in element, and wherein the method comprises the following steps: a) providing an air guidance element comprising at least one positioning element, an impact area and at least one deflection area; b) positioning the air guidance element on an electrical component via the positioning element, in particular on a stator base body, a stator sleeve and / or a cooling element, such that R.415072

[0038] - 7 - the impact area of ​​the air guide element is essentially perpendicular to the incident cooling airflow K and leads to at least one deflection area into the stator base body c) fixing the air guide element in the mounting direction by means of a limiting element, in particular by means of a housing, so that the air guide element is arranged between the electrical component and the limiting element.

[0039] Alternatively, according to the invention, a method for manufacturing an air guide arrangement, in particular an air guide arrangement according to the invention, is proposed, wherein the air guide element in this embodiment comprises at least one snap-in element, wherein the method comprises the following steps: a) providing an air guide element comprising at least one positioning element, an impact area, at least one deflection area and at least one snap-in element; b) positioning the air guide element on an electrical component via the positioning element, in particular on a stator base body, a stator sleeve and / or a cooling element.so that the impact area of ​​the air guide element is essentially perpendicular to the incident cooling airflow K and the at least one deflection area leads into an inner wall of the stator base body; c) Insertion of the at least one snap-in element of the air guide element into the recess of the electrical component, so that the air guide element is arranged essentially without movement; d) Fixation of the air guide element in the mounting direction by means of a limiting element, in particular by means of a housing, so that the air guide element is arranged between the electrical component and the limiting element.

[0040] In the method for manufacturing an air guide assembly, in which the air guide element additionally comprises at least one snap-in element, process steps b) and c) can be carried out sequentially, with process step b) being performed first and then process step c), or vice versa. Alternatively, process steps b) and c) can also be carried out simultaneously, which means that the positioning via the at least R.415072

[0041] - 8 - a positioning element and the fixing via the at least one snap-in element take place simultaneously.

[0042] Furthermore, according to the invention, the use of the air guide element and / or the air guide arrangement according to the invention is proposed for cooling a stator of an electric machine, in particular a stator which is permeated by a potting material, as part of an air compressor, in particular for providing compressed air for a fuel cell system.

[0043] Advantages of the invention

[0044] The air guide element according to the invention for detachable attachment to an electrical component in the area of ​​an end face of an electrical machine, in particular an air compressor, allows the contained stator, which may be permeated with a potting material and is therefore well electrically insulated, to be sufficiently cooled without the need for a special manufacturing process for introducing the potting material.

[0045] The air guide element according to the invention does not impair the electrical insulation in any way and can be flexibly attached to one or more electrical components in a space-saving manner, depending on the possible attachment method.

[0046] The manufacturing costs of the air guide element according to the invention are very low, since the air guide element provides improved cooling of the stator solely through its geometry and position in the electric machine, and no complex components such as fans or rotatable impellers are required.

[0047] The assembly of the air guide element according to the invention, or the manufacture of the air guide arrangement according to the invention, is also remarkably simple; it requires only a positioning element, optionally a snap-in element, and a limiting element. In embodiments where the limiting element is formed by the housing of the electric machine, no additional components are required; the air guide element is held in place solely by the pressure of the housing. R.415072

[0048] - 9 -

[0049] The embodiment of an air guide element according to the invention made of plastic offers the possibility of producing it in large quantities simply and cost-effectively using an injection molding process; the embodiment made of metal offers the advantages that the air guide element is particularly robust and has good resistance to thermal and mechanical stress.

[0050] In the air guidance arrangement according to the invention, the air guidance element according to the invention is arranged in a substantially motion-free manner, which means that there is little natural vibration of the air guidance element, thus avoiding noise formation.

[0051] Brief description of the drawings

[0052] Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

[0053] They show:

[0054] Figure 1 shows a schematic side and front view of an air guide element according to the invention;

[0055] Figure 2 shows a schematic cross-sectional view of an air guidance arrangement according to the invention;

[0056] Figure 3 shows a schematic cross-sectional view of a built-in air guide element according to the invention and

[0057] Figure 4 shows a schematic perspective view of a built-in air guide element according to the invention.

