Busbar with Phase Change Material

Abstract

The present invention comprises a busbar enclosing at least one cavity, wherein the busbar has at least one web projecting from the wall at least partially into the at least one cavity. The at least one cavity is at least partially filled with a phase change material which is in thermally conductive contact with the at least one web.

Claims

1. A busbar with a wall which encloses at least one cavity, wherein the busbar has at least one web which projects from the wall at least partially into the at least one cavity, wherein the at least one cavity is at least partially filled with a phase change material which is in thermally conductive contact with the at least one web.

2. The busbar according to claim 1, wherein the at least one web is formed integrally with the wall.

3. The busbar according to claim 1, wherein the busbar has a height and a width and the at least one web extends along the height.

4. The busbar according to claim 3, wherein the at least one web extends over the entire height.

5. The busbar according to claim 1, wherein the wall is made of an electrically conductive material, in particular metal.

6. The busbar according to claim 1, wherein the wall of the busbar comprises aluminum and/or an aluminum alloy and/or copper and/or a copper alloy.

7. The busbar according to claim 1, wherein a wall thickness of the wall is at least 0.2 mm.

8. The busbar according to claim 1, wherein the busbar has a circular cross-section, and the at least one web extends along a diameter of the cross-section.

9. The busbar according to claim 8, wherein the diameter of the busbar is between 5 mm and 25 mm.

10. The busbar according to claim 1, wherein a height of the busbar is between 1.5 mm and 25 mm and a width of the busbar is between 15 mm and 120 mm.

11. The busbar according to claim 1, wherein a cross-sectional area of the busbar is between 40 mm.sup.2 and 350 mm.sup.2, and wherein a cross-sectional area of the at least one web is not more than 60% of the cross-sectional area of the busbar.

12. The busbar according to claim 1, wherein the at least one cavity is sealed airtight.

13. The busbar according to claim 1, wherein a volume of the at least one cavity is filled to 30%-70% with the phase change material.

14. The busbar according to claim 1, wherein the phase change material has a phase change temperature between 60? C. and 140? C.

15. The busbar according to claim 1, wherein the phase change material has a paraffin-based organic material.

16. The busbar according to claim 1, wherein the busbar comprises a main section, a first connection section and a second connection section, and the main section comprises the at least one cavity.

17. The busbar according to claim 16, wherein a wall of the main section of the busbar is encased in electrical insulation.

18. The busbar according to claim 16, wherein the first connection section and/or the second connection section is fixed to the main section by a welding process and/or an ultrasonic welding process and/or a soldering process and/or a crimping process and/or a clamping process.

19. The busbar according to claim 16, wherein the first connection section and/or the second connection section are a cable lug.

20. The busbar according to claim 16, wherein the first connection section and/or the second connection section are formed integrally with the main section.

Description

[0039] FIG. 1 a busbar according to an embodiment of the invention;

[0040] FIG. 2 cross-section of a busbar according to a first embodiment of the invention;

[0041] FIG. 3 cross-section of a busbar according to a second embodiment of the invention;

[0042] FIG. 4 a further cross-section of a busbar according to the first embodiment of the invention;

[0043] FIG. 5 a further cross-section of a busbar according to the first embodiment of the invention;

[0044] FIG. 6 a further cross-section of a busbar according to the first embodiment of the invention;

[0045] FIG. 7 a further cross-section of a busbar according to the first embodiment of the invention;

[0046] FIG. 8 a further cross-section of a busbar according to the second embodiment of the invention;

[0047] FIG. 9 a further cross-section of a busbar according to the second embodiment of the invention;

[0048] FIG. 10 a further cross-section of a busbar according to the second embodiment of the invention;

[0049] FIG. 11 a longitudinal section of a busbar according to the first embodiment of the invention.

[0050] In the following, an advantageous embodiment of a busbar 100 is described with reference to FIG. 1. As can be seen from FIG. 1, the busbar 100 advantageously has a main section 170, a first connection section 172 and a second connection section 174. The main section 170 extends along a length L and is curved and angled.

[0051] FIGS. 2-10 explained below, and in particular the description of the cavity and the webs, refer to the main section 170 of the busbar.

[0052] The busbar 100 is advantageously arranged in a current line path of an electrically powered vehicle between a charging contact element and a battery of the vehicle. The fact that no volume flow of a coolant is provided means that galvanic isolation of different potentials can be achieved easily.

[0053] FIG. 2 shows a cross-section of a first embodiment of the busbar 100 along the sectional plane q (FIG. 1). The busbar 100 advantageously has an approximately cuboid shape with rounded corners. The busbar 100 has a wall 110, which determines the shape of the busbar 100. The wall 110 encloses at least one cavity 120 of the busbar 100. The cavity 120 can extend continuously along the length L of the main section of the busbar 100 or be limited in the longitudinal direction.

