Sealing arrangement and use thereof

Abstract

A sealing arrangement comprises a busbar (1) with at least one electrical conductor (2.1, 2.2, 2.3,…), and a two-component part (3), which comprises a supporting part (4) made of a semi-rigid material and a sealing body (5) made of a rubber-elastic sealing material, which is integrally bonded to the supporting part (4), and the sealing body (5) sealingly surrounds the electrical conductor (2.1, 2.2, 2.3,…) without adhering to it.

Description

[0001] Sealing arrangement and its use

[0002] Description

[0003] Technical area

[0004] The invention relates to a sealing arrangement and its use, wherein the sealing arrangement comprises a busbar with at least one electrical conductor which is sealed by a sealing body relative to a carrier part.

[0005] State of the art

[0006] Oil-cooled electric motors are being used in an increasing number of electric vehicles. These oil-cooled electric motors place increased demands on their sealing, particularly with regard to the power electronics of other electrical components, such as the power electronics of an inverter.

[0007] Electric vehicles also use busbars, which comprise electrical conductors made of copper or aluminum sheets that are punched out and then bent to the desired dimensions. Due to their manufacturing process, these copper or aluminum sheets have a rectangular conductor cross-section, which is unsatisfactory for standard sealing because the corners of the punched sheets do not allow for robust compression of the sealing material of standard gaskets.

[0008] For this reason, it is also state of the art for the rectangular conductors to be overmolded in a medium-tight thermoplastic or thermosetting material. If necessary, the conductors are additionally bonded with an adhesive. However, this generally does not achieve a permanently good sealing result. The sealing result is only initially satisfactory and often shows leaks after a short period of use, especially when the sealing points are exposed to temperature fluctuations. The reason for this is the different thermal expansion coefficients of the electrical conductors and the sealing materials that enclose the conductor. These different thermal expansion coefficients of the two materials lead to increased mechanical stresses at the boundary layers and thus to the leaks described above.

[0009] Another disadvantage is that the electrical conductors and the seals surrounding them cannot be separated without damaging them. In the event of a repair, the entire unit, consisting of the electrical conductors and seals, must be replaced, which is unsatisfactory in terms of environmental protection, responsible use of resources, and economics.

[0010] Description of the invention

[0011] The invention is based on the object of further developing a sealing arrangement of the type mentioned at the outset in such a way that the disadvantages mentioned above are avoided.

[0012] In particular, the sealing arrangement should exhibit consistently good performance characteristics over a long service life. Electrical conductors and seals should be replaceable separately as needed and recyclable.

[0013] In addition, a use of the sealing arrangement should be demonstrated.

[0014] This object is achieved according to the invention by the features of claim 1 and claim 14. The claims directly or indirectly referring back to claim 1 refer to advantageous embodiments of the sealing arrangement.

[0015] To achieve the object, a sealing arrangement is provided, comprising a busbar with at least one electrical conductor and a two-component component which comprises a carrier part made of a tough material and a sealing body made of a rubber-elastic sealing material, which is materially connected to the carrier part, wherein the sealing body encloses the electrical conductor in a non-adherent and sealing manner under elastic prestress.

[0016] The sealing body of the two-component component can be made of a conventional rubber-elastic sealing material. Rubber-elastic sealing materials are available inexpensively in many specifications, making the sealing arrangement simple and cost-effective to manufacture. The sealing body encloses the electrical conductor without adhesion and forms a seal under elastic preload. Therefore, if necessary, the sealing body and electrical conductor can be replaced separately. A particularly noteworthy advantage is the virtually unlimited reusability of the electrical conductor, which is made of an expensive material and is subject to virtually no wear during its service life.

[0017] According to an advantageous embodiment, the support body can be made of a tough, hard plastic, which is preferably electrically insulating. This is advantageous in that the two-component component is simple and cost-effective to manufacture and has a low weight. The electrically insulating properties of the support part have the advantage that it eliminates the need for separately manufactured and mounted electrical insulation compared to a housing to which the two-component component is usually attached.

[0018] The support body can, viewed in cross-section, be substantially L-shaped, with an axial flange and a radial flange, wherein the axial flange extends parallel to the electrical conductor and encloses it with a radial distance, wherein at least one inner sealing lip of the sealing body is arranged in the gap formed by the distance, which sealing lip encloses the outer circumference of the electrical conductor in a non-adherent manner and under elastic prestress.

[0019] More preferably, two inner sealing lips arranged in a functional series connection can be used to further increase the sealing reliability.

[0020] At least one outer sealing lip can be arranged on the side of the axial flange radially opposite the inner sealing lip. This outer sealing lip seals against a housing to which the two-component component is attached.

