Improved metal bellows and vacuum interrupter having an improved metal bellows of this kind

Abstract

The invention relates to a metal bellows (50) for fastening to a first insulator (2) of a vacuum interrupter (1), wherein the metal bellows (50) extends along a longitudinal extension (52) and has waves or folds (56) in a radial extension (54) perpendicular to the longitudinal extension (52), in order to enable movement in the direction of the longitudinal extension (52), and wherein the metal bellows (50) has a first end (58) and a second end (62), wherein the second end (62) has a triple-point shield (60), said triple-point shield (60) extending from a last wave (57) on the second end of the metal bellows (50) and away from the first end (58) of the metal bellows (50) in the longitudinal extension (52).

Description

[0001] 202305888 Foreign version 1 Description Improved metal bellows and vacuum interrupter with such an improved metal bellows The invention relates to an improved metal bellows and a vacuum interrupter with such an improved metal bellows. Metal bellows for vacuum interrupters are known from the prior art, which are connected on one side to a moving contact flange and on the other side to an insulator, for example a ceramic. The area where the insulator, metal bellows and vacuum meet, a so-called triple point, is known as a dielectric weak point and must be shielded accordingly. For this purpose, separate shielding arrangements that shield the triple point are found in the prior art. These shielding arrangements are often connected to other components of the vacuum interrupter using solder foil during closure soldering, whereby these components also have to be additionally centered.The object of the invention is to provide an improved arrangement. This object is achieved by independent claim 1 and the claims dependent thereon. One embodiment relates to a metal bellows for attachment to a first insulator of a vacuum interrupter, wherein the metal bellows extends along a longitudinal extent and has corrugations or folds in a radial extent perpendicular to the longitudinal extent, so as to enable mobility in the direction of the longitudinal extent, and wherein the metal bellows has a first end and a second end, and wherein the second end has a triple-point shield, which triple-point shield extends from a last corrugation at the second end of the metal bellows and away from the first end of the metal bellows in the longitudinal extent. In particular, the triple-point shield is formed from the second end of the metal bellows.Such a design minimizes potential assembly errors. Alternatively, the triple-point shielding can also be molded, welded, or soldered onto the second end of the metal bellows. Such a metal bellows with triple-point shielding is advantageous both for vacuum interrupters with a metal bellows arranged inside and for a metal bellows arranged outside the vacuum interrupter. In particular, the metal bellows with triple-point shielding is advantageous for a vacuum interrupter with a metal bellows arranged outside. In this context, "arranged outside" means that the metal bellows extends largely outside the body of the vacuum interrupter and thus the metal bellows is not protected by the body of the vacuum interrupter. Rather, in such vacuum interrupters with an externally arranged or externally located metal bellows, it is often supported, guided, and / or protected from mechanical damage by an additional support arrangement.In particular, such an additional support arrangement is fastened to an insulator or one of the flanges or other metal parts of the vacuum interrupter. It is also preferred that the metal bellows has a cylindrical shape, wherein the outer surface of the cylinder is structured in a wave-like manner in order to create mobility of the metal bellows. The cylindrical shape of the metal bellows is advantageously adapted to a cylindrical shape of the vacuum interrupter and thus reduces electric field peaks. It is also preferred that the triple-point shielding extends substantially or largely along the longitudinal extent, in particular extends linearly. In particular, it is also preferred that the triple-point shielding extends between the maximum width of the metal bellows and the minimum width 202305888 foreign socket 3 of the metal bellows 50 parallel to the longitudinal extent of the metal bellows.It is particularly preferred that an open end of the triple-point shield does not rest on the inside of the first insulator when fastened to the first insulator, i.e. the largest outer diameter of the triple-point shield is smaller than the smallest inner diameter of the first insulator. The diameters refer to the respective diameter in the radial extent. It is also particularly preferred that the second end of the metal bellows is twisted or bent in order to avoid or reduce potential electric field peaks. Furthermore, it is also preferred that the triple-point shield extends along the longitudinal extent and also extends outwards in the radial extent, i.e. in the direction of the maximum width of the metal bellows. It is particularly preferred that the edge of the triple-point shield is bent or twisted at the open end.Such twisting or bending reduces potential field peaks in the electric field distribution under operating conditions. It is also particularly preferred that the triple-point shield extends outwards in its radial extent such that an open end of the triple-point shield rests against the inside of the first insulator when fastened to the first insulator. The fastened state is the regular, normal operating state. The resting point in the fastened state to the first insulator causes self-centering when the metal bellows is mounted in a vacuum interrupter, which facilitates assembly and prevents assembly errors. It is also particularly preferred that the open end of the triple-point shield is bent in such a way that the open end of the triple-point shield does not point outwards parallel to the radial extent.It is particularly preferred that a) the open end of the triple-point shield points in the direction of the first end of the metal bellows, or b) the angle between the direction of the open end of the triple-point shield and the radial extension is greater than 90° and the open end of the