Liquid-cooled cable and charging cable assembly

Abstract

The present disclosure relates to a liquid-cooled cable and charging cable assembly. The liquid-cooled cable (1) comprises a conductor (2) comprising at least two cable strands (3). The conductor (2) is surrounded by a hose (5) which is at least partially spaced apart from the conductor (2) by a gap space (6) in a cross-sectional view. The gap space (6) is arranged between the inner wall (7) of the hose (4) and the cable strands (3) of the conductor (2). The gap space (6) is intended to guide a cooling liquid (15) along the conductor (2).

Description

Technical Field

[0001] This disclosure relates to liquid-cooled cables for charging electric vehicles and charging cable assemblies including such liquid-cooled cables. Background Technology

[0002] WO20064040A1 was first disclosed in March 2020 under the name Leoni Kabel GmbH. It relates to an electric stranded wire that can be cooled using a coolant. The electric stranded wire comprises a core element and a sheath element. The core element of the electric stranded wire is formed by a first strand and a second strand, wherein the particularly advantageous arrangement of the first and second strands forms a free region within the sheath element. This free region can be used for effective cooling of the electric stranded wire.

[0003] CN106448852A was first disclosed in February 2017 under the name of Yangzhou Fengming Cable Co., Ltd. This disclosure relates to mining cables. The mining cable includes three stranded cable cores, a water-blocking tape, an armor layer, and a sheath layer. The three stranded cable cores are evenly distributed along the periphery of the reinforcing core. Stranded reinforcing portions are arranged in the gaps between adjacent stranded cable cores.

[0004] WO17133893A1 was first disclosed in August 2017 under the name of the same applicant. It relates to a cable assembly comprising a cable having a cable hose and at least one conductor disposed therein. The cable hose is spaced apart from the conductor, thereby forming a first gap space between the at least one conductor and the cable hose. Furthermore, this disclosure relates to a connector and at least one conduit for conveying cooling fluid, the connector including at least one contact member interconnected with the at least one conductor. A chamber includes a first port and a second port, the first port interconnected with the first gap space between the at least one conductor and the cable hose, and the second port interconnected with the at least one conduit.

[0005] US6100467A was first disclosed in August 2000 under the name Northern Cable and Automation LLC. This disclosure relates to a water-cooled cable comprising a plurality of electrical conductors. A first terminal half includes a first sleeve and a fluid port configured to fluidly communicate with the first sleeve. A first crimping fitting disposed within and extending therefrom the first sleeve crimps around half of an electrical conductor associated with a first polarity. A second terminal half includes a second sleeve and a fluid port configured to fluidly communicate with the second sleeve. The second terminal half is connected to the first terminal half. A second crimping fitting disposed within and extending therefrom the second sleeve crimps around the remaining half of a plurality of electrical conductors associated with a second polarity.

[0006] US3772454A was first disclosed in November 1973 under the name of DE Corporation's USX A Corporation. This disclosure relates to a torque-balanced conductor cable comprising three to six strands spirally wound together with a torque applied by the cable, the torque being substantially equal to the torque applied by the strands. Each strand includes an insulated conductor as a core, with steel wires stranded around the core, and insulation extending into the gaps between the strands. Other types include an insulated conductor disposed in the outer valleys of the cable and a sheath extruded over the entire assembly. This second type can be used with the first type or with cables in which the strands have a steel wire core component. Summary of the Invention

[0007] To reduce charging time, electric vehicle charging cables and connectors (charging cable assemblies) are typically required to carry as much power as possible per charge to recharge the vehicle battery within a short period. To meet this requirement, high current is needed at a given voltage, which tends to heat the conductors through which they carry. Simultaneously, the overall cable diameter should be as small as possible to reduce cable weight and increase flexibility for better handling and operation. However, the smaller the cross-sectional area (diameter) of the current-carrying conductors in the charging cable, the higher the temperature rise during operation, as more current must be carried within the available area. One solution to this problem is active cooling of the conductors. A successful solution is proposed in WO17133893A1 of the same applicant mentioned above.

