Abstract
A cable shielding and an electrical conductor having such a cable shielding are provided. The cable shielding has a first wire winding and a second wire winding. The first wire winding has a plurality of turns. The first wire winding is wound in a first direction with a first pitch about a longitudinal axis. The second wire winding has a plurality of turns. The second wire winding is wound in a second direction, which is different from the first direction, with a second pitch about the longitudinal axis. Turns of the plurality of turns of the first wire winding and corresponding turns of the plurality of turns of the second wire winding cross one another in each case at a first crossing point in such a way that a plurality of first crossing points of the first wire winding and the second wire winding are present in the direction of the longitudinal axis. The plurality of first crossing points run at least approximately helically in the direction of the longitudinal axis.
Claims
1. Cable shielding having: a first wire winding with a plurality of turns, wherein the first wire winding is wound in a first direction with a first pitch about a longitudinal axis; a second wire winding with a plurality of turns, wherein the second wire winding is wound in a second direction, which is different from the first direction, with a second pitch about the longitudinal axis; wherein turns of the plurality of turns of the first wire winding and corresponding turns of the plurality of turns of the second wire winding cross in each case at a first crossing point such that a plurality of first crossing points of the first wire winding and of the second wire winding is present in the direction of the longitudinal axis and the plurality of first crossing points runs at least approximately helically in the direction of the longitudinal axis.
2. Cable shielding according to claim 1, wherein the turns of the plurality of turns of the first wire winding and the corresponding turns of the plurality of turns of the second wire winding cross in each case at a second crossing point such that a plurality of second crossing points of the first wire winding and of the second wire winding is present in the direction of the longitudinal axis and the plurality of second crossing points runs at least approximately helically in the direction of the longitudinal axis.
3. Cable shielding according to claim 1, wherein turns of the plurality of turns of the first wire winding and corresponding turns of the plurality of turns of the second wire winding cross in each case at several crossing points such that a plurality of several crossing points of the first wire winding and of the second wire winding is present in the direction of the longitudinal axis and the plurality of several crossing points runs respectively at least approximately helically in the direction of the longitudinal axis in each case.
4. Cable shielding according to claim 1, wherein the plurality of several crossing points runs respectively at least approximately parallel to one another in the direction of the longitudinal axis.
5. Cable shielding according to claim 1, wherein the first pitch and the second pitch have the same value.
6. Cable shielding according to claim 1, wherein the first direction and the second direction are at least virtually opposed to one another.
7. Electric cable having: at least one electrical conductor; and cable shielding according to claim 1 arranged around the electrical conductor.
Description
[0024] The present disclosure is to be explained further on the basis of figures. These figures show schematically:
[0025] FIG. 1a cable shielding according to an example;
[0026] FIG. 1b cable shielding according to a possible embodiment of the present invention.
[0027] In the following, without being restricted hereto, specific details are explained to deliver a complete understanding of the present disclosure, It is clear to an expert, however, that the present disclosure can be used in other exemplary embodiments that may differ from the details set out below.
[0028] FIG. 1a shows schematically cable shielding, more precisely braided shielding 1 for a cable. The braided shielding 1 has a first wire winding 2, which extends in a first rotary direction with a first pitch spirally in the direction of a longitudinal axis 1a of the braided shielding 1. Expressed another way, seen from the lower end of the braided shielding 1, i.e. in the direction of the arrow of the longitudinal axis 1a, the first wire winding 2 coils with a first pitch upwards in a counter-clockwise manner. The braided shielding 1 has a second wire winding 3, which extends in a second rotary direction with a second pitch spirally in the direction of the longitudinal axis 1a of the braided shielding 1. Expressed another way, seen from the lower end of the braided shielding 1, i.e. in the direction of the arrow of the longitudinal axis 1a, the second wire winding 3 coils with a second pitch upwards in a clockwise manner. In the example from FIG. 1a, the first pitch corresponds to the second pitch.
[0029] As is to be recognised in FIG. 1a, a turn of the first wire winding 2 and a turn of the second wire winding 3 overlap at a point. This point is described as crossing point 4 or overlap point. In the example from FIG. 1a, the two wire windings 2, 3 are intertwined with one another at the crossing point 4. Since each of the wire windings 2, 3 has a plurality of turns in the direction of the longitudinal axis 1a, several such crossing points exist in the direction of the longitudinal axis 1a, even in the case of one crossing point per turn. In the example from FIG. 1a, it is to be recognised that these crossing points lie on a straight line 5, which runs parallel to the direction of the longitudinal axis 1a, The two wire windings 2, 3 form two layers, so to speak, due to the intertwining and can accordingly also be described as two-layer wire covering and, on account of the parallelism of the crossing points to the longitudinal axis 1a, as two-layer wire covering with intersection running axially.