triple-point shield points in the direction of the fixed contact rod. These geometries allow, on the one hand, optimization of the electric fields and, on the other hand, an arrangement that is easy to assemble mechanically. It is also preferred that the metal bellows has one or more through openings between the fastening area and the second end of the metal bellows. The through openings are arranged such that, on the one hand, the triple-point shield continues to shield the triple point and, on the other hand, evacuation of the vacuum interrupter formed with the bellows is possible.It is also preferred that the open end of the triple-point shield has a second waveform, so that the open end of the triple-point shield, when attached to the first insulator, partially rests against the inside of the first insulator and forms through openings. A further embodiment relates to a vacuum interrupter with at least a first insulator, a fixed contact flange, a fixed contact rod, a fixed contact, a moving contact flange, a moving contact rod, a moving contact, and at least one first shielding element, wherein the vacuum interrupter has a metal bellows according to one of the preceding embodiments, and the metal bellows connects the moving contact flange to the first insulator in such a way that the moving contact is movable in the direction of the longitudinal extent of the metal bellows.It is preferred that the open end of the triple-point shield does not touch the first insulator on an inner side of the first insulator. This achieves optimal evacuability during the manufacturing process. It is also preferred that the open end of the triple-point shield at least partially or completely rests against an inner side of the first insulator. Complete contact refers to an uninterrupted annular surface that rests against the inner side of the first insulator. Partial contact refers to an interrupted annular surface that rests against the inner side of the first insulator. This additionally centers the bellows during an assembly process. It is further preferred that the vacuum interrupter has an external metal bellows, a second insulator, a metal intermediate piece, a second shield element, and a third shield element.It is also preferred that the metal bellows is an internal metal bellows, i.e., is arranged largely within the vacuum interrupter. The invention is explained in more detail below using an exemplary embodiment. The specific embodiment of the exemplary embodiment is in no way to be understood as limiting the general embodiment of the device according to the invention; rather, individual design features of the exemplary embodiment can be freely combined with one another and with the features described above in any way. 202305888 Foreign version 6 Regardless of the grammatical gender of a particular term, persons with male, female, or other gender identities are also included. Fig. 1 Schematic representation of a metal bellows from the prior art; Fig. 2 Schematic representation of a first embodiment of a metal bellows according to the invention with triple-point shielding; Fig.3 Schematic representation of a second embodiment of a metal bellows according to the invention with triple-point shielding; Fig. 4 Schematic representation of a third embodiment of a metal bellows according to the invention with triple-point shielding; Fig. 5 Schematic representation of a vacuum interrupter with a metal bellows according to the invention with triple-point shielding. Figure 1 shows a schematic representation of a metal bellows 50' from the prior art. The metal bellows 50' from the prior art has a first open edge, with one end of the first edge extending in the direction of a longitudinal extent 52. Furthermore, the metal bellows 50' from the prior art has a second open edge, with one end of the second edge extending in the direction of a radial extent 54. The first edge is designed to be connected to a fixed contact flange (not shown).The second edge is designed to be connected to an insulator (not shown). The second edge of the metal bellows 50' has a fastening region 64' for this purpose. Alternatively, and not shown here, the fastening region 64' is constructed as a sheath fastening region, wherein the fastening region 64' is arranged at a tapered end of the metal bellows 50', and wherein the tapered end extends parallel to the longitudinal extension 52. In other words, the second edge with the fastening region 54 extends, apart from the mirrored arrangement, like the first edge of the metal bellows 50'. Figure 2 shows a schematic representation of a first embodiment of a metal bellows 50 according to the invention with triple-point shielding 60, which triple-point shielding 60 is arranged at a second end 62 of the metal bellows 50. The metal bellows 50 further has a first end 58 which is arranged opposite the second end 62.The metal bellows 50 has a maximum width 66 of the metal bellows 50, i.e., maximum extension in the radial dimension 54. Furthermore, the metal bellows 50 has a minimum width 68 of the metal bellows 50, i.e., minimum extension in the radial dimension 54. The triple-point shield 60 is formed by an extension of the metal bellows 50. The triple-point shield 60 extends substantially or largely along the longitudinal dimension 52. This means that the triple-point shield 60 extends from a fastening region 64 on the last shaft 57 of the metal bellows 50 in the direction of the radial dimension 54 into an interior of the metal bellows 50 and then parallel to the longitudinal dimension 52.Due to this configuration, a cylindrical section of the metal bellows 50, when attached to a first insulator (not shown), protrudes into the first insulator, here in an optional configuration, without resting against the inside of the first insulator. The second end 62 of the metal bellows 50 thus forms the triple-point shield 60. Figure 3 shows a schematic representation of a second embodiment of a metal bellows 50 according to the invention with triple-point shield 60, wherein the triple-point shield 60 is arranged at a second end 62 of the metal bellows 50. The metal bellows 50 further has a first end 58, which is arranged opposite the second end 62. 