[0058] Embodiments of the invention

[0059] In the following description of embodiments of the invention, identical or similar elements are designated by the same reference numerals, and repeated descriptions of these elements are omitted in individual cases. The figures represent the subject matter of the invention only schematically. R.415072

[0060] - 10 -

[0061] Figure 1 shows on the left a side view of an air guide element 1 according to the invention and on the right the corresponding front view, the front being the side that, in the case of an installed air guide element 1, faces the electrical component 2 (not shown here). In the embodiment shown here, the air guide element 1 according to the invention has a positioning element 10, which is designed here as a rod-shaped protrusion. Furthermore, the air guide element 1 has an impact area 12 on its upper side, which is designed here as an arcuate shape. In the variant shown, the air guide element 1 according to the invention has a substantially triangular cross-section with an arcuate tip, the arcuate tip opening into the deflection areas 14 and 14' on both sides.According to the invention, a cooling airflow K strikes the impact area 12 and is guided or distributed via the two deflection areas 14 and 14' in such a way that the stator 8 is cooled (not shown here). Furthermore, the embodiment of the air guide element 1 according to the invention shown in Figure 1 has a snap-in element 18, which is located approximately in the middle of the triangular base shape in cross-section. The snap-in element 18 is designed and configured to be inserted into a recess 20 of the electrical component 2 (not shown here) and to form the releasable fastening.

[0062] Figure 2 shows a schematic cross-sectional view of an air guidance arrangement 100 according to the invention, which, for example, comprises an air guidance element 1 as shown in Figure 1. The electric machine 4, in the form of an air compressor 6, comprises a stator 8 with a stator base 22, a stator sleeve 24, and a cooling element 26, wherein the stator base 22 is filled with a potting material 38. Furthermore, the air compressor 6 has a rotor 30, which is designed as a shaft 32 with a compressor side 34 and a turbine side 36.

[0063] The air guide element 1 according to the invention is located on the compressor side 34 and is detachably attached to an electrical component 2, which in the variant shown here is formed by the stator sleeve 24. The individual elements of the air guide element 1 are not shown in Figure 2; however, it is evident that the air guide element 1 is positioned precisely between the stator sleeve 24 and the limiting element 16, which here is formed by the housing 28, and is held in its position by the pressure of the housing 28. A cooling airflow K leads from R.415072

[0064] - 11 - the cooling element 26 via the impact area 12 and the two deflection areas 14 and 14' of the air guide element 1 (not shown here) into the inner wall of the stator base body 22.

[0065] Figure 3 shows a schematic cross-sectional view of an air guide element 1 according to the invention, installed in an electric machine 4, in particular in an air compressor 6. The air guide element 1 according to the invention is detachably attached to an electrical component 2, here in the form of a stator sleeve 24, in the region of an end face of the electric machine 4. The air guide element 1 according to the invention has a positioning element 10, which is designed as a raised section and can be inserted into a recess in the stator sleeve 24. Furthermore, the air guide element 1 shown here has a snap-in element 18, which is located in the recess 20 in the stator sleeve 24 and thus forms the detachable fastening. The air guide element 1 is firmly fixed to the stator sleeve 24 by the pressure of the limiting element 16, which here is designed as a housing 28.According to the invention, a cooling airflow K, which leaves the cooling element 26, strikes the impact area 12 and is guided and / or distributed via the two deflection areas 14 and 14' (only 14 is shown here) in such a way that the stator 8 is cooled. As already discussed for Figure 2, the stator 8 comprises a stator base body 22, a stator sleeve 24, and a cooling element 26, wherein the stator base body 22 is filled with a potting material 38.

[0066] Figure 4 shows the air guide element 1, already discussed in Figure 3, again in a schematic perspective view. It is evident how the air guide element 1 is detachably attached to the stator sleeve 24 and that the impact area 12 of the air guide element 1 is essentially perpendicular to the incident cooling airflow K. After impacting the impact area 12, the cooling airflow K is guided and / or distributed to both sides via the deflection areas 14 and 14', thus cooling the stator 8, in particular the inner wall of the stator base body 22.

[0067] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, within the scope specified by the claims, a multitude of modifications are possible that fall within the bounds of what is considered skilled in the art.

