Connection Arrangement, Connection System and Method for Connecting Two Electrical Conductors

Abstract

A connection arrangement (4) for connecting a first electrical conductor (2) to a second electrical conductor (3) comprises a first fastening element (6) that is inserted into an aperture (9a) defined in the first electrical conductor (2) and which is supported on a side of the first electrical conductor (2) facing away from the second electrical conductor (3), and a second fastening element (7) which is supported on a side of the second electrical conductor (3) facing away from the first electrical conductor (2). The first fastening element (6) and the second fastening element (7) form a common primary threaded connection (18) to frictionally and electrically connect the first electrical conductor (2) to the second electrical conductor (3) in a screwed-together state. The first fastening element (6) further has a mechanical connection interface (13) for a captive connection to the first electrical conductor (2).

Claims

1. A connection arrangement (4) for connecting a first electrical conductor (2) to a second electrical conductor (3), comprising: a first fastening element (6) that can be inserted into an aperture (9a) defined in the first electrical conductor (2) and the first fastening element (6) has a support surface (11a) with which the first fastening element (6) is supported on a side of the first electrical conductor (2) facing away from the second electrical conductor (3); and a second fastening element (7) which has a support surface (11b) with which the second fastening element (7) is supported on a side of the second electrical conductor (3) facing away from the first electrical conductor (2); and wherein the first fastening element (6) and the second fastening element (7), when in a screwed together state, form a common primary threaded connection (18) that connects the first electrical conductor (2) frictionally and electrically to the second electrical conductor (3); and wherein the first fastening element (6) has a mechanical connection interface (13) for a captive connection to the first electrical conductor (2); and the mechanical connection interface (13) of the first fastening element (6) forms a secondary threaded connection (14) to the first electrical conductor (2) for captive connection of the first fastening element (6) within the aperture (9a) defined in the first electrical conductor (2).

2. The connection arrangement (4) as claimed in claim 1 and wherein the first fastening element (6) is sleeve-shaped and the first fastening element (6) has a primary internal thread (10) for the common primary threaded connection (18) to the second fastening element (7), and wherein the primary internal thread (10) of the first fastening element (6) extends through the first fastening element (6) starting from an end portion of the first fastening element (6) that faces the second fastening element (7); or the first fastening element (6) is bolt-shaped and the first fastening element (6) has a primary external thread (17) for the common primary threaded connection (18) to the second fastening element (7), and wherein the primary external thread (17) of the bolt-shaped first fastening element (6) extends at least partially along an end portion of the first fastening element (6), which protrudes from an aperture (9b) defined in the second electrical conductor (3) on a side of the second electrical conductor (3) facing away from the first electrical conductor (2).

3. The connection arrangement (4) as claimed in claim 1 and wherein the first fastening element (6) has a shank portion (8a) which extends from the support surface (11a) of the first fastening element (6) into the aperture (9a) defined in the first electrical conductor (2), and the shank portion (8a) has the mechanical connection interface (13) for making the captive connection of the first fastening element (6) to the first electrical conductor (2) within the aperture (9a) defined in the first electrical conductor (2).

4. The connection arrangement (4) as claimed in claim 3 and wherein the mechanical connection interface (13) of the first fastening element (6), does not emerge from the aperture (9a) defined in the first electrical conductor (2) on a side of the first electrical conductor (2) facing the second electrical conductor (3) when the support surface (11a) of the first fastening element (6) is supported on the first electrical conductor (2).

5. The connection arrangement (4) a claimed in claim 1 and wherein directions of rotation of the secondary threaded connection (14) and the primary threaded connection (18) are opposite to each other.

6. The connection arrangement (4) as claimed in claim 1 and wherein the mechanical connection interface (13) of the first fastening element (6) has a self-tapping, secondary external thread to cut a corresponding, secondary internal thread (15) into a circumferential extending edge of the aperture (9a) defined in the first electrical conductor (2).

7. The connection arrangement (4) as claimed in claim 1 and wherein the first fastening element (6), and the second fastening element (7), each define a mechanical interface (16) for connection to a screwing tool to transmit a torque from the screwing tool to the respective fastening element (6, 7).

