Switching device

Abstract

In an embodiment a switching device includes at least one stationary contact in a switching chamber containing a gas comprising H.sub.2 and one movable contact in the switching chamber, wherein the switching chamber has a switching chamber wall and a switching chamber base, and wherein the switching chamber at least partially comprises a polymer material configured to release hydrogen when heated.

Claims

1. A switching device comprising: at least one stationary contact in a switching chamber containing a gas comprising H.sub.2; and at least one movable contact in the switching chamber, wherein the switching chamber has a switching chamber wall and a switching chamber base, wherein he switching chamber wall has at least one opening, wherein the at least one stationary contact projects through the opening in the switching chamber wall, wherein the movable contact is connected to a shaft that projects through an opening in the switching chamber base, wherein the switching chamber wall and the switching chamber base are arranged in relation to one another such that a space is formed which is enclosed except for the above described openings, wherein the switching chamber base at least partially comprises a polymer material configured to release hydrogen when heated, and/or wherein the switching chamber wall at least partially comprises the polymer material configured to release the hydrogen when heated.

2. The switching device according to claim 1, wherein the switching chamber base has a plastic shield comprising the polymer material.

3. The switching device according to claim 1, wherein the switching chamber base consists essentially of the polymer material.

4. The switching device according to claim 1, wherein the switching chamber wall consists essentially of the polymer material.

5. The switching device according to claim 1, wherein the polymer material comprises a polyoxymethylene.

6. The switching device according to claim 5, wherein the polyoxymethylene has a (CH.sub.2O).sub.n structure.

7. The switching device according to claim 1, wherein at least one blowout magnet is arranged in the switching chamber.

8. The switching device according to claim 1, wherein the gas has an H.sub.2 content of at least 50%.

9. The switching device according to claim 1, wherein the at least one stationary contact comprises copper and the one movable contact comprises copper.

10. The switching device according to claim 1, wherein the at least one stationary contact comprises copper and a further metal and the one movable contact comprises copper and the further metal.

11. The switching device according to claim 10, wherein the further metal is W, Ni and/or Cr.

12. The switching device according to claim 1, wherein the one movable contact is connected to an armature comprising a magnetic core via the shaft.

13. The switching device according to claim 12, further comprising a housing and a magnetic coil, wherein the switching chamber and the magnetic coil are located inside the housing one above another in an axial direction, wherein the magnetic coil surrounds the magnetic core, and wherein magnetic coil is configured to move the magnetic core via a magnetic field.

14. A switching device comprising: at least one stationary contact in a switching chamber containing a gas comprising H.sub.2; and at least one movable contact in the switching chamber, wherein the switching chamber has a switching chamber wall and a switching chamber base, wherein he switching chamber wall has at least one opening, wherein the at least one stationary contact projects through the opening in the switching chamber wall, wherein the movable contact is connected to a shaft that projects through an opening in the switching chamber base, wherein the switching chamber wall and the switching chamber base are arranged in relation to one another such that a space is formed which is enclosed except for the above described openings, and wherein the switching chamber base and/or the switching chamber wall at least partially comprise(s) a polymer material configured to release hydrogen when heated.

15. The switching device according to claim 14, wherein the switching chamber base has a plastic shield comprising the polymer material.

16. The switching device according to claim 14, wherein the switching chamber base consists essentially of the polymer material.

17. The switching device according to claim 14, wherein the switching chamber wall consists essentially of the polymer material.

18. The switching device according to claim 14, wherein the polymer material comprises a polyoxymethylene.

19. The switching device according to claim 18, wherein the polyoxymethylene has a (CH.sub.2O).sub.n structure.

20. The switching device according to claim 14, wherein the gas has an H.sub.2 content of at least 50%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages, advantageous embodiments and developments can be found in the exemplary embodiments described below in conjunction with the Figures, in which:

(2) FIGS. 1A and 1B show schematic illustrations of a switching device according to an exemplary embodiment; and

(3) FIG. 2 shows a schematic illustration of a portion of a switching device according to a further exemplary embodiment.

