Liquid-cooled cable assembly

Abstract

Liquid-cooled cable assembly (1), comprising: • a connector, • at least two cables (2), each comprising a coolant line (3), several electrical conductors (4) arranged around the respective coolant line (3) and a cable sheath (5), • an outer sheath (50) which surrounds the at least two cables (2), and characterized by the fact that a single coolant hose (10) is arranged inside the outer casing (50) and outside the cables (2), next to the cables (2), the coolant hose (10) forms an inflow of coolant to the connector and the coolant lines (3) inside the cables (2) form a backflow of coolant away from the connector.

Description

[0001] The invention is based on a liquid-cooled cable structure according to the preamble of independent claim 1.

[0002] Such a liquid-cooled cable assembly comprises at least two cables, each containing a coolant line, several electrical conductors arranged around the respective coolant line, and a cable sheath. An outer sheath surrounds the at least two cables. This type of cable assembly is used particularly for transmitting high currents, for example, in charging connectors.

[0003] Similarly, in a generic method for cooling a cable assembly, the cable assembly comprises at least two cables, each comprising a coolant line, several electrical conductors arranged around the respective coolant line and a cable sheath, and an outer sheath surrounding the at least two cables.

[0004] High charging currents are particularly desirable for electric vehicles so that charging a battery can be as fast as refueling a combustion engine vehicle. However, high charging currents lead to significant heat generation at the cable and connector. State of the art

[0005] German patent application DE 10 2016 112 306 A1 discloses a cable construction in which the electrical contact elements of a connector are liquid-cooled. Each cable comprises a cable sheath containing a central coolant line surrounded by several copper conductors. A liquid-tight foil surrounds the copper conductors, creating an outer liquid line between the foil and the cable sheath. Coolant is then conveyed to the electrical contact element in the outer liquid line and returned in the central liquid line.

[0006] The dimensions of the central and outer fluid lines are chosen to allow for a sufficiently large coolant flow. This results in a relatively large cable cross-section, which makes handling more difficult.

[0007] From CN 106 782 835 A, a cable construction is known in which two cables are arranged within an outer sheath, each comprising a coolant line, electrical conductors arranged around it, and a cable jacket. The coolant lines are supply lines to a connector. Hoses arranged outside the cable jacket facilitate the return flow of the coolant.

[0008] US 2012 / 0199390 A1 describes a cable assembly with three cables, each enclosing a coolant line in the center. Additionally, another coolant line is formed in the area between the three cables.

[0009] German patent DE 10 2016 105 347 A1 describes a cable construction in which two cables are housed within an outer sheath, each containing a coolant line surrounded by an electrical conductor. These coolant lines provide a supply of coolant to the connector end of the cable. Additionally, two coolant hoses are located within the outer sheath, providing a return flow of the coolant. Task

[0010] One object of the invention is to provide a liquid-cooled cable assembly for cooling a cable assembly, which provides efficient cooling with the simplest possible handling.

[0011] The problem is solved by the liquid-cooled cable assembly with the features of independent claim 1.

[0012] Advantageous embodiments of the invention are specified in the dependent claims and the following description.

[0013] According to the invention, in the liquid-cooled cable construction of the type mentioned above, at least one coolant hose is arranged inside the outer sheath, i.e. in the space enclosed by the outer sheath, and outside the cables.

[0014] In the aforementioned method according to the invention, a coolant is conveyed through the coolant lines and through at least one coolant hose which is arranged inside the outer shell and outside the cables.

[0015] By separating the coolant supply and return lines within a single cable, the cable cross-section can be reduced. This decreases bending stiffness and simplifies handling. The overall diameter, meaning the diameter of the cable's outer sheath, is largely determined by the diameters of the two cables it houses. Since each cable only contains the return line, the overall diameter is smaller compared to conventional cable designs. The other, at least one, supply line for the coolant can be positioned alongside the cables, thus preventing an increase in the overall diameter of the outer sheath.Compared to a conventional cable design where both the supply and return flow of coolant are integrated within a single cable, the invention allows for a smaller overall diameter while maintaining the same flow cross-sections for the coolant. In particular, it can be provided that only a single coolant line is arranged within each cable.

