Switching Device

Abstract

In an embodiment a switching device includes two fixed contacts and a rotary contact bridge in a switching chamber in a gas-tight region, wherein the rotary contact bridge is rotatable about an rotation axis, wherein, in a first switching state, the fixed contacts are electrically conductively connected by the rotary contact bridge, wherein, in a second switching state, the rotary contact bridge is rotatable about the rotation axis relative to the first switching state, and the fixed contacts are electrically insulated from one another, and wherein the gas-tight region includes H.sub.2.

Claims

1.-15. (canceled)

16. A switching device comprising: two fixed contacts and a rotary contact bridge in a switching chamber in a gas-tight region comprising H.sub.2, wherein the rotary contact bridge is rotatable about an rotation axis, wherein, in a first switching state, the fixed contacts are electrically conductively connected by the rotary contact bridge, and wherein, in a second switching state, the rotary contact bridge is rotatable about the rotation axis relative to the first switching state, and the fixed contacts are electrically insulated from one another.

17. The switching device according to claim 16, wherein the switching chamber comprises a cylindrical switching chamber wall and the fixed contacts project through the switching chamber wall into the switching chamber.

18. The switching device according to claim 17, wherein the switching chamber wall comprises an inner wall facing the rotary contact bridge and the rotary contact bridge is spaced from the inner wall.

19. The switching device according to claim 16, wherein the rotary contact bridge comprises an electrically conductive element having two contact pieces on a side facing away from the rotation axis in a radial direction, wherein one of the contact pieces is configured to contact one of the two fixed contacts and another one of the contact pieces is configured to contact another of the two fixed contacts.

20. The switching device according to claim 19, wherein the contact pieces are spring-mounted.

21. The switching device according to claim 19, wherein the rotary contact bridge comprises an insulator element and the electrically conductive element is at least partially surrounded by the insulator element.

22. The switching device according to claim 21, wherein the insulator element is part of a disc.

23. The switching device according to claim 16, wherein the rotary contact bridge is fixed to a shaft in an electrically insulated manner.

24. The switching device according to claim 16, wherein each of the fixed contacts comprises a beveled contact surface facing the rotary contact bridge.

25. The switching device according to claim 16, further comprising two auxiliary contacts which are electrically conductively connected to each other by the rotary contact bridge in the first or second switching state.

26. The switching device according to claim 16, further comprising a magnet arranged above each of the fixed contacts in a direction parallel to the rotation axis.

27. The switching device according to claim 16, further comprising a driver configured to rotate the rotary contact bridge in order to change a switching state.

28. The switching device according to claim 27, wherein the driver is configured to rotate further by an angle of greater than or equal to 1° and less than or equal to 15° when the first switching state is reached.

29. The switching device according to claim 16, wherein the rotary contact bridge is configured to rotate through an angle of greater than or equal to 10° and less than or equal to 170° when switching between the first and second switching states.

30. The switching device according to claim 16, wherein the gas-tight region comprises H.sub.2 with a proportion of at least 50%.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Further advantages, advantageous embodiments and developments are revealed in the exemplary embodiments described below in association with the figures.

[0032] FIGS. 1A to 1I show schematic illustrations of a switching device according to an exemplary embodiment;

[0033] FIG. 2 shows a schematic illustration of a drive unit for a switching device according to an exemplary embodiment; and

[0034] FIGS. 3A and 3B show schematic illustrations of a part of a switching device according to a further exemplary embodiment.

[0035] In the exemplary embodiments and figures, identical, similar or identically acting elements may each be denoted by the same reference signs. The elements illustrated and their mutual proportions should not be considered true to scale; instead, individual elements, for example layers, components, structural elements and regions, may be shown exaggerated in size for better illustration and/or for better understanding.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0036] FIGS. 1A to 1I show an exemplary embodiment of a switching device 100 that may be used, for example, for switching high electric currents and/or high electric voltages of a load circuit connectable to the switching device 100 and that may be a relay or contactor, in particular a power contactor. FIGS. 1A and 1B show three-dimensional sectional views of the switching device 100, while FIGS. 1C and 1D show exterior views of the switching device 100 in a top view and a side view, respectively. The sectional view shown in FIG. 1A corresponds to the sectional plane AA indicated in FIG. 1C, while the sectional view shown in FIG. 1B corresponds to the sectional plane BB shown in FIG. 1C. FIGS. 1E and 1F show sectional views of the switching device 100 along the sectional plane CC indicated in FIG. 1D and thus with a viewing direction along the rotation axis 99 indicated in FIGS. 1A, 1B, and 1G, wherein the switching device 100 is shown in a first switching state in FIGS. 1E and 1n a second switching state in FIG. 1F, as also shown in FIGS. 1A, 1B, and 1G. In FIG. 1G, the gas-tight region 16 of the switching device 100 is shown in a sectional view corresponding to the sectional plane BB, which corresponds substantially to the switching device 100 without the housing 1. FIGS. 1H and 1I show in three-dimensional views substantially the gas-tight region 16 and thus the switching device 100 without housing 1, as well as an external view of the switching device 100. The following description refers equally to FIGS. 1A to 1I. The geometries shown are to be understood as exemplary and non-limiting only, and may also be designed alternatively.