202305888 Foreign version 8 The metal bellows 50 has here on the last shaft 57 at the second end 62 of the metal bellows 50 a fastening area 64 for fastening to a first insulator 2, not shown here.The metal bellows 50 also has a maximum width 66 of the metal bellows 50, i.e., maximum extension in the radial dimension 54. Furthermore, the metal bellows 50 has a minimum width 68 of the metal bellows 50, i.e., minimum extension in the radial dimension 54. The triple-point shield 60 is again formed by an extension of the metal bellows 50. In this embodiment, the triple-point shield 60 extends outward along the longitudinal dimension 52 and along the radial dimension 54, i.e., in the direction of the maximum width 66 of the metal bellows 50.In the example shown in Figure 3, the second end 62 of the metal bellows 50 is bent or twisted toward the first end 58 of the metal bellows, so that the second end 62 of the metal bellows 50, with the triple-point shielding 60, can be inserted into a first insulator (not shown) and optionally slides along the inner side 2' of the first insulator 2 (not shown here) with the second end 62 of the metal bellows 50. Furthermore, Figure 3 optionally shows through-openings 70 in the metal bellows 50, which enable or simplify the evacuation of a vacuum interrupter (not shown) with the metal bellows 50. The through-openings 70 are located as far as possible from the triple point 61 to be shielded (not shown here, see Figure 4), in the region of the second end 62 of the metal bellows 50.Figure 4 shows, at the top, a schematic representation of a third embodiment of a metal bellows 50 according to the invention, with a triple-point shield 60 having a waveform 63 on one edge at a second end 62 of the metal bellows 50, and, at the bottom, shows a schematic representation of the waveform 63 of the same edge at the second end 62 of the metal bellows 50. The metal bellows 50 also has a first end 58, which is arranged opposite the second end 62. The metal bellows 50 has a maximum width 66 of the metal bellows 50, i.e., maximum extension in the radial dimension 54. Furthermore, the metal bellows 50 has a minimum width 68 of the metal bellows 50, i.e., minimum extension in the radial dimension 54. The triple point shield 60 is formed by an extension of the metal bellows 50.The metal bellows 50 has here on the last shaft 57 at the second end 62 of the metal bellows 50 a fastening area 64 for fastening to a first insulator 2, not shown. In this embodiment, the triple point shield 60 extends outwards along the longitudinal extent 52 and along the radial extent 54, i.e. in the direction of the maximum width 66 of the metal bellows 50. In the example shown in Figure 4, the second end 62 of the metal bellows 50 is bent or twisted in the direction of the first end 58 of the metal bellows, so that the second end 62 of the metal bellows 50 with the triple point shield 60 can be pushed into a first insulator 2 (not shown) and optionally slides along the inside 2' of the first insulator 2 (not shown here) with the second end 62 of the metal bellows 50.The wave shape of the edge at the second end 62 of the metal bellows 50 causes through openings 70' to be formed in interaction with the inner side 2' of the insulator 2 (not shown). Figure 5 shows a schematic representation of a vacuum interrupter 1 with a metal bellows 50 according to the invention with triple-point shielding 60, the metal bellows 50 being in the form of the second embodiment from Figure 3. The vacuum interrupter 1 has a fixed contact flange 4 which is connected to a fixed contact rod 5, with a fixed contact 6 being arranged on the fixed contact rod 5. The fixed contact flange 4 is connected here, for example, to a second insulator 3 via a third shielding element 14. On the side of the second insulator 3 opposite the third shielding element 14, a second shielding element 12 and a metal intermediate piece 15 are arranged here.On the side of the metal intermediate piece 15 opposite the second insulator 3, a first shielding element 10 and a first insulator 2 are connected to an inner side 2' of the first insulator 2. On the side of the first insulator 2 opposite the metal intermediate piece 15, the metal bellows 50 according to the invention is arranged, here in the second embodiment of Figure 3. Alternatively, and not shown, the first embodiment of Figure 2 or the third embodiment of Figure 4 can also be installed as a metal bellows 50 in the vacuum interrupter 1. Also alternatively, and not shown, the second end 62 of the metal bellows 50 is arranged in the insulator 2 such that the second end 62 does not touch the inner side 2' of the first insulator 2, which means that no through openings 70, 70' are required.On the side of the metal bellows 50 opposite the first insulator 2, there is a moving contact flange 7 with a moving contact rod 8 and a moving contact 9 fastened to the moving contact rod 8. The vacuum interrupter 1 here has a cylindrical basic shape that extends in the longitudinal dimension 52 and the radial dimension 54 of the metal bellows 50. In Figure 5, the metal bellows 50 has a fastening area 64 on the last shaft 57 at the second end 62 of the metal bellows 50, at which fastening area 64 the metal bellows 50 is connected to the first insulator 2.From the fastening region 64, the metal bellows 50 extends, on the one hand, in the direction of the first end 58 of the metal bellows 50, and, on the other hand, the metal bellows 50 extends further in the direction of the radial extension toward the moving contact rod 8, in order to then, by changing direction, additionally extend in the direction of the longitudinal extension toward the moving contact and then extend again in the direction of the radial extension outward, i.e., toward the inner side 2' of the first insulator 2. 202305888 Foreign version 11 A region of the metal bellows 50 rests here near the second end 62 of the metal bellows 50 on the inner side 2' of the first insulator 2. The second end 62 of the metal bellows 50 is here twisted or bent in the direction of the moving contact rod 8 in order to avoid electrical field peaks on the one hand and to allow the second end 62 of the metal bellows 50 to slide into the first insulator on the other hand.Furthermore, the metal bellows 50 has through openings 70 which enable or facilitate evacuation of the area enclosed between the metal bellows 50 and the first insulator 2.

