Vacuum switch

Abstract

The invention relates to a vacuum switch (1). The vacuum switch (1) comprises two base elements (3, 5) spaced apart from each other, a vacuum switch tube (7) arranged between the base elements (3, 5), and a mechanically rigid carrier element (9) made of an insulating material. The carrier element (9) is connected to the two base elements (3, 5) and tubularly and contactlessly surrounds the vacuum switch tube (7) and has a plurality of recesses (11). Furthermore, the carrier element (9) is surrounded by an electrically non-conducting elastomer (13) which fills the recesses (11) in the carrier element (9) and an intermediate space between the carrier element (9) and the vacuum switch tube (7).

Description

Technical Field

[0001] The present invention relates to a vacuum switch having two base elements spaced apart from each other and a vacuum switch tube disposed between the base elements. Background Technology

[0002] This type of vacuum switch is a circuit breaker in which movable switch contact elements are arranged within a vacuum switch tube to avoid or reduce arcing when the switch contact elements separate. In known structures of vacuum switches, the vacuum switch tube is housed within an electrically insulating housing containing an insulating gas compressed under high pressure to increase its dielectric strength, allowing metal components to be arranged closer together within the housing and thus saving structural space. Due to the pressure of the insulating gas, this type of vacuum switch is relatively complex and expensive, and furthermore, it cannot function properly under reduced pressure. In another type of vacuum switch, the vacuum switch tube is alternatively or additionally encased in plastic, which replaces or complements the dielectric function of the insulating gas. However, in this structure, forces, particularly those caused by temperature changes, are transmitted from the plastic to the housing of the vacuum switch tube, making this structure suitable only for relatively small vacuum switch tubes where the generated forces are so small that they do not damage the vacuum switch tube. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a vacuum switch, which is particularly improved in terms of its functional reliability and the reduction of the force acting on the vacuum switch tube.

[0004] The vacuum switch according to the invention comprises two spaced-apart base elements, a vacuum switch tube disposed between the base elements, and a mechanically rigid support element made of an insulating material. The support element is connected to the two base elements, tubularly and non-contactly surrounds the vacuum switch tube, and has a plurality of recesses. Furthermore, the support element is surrounded by a non-conductive elastomer that fills the recesses in the support element and the intermediate space between the support element and the vacuum switch tube.

[0005] This invention combines a mechanically rigid carrier element of a vacuum switch with a non-conductive elastomer surrounding the carrier element. The carrier element imparts mechanical strength to the vacuum switch by connecting the base elements of the vacuum switch to each other. Furthermore, the carrier element contributes to dielectric strength, which in other vacuum switch configurations is achieved through an insulating gas under pressure and / or a plastic coating the vacuum switch tube. By non-contactly surrounding the vacuum switch tube with the carrier element and connecting to it solely through the elastomer, almost no force is transmitted from the carrier element to the vacuum switch tube. Although temperature changes cause volume changes in the elastomer, these volume changes are transferred outward through recesses in the carrier element, thus generating only a small amount of stress at the vacuum switch tube. Figuratively speaking, the elastomer can "breathe" through the recesses in the carrier element.

[0006] Therefore, the present invention realizes a vacuum switch without insulating gas, in which almost no force from the supporting structure is transmitted to the vacuum switch tube, thus making the vacuum switch suitable for large vacuum switch tubes as well. The gas-free design eliminates the need for components for gas monitoring, pressure sealing systems, and pressure vessels. The vacuum switch according to the invention can also be designed in a simple manner for different requirements through corresponding designs, particularly of the load-bearing elements, to achieve, for example, specific shielding geometries, creepage paths, thicknesses, and / or breakdown distances.

[0007] In one design of a vacuum switch, at least one base element has a fastening flange that connects to a carrier element. This achieves a simple and suitable connection between the carrier element and the base element.