(4) In the embodiments and Figures, identical, similar or identically acting elements are provided in each case with the same reference numerals. The elements illustrated and their size ratios to one another should not be regarded as being to scale, but rather individual elements, such as for example layers, components, devices and regions, may have been made exaggeratedly large to illustrate them better and/or to aid comprehension.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

(5) FIGS. 1A and 1B show an exemplary embodiment of a switching device 100 which can be used, for example, for switching high electric currents and/or high electric voltages and which can be a relay or a contactor, in particular a power contactor.

(6) FIG. 1A shows a three-dimensional sectional illustration, while a two-dimensional sectional illustration is illustrated in FIG. 1B. The description which follows relates equally to FIGS. 1A and 1B. The geometries shown are to be understood merely by way of example and in a non-limiting manner, and can also be embodied in an alternative manner.

(7) The switching device 100 has two stationary contacts 2, 3 and one movable contact 4 in a housing 1. The movable contact 4 is embodied as a contact plate. The stationary contacts 2, 3 together with the movable contact 4 form the switching contacts. The housing 1 serves primarily as protection against contact with the components which are arranged in the interior and comprises or consists of a plastic, for example polybutylene terephthalate (PBT) or glass-filled PBT. The contacts 2, 3, 4 can, for example, contain or consist of copper, a copper alloy or a mixture of copper with at least one further metal, for example tungsten, nickel and/or chromium.

(8) FIGS. 1A and 1B show the switching device 100 in an inoperative state in which the movable contact 4 is spaced apart from the stationary contacts 2, 3, so that the contacts 2, 3, 4 are DC-isolated from one another. The design shown for the switching contacts and in particular the geometry thereof are to be understood purely by way of example and in a non-limiting manner. As an alternative, the switching contacts can also be embodied differently. For example, it may be possible for just one of the switching contacts to be embodied to be stationary.

(9) The switching device 100 has a movable magnet armature 5 which substantially performs the switching movement. The magnet armature 5 has a magnetic core 6, for example comprising or consisting of a ferromagnetic material. Furthermore, the magnet armature 5 has a shaft 7 which is guided through the magnetic core 6 and, at one shaft end, is fixedly connected to the magnetic core 6. At the other shaft end which is situated opposite the magnetic core 6, the magnet armature 5 has the movable contact 4 which is likewise connected to the shaft 7. The shaft 7 can for example be manufactured with or from stainless steel.

(10) The magnetic core 6 is surrounded by a coil 8. A current flow, which can be introduced from outside, in the coil 8 generates a movement of the magnetic core 6 and therefore of the entire magnet armature 5 in an axial direction until the movable contact 4 makes contact with the stationary contacts 2, 3. The magnet armature 5 therefore moves from a first position, which corresponds to the inoperative state and simultaneously to the isolating, that is to say non-switched-through, state, to a second position, which corresponds to the active, that is to say switched-through, state. In the active state, the contacts 2, 3, 4 are electrically conductively connected to one another. In another embodiment, the magnet armature 5 can alternatively also execute a rotary movement. The magnet armature 5 can be embodied, in particular, as a tie rod or as a hinged armature. In order to guide the shaft 7 and therefore the magnet armature 5, the switching device 100 has a yoke 9 which can comprise or consist of pure iron or a low-doped iron alloy and forms a portion of the magnetic circuit. The yoke 9 has an opening in which the shaft 7 is guided. If the current flow in the coil 8 is interrupted, the magnet armature 5 is moved back to the first position by one or more springs 10. The switching device 100 is then back in the inoperative state in which the contacts 2, 3, 4 are open.