[0002] 202305888 Foreign version 12 List of reference symbols 1 vacuum interrupter; 2 first insulator; 2' inside of the first insulator 2; 3 second insulator; 4 fixed contact flange; 5 fixed contact rod; 6 fixed contact; 7 moving contact flange; 8 moving contact rod; 9 moving contact; 10 first shielding element; 12 second shielding element; 14 third shielding element; 15 metal intermediate piece; 50 metal bellows for a vacuum interrupter; 50' metal bellows from the prior art for a vacuum interrupter; 52 longitudinal extension; 54 radial extension; 56 corrugations or folds of the metal bellows 50; 57 last corrugation at the second end 62 of the metal bellows 50; 58 first end of the metal bellows 50; 60 triple point shielding of the metal bellows 50; 61 Triple point of the vacuum interrupter 1 to be shielded; 62 Second end of the metal bellows 50 with a triple point shield 60; 63 Second waveform at the second end 62 of the metal bellows 50; 64 Fastening area of ​​the metal bellows 50 for fastening to a first insulator;64' fastening area of ​​the metal bellows 50'; 66 maximum width of the metal bellows 50, i.e. maximum extension in the radial expansion 54; 68 minimum width of the metal bellows 50, i.e. minimum extension in the radial expansion 54; 202305888 Foreign version 13 70 through opening in the metal bellows 50; 70' through opening between the metal bellows 50 and the first insulator 2;