[0008] In another design of the vacuum switch, the carrier element is connected to the base element via a threaded connection and / or adhesive connection. The threaded connection can be achieved, for example, by introducing a threaded bushing into the carrier element, and allows for a detachable connection between the carrier element and the base element.

[0009] In another design of the vacuum switch tube, the vacuum switch tube is connected to a first base element, and the movable switch contact element of the vacuum switch tube extends into a second base element. The first base element thus carries the vacuum switch. For example, the vacuum switch tube can be arranged at the first base element by a fixed (non-movable) switch contact element having an end extending from the vacuum switch tube and connected to the first base element. The second base element can, for example, house components of a mechanism for moving the movable switch contact element.

[0010] In another design of the vacuum switch, the first base element has a shielding region and a hollow cylindrical region or a bolt-shaped solid cylindrical region. The shielding region covers the end region of the vacuum switch tube facing the first base element, and the hollow or solid cylindrical region is adjacent to the shielding region away from the vacuum switch tube. In another design of the vacuum switch, the second base element is essentially designed as a hollow cylinder, with the end region of the vacuum switch tube facing the second base element extending into this hollow cylinder. The base element thus helps to shield the electric field at the end region of the vacuum switch tube.

[0011] In another design of the vacuum switch, the vacuum switch has an outer surface formed of an elastomer that extends around a carrier element. The outer surface formed of the elastomer can particularly have multiple dome-shaped surface areas that extend concentrically around the carrier element. In this design of the vacuum switch, the elastomer is also advantageously used to construct the outer surface of the vacuum switch, particularly to construct an insulating shield that extends the creepage path of leakage current along the outer surface of the vacuum switch.

[0012] In another design of the vacuum switch, the elastomer is a silicone elastomer. Silicone elastomers are resistant to ultraviolet (UV) radiation and are therefore particularly suitable for forming the outer surface of the vacuum switch.

[0013] In another design of the vacuum switch, the carrier element is made of plastic, fiber-plastic composite, or ceramic. Plastic and fiber-plastic composites are preferred materials for manufacturing the carrier element because they allow for relatively simple production of carrier elements with suitable shapes and the required mechanical and dielectric properties. Ceramic materials can also be used, but they are relatively brittle and heavy, and therefore generally less preferred.

[0014] In another design of the vacuum switch, at least one recess in the carrier element has an oval shape. Here, the oval shape also includes shapes with segmented straight edges, such as a "racetrack shape." By having an oval-shaped recess, unfavorable dielectric corners are avoided, and a suitable trade-off between the mechanical strength and dielectric strength of the carrier element is achieved.

[0015] In another design of the vacuum switch, at least one recess in the carrier element is formed by a groove in the substrate of the carrier element, and at least one filler of the carrier element is disposed in the groove. The filler is connected to the substrate by an elastic web. The elasticity of the web allows the filler to move relative to the substrate. Thus, the filler embedded in the elastomer can move relative to the substrate when the volume of the elastomer varies, particularly with temperature. Therefore, the elastomer can "breathe" through the groove in the substrate despite the presence of the filler. The use of the filler saves on the elastomer, thereby reducing the production cost of the vacuum switch, since the materials used to manufacture the carrier element are generally cheaper than those used for the elastomer.

[0016] In another design of the vacuum switch, the load-bearing element has a lattice structure. Here, the load-bearing element with a lattice structure is understood as a load-bearing element with relatively uniformly distributed recesses. This achieves uniform load distribution on the load-bearing element without critical load areas, and enables uniform transfer of volume changes of the elastomer through the recesses.

[0017] In another design of the vacuum switch, the load-bearing element has a substantially constant wall thickness. This advantageously avoids load-critical areas of the load-bearing element with very small wall thicknesses and varying dielectric strength of the load-bearing element. Areas of the load-bearing element that bear particularly strong local loads can, of course, have a larger wall thickness than the rest.