[0016] The coolant lines within the cables create a return flow of coolant away from a connector, while the at least one coolant hose creates a supply flow of coolant towards the connector. A large portion of the heat to be dissipated is generated at the electrical contacts to which the cables lead. The coolant should therefore be as cool as possible at the electrical contacts. The electrical conductors of the cables heat the coolant lines within the cables more than the at least one coolant hose. By using the hose as the supply flow, cooler coolant can be provided at the electrical contacts than if the coolant lines within the cables were the supply flow.

[0017] A connector is attached to one end of the outer casing, with the inflow defined as the direction towards the connector and the return flow as the opposite direction. A pump or other fluid transfer device may be provided and configured to transfer coolant along the at least one coolant hose towards the connector and along the coolant lines away from the connector. A closed circuit for the coolant may be provided via the connector. An appropriately configured electronic control unit may be provided to control the pump. A heat exchanger for heat dissipation may be located at a point in the circuit away from the connector.

[0018] The connector can provide a fluid connection between the at least one coolant hose and the coolant lines. For this purpose, a cavity can be formed within the connector, which is fluidically connected to the at least one coolant hose and both coolant lines, and is otherwise fluid-tight.

[0019] It may be preferred that two or more coolant hoses are present. These can be arranged side by side, in particular touching each other, and running essentially parallel to one another. Two coolant hoses offer considerable design flexibility with regard to the fluid connection within the connector to the two coolant lines in the cables. Conversely, a single coolant hose may be advantageous to enable more compact designs while maintaining the same flow cross-section. For this purpose, the single coolant hose can be arranged within the outer sheath in such a way that it touches both cables.

[0020] In the case of two coolant hoses, one of them can be fluidically connected to one of the coolant lines within the connector, while the other coolant hose is fluidically connected to the other coolant line within the connector. This allows for two, in particular separate, coolant circuits. Among other things, this enables efficient cooling of spatially separated parts of the connector. The two coolant circuits can be connected at an end opposite the connector. In this way, a single pump can suffice to circulate the coolant through both coolant hoses.

[0021] The outer casing can also accommodate multiple control lines, which can run freely, meaning without a common casing that would separate them from other lines and cables. Because the control lines run freely, gaps between or next to cables and coolant hoses can be used efficiently. Furthermore, handling is simplified, as the bending stiffness is not increased by omitting a common casing.

[0022] The two cables can be arranged side by side within the outer sheath. The at least one coolant hose can be located on one side of the two cables within the outer sheath, while a protective conductor providing grounding is located on the opposite side. With this arrangement, the overall diameter of the outer sheath can be determined by the two cables, while the protective conductor and the at least one coolant hose do not increase the overall diameter, or only increase the diameter defined by the two adjacent cables slightly, for example, by no more than 10% or 20%.

[0023] The inner diameter of one of the cable sheaths can correspond precisely to the diameter of the coolant line it contains plus the diameter of two electrical conductors. This slim design, which specifically avoids enclosing multiple fluid lines within the cable sheath, allows for easy handling and overall compact configurations.

[0024] The cable sheath is understood as the outer boundary of the cable and can be, for example, a hose or an extruded sheath. The electrical conductors contained within the cable sheath can be metallic wires, particularly copper wires. They can be in direct contact with the outside of the coolant line and with the inside of the cable sheath. The wires can be arranged concentrically around the respective coolant line. The coolant lines can be formed by, for example, flexible hoses.

[0025] The outer sheath, which surrounds the cables, at least one coolant hose, and other components such as a protective conductor and control lines, can be a hose, a tube, or an extruded jacket. In the case of an extruded jacket, filler elements, such as fibers, can also be incorporated within the extruded jacket. Any liquid can be used as the coolant, for example, water, an aqueous solution, oil, or an oil-containing mixture. In principle, the liquid can also be replaced by a fluid, in particular a vapor or a gas.