[0030] The wires / wire windings 2, 3 of the braid / braided shield 1 from FIG. 1a experience a movement relative to one another with accompanying friction when they are exposed to movement. Furthermore, these wires / wire windings 2, 3 experience tractive and thrust loads, This results in a limited service life of the wires / wire windings 2, 3 and thus of the braid / braided shield 1.
[0031] Although a braided shield 1 from FIG. 1a with the opposed wire covering shown has a relatively high mechanical service life and a higher mechanical service life than conventional braids, for example of wires with the same orientation, the braided shielding 1 can move, or more precisely, the wires of the braided shielding 1 can move and form e.g. nests and holes, This has a negative influence on the electrical properties of the braided shielding 1.
[0032] FIG. 1b shows cable shielding, more precisely braided shielding 10 for a cable, schematically according to an exemplary embodiment with improved properties compared with the cable shielding from FIG. 1a. The braided shielding 10 has a first wire winding 20, which extends in a first rotary direction with a first pitch spirally in the direction of a longitudinal axis 10a of the braided shielding 10. Expressed another way, seen from the lower end of the braided shielding 10, i.e. in the direction of the arrow of the longitudinal axis 10a, the first wire winding 20 coils with a first pitch upwards in a counter-clockwise manner. The braided shielding 10 has a second wire winding 30, which extends in a second rotary direction with a second pitch spirally in the direction of the longitudinal axis 10a of the braided shielding 10. Expressed another way, seen from the lower end of the braided shielding 10, i.e. in the direction of the arrow of the longitudinal axis 10a, the second wire winding 30 coils with a second pitch upwards in a clockwise manner. In the example from FIG. 1b, the first pitch corresponds to the second pitch, i.e. each individual complete turn of the wire windings 20, 30 covers the same path W in the direction of the longitudinal axis 10a, A turn describes here a complete revolution of a wire of the respective wire winding 20, 30,
[0033] As is to be recognised in FIG. 1b, a turn of the first wire winding 20 and a turn of the second wire winding 30 each overlap at a point. This point is described as crossing point 40 or overlap point. In the example from FIG. 1b, the two wire windings 20, 30 are also intertwined with one another at the crossing point 40. Since each of the wire windings 20, 30 has a plurality of turns in the direction of the longitudinal axis 10a, several such crossing points 40 exist in the direction of the longitudinal axis 10a, even with one crossing point per turn. In the example from FIG. 1b, it is to be recognised that these crossing points 40 run in the form of a helix 50 or spiral, i.e. do not form any straight lines running parallel to the direction of the longitudinal axis 10a. The two wire windings 20, 30 form two layers, so to speak, due to the intertwining and can accordingly also be described as two-layer wire covering and, on account of the helical progression 50 of the crossing points 40, as two-layer wire covering with intersection running helically,
[0034] For the sake of simplicity and clarity, only one crossing point 40 per turn, more precisely per turn of the wire winding 20 and corresponding turn of the wire winding 30, is shown in FIG. 1b, A turn of the wire winding 20 and a corresponding turn of the wire winding 30 can cross at more than one point, however, i.e. at several points, i.e. have several crossing points respectively at which they are intertwined with one another. For example, the wire winding 20 and the wire winding 30 are intertwined with one another at one or more, e.g. at each, of their turns not only once, but twice or if applicable several times and accordingly have a first crossing point 40, a second crossing point and if applicable further crossing points per turn. In this case a plurality of first crossing points 40, a plurality of second crossing points and if applicable a plurality of further crossing points are present in the direction of the longitudinal axis 10a. The plurality of first crossing points 40 can be described by a first helix / spiral 50 in the direction of the longitudinal axis 10a. The plurality of second crossing points can be described by a second helix / spiral in the direction of the longitudinal axis 10a that runs parallel to the first helix / spiral 50. The plurality of further crossing points can be described by a further helix / spiral in the direction of the longitudinal axis 10a that runs parallel to the first helix / spiral 50 and the second helix / spiral.
[0035] The braided shielding 10 described with regard to FIG. 1b with overlap points 40 running helically is more stable against drag, torsional and flexural fatigue movement than the braided shielding 1 with overlap points 4 running axially and described with regard to FIG. 1a, A shielding as a combination of wire covering and braid is provided by the braided shielding 10 that is intertwined with itself, per turn pair, only at one point of the circumference or at several points of the circumference. The intertwined point(s) runs/run helically along the longitudinal axis 10a, such as e.g. the product axis, of the braided shielding 10, This increases the service life of the shielding 10 of cables in the event of mechanical stress in two or three dimensions. Better electrical properties (i.e. a better electrical performance) are additionally achieved thus over the service life (e.g. in respect of EMC, leakage currents etc.),