[0018] In another design of the vacuum switch, the carrier element is shaped such that the vacuum switch tube can be pushed into the carrier element. This achieves an assembly method for the vacuum switch in which the vacuum switch tube is pushed into the carrier element or the carrier element is fitted onto the vacuum switch tube.

[0019] In the method for manufacturing the vacuum switch according to the invention, a carrier element is assembled around the vacuum switch tube and connected to a base element, and then cast together with an elastomer in a mold.

[0020] Therefore, the elastomer can be applied in a simple manner after the other components of the vacuum switch have been pre-assembled in the mold, and the pre-assembled vacuum switch is introduced into the mold. Attached Figure Description

[0021] The features, characteristics, advantages, and implementations of the invention described above will become clearer and more apparent in conjunction with the following description of embodiments, which are illustrated in more detail with reference to the accompanying drawings. In the drawings:

[0022] Figure 1 A cross-sectional view of a first embodiment of the vacuum switch is shown.

[0023] Figure 2This shows a pre-assembled state without an elastomer. Figure 1 The vacuum switch shown,

[0024] Figure 3 A cross-sectional view of a second embodiment of the vacuum switch is shown.

[0025] Figure 4 A cross-sectional view of a third embodiment of the vacuum switch is shown.

[0026] Figure 5 A cross-sectional view of a fourth embodiment of the vacuum switch is shown.

[0027] Figure 6 A cross-sectional view of a fifth embodiment of the vacuum switch is shown.

[0028] Figure 7 A cross-sectional view of a sixth embodiment of the vacuum switch is shown.

[0029] Figure 8 A cross-sectional view of a seventh embodiment of the vacuum switch is shown.

[0030] Figure 9 This shows a pre-assembled state without an elastomer. Figure 8 The vacuum switch shown.

[0031] Corresponding components are given the same reference numerals in the accompanying drawings. Detailed Implementation

[0032] Figure 1 A cross-sectional view of a first embodiment of the vacuum switch 1 is shown. The vacuum switch 1 includes two spaced-apart base elements 3 and 5, a vacuum switch tube 7 disposed between the base elements 3 and 5, and a mechanically rigid support element 9 connected to the two base elements 3 and 5. The support element 9 tubularly and non-contactly surrounds the vacuum switch tube 7, is made of an insulating material, and has a plurality of recesses 11. The support element 9 is surrounded by a non-conductive elastomer 13, which fills the recesses 11 in the support element 9, the intermediate space between the support element 9 and the vacuum switch tube 7, and the intermediate space between the support element 9 and the base elements 3 and 5, and forms the outer surface 15 of the vacuum switch 1, which extends around the support element 9.

[0033] Figure 2 The diagram shows the pre-assembled state without the elastomer 13. Figure 1 Vacuum switch 1 is shown.

[0034] The vacuum switch tube 7 has a metallic intermediate region 17, two metallic end regions 19 and 21, and two insulating regions 23 and 25. The intermediate region 17 has a larger diameter than the end regions 19 and 21 and the insulating regions 23 and 25, and is arranged between the insulating regions 23 and 25. The insulating regions 23 and 25 are each made of a non-conductive material. The first end region 19 extends into the first base element 3 and is adjacent to the first insulating region 23. The second end region 21 extends into the second base element 5 and is adjacent to the second insulating region 23.

[0035] Two conductive switch contact elements 27 and 29 are arranged in the vacuum switch tube 7. Here, the first switch contact element 27 is fixedly connected to the first end region 19 of the vacuum switch tube 7. The end of the first switch contact element 27 extending from the vacuum switch tube 7 is connected to the first base element 3, for example, via a threaded connection (not shown). Thus, the vacuum switch tube 7 is connected to the first base element 3. The second switch contact element 29 can be positioned relative to the first switch contact element 27 in a first switching position via a mechanism (not shown). Figure 1 The switch contacts 27 and 29 are in contact in the first switch position and spaced apart from each other in the second switch position. One end of the second switch contact 29 extends from the vacuum switch tube 7 through an opening in the second end region 21.

