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 plurality of mechanically rigid carrier elements (9) which are each made of an insulating material. Each carrier element (9) is connected to both base elements (3, 5) and partially circumferentially and contactlessly surrounds the vacuum switch tube (7). The carrier elements (9) are arranged spaced apart from each other around the vacuum switch tube (7) and are surrounded by an electrically non-conductive elastomer (13) which fills the intermediate spaces between the carrier elements (9) and the intermediate spaces between the carrier elements (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] According to the present invention, the above-mentioned technical problem is solved by a vacuum switch having the features of the present invention.

[0005] Advantageous design features of the present invention are the subject of the present invention.

[0006] The vacuum switch according to the invention comprises two spaced-apart base elements, a vacuum switch tube disposed between the base elements, and a plurality of mechanically rigid support elements, each of which is made of an insulating material. Each support element is connected to the two base elements and partially circumferentially and non-contactly surrounds the vacuum switch tube. The support elements are arranged spaced apart from each other around the vacuum switch tube and are surrounded by a non-conductive elastomer that fills the intermediate spaces between the support elements and the intermediate space between the support elements and the vacuum switch tube.

[0007] This invention combines a multi-piece carrier structure of a vacuum switch, formed by carrier elements, with a non-conductive elastomer surrounding the carrier elements. The carrier elements impart mechanical strength to the vacuum switch by connecting its base elements to each other. Furthermore, the carrier elements contribute to dielectric strength, which in other vacuum switch designs is achieved through an insulating gas under pressure and / or a plastic coating the vacuum switch tube. By having the carrier elements surround the vacuum switch tube without contact and spaced apart from each other, and connected to the vacuum switch tube only through the elastomer, almost no force is transmitted from the carrier elements to the vacuum switch tube. Although temperature changes cause volume changes in the elastomer, these volume changes are transferred outward through the intermediate space between the carrier elements, thus generating only a small amount of stress at the vacuum switch tube. Figuratively speaking, the elastomer can "breathe" through the intermediate space between the carrier elements.

[0008] A vacuum switch has multiple carrier elements distributed around a vacuum switch tube. These carrier elements can also be mounted individually, and their shapes can be adapted to the shape of the vacuum switch tube, so that each carrier element has a substantially constant distance from the vacuum switch tube along its overall length. Conversely, a one-piece, tubular carrier element must have a minimum inner diameter larger than the maximum outer diameter of the vacuum switch tube to allow for assembly around the tube. Therefore, in the case of a vacuum switch tube with a varying outer diameter, the distance between the carrier element and the tube will vary along the tube, causing changes in the wall thickness and, consequently, the mechanical and dielectric strength of the sleeve formed by the carrier element and elastomer around the tube. Furthermore, due to the varying distance, more elastomer will be needed to fill the space between the vacuum switch tube and the carrier element, which can significantly increase the cost of the vacuum switch, as suitable elastomers are typically relatively expensive.

[0009] Therefore, the present invention realizes a vacuum switch without insulating gas, in which almost no force from the load-bearing 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.

[0010] 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.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] In another design of the vacuum switch, each carrier element is made of plastic, fiber-plastic composite, or ceramic. Plastic and fiber-plastic composites are preferred materials for manufacturing carrier elements 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.

[0017] In another design of the vacuum switch, at least one carrier element has at least one recess filled with an elastomer. The recess in the carrier element serves to transfer volume changes of the elastomer outward, similar to the intermediate space between carrier elements, in order to avoid or reduce stress at the vacuum switch tube.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] In another design of the vacuum switch, each carrier element has a shape corresponding to the vacuum switch tube, thus maintaining a substantially constant distance between the carrier element and the vacuum switch tube. This advantageously allows for a uniform wall thickness and therefore uniform mechanical and dielectric strength in the sheath formed by the carrier element and the elastomer surrounding the vacuum switch tube. Furthermore, by minimizing the distance between the carrier element and the vacuum switch tube, and thus the intermediate space filled with the elastomer, the amount of elastomer required to manufacture the vacuum switch can be advantageously minimized.

[0022] In the method for manufacturing the vacuum switch according to the invention, the carrier element is first assembled around the vacuum switch tube, and then cast together with the elastomer in a mold.

[0023] 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

[0024] 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:

[0025] Figure 1 A cross-sectional view of a first embodiment of the vacuum switch is shown.