[0021] According to a first embodiment, the inner sealing lip and the outer sealing lip can be designed to merge into one another in one piece and be made of the same material. This is advantageous because the production of the two-component component is particularly simple and cost-effective. The inner sealing lip and the outer sealing lip are preferably made of an electrically insulating sealing material. Particularly when the carrier part is also made of an electrically insulating material, the electrical conductors of the busbar and a housing to which the two-component component is attached are effectively electrically insulated from one another.

[0022] According to a second embodiment, the inner sealing lip and the outer sealing lip can be produced separately from one another and are arranged so that they do not touch each other. This is advantageous because the inner sealing lip and the outer sealing lip can each be functionally customized. The material properties of the sealing lips can be easily adapted to their respective functions.

[0023] At least the inner sealing lip can be made of an electrically insulating sealing material. If the electrical conductor is sealed by the inner sealing lip and contact with the carrier part is prevented by the inner sealing lip, it is not absolutely necessary for the outer sealing lip to also be made of an electrically insulating sealing material. Sealing materials can also be used that do not have a particularly high electrical resistance but enable a particularly durable and reliable seal, for example, because they are particularly oil-resistant.

[0024] Additional sealing of the two-component component with respect to a housing to which it is attached can be achieved by the radial flange having at least one axial sealing lip extending axially in the direction of the outer sealing lip and substantially along the outer circumference of the support part. In such a case, the sealing of the two-component component is achieved through the interaction of the axial sealing lip and the outer sealing lip. The axial sealing lip and outer sealing lip seal an opening of a housing in which the two-component component is arranged from the environment.

[0025] According to an advantageous embodiment, the electrical conductor can have a round or oval cross-section. This is advantageous because, unlike an electrical conductor made of punched sheet metal, it has no corners or process-related punching burrs, thus enabling robust compression of the sealing material. The round or oval cross-section of the electrical conductor does not damage the inner sealing lip, even under greater elastic preloads.

[0026] The support part can have at least one mounting hole in which a force-limiting element is arranged. The support part can be screwed to a housing, for example. To do this, a screw first penetrates the mounting hole and is screwed into the housing. To prevent damage to the support part when screwing it to the housing due to excessive tightening torque, force-limiting elements, which can be formed, for example, by force-limiting rings, are provided. This prevents an undesirably high force, which without the force-limiting elements could lead to destruction of the support part.

[0027] In addition, the sealing arrangement can comprise a liquid-cooled electrical component with a housing, wherein the housing has an installation opening in which the two-component component is sealingly arranged.

[0028] The electrical component can be an electric motor. As already described above, it is particularly important for oil-cooled electric motors in electric vehicles to securely seal sensitive power electronics, such as the power electronics of an inverter.

[0029] Furthermore, the invention relates to the use of a sealing arrangement as described above for sealing a busbar of a liquid-cooled electrical component.

[0030] The sealing arrangement described above is simple and cost-effective to manufacture. In the event of a repair, the electrical conductor can always be reused thanks to the non-adhesive connection between the electrical conductor and the inner seal. To do this, the electrical conductor is simply pulled out of the inner seal, the previous carrier part with the previous sealing body (i.e., the two-component component) is replaced with a corresponding new pre-assembled unit, and the electrical conductor is reinstalled in the sealing body.

[0031] The sealing assembly also features a component-free design. Assembly is process-reliable because the assembly of separately manufactured sealing rings is not required.

[0032] Short description of the drawing

[0033] An embodiment of the sealing arrangement according to the invention is explained in more detail below with reference to Figures 1 and 2.

[0034] These show in schematic representation:

[0035] Figure 1 shows a detail of an embodiment of a sealing arrangement in a perspective view, Figure 2 shows a section through the sealing arrangement from Figure 1.

[0036] Implementation of the invention

[0037] Figures 1 and 2 show an embodiment of a sealing arrangement according to the invention.

[0038] In this exemplary embodiment, the busbar 1 comprises three electrical conductors 2.1, 2.2, 2.3, each with a round cross-section. The electrical conductors 2.1, 2.2, 2.3 are enclosed by the two-component component 3, which comprises the carrier part 4 and the sealing body 5. In this exemplary embodiment, the carrier part 4 is made of a tough and electrically insulating plastic, and the sealing body 5 is made of a rubber-elastic sealing material. The carrier part 4 and the sealing body 5 form a preassembled unit and are integrally connected to one another.