[0026] At least one coolant hose is located alongside the cables, meaning that no cable is located inside a coolant hose. If there are two coolant hoses, they can both have the same cross-section. This cross-section can, in turn, be the same as the cross-section of the coolant lines inside the cables. If only a single coolant hose is used, it can have a larger cross-section than either of the coolant lines. The cross-section of the single coolant hose can be smaller than the sum of the cross-sections of both coolant lines, because with the larger cross-section of the coolant hose, a reduction in flow velocity due to friction at the hose wall is comparatively less significant.

[0027] The cable construction according to the invention is particularly suitable for charging connectors, which are used, for example, for charging the batteries of electric cars. In principle, however, the cable construction is also suitable for essentially any application where cooling of the electrical conductors in the cables and / or the electrical connections in or on the connector is desired.

[0028] Variants of the inventive method result from the intended use of the described embodiments of the cable construction of the invention. Examples of implementation

[0029] Exemplary embodiments of the invention are shown in the drawings and are explained in more detail below. They show: Fig. 1 a cross-section of a cable structure; Fig. 2 a perspective sectional view of the cable construction made of Fig. 1; Fig. 3 a cross-section of another cable structure and Fig. 4 a perspective sectional view of the cable structure made of Fig. 3.

[0030] The figures contain some simplified, schematic representations. Identical elements are generally marked with matching reference symbols.

[0031] A first embodiment of a liquid-cooled cable assembly 1 according to the invention is described with reference to the Fig. 1 and Fig. 2 described. The Fig. Figure 1 shows a cross-section of the cable structure 1, while Fig. Figure 2 shows a perspective sectional view of the cable structure 1.

[0032] The cable assembly 1 comprises an outer sheath 50, which surrounds at least two cables 2. Each cable 2 contains a central coolant line 3, which may, for example, be in the form of a hose. This is surrounded by several electrical conductors 4, for example, copper wires. Radially outwards, the copper wires are enclosed by a cable jacket 5. The two cable jackets 5 of the two cables 2 may be arranged next to each other in contact.

[0033] To provide a supply and return flow of coolant, at least one coolant hose 10 is also present inside the outer casing 50. In the example of Fig. Figure 1 shows two coolant hoses 10, although a different number is also possible in principle. The coolant hoses 10 allow coolant to flow to a connector (not shown), while the coolant lines 3 contained in the cables 2 provide a return flow away from the connector. The coolant is intended to cool the electrical contacts in the connector as well as the electrical conductors 4. To provide the most effective cooling of the electrical contacts in the connector, it can be advantageous for the coolant hoses 10 to provide the inflow, as they are heated less by the electrical conductors 4 than the coolant lines 3.

[0034] By arranging the coolant hoses 10 alongside the cables 2, the overall diameter of the outer sheath 50 can be smaller than if both the inflow and return flow of coolant were provided in each cable 2.

[0035] For a space-efficient arrangement, the two coolant hoses 10 can touch each other, and each coolant hose 10 touches one of the cable sheaths 5. The two coolant hoses 10 are thus arranged on the same side with respect to a line connecting the midpoints of the two cables 2, while a protective conductor 30, which is also present within the outer sheath 50, is arranged on the other side with respect to this line connecting.

[0036] There may also be several other lines that do not require cooling, in the example shown, several control lines 20. These can be distributed in the spaces between the cables 2, the coolant hoses 10, and the protective conductor 30. As shown, for example, some of the control lines 20 can be located on one side of the protective conductor 30, and others on the opposite side.

[0037] The inner diameter of the outer sheath 50 can, by this arrangement, correspond exactly to the two diameters of the cables 2. The other components do not lead to an increase in the inner diameter, or only minimally.

[0038] A variation of the embodiment of Fig. 1 and Fig. 2 is in the Fig. 3 and Fig. 4 shown. Here, it shows Fig. 3 a cross-section of the in Fig. 4 perspectively shown cable arrangement 1.