[0026] Figure 2 This shows a pre-assembled state without an elastomer. Figure 1 The vacuum switch shown,

[0027] Figure 3 It shows Figure 1 The diagram shows a perspective view of the carrier element of the vacuum switch.

[0028] Figure 4 A cross-sectional view of a second embodiment of the vacuum switch is shown.

[0029] Figure 5 This shows a pre-assembled state without an elastomer. Figure 4 The vacuum switch shown,

[0030] Figure 6 It shows Figure 4 The diagram shows a perspective view of the carrier element of the vacuum switch.

[0031] Figure 7 A cross-sectional view of a third embodiment of the vacuum switch is shown.

[0032] Figure 8 A cross-sectional view of a fourth embodiment of the vacuum switch is shown.

[0033] Figure 9 A cross-sectional view of a fifth embodiment of the vacuum switch is shown.

[0034] Figure 10 This shows a pre-assembled state without an elastomer. Figure 9 The vacuum switch shown,

[0035] Figure 11 A cross-sectional view of a sixth embodiment of the vacuum switch is shown.

[0036] Figure 12 This shows a pre-assembled state without an elastomer. Figure 11 The vacuum switch shown.

[0037] Corresponding components are given the same reference numerals in the accompanying drawings. Detailed Implementation

[0038] Figure 1 A cross-sectional view of a first embodiment of a 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 two mechanically rigid support elements 9 connected to the two base elements 3 and 5, respectively. Each support element 9 surrounds the vacuum switch tube 7 in a nearly semi-circular and non-contact manner and is made of an insulating material. The support elements 9 are arranged spaced apart from each other around the vacuum switch tube 7, such that the support elements, together with the gaps 10 extending therebetween, tubularly surround the vacuum switch tube 7. The support elements 9 are surrounded by a non-conductive elastomer 13, which fills the intermediate space forming the gaps 10 between the support elements 9 and the intermediate space between the support elements 9 and the vacuum switch tube 7, and forms the outer surface 15 of the vacuum switch 1, which extends around the support elements 9.

[0039] Figure 2 The diagram shows the pre-assembled state without the elastomer 13. Figure 1 Vacuum switch 1 is shown.

[0040] Figure 3 It shows Figure 1 A perspective view of the carrier element 9 of the vacuum switch 1 shown.

[0041] 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.

[0042] 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 1The 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.

[0043] 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 protruding fastening flanges 33 and 35, at which the ends of the two carrier elements 9 are fastened by threaded connections. For this purpose, threaded bushings 12 are introduced (e.g., cast into) into the ends of the carrier elements 9 to accommodate the threaded elements respectively. The fastening flange 33 of the first base element 3 is located near the first end region 19 of the vacuum switch tube 7, and the fastening flange 35 of the second base element 5 is located near the second end region 21 of the vacuum switch tube 7.

[0044] Two carrier elements 9 extend along the vacuum switch tube 7 between fastening flanges 33 and 35. Each carrier element 9 has a shape corresponding to the vacuum switch tube 7, such that the carrier element 9 has a substantially constant distance from the vacuum switch tube 7. Each carrier element 9 is widened, particularly in the intermediate section 9.1 corresponding to the intermediate region 17 of the vacuum switch tube 7, relative to the side sections 9.2 and 9.3 adjacent to the intermediate section 9.1 on both sides, which correspond to the insulating regions 23 and 25 of the vacuum switch tube 7. End sections 9.4 and 9.5 of the carrier element 9 are adjacent to each side section 9.2 and 9.3, into which threaded bushings 12 are introduced, and for this purpose, the end sections have a greater wall thickness than the intermediate section 9.1 and the side sections 9.2 and 9.3. The carrier elements 9 are made, for example, of plastic, fiber-plastic composite, or ceramic material.

[0045] The elastomer 13 is, for example, a silicone elastomer. 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.

[0046] 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. Figure 2The 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 intermediate space between the carrier elements 9 and the intermediate space between the carrier elements 9 and the vacuum switch tube 7, and the elastomer forms the outer surface 15 of the vacuum switch 1.

[0047] Figure 4 A cross-sectional view of a second embodiment of the vacuum switch 1 is shown. This embodiment is similar to... Figure 1 The only difference in the first embodiment shown is that each support element 9 has a plurality of recesses 11. Here, the recesses 11 are respectively arranged in the middle section 9.1 and the two side sections 9.2, 9.3 of the support element 9. The recesses 11 are respectively oval in shape and are respectively filled with an elastomer 13, the oval shape having straight edges segment by segment.