[0008] To achieve a relatively small copper cross-section, the conductor must be effectively cooled by the coolant circulating in the cooling circuit. One object of this disclosure is to provide an optimized charging cable that is less expensive to manufacture and offers better charging performance compared to existing technologies. Parameters beneficial to the charging cable performance include a large copper cross-section (area), a large coolant channel cross-section (area), a large inner radius, smooth coolant channel surfaces, low flow resistance, and avoidance of selective heat storage.

[0009] The liquid-cooled cable according to this disclosure is preferably arranged in a charging cable for an electric vehicle to deliver current to the electric vehicle for charging. The charging cable typically includes a connector at the vehicle end through which the charging cable interconnects with the vehicle during charging. The charging cable and connector form a charging cable assembly. The connector is preferably self-cooled to prevent undesirable localized temperature rise. In a preferred variation, the charging cable according to this disclosure includes a first liquid-cooled cable and a second liquid-cooled cable, which typically have similar designs for equalizing current delivery and preventing undesirable localized temperature rise. The first and second liquid-cooled cables are typically arranged in an external hose that helps protect them from external influences during operation. Depending on the design of the charging cable, an additional flow hose may be provided within the external hose. This allows, for example, coolant to be supplied to the connector through which the charging cable interconnects with the vehicle during charging. The coolant then returns in the liquid-cooled cable, preferably from the vehicle to the charging station. Depending on the application, the two liquid-cooled cables may share a common flow hose. Alternatively or additionally, each liquid-cooled cable may include its own flow hose. This may become suitable if independent control of each conductor is required. Furthermore, the charging cable may include a ground wire and / or at least one or more data lines to transmit information along the charging cable.

[0010] The liquid-cooled cable according to this disclosure typically includes a conductor comprising at least two cable strands. Good results are achieved when the cable strands of the conductor are surrounded by a stable, self-supporting hose, which, in cross-section, is at least partially spaced from the cable strands by a gap space arranged between the inner wall of the hose and the cable strands of the conductor. Depending on the shape of the cable in space, the gap space along the cable may be variable relative to the conductor. The cable strands of the conductor may be arranged to be laterally displaceable within the hose such that on one side they are in positional contact with the inner wall of the hose, while on the opposite side they are spaced apart from the inner wall of the hose. The inner diameter of the hose is preferably larger than the outer diameter of the conductor, as will be explained in more detail below.

[0011] The space between the conductors is intended to guide the coolant (e.g., in the form of oil or another suitable coolant) along the conductor. Good results are achieved when the coolant is in direct contact with the outer layer of the cable strands. However, if suitable, the cable strands can be sheathed with sheets, as long as this does not negatively impede cooling. For reliable and robust results, the at least two cable strands are helically twisted relative to each other in the longitudinal direction of the conductor. As a result, the space between the conductor strands and the inner wall of the hose is also helically shaped, thus driving the coolant along a helical path around the center of the conductor. Preferably, the inner wall of the hose is smooth, thereby not negatively increasing resistance and supporting linear flow of coolant along the conductor. Typically, each cable strand consists of a bundle of wires twisted relative to each other. To obtain a larger current-carrying cross-section, the wires of one strand can be mechanically compressed relative to each other. Good results are achieved, for example, by rotary forging and / or drawing the bundle of wires through a suitable die, thus compacting the wire. At least, the conductor may comprise two cable strands spaced 180° apart from each other in cross-section relative to the center of the conductor. Preferably, the conductor comprises three cable strands, which are spaced 120° apart from each other relative to the center of the conductor in cross-section. If suitable, the at least two cable strands can be spaced apart by spacers arranged longitudinally between them. While the spacers may negatively impact the current-carrying cross-section, they increase the surface area of ​​the conductor in contact with the coolant, as they further separate the cable strands. If suitable, the spacers can be made of the conductive material itself.