[0039] The schematically indicated liquid-cooled electric component 14 is formed by an oil-cooled electric motor for an electric vehicle and comprises the housing 15, which has an installation opening 16 for the two-component component 3. The two-component component 3 is arranged in a sealing manner in the installation opening 16 of the housing 15. The two-component component 3 is screwed to the housing 15. The carrier part 4 contains two fastening bores 12.1, 12.2, in each of which an annular force-limiting element 13.1, 13.2 is arranged, which consists, for example, of a metallic material. The comparatively more sensitive material of the carrier part 4 is thus protected from excessive tightening torques, which could destroy the carrier part 4 during its assembly on the housing 15. Figure 2 shows a cross-sectional view of the sealing arrangement from Figure 1.Here, it can be seen that the support body 4, viewed in cross-section, is essentially L-shaped and has an axial flange 6 and a radial flange 7. The axial flange 6 extends parallel to the electrical conductors 2.1, 2.2, 2.3, while the radial flange 7 extends perpendicularly thereto. The axial flange 6 is essentially completely enclosed by the sealing material of the sealing body 5, on the inside by the inner sealing lips 9.1, 9.2 and on the outside by the outer sealing lip 10.

[0040] In the illustrated embodiment, the inner sealing lips 9.1, 9.2 and the outer sealing lip 10 merge into one another in one piece and are made of the same electrically insulating sealing material. Such a one-piece, uniform design is well suited for most applications and can be manufactured easily and cost-effectively.

[0041] The axial sealing lip 11, which also merges into one another and is formed of the same material as the outer sealing lip 10 and the inner sealing lips 9.1, 9.2, is arranged on the radial flange 7 of the support part 4 and is bead-shaped and axially protrudes in the direction of the outer sealing lip 10. The axial sealing lip 11 seals the end face of the housing 15, while the outer sealing lip 10 seals the circumferential boundary of the installation opening 16.

[0042] The sealing body 5 encloses the electrical conductors 2.1, 2.2, and 2.3 in a non-adherent manner and provides a seal under elastic prestress. If necessary, the electrical conductors 2.1, 2.2, and 2.3 can therefore be easily and non-destructively removed from the sealing body 5.

Claims

Patent claims 1. Sealing arrangement, comprising a busbar (1) with at least one electrical conductor (2.1, 2.2, 2.3, ...) and a two-component component (3) which comprises a carrier part (4) made of a tough material and a sealing body (5) made of a rubber-elastic sealing material, which is integrally connected to the carrier part (4), wherein the sealing body (5) surrounds the electrical conductor (2.1, 2.2, 2.3, ... ) without adhesion and sealingly under elastic prestress.

2. Sealing arrangement according to claim 1, characterized in that the supporting body (4) consists of an electrically insulating plastic.

3. Sealing arrangement according to one of claims 1 or 2, characterized in that the support body (4), viewed in cross section, is substantially L-shaped, with an axial flange (6) and a radial flange (7), wherein the axial flange (6) extends parallel to the electrical conductor (2.1, 2.2, 2.3, ... ) and encloses it with a radial distance, wherein in the gap (8) formed by the distance at least one inner sealing lip (9.1, 9.2, ... ) of the sealing body (5) is arranged, which surrounds the outer circumference of the electrical conductor (2.1, 2.2, 2.3, ... ) without adhesion and sealingly under elastic pre-tension.

4. Sealing arrangement according to claim 3, characterized in that at least one outer sealing lip (10) is arranged on the side of the axial flange (6) radially facing away from the inner sealing lip (9.1, 9.2, ...).

5. Sealing arrangement according to one of claims 3 or 4, characterized in that the inner sealing lip (9.1, 9.2,...) and the outer sealing lip (10) are formed integrally into one another and are made of the same material.

6. Sealing arrangement according to one of claims 3 to 5, characterized in that the inner sealing lip (9.1, 9.2,...) and the outer sealing lip (10) consist of an electrically insulating sealing material.

7. Sealing arrangement according to one of claims 3 or 4, characterized in that the inner sealing lip (9.1, 9.2,...) and the outer sealing lip (10) are each produced separately from one another and are assigned to one another in a non-contacting manner.

8. Sealing arrangement according to claim 7, characterized in that at least the inner sealing lip (9.1, 9.2,...) consists of an electrically insulating sealing material.

9. Sealing arrangement according to one of claims 1 to 8, characterized in that the radial flange (7) has at least one axial sealing lip (11) which extends axially in the direction of the outer sealing lip (10) and substantially along the outer circumference of the carrier part (4).

10. Sealing arrangement according to one of claims 1 to 9, characterized in that the electrical conductor (2.1, 2.2, 2.3,...) has a round or oval cross-section.

11. Sealing arrangement according to one of claims 1 to 9, characterized in that the carrier part (4) has at least one fastening bore (12.1, 12.2,...) in which a force limiting element (13.1, 13.2,...) is arranged.

12. Sealing arrangement according to one of claims 1 to 11, characterized in that it also comprises a liquid-cooled electrical component (14) with a housing (15), wherein the housing (15) has an installation opening (16) in which the two-component component (3) is arranged in a sealing manner.

13. Sealing arrangement according to claim 12, characterized in that the electrical component (14) is formed by an electric motor.

14. Use of a sealing arrangement according to one of claims 1 to 13 for sealing a busbar (1) of a liquid-cooled electrical component (14).

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