[0048] Figure 5 and Figure 2 Similarly, the pre-assembled state without elastomer 13 is shown. Figure 4 Vacuum switch 1 is shown.

[0049] Figure 6 It shows Figure 4 A perspective view of the carrier element 9 of the vacuum switch 1 shown.

[0050] Figure 7 A cross-sectional view of a third embodiment of the vacuum switch 1 is shown. This embodiment is similar to... Figure 1 The difference in the first 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 may be constructed as a one-piece completely solid cylinder. With Figure 1Compared to the first 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.

[0051] Figure 8 A cross-sectional view of a fourth embodiment of the vacuum switch 1 is shown. This embodiment is similar to... Figure 7 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 7 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 7 Unlike the embodiment shown, the carrier element 9 extends to the end of the first base element 3 away from the vacuum switch tube.

[0052] Figure 9 and Figure 10 A fifth embodiment of vacuum switch 1 is shown. This embodiment is similar to... Figures 4 to 6 The difference in the embodiment shown lies in the design of the support element 9. The support element 9 is not widened in its middle section 9.1 relative to its side sections 9.2 and 9.3, but instead has a constant outer diameter over its overall length. Furthermore, each support element 9 has only two recesses 11 arranged sequentially along the longitudinal direction. Figure 9 A cross-sectional view of vacuum switch 1 is shown. (Compared to...) Figure 5 Similarly, Figure 10 The diagram shows the pre-assembled state without the elastomer 13. Figure 9 Vacuum switch 1 is shown.

[0053] Figure 11 and Figure 12 A sixth embodiment of vacuum switch 1 is shown. This embodiment is similar to... Figure 9 and Figure 10The difference in the embodiment shown lies 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 elastically designed 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 11 A cross-sectional view of vacuum switch 1 is shown. (Compared to...) Figure 5 Similarly, Figure 12 The diagram shows the pre-assembled state without the elastomer 13. Figure 11 Vacuum switch 1 is shown.

[0054] exist Figures 1 to 12 The features of the embodiment of vacuum switch 1 shown can be combined with each other to form other embodiments. Figure 7 and Figure 8 The embodiments shown can be modified in particular to make their carrier element 9 have a similar shape to that in Figure 5 , Figure 10 or Figure 12 The recess 11 of the support element 9 is shown in the diagram. Furthermore, in... Figure 9 and Figure 10 The embodiment shown can be modified so that the carrier element 9 is designed without the recess 11.

[0055] 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 - Multiple mechanically rigid load-bearing elements (9), among which - Each carrier element (9) is connected to two base elements (3, 5) and partially circumferentially and non-contactly surrounds the vacuum switch tube (7), and is made of insulating material, and - The carrier elements (9) are arranged spaced apart from each other around the vacuum switch tube (7) and surrounded by a non-conductive elastomer (13), which fills the intermediate spaces between the carrier elements (9) and between the carrier elements (9) and the vacuum switch tube (7). Its features are, At least one support element (9) has at least one recess (11) filled with the elastomer (13).

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 claim 1 or 2. in, Each carrier element (9) is connected to the base element (3, 5) by threaded connection and / or adhesive connection.

4. The vacuum switch (1) according to claim 1 or 2. 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).

5. The vacuum switch (1) according to claim 4. 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.

6. The vacuum switch (1) according to claim 4. 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.

7. The vacuum switch (1) according to claim 1 or 2. The vacuum switch has an outer surface (15) formed by the elastomer (13) extending around the carrier element (9).

8. The vacuum switch (1) according to claim 7. 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).

9. The vacuum switch (1) according to claim 1 or 2. in, The elastomer (13) is a silicone elastomer.

10. The vacuum switch (1) according to claim 1 or 2. in, Each load-bearing element (9) is made of plastic or fiber-plastic composite or ceramic material.

11. The vacuum switch (1) according to claim 1 or 2. in, At least one recess (11) in the bearing element (9) has an oval shape.

12. The vacuum switch (1) according to claim 11. 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, the filler being connected to the base (9.6) by an elastic web (9.8).

13. The vacuum switch (1) according to claim 1 or 2. in, Each carrier element (9) has a shape corresponding to the vacuum switch tube (7), such that the carrier element (9) has a constant distance from the vacuum switch tube (7).

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

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