8. The connection arrangement (4) as claimed in claim 1 and wherein the first fastening element (6), and the second fastening element (7), are each formed from a material that has a higher mechanical strength than the first electrical conductor (2) or a higher mechanical strength than the second electrical conductor (3).

9. The connection arrangement (4) as claimed in claim 1 and wherein the second fastening element (7) is a screw which can be guided through an aperture (9b) defined in the second electrical conductor (3) and the screw second fastening element (7) can be screwed into the first fastening element (6) when the first fastening element (6) is received in the aperture (9a) defined in the first electrical conductor (2); or the second fastening element (7) is designed as a screw nut which can be screwed onto a primary external thread (17) defined by the first fastening element (6) protruding from an aperture (9b) defined in the second electrical conductor (3) when the first fastening element (6) is received in the aperture (9a) defined in the first electrical conductor (2).

10. A connection system (1) for high-voltage technology, comprising: a first electrical conductor (2); a second electrical conductor (3); and a connection arrangement (4) for connecting the first electrical conductor (2) to the second electrical conductor (3), the connection arrangement (4) having, a first fastening element (6) that can be inserted into an aperture (9a) defined in the first electrical conductor (2) and the first fastening element (6) has a support surface (11a) with which the first fastening element (6) is supported on a side of the first electrical conductor (2) facing away from the second electrical conductor (3); and a second fastening element (7) which has a support surface (11b) with which the second fastening element (7) is supported on a side of the second electrical conductor (3) facing away from the first electrical conductor (2); and wherein the first fastening element (6) and the second fastening element (7), when in a screwed together state, form a common primary threaded connection (18) that connects the first electrical conductor (2) frictionally and electrically to the second electrical conductor (3); and wherein the first fastening element (6) has a mechanical connection interface (13) for a captive connection to the first electrical conductor (2); and the mechanical connection interface (13) of the first fastening element (6) forms a secondary threaded connection (14) to the first electrical conductor (2) for captive connection of the first fastening element (6) within the aperture (9a) defined in the first electrical conductor (2); and the first fastening element (6) is inserted into the aperture (9a) defined in the first electrical conductor (2) and is connected to the second fastening element (7) via the common primary threaded connection (18).

11. The connection system (1) as claimed in claim 10 and wherein the aperture (9a) defined in the first electrical conductor (2) is arranged coaxially to an aperture (9b) defined in the second electrical conductor (3), through which the first fastening element (6) or the second fastening element (7) extends.

12. The connection system (1) as claimed in claim 10 and wherein the aperture (9a) defined in the first electrical conductor (2) or an aperture (9b) defined in the second electrical conductor (3) are formed as a round through-hole.

13. The connection system (1) as claimed in claim 10 and further comprising: an electrical contact surface (5) on both the first electrical conductor (2) and on the second electrical conductor (3) and the electrical contact surface (5) is on a side of each respective electrical conductor (2, 3) facing the other electrical conductor (2, 3), and the electrical contact surface (5) provides mutual connection for current transmission; and wherein, the first electrical conductor (2), and the second electrical conductor (3), are each high-voltage contact elements.

14. The connection system (1) as claimed in claim 10 and further comprising: an electrical contact sleeve (20) that is arranged between the first electrical conductor (2) and the second electrical conductor (3), and the electrical contact sleeve (2) establishes an indirect electrical and mechanical connection between the first electrical conductor (2) and the second electrical conductor (3) when the first fastening element (6) is connected to the second fastening element (7).

15. A method for connecting a first electrical conductor (2) to a second electrical conductor (3), comprising the steps: providing a first fastening element (6) that has a support surface (11a) and a mechanical connection interface (13) for a captive connection to the first electrical conductor (2); and inserting the first fastening element (6) into an aperture (9a) defined in the first electrical conductor (2) until the captive connection of the first fastening element (6) to the first electrical conductor (2) is established; providing a second fastening element (7) that has a support surface (11b); and screwing the second fastening-element (7) to the first fastening element (6) via a common primary threaded connection (18) until the support surface (11b) of the second fastening element (7) is supported on a side of the second electrical conductor (3) facing away from the first electrical conductor (2), and the first electrical conductor (2) and the second electrical conductor (3), are frictionally and electrically connected.