[0037] The switching device 100 comprises two fixed contacts 2, 3 and a rotary contact bridge 4. A load circuit can be connected to the fixed contacts 2, 3, which are arranged separately from one another in the switching device 100. The fixed contacts 2, 3 together with the rotary contact bridge 4 as a rotatable contact form the switching contacts.

[0038] The switching contacts and the other components described in the following are arranged in a housing 1. The housing 1 serves primarily as contact protection for the components arranged inside and comprises or is made of a plastic, for example PBT or glass-filled PBT.

[0039] The rotary contact bridge 4 forms a contact rotatable about an rotation axis 99 and is rotatable in the switching device 100 such that the rotary contact bridge 4 can switch between the first switching state shown in FIG. 1E and the second switching state shown in FIG. 1F as also shown in FIGS. 1A, 1B and 1G. Thus, the switching activity of the switching device 100 is substantially performed by the rotary contact bridge 4. In the first switching state, which is an interconnecting state of the switching device 100, the fixed contacts 2, 3 are electrically conductively connected to each other by the rotary contact bridge 4 so that the current of a connected load circuit can flow through the switching device 100 and in particular through the fixed contacts 2, 3 and the rotary contact bridge 4. In the second switching state, which is a non-interconnecting state of the switching device 100 and in which the rotary contact bridge is rotated by an angle about the rotation axis 99 relative to the first switching state, the fixed contacts 2, 3 are electrically insulated from one another. As can be seen in FIG. 1E, in the first switching state the fixed contacts 2, 3 are in mechanical contact with the rotary contact bridge 4 and are thus galvanically connected with it, while in the second switching state the fixed contacts 2, 3 are mechanically and thus also galvanically separated from the rotary contact bridge 4. As shown, it is possible, for example, to switch between the first and second switching states by rotating the rotary contact bridge 4 through an angle of 90°. Alternatively, other configurations are possible in which switching between the switching states can be accomplished by rotating the rotary contact bridge 4 through an angle greater than or equal to 10° and less than or equal to 170° such as 10°, 15°, 30°, 45°, or multiples thereof.

[0040] The rotary contact bridge 4 comprises an electrically conductive element 40 which contacts the fixed contacts 2, 3 in the first switching state and establishes an electrical connection between the fixed contacts 2, 3. For contacting each of the fixed contacts 2, 3, the electrically conductive element 40 comprises a contact piece 41 on a side of the rotary contact bridge 4 facing away from the rotation axis 99 in the radial direction. In the first switching state, each of the contact pieces 41 of the electrically conductive element 40 is in mechanical contact with a contact surface 21, 31 of a contact region 20, 30 of a fixed contact 2, 3. In the second switching state, the rotary contact bridge 4 is rotated relative to the first switching state such that the contact pieces 41 are galvanically separated from the fixed contacts 2, 3.

[0041] The switching device 100 further comprises a drive unit 5 by means of which the rotary contact bridge 4 can be rotated for switching, i.e. for changing the switching state. In the exemplary embodiment shown, the drive unit 5 comprises or is configured as a motor, in particular a stepper motor. By means of a stepper motor, a rotation by a defined angle can be affected in incremental steps and a high torque can be provided. Alternatively, the drive unit can comprise a magnetic drive, as described below in connection with FIG. 2. For controlling the drive unit, there may be, for example, a connection element 6 and supply lines as shown.