[0054] A busbar 100 of this type can have a length L of up to 2 m, for example. Further preferred dimensions of such a busbar 100 are a width b of 15 mm to 120 mm and a height a of 1.5 mm to 25 mm. The thickness c of the wall 110 is, for example, at least 0.2 mm. Such dimensions advantageously offer sufficient stability and are light at the same time.

[0055] The wall 110 of the busbar 100 advantageously consists of an electrically conductive material, in particular metal. For example, the wall 110 may comprise aluminum, an aluminum alloy, copper and/or a copper alloy. However, other electrically conductive materials that prove to be suitable for the aforementioned purpose of the busbar are conceivable.

[0056] A cross-section of a second embodiment of the busbar 200 according to the invention is shown schematically in FIG. 3. Such a busbar is designed with an essentially circular cross-section. The busbar 200 is again bounded by a wall 210, which encloses at least one cavity 220. The cavity 220 can extend continuously along the length L of the main section of the busbar 200 or be limited in the longitudinal direction.

[0057] The thickness of the wall 210 is, for example, at least 0.2 mm. The diameter d of the busbar 200 is advantageously in a range between 5 mm and 25 mm. This again achieves sufficient stability with low weight.

[0058] FIG. 4 shows a further cross-section of a first embodiment of a busbar 100 according to the invention. At least one web 150 protrudes at least partially from the wall 110 into the at least one cavity 120. A plurality of webs 150 with different lengths are shown as examples in FIG. 4.

[0059] In this case, the plurality of webs 150 protrude only partially into the at least one cavity 120 and a further plurality of webs 150 protrude from one side of the wall 120 over the entire height a to the opposite side of the wall 120, so that advantageously a plurality of cavities 120 is formed. By way of example, the webs 150 and thus also the cavities 120 extend along the entire length L of the main section of busbar 100, which results in cavities 120 that are separate from one another and not connected to one another.

[0060] However, it is also possible that the webs 150 do not extend continuously along the length L of the busbar 100, but are limited in the longitudinal direction, so that the cavities 120 are connected to each other.

[0061] The number and shape of the webs 150 shown in FIG. 4 is by no means limited to the illustration shown.

[0062] The cavity 120 enclosed by the wall 110 is at least partially filled with a phase change material. In the busbar shown in FIG. 4 with several cavities 120, it is advantageous if a plurality or all of the cavities 120 are filled with the phase change material.

[0063] As soon as the busbar is heated by the current flow to such an extent that a certain phase change temperature is exceeded, the phase transition of the material takes place. This does not have to occur completely in the entire volume of the phase change material, but can also occur only partially. During the phase transition, the material can absorb heat, which is used to carry out the phase transition. The phase change material can absorb heat until the phase transition is complete.

[0064] This has the advantage of delaying the heating of the busbar. Due to the arrangement of the phase change material directly in the cavity 120 of the busbar 100, there is direct contact between the phase change material and the busbar, which additionally increases the cooling effect.

[0065] An exemplary representation of the busbar 100 with exclusively continuous webs 150 over the entire height a of the busbar 100 is shown in cross-section in FIG. 5. Here, a plurality of webs 150 protrude from the wall 110 such that a plurality of cavities 120 extend continuously or longitudinally along the length L of the main section 170 of the busbar 100. The webs 150 project from one side of the wall 110 over the entire height a of the busbar 100 up to the wall 110 of the opposite side.

[0066] Advantageously, the cavities 120 are at least partially filled with the phase change material in order to delay heating of the busbar 100.

[0067] However, the webs shown in FIGS. 4 and 5 are not limited to the shape shown. With regard to FIGS. 6 and 7, it is clear that a wide variety of embodiments of the webs are within the scope of the present invention.

[0068] The height of the webs protruding into the cavity and the width can be adjusted depending on the area of application and the phase change material used, so that improved heat conduction through the phase change material is ensured.

[0069] The cross-sectional area of the webs 150 is advantageously no more than 60% of the cross-sectional area of the busbar 100, so that at least 40% of the cross-sectional area of the busbar can be filled with the phase material.

[0070] Further representations of the busbar 100 with different embodiments of the at least one web 150 are shown in FIGS. 6 and 7.

[0071] FIG. 6 shows a further cross-section of the busbar 100 along surface q (see FIG. 1). The busbar 100 comprises a plurality of webs 150 along its width b, which are arranged adjacent to one another. Different variants of webs 150 are shown on the two opposite sides of the wall 110. The plurality of webs 150 are advantageously rectangular in shape with or without rounded corners. In the busbar shown in FIG. 6, the plurality of webs 150 protrude from the wall 110 in such a way that only a cavity 120 is formed. It is clear that the plurality of webs 150 and the cavity 120 again extend along the entire length L of the main section of the busbar 100, or are limited in the longitudinal direction.