[0012] The hose preferably comprises a substantially circular cross-section, thereby providing a uniform distribution of coolant around the cable strands of the conductor. Other cross-sectional shapes may be suitable depending on the application. To avoid undesirable deformation of the gap space, the hose is typically self-supporting. Alternatively or additionally, it may be surrounded by a support structure (e.g., in the form of a helical coil, for example, made of spring steel) to maintain the cross-section under lateral forces or during bending. As mentioned above, good results are achieved when the conductor is arranged at least to some extent to allow lateral movement relative to the hose, resulting in variable gap space. The twist length of the cable strands is preferably in the range of 7 to 15 times the diameter of the envelope curve of the corresponding conductor. Furthermore, the inner wall diameter of the hose is preferably in the range of 5% to 15% larger than the diameter of the envelope curve of the corresponding conductor. In both cases, other values ​​may be possible depending on the application. In a preferred variation, the charging cable comprises two liquid-cooled cables arranged substantially adjacent to each other. Additionally, the charging cable may include a flow hose for the coolant. For better protection, the charging cable typically includes an outer hose.

[0013] A method for manufacturing a liquid-cooled cable typically includes the following steps: providing a conductor comprising at least two cable strands; surrounding the conductor with a hose, preferably the hose being continuously extruded above the at least two cable strands, the hose being at least partially spaced from the conductor by a gap in cross-section. The gap is arranged between the inner wall of the hose and the cable strands of the conductor. During production, preferably, before applying the hose, the at least two cable strands are helically twisted relative to each other in the longitudinal direction of the conductor. If suitable, at least one cable strand can be mechanically compressed relative to each other before the hose is extruded above the at least two cable strands. Good results can be achieved, for example, by rotary forging and / or dies. Preferably, the hose is continuously extruded above the cable strands using corresponding nozzles arranged coaxially relative to the conductor comprising at least two cable strands.

[0014] It should be understood that both the above general description and the following detailed description illustrate embodiments and are intended to provide an overview or framework for understanding the nature and characteristics of this disclosure. The accompanying drawings, included to provide further understanding, are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments and, together with the description, serve to illustrate the principles and operation of the disclosed concepts. Attached Figure Description

[0015] The present disclosure described herein will be more fully understood in light of the following detailed description and accompanying drawings, which should not be construed as limiting of the present disclosure as described in the appended claims. The drawings show:

[0016] Figure 1 It is a deformation of the cross-section of the charging cable according to this disclosure;

[0017] Figure 2 This is a perspective view of a first modified form of the liquid-cooled cable according to the present disclosure;

[0018] Figure 3 It is based on Figure 2 Side view of the liquid-cooled cable;

[0019] Figure 4 It is based on Figure 3 A cross-sectional view along the section line DD;

[0020] Figure 5 This is a perspective view of a second variant of the liquid-cooled cable according to this disclosure;

[0021] Figure 6 It is based on Figure 5 Side view of the liquid-cooled cable;

[0022] Figure 7 It is based on Figure 6 A cross-sectional view along the section line EE. Detailed Implementation

[0023] Reference will now be made in detail to certain embodiments, examples of which are illustrated in the accompanying drawings, which show some, but not all, of the features. In fact, the embodiments disclosed herein can be implemented in many different forms and should not be construed as limited to those set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Similar reference numerals will be used to denote similar parts or components whenever possible.

[0024] Figure 1 A variation of the charging cable 10 according to this disclosure is shown. Figure 2 A first variant of the liquid-cooled cable 1 according to this disclosure is shown in a perspective view. Figure 3 The side view shows the following... Figure 2 Liquid-cooled cable 1, Figure 4 It shows that according to Figure 3 The cross-sectional view of the liquid-cooled cable 1 with cross-section line DD. Figure 5 A second variation of the liquid-cooled cable 1 according to this disclosure is shown in a perspective view. Figure 6 The side view shows the following... Figure 5 Liquid-cooled cable 1, Figure 7 It shows that according to Figure 6 The cross-sectional view of the liquid-cooled cable 1 with cross-section line EE.