[0039] Cable arrangement 1 of the Fig. 3 and Fig. 4 differs from the embodiment of the Fig. 1 and Fig. 2 in that instead of two coolant hoses 10, there is only a single coolant hose 10. This coolant hose 10 is fluidically connected to both coolant lines 3 in a connector (not shown).

[0040] The design shown in the figures advantageously allows for a relatively small diameter of the cables 2, thus improving handling and increasing flexibility. Furthermore, the construction is comparatively simple to manufacture. Reference symbol list 1 Cable construction 2 cables 3 Coolant line 4 Electrical conductors 5 cable sheath 10 Coolant hose 20 control lines 30 protective conductors 50 Outer shell QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2016 112 306 A1

[0005] CN 106 782 835 A

[0007] US 2012 / 0199390 A1

[0008] DE 10 2016 105 347 A1

[0009]

Claims

[1] Liquid-cooled cable assembly (1) comprising: • a connector, • at least two cables (2), each comprising a coolant line (3), several electrical conductors (4) arranged around the respective coolant line (3) and a cable sheath (5), • an outer sheath (50) which surrounds the at least two cables (2), and characterized by , that a single coolant hose (10) is arranged inside the outer casing (50) and outside the cables (2), next to the cables (2), the coolant hose (10) forms an inflow of coolant to the connector and the coolant lines (3) inside the cables (2) form a backflow of coolant away from the connector. [2] Liquid-cooled cable assembly (1) according to claim 1, characterized bythat within each of the cables (2) only a single coolant line (3) is arranged. [3] Liquid-cooled cable assembly (1) according to any one of the preceding claims, characterized by , that the inner diameter of the outer shell (50) exactly corresponds to the combined diameters of the cables (2). [4] Liquid-cooled cable assembly (1) according to any one of the preceding claims, characterized by , that a pump is present and is set up to transport coolant along the coolant hose (10) towards the connector and along the coolant lines (3) away from the connector. [5] Liquid-cooled cable assembly (1) according to any one of the preceding claims, characterized by , that a fluid connection is established in the connector between the coolant hose (10) and the coolant lines (3). [6] Liquid-cooled cable assembly (1) comprising: • a connector, • at least two cables (2), each comprising a coolant line (3), several electrical conductors (4) arranged around the respective coolant line (3) and a cable sheath (5), • an outer sheath (50) which surrounds the at least two cables (2), and • two or more coolant hoses (10) arranged inside the outer casing (50) and outside the cables (2), • Control lines (20) that run between or alongside the cables (2) and coolant hoses (10) inside the outer casing (50), characterized by , that the cable sheaths (5) of the at least two cables (2) are arranged next to each other in contact with each other, the two or more coolant hoses (10) touch each other and each coolant hose (10) touches one of the cable sheaths (5), an inner diameter of the outer sheath (50) exactly corresponds to the combined diameters of the cables (2), the two or more coolant hoses (10) form a flow of coolant to the connector and the coolant lines (3) inside the cables (2) form a backflow of coolant away from the connector. [7] Liquid-cooled cable assembly (1) according to the preceding claim, characterized by , that in the connector one of the coolant hoses (10) is fluidically connected to one of the coolant lines (3) and in the connector another of the coolant hoses (10) is fluidically connected to another of the coolant lines (3). [8] Liquid-cooled cable assembly (1) according to any one of the preceding claims, characterized by , that several control lines (20) are arranged freely within the outer shell (50). [9] Liquid-cooled cable assembly (1) according to claim 6, characterized by , that the two or more coolant hoses (10) are arranged on one side of the at least two cables (2) inside the outer sheath (50) and a protective conductor (30) is arranged on the opposite side of at least two cables (2). [10] Liquid-cooled cable assembly (1) according to any one of the preceding claims, characterized by , that an inner diameter of one of the cable sheaths (5) corresponds exactly to the diameter of the coolant line (3) contained therein plus twice the diameter of one of the electrical conductors (4) contained therein.

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