[0042] Furthermore, the switching device 100 comprises a shaft 7 which is, for example, made of stainless steel or comprises stainless steel and which is connected at one end to the rotary contact bridge 4 in such a way that the rotary contact bridge 4 can be rotated by means of the shaft 7. At the opposite end, the shaft 7 is connected with the drive unit 5 such that the drive unit 5 can rotate the rotary contact bridge 4. The shaft 7 thus defines the rotation axis 99 of the rotary contact bridge 4. The rotary contact bridge 4 is particularly preferably attached to the shaft 7. In particular, the rotary contact bridge 4 may be attached to the shaft 7 in an electrically insulated manner. As shown, an electrically insulating material 8, in particular a plastic such as PBT or POM, can be arranged between the shaft 7 and the rotary contact bridge 4, in particular at least between the shaft 7 and electrically conductive parts of the rotary contact bridge 4. The attachment of the rotary contact bridge 4 to the shaft 7 can be carried out, as shown, for example by means of a pinned fitting 9. The electrically insulating material 8 can be additionally secured to the shaft 7, for example as shown, by a snap ring 87.

[0043] By means of the drive unit 5, the switching device 100 can be switched from the second to the first switching state, for example. The rotational motion of the rotary contact bridge 4 for switching from the first to the second switching state can also be affected by the drive unit 5 or, preferably alternatively or additionally, by a return spring 10. By means of the return spring 10, it can be achieved that when a control current for switching the switching device 100 is omitted, the switching device 100 automatically changes from the first switching state to the second switching state and thus interrupts the load circuit.

[0044] The drive unit 5 alone or with part of the shaft 7 or with the entire shaft 7 can form a drive system that continues to rotate by a predetermined angle after the first switching state is reached. This means that the drive unit 5 or the drive unit 5 and at least part of the shaft 7 or even the drive unit 5 and the shaft 7 can continue to rotate by a predetermined angle when switching to the first switching state after the first switching state has been reached, while the rotary contact bridge 4 is no longer rotated. The predetermined angle may particularly preferably be greater than or equal to 1° and less than or equal to 15°. For example, the attachment of the rotary contact bridge 4 to the shaft 7 can be embodied with a corresponding tolerance or elastically. For example, the pinned fitting 9 can be arranged with a tolerance on the shaft 7 and/or the rotary contact bridge 4. Furthermore, it may also be possible for the pinned fitting 9 to comprise an elastic material. By continuing to rotate the drive system, it can be achieved that the drive system can already perform a rotational motion at the beginning of the switching from the first to the second operating state before the rotary contact bridge 4 and in particular the electrically conductive element 40 of the rotary contact bridge 4 starts to rotate. As a result, the drive system can pick up speed and a rotational pulse can be generated, whereby it can be achieved that the electrically conductive connection between the fixed contacts 2, 3 can be separated more quickly after transmission of this rotational pulse to the rotary contact bridge 4.

[0045] The switching device 100 further comprises a switching chamber 11 in which the rotary contact bridge 4 and the fixed contacts 2, 3 are arranged. Thereby, the fixed contacts 2, 3 protrude into the switching chamber 11 through the housing 1 and a switching chamber wall 12 as described above in the general part. In particular, this may mean that at least a part of the contact regions 20, 30 or at least a part of the contact surfaces 21, 31 of each of the fixed contacts 2, 3 may project beyond an inner wall of the switching chamber wall 12 facing the rotary contact bridge 4. In particular, the switching chamber 11 comprises a cylindrical switching chamber wall 12. As shown, the fixed contacts 2, 3 are particularly preferably aligned radially with respect to the rotation axis 99 in the switching chamber wall 12 and preferably face each other in a radial direction.

[0046] The switching chamber 11 further comprises a switching chamber base 13, which comprises an opening through which the shaft 7 projects. The drive unit 5 is arranged outside the switching chamber 11. The switching chamber 11, i.e. in particular the switching chamber wall 12 and/or the switching chamber base 13, may at least partially preferably comprise or be made of a metal oxide ceramic such as for example Al.sub.2O.sub.3 or a plastic such as for example PEEK, PE, glass-filled PBT or POM. The switching chamber wall 12 and the switching chamber base 13 may also be of different materials. For example, the switching chamber wall 12 is made of a ceramic material, while the switching chamber base 13 is made of a plastic material.

[0047] The drive unit 5 is arranged in a pot made of a gas-tight wall 14 below the switching chamber 11. Between the switching chamber 11 and the region with the drive unit 5 arranged therebelow, in the exemplary embodiment shown, a connecting plate 15 is arranged which, like the gas-tight wall 14, may be made of, for example, pure iron, aluminum or stainless steel. As indicated in FIGS. 1B and 1G, the connecting plate 15 may be screwed to the switching chamber 11, for example, while the gas-tight wall 14 may be soldered or welded to the connecting plate 15.