[0025] In variations, the charging cable 10 according to this disclosure typically includes first and second liquid-cooled cables 1, which generally have similar designs. The liquid-cooled cables 1 are intended to deliver current to an electric vehicle (not shown in detail) for charging the electric vehicle. The first and second liquid-cooled cables 1 are arranged in an external hose 11, which helps protect the first and second liquid-cooled cables from external influences during operation. Figure 1 As shown, the flow hose 12 may be arranged within the external hose 11 to return the coolant 15 flowing in the liquid-cooled cable 1, as described in more detail below. Depending on the application, the two liquid-cooled cables 1 may share a common flow hose 12. Alternatively or additionally, each liquid-cooled cable 1 may include its own flow hose 12. If necessary, the charging cable 10 may include a ground wire 13 and / or at least one data line 14 to transmit information along the charging cable 10.

[0026] The liquid-cooled cable 1 according to this disclosure typically includes a conductor 2, which comprises at least two cable strands 3. The cable strands 3 of the conductor 2 are surrounded by a hose 5. In a cross-sectional view, they are typically at least partially spaced from the hose 5 by a gap space 6 arranged between the inner wall 7 of the hose 5 and the cable strands 3 of the conductor 2. The gap space 6 is intended to guide coolant 15 along the conductor 2. Good results are achieved when the coolant 15 is in direct contact with the outer layer 4 of the cable strands 3. Typically, the at least two cable strands 3 are helically twisted relative to each other in the longitudinal direction x of the conductor 2. As a result, the gap space 6 defined by the strands 3 of the conductor 2 and the inner wall 7 of the hose 5 is also helically shaped, thereby driving the coolant 15 along a helically shaped path around the center 16 of the conductor 2. Preferably, the inner wall 7 of the hose 5 is flat, thereby supporting the linear flow of the coolant 15. Preferably, each cable strand 3 is composed of a bundle of wires 4 twisted relative to each other. To obtain a larger current-carrying cross-section, the wires 4 of one conductor 3 can be mechanically compressed relative to each other. Preferably, the conductor 2 comprises: two cable strands 3, which are spaced 180° apart from each other in cross-section relative to the center 16 of the conductor 2; or three cable strands 3, which are spaced 120° apart from each other in cross-section relative to the center 16 of the conductor 2. If suitable, the at least two cable strands 3 can be spaced apart from each other by spacers (not shown in detail) arranged between them in the longitudinal direction. This allows for more uniform internal cooling. Preferably, the hose 5 comprises a substantially circular cross-section, thereby providing a uniform distribution of the coolant 15. Depending on the field of application, other cross-sectional shapes may be suitable. The hose 5 is preferably self-supporting. Alternatively, it may be surrounded, for example, by a support structure (e.g., in the form of a helical coil made of spring steel) to maintain the cross-section when lateral forces are applied or during bending. Good results can be achieved when the conductor 2 is arranged to be laterally movable relative to the hose 5 to obtain variable clearance space. The twist length of the cable strands 3 is preferably in the range of 7 to 15 times the diameter of the envelope curve 9 of the corresponding conductor 2. Furthermore, the diameter of the inner wall 7 of the hose 5 is preferably in the range of 5% to 15% larger than the diameter of the envelope curve 9 of the corresponding conductor 2. In both cases, other values ​​may be possible depending on the application. In a preferred variation, the charging cable 10 comprises two liquid-cooled cables 1 arranged adjacent to each other. Additionally, the charging cable 10 may include a flow hose 12 for the coolant 15. For better protection, the charging cable 10 includes an outer hose 11.

[0027] The terms used in this specification are descriptive rather than limiting, and it is to be understood that various changes may be made without departing from the spirit and scope of this disclosure.