Claims

R.415072 - 12 - Claims 1. Air guide element (1) for detachable attachment to an electrical component (2) in the region of an end face of an electrical machine (4), in particular an air compressor (6), wherein the electrical machine (4) comprises at least one stator (8) comprising at least one positioning element (10), an impact area (12) and at least one deflection area (14, 14'), wherein the at least one positioning element (10) is designed and configured to position the air guide element (1) on an electrical component (2), wherein the air guide element (1) is fixed to the electrical component (2) by at least one limiting element (16), wherein the air guide element (1) is designed and configured to guide and / or distribute a cooling airflow K, which strikes the impact area (12), over the at least one deflection area (14, 14') in such a way that the stator (8) is cooled.

2. Air guide element (1) according to claim 1, further comprising at least one snap-in element (18), designed and configured to be inserted into a recess (20) of the electrical component (2) and thus to form the releasable fastening.

3. Air guide element (1) according to claim 1 or 2, wherein the electrical component (2) for fastening is selected from a stator base body (22), a stator sleeve (24) and / or a cooling element (26).

4. Air guide element (1) according to at least one of the preceding claims, wherein the limiting element (16) is part of the electric machine (4), in particular comprising a housing (28). R.415072 - 13 - 5. Air guide element (1) according to at least one of the preceding claims, wherein the air guide element (1) comprises plastic or metal.

6. Air guide element (1) according to at least one of the preceding claims, wherein the electric machine (4), in particular the air compressor (6), further comprises a rotor (30) designed as a shaft (32) with a compressor side (34) and / or a turbine side (36), wherein the air guide element (1) is attached to the compressor side (34) and / or the turbine side (36).

7. Air guide element (1) according to at least one of the preceding claims, wherein the electric machine (4) is designed as an air compressor (6) for providing compressed air for a fuel cell system, in particular as an air compressor (6) comprising a stator (8) through which a potting material (38) is traversed.

8. Air guidance arrangement (100) in an electric machine (4), in particular in an air compressor (6), comprising an electrical component (2), in particular a stator base body (22), a stator sleeve (24) and / or a cooling element (26), an air guidance element (1), in particular according to at least one of claims 1 to 7, and at least one limiting element (16), wherein the air guidance element (1) is arranged between the electrical component (2) and the limiting element (16) such that when guiding and / or distributing a cooling air flow K over the at least one deflection area (14, 14') into the stator (8) the air guidance element (1) is positioned essentially without movement and noise formation is avoided.

9. Method for manufacturing an air guidance arrangement (100), in particular according to claim 8, comprising the steps: R.415072 - 14 - a) Provision of an air guide element (1) comprising at least one positioning element (10), an impact area (12) and at least one deflection area (14, 14') b) Positioning of the air guide element (1) on an electrical component (2) via the positioning element (10), in particular on a stator base body (22), a stator sleeve (24) and / or a cooling element (26), such that the impact area (12) of the air guide element (1) is substantially perpendicular to the incident cooling airflow K and the at least one deflection area (14, 14') leads into the stator base body (22) c) Fixing of the air guide element (1) in the mounting direction by means of a limiting element (16), in particular by means of a housing (28), such that the air guide element (1) is arranged between the electrical component (2) and the limiting element (16).

10. The method of claim 9, wherein the air guide element (1) further comprises at least one snap-in element (18), and the method comprises the following steps: a) providing an air guide element (1) comprising at least one positioning element (10), an impact area (12), at least one deflection area (14, 14') and at least one snap-in element (18); b) positioning the air guide element (1) on an electrical component (2) via the positioning element (10), in particular on a stator base body (22), a stator sleeve (24) and / or a cooling element (26), such that the impact area (12) of the air guide element (1) is substantially perpendicular to the incident cooling airflow K and the at least one deflection area (14, 14') leads into an inner wall of the stator base body (22); c) inserting the at least one snap-in element (18) of the air guide element (1) into the recess (20) of the electrical component (2),so that the air guide element (1) is arranged essentially without movement d) Fixing the air guide element (1) in the mounting direction by means of a limiting element (16), in particular by means of a housing (28), so that the air guide element (1) is arranged between the electrical component (2) and the limiting element (16), R.415072 - 15 - 11. Use of the air guide element (1) according to at least one of claims 1 to 7 and / or the air guide arrangement (100) according to claim 8 for cooling a stator (8) of an electric machine (4), in particular a stator (8) which is traversed by a potting material (38), as part of an air compressor (6), in particular for providing compressed air for a fuel cell system.

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