16. The connection arrangement (4) as claimed in claim 7 and wherein the same type of mechanical interface (16) is provided in both the first fastening element (6) and in the second fastening element (7).

17. The connection arrangement (4) as claimed in claim 1 and wherein the first fastening element (6) or the second fastening element (7) is formed of steel.

18. The connection system (1) as claimed in claim 13 and wherein the first electrical conductor (2) and the second electrical conductor (3), are each designed as a busbar or as a cable lug.

Description

[0109] The figures each show preferred embodiments in which individual features of the present invention are shown in combination with one another. Features of an exemplary embodiment can also be implemented separately from the other features of the same exemplary embodiment and can accordingly be readily combined by a person skilled in the art to form further useful combinations and sub-combinations with features of other exemplary embodiments.

[0110] In the figures, elements with the same function are provided with the same reference signs.

[0111] The figures show schematically:

[0112] FIG. 1 a connection system according to a first exemplary embodiment of the invention, comprising a two-part connection arrangement and two electrical conductors, in a sectional side view during assembly;

[0113] FIG. 2 the connection arrangement according to FIG. 1 in an assembled state, in a sectional perspective view;

[0114] FIG. 3 an enlarged detail of the mechanical connection interface of the first fastening element of the connection arrangement according to FIG. 2, which connection interface is connected to the first electrical conductor:

[0115] FIG. 4 a connection system according to a second exemplary embodiment of the invention in an assembled state, in a sectional perspective view;

[0116] FIG. 5 a connection system according to a third exemplary embodiment of the invention in an assembled state, in a sectional side view; and

[0117] FIG. 6 a connection system according to a fourth exemplary embodiment of the invention in an assembled state, in a sectional side view.

[0118] FIGS. 1 to 3 show a connection system 1 according to a first exemplary embodiment of the invention. The connection system 1 described in the exemplary embodiments is particularly suitable for use in high-voltage technology, but can, in principle, be used in all electrical engineering applications. FIG. 1 shows a disassembled state of the connection system 1 in a sectional side view and FIG. 2 shows an assembled state in a perspective sectional view. FIG. 3 shows an enlarged detail in the assembled state.

[0119] The connection system 1 has a first electrical conductor 2 and a second electrical conductor 3, as well as a connection arrangement 4 to connect the two electrical conductors 2, 3 to each other electrically and frictionally. The electrical conductors 2, 3 can, for example, be high-voltage contact elements, in particular busbars or cable lugs.

[0120] It is provided to press two opposing contact surfaces 5 (cf. FIG. 1) of the electrical conductors 2, 3 flat against each other, wherein in principle any contacting, for example also an end-face or other contacting of the electrical conductors 2, 3 can be provided.

[0121] The connection arrangement 4 has a first fastening element 6 and a second fastening element 7. The first fastening element 6 can be inserted into an aperture 9a of the first electrical conductor 2 with a shank portion 8a that is located in front in the mounting direction M.sub.1, i.e. facing the second fastening element 7. In the exemplary embodiment, the aperture 9a of the first electrical conductor 9 is a round, threadless through-hole.

[0122] In the exemplary embodiments shown in FIGS. 1 to 3 and 5, the first fastening element 6 is sleeve-shaped for example, in the manner of a screw nut. Accordingly, the first fastening element 6 has a primary internal thread 10. The primary internal thread 10 extends along the shank portion 8a, which is directly connected to a support surface 11a (see FIG. 1), which is formed on the end face of a shoulder of a head portion 12a (screw-head-like shaping) of the first fastening element 6. The first fastening element 6 is able to support itself with said support surface 11a on the side of the first electrical conductor 2 facing away from the second electrical conductor 3 when the first fastening element 6 is in its mounted state in the aperture 9a of the first electrical conductor 2.