[0072] The cross-sectional area of the webs 150 is advantageously no more than 60% of the cross-sectional area of the busbar 100. The special design of the webs 150 as projecting elements can nevertheless ensure improved and uniform heat conduction over the thickness of the entire phase change material.

[0073] FIG. 7 again shows a cross-section of a busbar 100 according to the invention. This figure again shows a further embodiment of the webs 150.

[0074] As shown, the plurality of webs 150 protrude from the wall 110. The webs 150 are arranged adjacent to one another along the width b of the busbar 100. The plurality of webs 150 is arranged on the two opposite sides of the wall 110.

[0075] The webs 150 on the opposite sides of the wall 110 are preferably arranged offset from one another in a comb pattern in such a way that the cross-sectional area of the cavity 120 follows a periodic sequence of elevations and depressions.

[0076] This cavity 120 is in turn at least partially filled with the phase change material. In such a configuration of the busbar 100, phase change material with poor thermal conductivity in particular absorbs the heat evenly.

[0077] Further representations of a cross-section of the busbar 200 are shown in FIGS. 8 and 9. It becomes clear that in this embodiment, too, at least one web 250 projects from the wall 210 into the at least one cavity 220.

[0078] As an example, the busbar 200 has a plurality of webs 250. The length of the plurality of webs 250, how far they project into the cavity 220 and their shape can vary. The webs 250 in FIGS. 8 and 9 are exemplary, but the solution according to the invention is not limited to the variants shown and it is clear that embodiments of the webs as explained with reference to the previous figures are also applicable to the busbar 200.

[0079] FIG. 8 comprises, by way of example, a plurality of webs 250 which project from the wall 210 partially into the cavity 220 and a plurality of webs 250 which extend continuously along the diameter d of the busbar 200. This advantageously results in a plurality of cavities 220.

[0080] FIG. 9 shows, by way of example, only a plurality of webs 250, which extend continuously along the diameter d of the cross-section of the busbar 200 from one side of the wall 210 to the opposite side, resulting in a plurality of cavities 220.

[0081] The webs 250 can extend continuously along the length L of the main section of the busbar 200 or be limited in the longitudinal direction.

[0082] The cavities 220 are advantageously at least partially filled with a phase change material for passive cooling of the busbar 200.

[0083] FIG. 10 shows a further cross-section of the busbar 200 in a further embodiment. Here, by way of example, four webs 250, evenly spaced along the circumference of the busbar 200, protrude from the wall 210 into the cavity 220. The busbar 200 thus comprises, by way of example, a cavity 220 which is at least partially filled with the phase change material. This embodiment also enables improved and more uniform heat conduction through the phase change material.

[0084] It is clear that advantageous embodiments of the busbar and/or the phase change material are not limited to one or the other embodiment and are applicable regardless of the geometric shape of the busbar and the webs.

[0085] Preferably, the cross-sectional area of the webs that project from the wall into the cavity is no more than 60% of the cross-sectional area of the busbar.

[0086] An exemplary busbar 100 in a longitudinal section is shown in FIG. 11. The wall 110 of the main section 170 has a front end face and/or a rear end face, each of which is arranged perpendicular to the length L of the main section 170 of the busbar 100 and closes off the cavity 120 towards the outside. The cavity 120 is usually completely enclosed by the wall 110.

[0087] The first and second connection sections 172, 174 are arranged at the front and rear end faces of the busbar described according to the invention.

[0088] The length L along which the cavities 120, 220 and the webs 150, 250 advantageously extend defines the length of the main section 170. Preferably, the wall 110 of the main section 170 may be encased in electrical and thermal insulation 160 to protect surrounding components from the heat generated.

[0089] The first connection section 172 and/or the second connection section 174 can be formed integrally with the main section 170 or in multiple pieces. Various attachment methods such as welding, ultrasonic welding, soldering, crimping or clamping are only preferred methods for arranging the first and second connection sections 172, 174 on the main section 170 and do not form an exhaustive catalog.

[0090] In order to fasten the busbar 100 when used by means of screws, it is also possible to form the first and second connection sections 172, 174 as cable lugs.

[0091] It is clear that the design of the section with connection sections described in FIG. 11 is also applicable to the second embodiment of the busbar 200 according to the invention as shown, for example, in FIGS. 8 to 10.

LIST OF REFERENCE NUMERALS

[0092]

TABLE-US-00001 Reference number Description 100, 200 busbar 110, 210 wall 120, 220 cavity 150, 250 web 160 insulation 170 main section 172 first connection section 174 second connection section a height of the busbar b width of the busbar c wall thickness d diameter of the busbar L length of the main area of the busbar q cross-sectional area