[0036] The base elements 3 and 5 are made of metal (e.g., aluminum) or alloy. Each base element 3 and 5 is essentially constructed as a hollow cylinder, wherein the end of the first base element 3 facing the vacuum switch tube 7 is designed as a shielding region 31, which encloses the hollow cylindrical region 39 on the vacuum switch tube side and covers the first end region 19 of the vacuum switch tube 7 in a dome-like manner. The end of the first switch contact element 27 extending from the vacuum switch tube 7 is centrally located at the shielding region 31. Furthermore, each base element 3 and 5 has outwardly projecting fastening flanges 33 and 35, which form the end of the base element 3 and 5 opposite to the vacuum switch tube 7 and are connected to the end of the carrier element 9, for example, by a threaded connection and / or adhesive connection (not shown).

[0037] The carrier element 9 connects the two base elements 3, 5 to each other and surrounds the vacuum switch tube 7 and the base elements 3, 5 up to the fastening flanges 33, 35 of the base elements. The carrier element 9 has the shape of a hollow cylinder with recesses 11 in its cylindrical wall. Here, the middle section of the carrier element 9 surrounding the vacuum switch tube 7 has a plurality of recesses 11, which extend substantially along the entire longitudinal extension of the vacuum switch tube 7, wherein the longitudinal extension is understood as the extension of the vacuum switch tube 7 between its end regions 19, 21. In addition, each end section of the carrier element 9 also has a plurality of recesses 11 in the region of the base elements 3, 5. Each recess 11 has two edges extending parallel to the longitudinal axis of the vacuum switch 1, which are connected to each other by curved edges, so that the recess 11 has an oval shape (“racetrack shape”) composed of straight edges and curved edges. The carrier element 9 has a lattice structure in general. The carrier element 9 is made of, for example, plastic, fiber-plastic composite material, or ceramic material.

[0038] The elastomer 13 is, for example, a silicone elastomer. To manufacture the vacuum switch 1, the carrier element 9 is first assembled around the vacuum switch tube 7 and connected to the base elements 3 and 5. For this purpose, for example, the carrier element 9 is fitted onto the vacuum switch tube 7 and the first base element 3 and connected to the fastening flange 33 of the first base element 3. Then, the second base element 5 is pushed into the carrier element 9 and its fastening flange 35 is connected to the carrier element 9. Alternatively, the carrier element 9 can similarly be connected first to the second base element 5 and then to the first base element 3. Figure 2 The vacuum switch 1 pre-assembled as shown is illustrated. The pre-assembled vacuum switch 1 is then cast in a mold together with an elastomer 13, wherein the elastomer 13 fills the recess 11 in the carrier element 9, the intermediate space between the carrier element 9 and the vacuum switch tube 7, and the intermediate space between the carrier element 9 and the base elements 3, 5, and the elastomer forms the outer surface 15 of the vacuum switch 1.

[0039] Figure 3 A cross-sectional view of a second embodiment of the vacuum switch 1 is shown. This embodiment is similar to... Figure 1 and Figure 2 The difference in the first embodiment shown is only that the outer surface 15 formed by the elastomer 13 has a plurality of surface regions 37, which are dome-shaped and extend concentrically around the support element 9. Compared with... Figure 1 and Figure 2 Compared to the first embodiment shown, this advantageously extends the creepage path of the leakage current along the outer surface 15.