[0123] The first fastening element 6 also has a mechanical connection interface 13 for a captive connection to the first electrical conductor 2. The captive connection is preferably a secondary threaded connection 14 with the first electrical conductor 2. In the exemplary embodiments, the mechanical connection interface 13 is designed as a self-tapping, secondary external thread 13, with which a corresponding, secondary internal thread 15 (cf. FIG. 3) can be cut into the aperture 9a or the through-hole of the first electrical conductor 2. The mechanical connection interface 13 of the first fastening element 6 thus forms the secondary threaded connection 14 within the aperture 9a of the first electrical conductor 2 with the first electrical conductor 2.

[0124] The mechanical connection interface 13 or the self-tapping, secondary external thread 13 is formed along the shank portion 8a and, in the assembled state of the first fastening element 6, is arranged within the aperture 9a or the through-hole of the first electrical conductor 2. Optionally, a safety distance d can be provided between the front end of the shank portion 8a in the mounting direction M.sub.1 and the end of the aperture 9a on the contact surface side in the mounted state of the first fastening element 6, as shown in FIG. 3. In this way, it can be ensured that the first fastening element 6 does not protrude from the aperture 9a in a disruptive manner and, for example, does not damage the contact surface 5 of the second electrical conductor 3, even in a case with tolerances.

[0125] Preferably, as part of a first method step for connecting the two electrical conductors 2, 3, it can be provided to insert the first fastening element 6 into the aperture 9a of the first electrical conductor 2 until it forms the captive connection, i.e. in particular the secondary threaded connection 14 (preferably until the support surface 11a is supported on a side of the first electrical conductor 2 facing away from the second electrical conductor 3). In order to transmit a suitable torque from a screwing tool (not shown) to the first fastening element 6, the latter preferably has a mechanical interface 16 for connection to the screwing tool, for example a hexagon socket drive.

[0126] The second fastening element 7 of the connection arrangement 4 also has a support surface 11b (cf. FIG. 1), with which it can be supported on a side of the second electrical conductor 3 facing away from the first electrical conductor 2. In the exemplary embodiments of FIGS. 1 to 3 and 5, the second fastening element 7 is bolt-shaped in the manner of a screw element and has a primary external thread 17, which extends along a shank portion 8b (see FIG. 1) of the second fastening element 7. The support surface 11b is formed on the end face of a head portion 12b of the second fastening element 7, which can also have a mechanical interface 16 for connection to a screwing tool, preferably a mechanical interface 16 of the same interface type as in the case of the first fastening element 6. In the exemplary embodiments, however, different interface types are shown by way of example.

[0127] The second fastening element 7 can be passed through an aperture 9b, in the exemplary embodiments again a through-hole, of the second electrical conductor 3 and in this way can be screwed into the first fastening element 6. The primary internal thread 10 of the first fastening element 6 and the primary external thread 17 of the second fastening element 7 ultimately form a common primary threaded connection 18 in order to connect the first electrical conductor 2 frictionally and electrically to the second electrical conductor 3 in a screwed-together state.

[0128] Thus, in a second method step, the second fastening element 7 can be connected to the first fastening element 6 via the common primary threaded connection 18 until the support surface 11b of the second fastening element 7 is supported on the side of the second electrical conductor 3 facing away from the first electrical conductor 2 and the two electrical conductors 2, 3 are frictionally connected to one another.

[0129] The primary threaded connection 18 and the secondary threaded connection 14 are preferably designed with an opposite direction of rotation, as indicated by corresponding arrows in FIG. 1. For example, the direction of rotation of the primary threaded connection 18 can be clockwise along the mounting direction M.sub.2 of the second fastening element 7 and the direction of rotation of the secondary threaded connection 14 can be counterclockwise along the mounting direction M.sub.1 of the first fastening element 6. In this way, the secondary threaded connection 14 is not able to loosen during the screwing of the first fastening element 6 into the second fastening element 7, but rather is screwed even more tightly to the first electrical conductor 2 in case of doubt.