[0048] The switching contacts of the switching device 100 are arranged in a gas atmosphere. In particular, the rotary contact bridge 4 is arranged completely in the gas atmosphere, while a part of the fixed contacts 2, 3, such as their contact regions 20, 30, is arranged in the gas atmosphere. For this purpose, the switching device 100 comprises a gas-tight region 16 in which the gas atmosphere is kept hermetically sealed from the environment and in which the described components can be arranged. In the exemplary embodiment shown, the gas-tight region 16 is formed by parts of the switching chamber wall 12, by the gas-tight walls 14 and by the connecting plate 15, wherein a gas-tight wall 14 is additionally provided between the switching chamber wall 12 and the connecting plate 15 in the exemplary embodiment shown. As a result, it may be possible to use a material that is not gas-tight as the switching chamber base 13. The switching device 100 is thus a gas-filled switching device such as a gas-filled contactor. The gas atmosphere, by increasing the are voltage, may in particular promote extinction of arcs that may occur between contacts during switching operations. The gas of the gas atmosphere may preferably comprise H.sub.2 and particularly preferably comprise at least 50% H.sub.2. In addition to hydrogen, the gas may comprise an inert gas, particularly preferably N.sub.2 and/or one or more noble gases.

[0049] The gas-tight region 16 is arranged in the housing 1 in the exemplary embodiment shown by means of damping elements 17. The damping elements 17 can be made of an elastic plastic, for example in the form of rubber buffers, and reduce a transmission of mechanical stresses, shocks and vibrations acting on the housing 1 from the housing 1 to the gas-tight region 16 and thus in particular to the switching chamber 11.

[0050] As indicated in FIGS. 1E and 1F, the fixed contacts 2, 3 may each comprise a beveled contact surface 21, 31 facing the rotational contact bridge 4 and arranged not tangential to the rotational motion of the rotational contact bridge 4 and thus not tangential to the inner wall of the switching chamber wall 12. In this respect, the contact surfaces 21, 31 can be beveled on one side as shown or alternatively on several sides. By beveling the contact surfaces 21, 31, the mechanical contact to the rotary contact bridge 4 and in particular to the contact pieces 41 can be improved. Furthermore, the contact surfaces 21, 31 can be beveled in such a way that the contact surfaces 21, 31 counteract an undesired rotational motion of the rotary contact bridge 4 in one direction, so that it can be prevented that the rotary contact bridge 4 continues to rotate beyond the first switching state when rotating from the second to the first switching state.

[0051] The contact pieces 41 of the rotary contact bridge 4 are particularly preferably spring-mounted. For this purpose, the rotary contact bridge 4 comprises a middle part 42 which is fastened to the shaft 7 and on which the contact pieces 41 are arranged with spring elements 43 arranged therebetween. The contact pieces 41, the middle part 42 and the spring elements 43 substantially form the electrically conductive element 40 and may be formed in one piece or may be formed from separately manufactured parts which are joined together to form the electrically conductive element 40, for example by means of soldering or welding or mechanical joining techniques. As described in the general part, the resilient mounting of the contact pieces 41 in the first switching state can provide increased contact pressure against the contact surfaces 21, 31 and thus a secure mechanical contact.

[0052] Preferably, at least the contact pieces 41 and particularly preferably the rotary contact bridge 4 are spaced from the inner wall of the switching chamber wall 12. Preferably, at least the contact pieces 41 and particularly preferably the rotary contact bridge 4 are spaced from the inner wall of the switching chamber wall 12 in any state and also during the switching operations. For example, as can be seen in FIGS. 1A, 1B, 1E, 1F and 1G, the inner wall of the switching chamber wall 12 may comprise a diameter that is larger than the largest dimension of the rotary contact bridge 4 perpendicular to the rotation axis 99. Thus, a gap is present between the rotary contact bridge 4 and the inner wall of the switching chamber wall 12 in the radial direction. The narrower the gap, the easier it is to cause switching arcs occurring during switching to extinguish, since there is less space for the switching arcs to propagate. In particular, it is advantageous if the switching chamber 11 is filled with as much electrically insulating material as possible. In the exemplary embodiment shown, the rotary contact bridge 4 therefore comprises at least one insulator element 44 which comprises or is made of an electrically insulating material. For example, PBT or POM may be used for this purpose. The electrically conductive element 40 is preferably at least partially surrounded by the insulator element 44. As shown, the rotary contact bridge 4 may be formed substantially by the electrically conductive element 40 and the at least one insulator element 44 as a disc, wherein the contact pieces 41 may protrude in radial direction from the insulator element 44. Particularly preferably, the electrically conductive element 40 is enclosed by the at least one insulator element 44 except for a portion of the contact pieces 41, so that the electrically conductive element 40 is embedded in the at least one insulator element 44. As an alternative to the configuration of the rotary contact bridge 4 as shown in FIGS. 1E and 1F as a substantially circular disk, the insulator material 44 may comprise cutouts, as indicated by the dashed lines as an example. The spring elements 43 and the contact pieces 41 may be arranged in corresponding pockets in the insulator material 44, which provide sufficient space for the spring function.