[0040] Figure 4 A cross-sectional view of a third embodiment of the vacuum switch 1 is shown. This embodiment is similar to... Figure 3The difference in the second embodiment shown is that the fastening flange 33 of the first base element 3 is arranged near the first end region 19 of the vacuum switch tube 7, and the fastening flange 35 of the second base element 5 is arranged near the second end region 21 of the vacuum switch tube 7. Therefore, the carrier element 9 extends essentially only around the vacuum switch tube 7. Furthermore, the first segment of the carrier element 9 extending around the first insulating region 23 has a smaller diameter than the second segment, which extends around the second insulating region 25 and the adjacent intermediate region 17. In other words, the carrier element 9 widens from the first segment toward the second segment, so that the carrier element 9 can only be fitted onto the vacuum switch tube 7 in the direction from the first end region 19 toward the second end region 21. The outer surface 15 of the vacuum switch 1 formed by the elastomer 13 around the carrier element 9 is also correspondingly widened. Furthermore, the carrier element 9 has recesses 11 in both the first and second segments. Figure 2 Compared to the embodiment shown, the carrier element 9 is therefore shorter and its first section is closer to the vacuum switch tube 7, thereby saving materials, especially expensive elastomer materials, and thus reducing the material cost for the vacuum switch 1.

[0041] Figure 5 A cross-sectional view of a fourth embodiment of the vacuum switch 1 is shown. This embodiment is similar to... Figure 4 The difference in the third embodiment shown lies in the design of the first base element 3. Instead of a hollow cylindrical region 39, a bolt-shaped solid cylindrical region 41 is adjacent to the shielding region 31 of the first base element 3, away from the vacuum switch tube. This solid cylindrical region has a smaller diameter than the shielding region 31. Here, the solid cylindrical region 41 may include at least one screw extending through the region to secure the first switch contact element 27 to the first base element 3. In other words, the first base element 3 may have a base through which at least one screw is guided longitudinally into the first switch contact element 27. Thus, in this case, the base in the solid cylindrical region 41 is not constructed as a completely solid cylinder, but has at least one hole for the screw. However, the base, together with at least one screw, substantially forms a solid cylinder in the solid cylindrical region 41. However, the first switch contact element 27 may also be connected to the first base element 3 in other ways, such as by welding or shrinking. In this case, the solid cylindrical region 41 can be constructed as a one-piece solid cylinder. (The last sentence appears to be incomplete and unrelated to the preceding text.) Figure 4 Compared to the third embodiment shown, the smaller diameter of the first base element 3 in the solid cylindrical region 41 saves material for the first base element 3 and for the elastomer 13, and reduces the weight of the vacuum switch 1.

[0042] Figure 6A cross-sectional view of a fifth embodiment of the vacuum switch 1 is shown. This embodiment is similar to... Figure 5 The difference in the embodiment shown is that the shielding region 31 of the first base element 3 extends obliquely from the solid cylindrical region 41 toward the vacuum switch tube 7 and has a central region 43 that extends the solid cylindrical region 41 on the vacuum switch tube side, and the end of the first switch contact element 27 extending from the vacuum switch tube 7 is arranged in this central region. Figure 5 As shown in the embodiment, the solid cylindrical region 41 may include at least one screw extending through the region to secure the first switch contact element 27 to the first base element 3. Furthermore, compared with... Figure 5 Unlike the embodiment shown, the carrier element 9 extends to the ends of the two base elements 3, 5 away from the vacuum switch tube. In this embodiment, compared to... Figure 4 Compared to the third embodiment shown, it also saves material for the first base element 3 and the elastomer 13 and reduces the weight of the vacuum switch 1.

[0043] Figure 7 A cross-sectional view of a sixth embodiment of the vacuum switch 1 is shown. This embodiment is similar to... Figure 3 The only difference in the embodiment shown is that the second base element 5 is shorter than the first base 3, and the vacuum tube 7 is not centrally arranged in the vacuum switch 1.