[0130] In the proposed manner, a frictional and electrical connection between the two electrical conductors 2, 3 can be established by the screw connection of the two fastening elements 6, 7. The first fastening element 6 and the second fastening element 7 are preferably each made of a material with higher mechanical strength than the electrical conductors 2, 3. Particularly preferably, the two fastening elements 6, 7 are made of the same material, but of a different material than the electrical conductors 2, 3. The electrical conductors 2, 3 can be made of copper or aluminum, for example, and the fastening elements 6, 7 can be made of steel. Therefore, signs of fatigue of the mechanical connection can be avoided even at high temperatures.

[0131] As shown in the exemplary embodiments, the through-hole or the aperture 9b of the second electrical conductor 3 in particular can be oversized with respect to the second fastening element 7 (or the first fastening element 6), for example also as a slot.

[0132] It should be noted at this juncture that the second electrical conductor 3 does not necessarily have to have an aperture 9b. In principle, the second fastening element 7 can also be mounted laterally, optionally in a lateral recess in the second electrical conductor 3.

[0133] Optionally, when using the self-tapping, secondary external thread 13 of the first fastening element 6, one or more chip traps 19 can be provided between the first fastening element 6 and the first electrical conductor 2. This is illustrated in FIG. 3.

[0134] FIG. 3 shows an example of two cavities between the first fastening element 6 and the first electrical conductor 2 in the fully assembled state, in which chips may accumulate. The cavities or chip traps 19 are completely closed by a diameter step within the aperture 9a of the first electrical conductor 2 and the support surface 11a of the first fastening element 6, so that the chips cannot escape during operation.

[0135] FIG. 4 illustrates a second exemplary embodiment of a connection system 1 according to the invention, in which the first fastening element 6 is in the form of a bolt or is designed in the manner of a screw element. Again, a self-tapping, secondary external thread 13 is provided in order to cut a corresponding secondary internal thread 15 into the aperture 9a of the first electrical conductor 2. However, the connection to the second fastening element 7 is not made within the first fastening element 6, but on the shank portion 8a of the first fastening element 6, on which there is a primary external thread 17 for the primary threaded connection 18 to the second fastening element 7. The cross-section of the first fastening element 6 can optionally be reduced in the region of the primary external thread 17 (depending on the cross-section of the aperture 9b in the second electrical conductor 3). Lastly, the second fastening element 7 can be designed as a corresponding screw nut, which can be screwed onto the shank portion 8a of the first fastening element 6 protruding from the aperture 9b of the second electrical conductor 3 in the assembled state.

[0136] At this juncture, it should be mentioned that the second fastening element 7, if it is to be screwed onto a primary external thread 17 of the first fastening element 6, does not necessarily have to be designed in the manner of a screw nut arranged completely outside the aperture 9b of the second electrical conductor 3. The second fastening element 7 can, for example, also be designed in the form of a sleeve, wherein an axial portion of the sleeve-shaped second fastening element 7 can then, for example, also extend into the aperture 9b of the second electrical conductor 2 in order to enter into the primary threaded connection 18 to the first fastening element 6 within the aperture 9b or on the side of the second electrical conductor 3 facing the first electrical conductor 2. In this respect, the second fastening element 7 can, for example, be constructed similarly to the first fastening element 6 shown in FIGS. 1 and 2. This also applies analogously to the embodiment described below according to FIG. 6.

[0137] FIGS. 5 and 6 illustrate two further embodiments of a fastening system 1 according to the invention. FIG. 5 relates to a sleeve-shaped first fastening element 6 in combination with a screw-shaped second fastening element 7 and FIG. 6 relates to a bolt-shaped first fastening element 6 in combination with a second fastening element 7 designed as a screw nut. In contrast to the previous embodiments, the two electrical conductors 2, 3 are not directly connected to each other via their contact surfaces 5. An additional electrical contact sleeve 20 is arranged between the first electrical conductor 2 and the second electrical conductor 3 in order to establish an indirect electrical and mechanical connection between the electrical conductors 2, 3 when the two fastening elements 6, 7 are in their screwed state.

[0138] The use of a contact sleeve 20 can be advantageous for various technical reasons, for example to provide a defined spacing between the electrical conductors 2, 3.