(11) When the contacts 2, 3, 4 are opened, an arc may be formed which can damage the contact areas. As a result, there may be a risk of the contacts 2, 3, 4 remaining “stuck” to one another owing to welding caused by the arc and no longer being separated from one another. In order to prevent the formation of arcs of this kind or at least to assist in quenching of arcs which occur, the contacts 2, 3, 4 are arranged in a gas atmosphere, so that the switching device 100 is embodied as a gas-filled relay or gas-filled contactor. To this end, the contacts 2, 3, 4 are arranged within a switching chamber 11, formed by a switching chamber wall 12 and a switching chamber base 13, in a hermetically sealed portion of the housing 1. The housing 1 and, in particular, the hermetically sealed portion of the housing 1 completely surround the magnet armature 5 and the contacts 2, 3, 4. The hermetically sealed portion of the housing 1 and therefore also the switching chamber 11 are filled with a gas 14. The gas 14, which can be introduced via a gas-filling port 15 within the scope of the production of the switching device 100, can particularly preferably contain hydrogen. In particular, the gas 14 can comprise at least 50% or more H.sub.2 in an inert gas such as N.sub.2 and/or one or more noble gases since hydrogen-containing gas can promote quenching of arcs.

(12) In the exemplary embodiment shown, the switching chamber wall 12 is of cap-like design and can be in one or several parts. The switching chamber base 13 is of plate-like design and can likewise be in one or several parts. The shaft 7, which is connected to the movable contact 4, and the stationary contacts 2, 3 can project through the switching chamber base 13 and the switching chamber wall 12 through openings in said parts. The switching chamber wall 12 and the switching chamber base 13 therefore surround a space in which the switching processes take place. As an alternative to the exemplary embodiment shown, other geometries of the switching chamber wall 12 and of the switching chamber base 13 are also possible.

(13) Furthermore, the switching chamber 11 at least partially comprises a polymer material from which hydrogen can be released when it is heated. In particular, the polymer material is formed in such a way that hydrogen can be released owing to an arc which strikes the polymer material, so that the additionally released hydrogen, particularly preferably in the form of H.sub.2, can improve arc quenching. The polymer material comprises a polyoxymethylene (POM), in particular with the structure (CH.sub.2O).sub.n, or is formed by it. As is described in the general part, a polymer material of this kind is distinguished by a carbon content which is low in comparison to other polymers and a very low tendency to form graphite, wherein predominantly gaseous CO and H.sub.2 are produced in the case of in particular arc-induced decomposition.

(14) The switching chamber base 13 particularly preferably comprises the polymer material. For example, a polymer shield which forms a portion of the switching chamber base 13 comprising and preferably consisting of the polymer material can prevent an arc reaching the flange arc situated beneath it. Furthermore, the switching chamber base 13 as a whole can also be formed from the polymer material. As an alternative or in addition, portions of the switching chamber wall 12 or else the switching chamber wall 12 as a whole can also be formed with or from the polymer material. Those portions of the switching chamber 11 that are not formed by the described polymer material, that is to say in particular portions of the switching chamber wall 12 and/or of the switching chamber base 13 that are not formed by the described polymer material, can be manufactured, for example, with or from a metal oxide, such as Al.sub.2O.sub.3 for example.

(15) FIG. 2 shows a detail of the contacts 2, 4 which are arranged in the switching chamber, wherein the illustration of FIG. 2 is rotated through 90° in relation to the sectional planes of FIGS. 1A and 1B. As is indicated in FIG. 2, one or more blowout magnets 16, that is to say preferably permanent magnets, can be arranged within the switching chamber, which magnets can extend the arc path and deflect the arcs from the region between the contacts. In this case, the arcs can also reach a part of the switching chamber, for example the switching chamber base or the switching chamber wall. By heating this portion, which comprises or preferably consists of the described polymer material, that is to say in particular containing or consisting of POM, additional hydrogen can then be released as described above, so that extinguishing of the arc can be accelerated.

(16) The features and exemplary embodiments described in conjunction with the Figures can be combined with one another according to further exemplary embodiments, even if not all combinations have been explicitly described. Furthermore, the exemplary embodiments described in conjunction with the Figures may alternatively or additionally comprise further features in accordance with the description in the general part.

(17) The invention is not restricted to the exemplary embodiments by the description on the basis of said exemplary embodiments. Rather, the invention encompasses any novel feature and any combination of features, which in particular comprises any combination of features in the patent claims, even if this feature or this combination is not itself explicitly specified in the patent claims or exemplary embodiments.