Claims

202305888 Foreign version 14 claims 1. Metal bellows (50) for fastening to a first insulator (2) of a vacuum interrupter (1), wherein the metal bellows (50) extends along a longitudinal extent (52) and has waves or folds (56) in a radial extent (54) perpendicular to the longitudinal extent (52) in order to generate mobility in the direction of the longitudinal extent (52), and wherein the metal bellows (50) has a first end (58) and a second end (62), characterized in that the second end (62) has a triple-point shield (60), which triple-point shield (60) extends from a last wave (57) at the second end of the metal bellows (50) and from the first end (58) of the metal bellows (50) extends longitudinally (52). 2.Metal bellows (50) according to claim 1, characterized in that the triple point shield (60) extends substantially or for the greater part along the longitudinal extent (52).

3. Metal bellows (50) according to claim 1, characterized in that the triple point shield (60) extends along the longitudinal extent (52) and extends outwards in the radial extent (54), thus also in the direction of the maximum width (66) of the metal bellows (50).

4. Metal bellows (50) according to claim 3, characterized in that the triple point shield (60) extends outwards in the radial extent (54) in such a way that an open end (61) of the triple point shield (60) in a on the. 202305888 Foreign version 15 first insulator (2) fastened state rests against the inside of the first insulator (2).

5. Metal bellows (50) according to claim 4, characterized in that the open end of the triple-point shield (60) is bent such that the open end of the triple-point shield (60) does not point outward parallel to the radial extension (54).

6. Metal bellows (50) according to claim 4 or 5, characterized in that the metal bellows (50) has one or more through-openings (70) between the fastening region (64) and the second end (62) of the metal bellows (50). 7.Metal bellows (50) according to claim 4, 5 or 6, characterized in that the open end of the triple-point shield (60) has a second waveform, and thus the open end of the triple-point shield (60), when fastened to the first insulator (2), partially rests against the inside of the first insulator (2) and forms through openings (70'). 8.Vacuum interrupter (1) with at least a first insulator (2), a fixed contact flange (4), a fixed contact rod (5), a fixed contact (6), a moving contact flange (7), a moving contact rod (8), a moving contact (9) and at least one first shielding element (10), characterized in that the vacuum interrupter (1) has a metal bellows (50) according to one of the preceding claims and the metal bellows (50) connects the moving contact flange (7) to the first insulator (2) in such a way that the moving contact (9) is movable in the direction of the longitudinal extent (52) of the metal bellows (50). 202305888 Foreign version 16 9. Vacuum interrupter (1) according to claim 8, characterized in that the open end of the triple-point shield (60) does not touch the first insulator (2) on an inner side (2') of the first insulator (2).

10. Vacuum interrupter (1) according to claim 9, characterized in that the open end of the triple-point shield (60) bears at least partially against an inner side of the first insulator (2).

11. Vacuum interrupter (1) according to one of the preceding claims, characterized in that the vacuum interrupter has an external metal bellows (50), a second insulator (3), a metal intermediate piece (15), a second shield element (12), and a third shield element (14).

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