[0028] Name List

[0029] 1 Liquid-cooled cable

[0030] 2 conductors

[0031] 3 cable strands

[0032] 4-wire (cable)

[0033] 5. Hose (Conductor Hose)

[0034] 6 gap space

[0035] 7. Inner wall (hose)

[0036] 9. Envelope Curve (Conductor)

[0037] 10 charging cable

[0038] 11 External hoses

[0039] 12 Flow hoses (coolant)

[0040] 13 Grounding wire / ground cable

[0041] 14 data cables

[0042] 15 Coolant

[0043] 16 (Conductor's) center

Claims

1. A liquid-cooled cable (1), comprising: a. a conductor (2) comprising three cable strands (3) which are not jacketed and which are spaced apart from one another by 120° in cross-section relative to a center (16) of the conductor (2) and which are twisted relative to one another in a helical manner in a longitudinal direction (x) of the conductor (2); b. the conductor (2) is surrounded by a hose (5) which is at least partially spaced apart from the conductor (2) by a gap space (6) in a cross-sectional view, the gap space (6) being arranged between an inner wall (7) of the hose (5) and the cable strands (3) of the conductor (2); c. the gap space (6) is configured to guide a cooling liquid (15) in the hose (5) along the conductor (2) such that the cooling liquid comes into direct contact with outer layers of the cable strands; d. wherein the three cable strands (3) are arranged to be laterally displaceable in the hose (5) such that on one side they are in contact with the inner wall (7) of the hose (5) in a position-related manner and on the opposite side they are spaced apart from the inner wall (7) of the hose (5).

2. The liquid-cooled cable (1) according to claim 1, wherein The three cable strands (3) consist of wires (4) which are twisted relative to one another.

3. The liquid-cooled cable (1) according to claim 2, wherein The wires (4) of one cable strand (3) are mechanically compressed relative to one another.

4. The liquid-cooled cable (1) according to any one of claims 1 to 3, wherein, The three cable strands (3) are spaced apart from one another by spacers.

5. The liquid-cooled cable (1) according to any one of claims 1 to 3, wherein, The hose (5) comprises a circular cross-section.

6. The liquid-cooled cable (1) according to any one of claims 1 to 3, wherein The hose (5) is self-supporting.

7. The liquid-cooled cable (1) according to any one of claims 1 to 3, wherein The twist length of the cable strands (3) is in the range of 7 to 15 times a diameter of an envelope curve (9) of the corresponding conductor (2).

8. The liquid-cooled cable (1) according to any one of claims 1 to 3, wherein, The diameter of the inner wall (7) of the hose (5) is in the range of 5% to 15% larger than a diameter of an envelope curve (9) of the corresponding conductor (2).

9. A charging cable (10) comprising at least one liquid-cooled cable (1) according to any one of claims 1 to 8.

10. The charging cable (10) according to claim 9, wherein, The charging cable (10) comprises two liquid-cooled cables (1) arranged next to one another.

11. The charging cable (10) according to claim 9 or 10, wherein, The charging cable (10) comprises a flow hose (12) for the cooling liquid (15).

12. The charging cable (10) according to claim 9 or 10, wherein, The charging cable (10) comprises an outer hose (11).

13. A method of manufacturing a liquid-cooled cable (1) according to any one of claims 1 to 8, the method comprising the following method steps: a. providing a conductor (2) comprising three cable strands (3) which are spaced apart from one another by 120° in cross-section relative to a center (16) of the conductor (2); b. surrounding the conductor (2) by a hose (5) which is extruded in a continuous manner over the three cable strands (3), the hose (5) being at least partially spaced apart from the conductor (2) by a gap space (6) in a cross-sectional view, the gap space (6) being arranged between an inner wall (7) of the hose (5) and the cable strands (3) of the conductor (2); b. surrounding the conductor (2) by a hose (5) which is extruded in a continuous manner over the three cable strands (3), the hose (5) being at least partially spaced apart from the conductor (2) by a gap space (6) in a cross-sectional view, the gap space (6) being arranged between an inner wall (7) of the hose (5) and the cable strands (3) of the conductor (2); c. said gap space (6) is configured to guide cooling liquid (15) in said hose (5) along said conductor (2) such that said cooling liquid is in direct contact with the outer layer of the cable strands.

14. The method of claim 13, wherein, During production, said three cable strands (3) are twisted in relation to each other in a helical manner in the longitudinal direction (x) of said conductor (2).

15. The method of claim 13 or 14, wherein, Before said hose (5) is extruded over said three cable strands (3), the wires (4) of at least one cable strand (3) are mechanically compressed in relation to each other.

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