[0044] Figure 8 and Figure 9 A seventh embodiment of vacuum switch 1 is shown. This embodiment is similar to... Figure 4 The difference in the embodiments shown is essentially only in the design of the recesses 11 in the support element 9. Each recess 11 in the support element 9 is formed by an oval groove 11.1 in the base 9.6 of the support element 9, in which at least one filler 9.7 of the support element 9 is arranged, which is connected to the base 9.6 via a web 9.8. Each web 9.8 is narrow and thus designed to be flexible, so that the filler 9.7 connected to the base 9.6 via the web can move relative to the base 9.6. Thus, when the volume of the elastomer 13 varies particularly with temperature, the filler 9.7 embedded in the elastomer 13 can move relative to the base 9.6. The elastomer 13 is saved by the filler 9.7, thereby reducing the production cost for the vacuum switch 1, since the material used to manufacture the support element 9 is generally cheaper than that of the elastomer 13. Figure 8 A cross-sectional view of vacuum switch 1 is shown. (Compared to...) Figure 2 Similarly, Figure 9 The diagram shows the pre-assembled state without the elastomer 13. Figure 8 Vacuum switch 1 is shown.

[0045] Although the invention has been described and illustrated in more detail through preferred embodiments, the invention is not limited to the disclosed examples and other variations can be derived by those skilled in the art without departing from the scope of protection of the invention.

Claims

1. A vacuum switch (1), comprising - Two base elements spaced apart from each other (3, 5). - A vacuum switch tube (7) arranged between the base elements (3, 5), and - A mechanically rigid support element (9) connected to two base elements (3, 5) and tubularly and non-contactly surrounding the vacuum switch tube (7), and having a plurality of recesses (11), wherein, - The carrier element (9) is surrounded by a non-conductive elastomer (13), which fills the recess (11) in the carrier element (9) and the intermediate space between the carrier element (9) and the vacuum switch tube (7). The bearing element (9) is connected to the base element (3, 5) by threaded connection and / or adhesive connection.

2. The vacuum switch (1) according to claim 1. in, At least one base element (3, 5) has a fastening flange (33, 35) connected to the bearing element (9).

3. The vacuum switch (1) according to any one of the preceding claims. in, The vacuum switch tube (7) is connected to the first base element (3), and the movable switch contact element (29) of the vacuum switch tube (7) extends into the second base element (5).

4. The vacuum switch (1) according to claim 3. in, The first base element (3) has a shielding region (31) that surrounds the end region (19) of the vacuum switch tube (7) facing the first base element (3) in a dome shape, and the first base element has a hollow cylindrical region (39) or a bolt-shaped solid cylindrical region (41) that is adjacent to the shielding region (31) away from the vacuum switch tube.

5. The vacuum switch (1) according to claim 3. in, The second base element (5) is designed as a hollow cylinder, and the end region (21) of the vacuum switch tube (7) facing the second base element (5) extends into the hollow cylinder.

6. The vacuum switch (1) according to claim 1. The vacuum switch has an outer surface (15) formed by the elastomer (13) extending around the carrier element (9).

7. The vacuum switch (1) according to claim 6. in, The outer surface (15) formed by the elastomer (13) has a plurality of dome-shaped surface regions (37) that extend concentrically around the support element (9).

8. The vacuum switch (1) according to claim 1. in, The elastomer (13) is a silicone elastomer.

9. The vacuum switch (1) according to claim 1. in, The load-bearing element (9) is made of plastic or fiber-plastic composite material or ceramic material.

10. The vacuum switch (1) according to claim 1. in, At least one recess (11) in the bearing element (9) has an oval shape.

11. The vacuum switch (1) according to claim 1. in, At least one recess (11) in the support element (9) is formed by a groove (11.1) in the base (9.6) of the support element (9), and at least one filler (9.7) of the support element (9) is arranged in the groove, and the at least one filler is connected to the base (9.6) by an elastic web (9.8).

12. The vacuum switch (1) according to claim 1. in, The carrier element (9) has a lattice structure.

13. The vacuum switch (1) according to claim 1. in, The carrier element (9) is shaped such that the vacuum switch tube (7) can be pushed into the carrier element (9).

14. A method for manufacturing a vacuum switch (1) according to any one of the preceding claims, in, The carrier element (9) is assembled around the vacuum switch tube (7) and connected to the base element (3, 5), and then cast together with the elastomer (13) in a mold.

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