[0053] Further, as shown, the switching device 100 may comprise secondary contacts in the form of auxiliary contacts 18 which, in the second switching state, are electrically conductively connected to each other by the rotary contact bridge 4. In the first switching state, however, the auxiliary contacts 18 are electrically separated from each other. By measuring the electrical resistance, a voltage drop or an auxiliary current flow at the auxiliary contacts 18, it can be determined whether the switching device 100 is in the second switching state or whether, for example, a sticking of the switching contacts has occurred and the rotary contact bridge 4 can no longer rotate from the first to the second switching state. Alternatively, it may also be possible that a further electrically conductive element in the form of an electrically conductive auxiliary element is present in the rotary contact bridge 4, by means of which the auxiliary contacts are electrically conductively connected to one another either in the first or in the second switching state.

[0054] The control of the drive unit 5 and, if necessary, the contacting of the auxiliary contacts 18 from the outside can be carried out, for example, by means of a connection element in the housing 1. In FIG. 1I, such a connection element is indicated on the outer side surface of the housing 1.

[0055] In the exemplary embodiment shown, the switching device 100 further comprises a magnet 19, in particular a permanent magnet, above each of the fixed contacts 2, 3 along a direction parallel to the rotation axis 99. The magnets 19 are preferably arranged outside the switching chamber 11, for example on the switching chamber 11 or on the outside of the switching chamber 11. By means of the magnets, which act as so-called quenching magnets, a magnetic field can be generated in the region of the fixed contacts 2, 3, which can facilitate quenching of the switching arcs.

[0056] The switching device 100 need not necessarily comprise all elements included in the exemplary embodiment shown, such as spring elements, electrically insulating materials, magnets, damping elements or auxiliary contacts. Further, the switching device 100 may comprise a plurality of pairs of fixed contacts, each of which may be interconnected by an associated electrically conductive element in the rotary contact bridge 4.

[0057] FIG. 2 shows an exemplary embodiment of a drive unit 5, which is a magnetic drive that can be used as an alternative to a stepper motor described in connection with the previous embodiment. The magnetic drive comprises a rotatable magnetic armature 50, which is rotatable by a magnetic circuit to affect the switching operations described above. For this purpose, the magnetic circuit comprises a yoke 51. The magnetic armature 50 may comprise, or be formed as, a rotary magnetic core which is attached to an end of the shaft opposite the rotary contact bridge and which forms part of the magnetic circuit. The rotatable magnetic armature 50 is thus connected to the rotary contact bridge via the shaft. The yoke 51 and/or the magnetic armature 50 may preferably comprise or be made of pure iron or a low-doped iron alloy. A magnetic field can be generated in the magnetic circuit, indicated by the dashed arrows, by means of a coil 52 which can be connected with a control circuit, and by means of which a rotation 53 of the magnetic armature 51 and thus also of the rotary contact bridge is achieved. The reverse rotation can be achieved, for example, by the return spring described above.

[0058] FIGS. 3A and 3B show a part of the switching device 100 according to a further exemplary embodiment. For clarity, only a portion of the switching chamber wall 12 and of a contact piece 41 are shown in FIGS. 3A and 3B in the first switching state in contact with the contact surface 21 of a fixed contact 2 (FIG. 3A) and in the second switching state (FIG. 3B). The switching chamber wall 12 comprises an inner wall 120 facing the rotary contact bridge, which comprises an enlarged diameter at least in the region of the rotary contact bridge. As can be seen, the fixed contacts may be arranged in a groove 121 in the inner wall 120 at least partially surrounding the rotary contact bridge.

[0059] The features and exemplary embodiments described in association with the figures can be combined with one another according to further exemplary embodiments, even if not all combinations have been explicitly described. The exemplary embodiments described in association with the figures can furthermore alternatively or additionally have further features according to the description in the general part.

[0060] The description based on the exemplary embodiments does not restrict the invention thereto. Instead, the invention comprises any novel feature and any combination of features, which, in particular, includes any combination of features in the claims, even if this feature or this combination itself is not explicitly specified in the claims or exemplary embodiments.