Vacuum interrupter for establishing or disconnecting an electrical connection between two DC voltage connections

Abstract

The invention relates to a vacuum interrupter (1) for establishing or disconnecting an electrical connection between DC voltage connections, comprising: - a first connection side (2) and a second connection side (3), - a tube housing (5), - a first switch contact (6) which is movably arranged in the tube housing (5) and is electrically connected to the first connection side (2), wherein the first switching contact (6) has a mass, - a second switching contact (7) which is arranged in the tube housing (5) and is electrically connected to the second connection side (3), wherein the first switching contact (6) and the second switching contact (7) are arranged at a distance from one another in the tube housing (5), and - a switching unit (8) which is designed to establish or disconnect, on the basis of mechanical switch actuation (4), an electrical connection between the first and second switching contact (6, 7), characterised in that - the mass of the first switching contact (6) corresponds to a proportion in the range from 1% to 40% of the total mass of the vacuum interrupter (1).

Description

[0001] 2023PF 12576

[0002] 1

[0003] Description

[0004] Vacuum switching tube for making or breaking an electrical connection between two DC voltage terminals

[0005] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.

[0006] The invention relates to a vacuum switching tube for establishing or disconnecting an electrical connection between two DC voltage terminals for use, for example, in a DC voltage circuit breaker.

[0007] Circuit breakers for AC applications, such as high-voltage circuit breakers, are well-known in the art, so no separate printed documentation is required. High voltage, as defined by standards, is an electrical voltage that is either an AC voltage greater than 1000 volts or a DC voltage greater than 1500 volts. This definition of high voltage, which is also covered by the relevant standards, is regularly subdivided into two ranges: a first range, referred to as medium voltage, which extends over a

[0008] The voltage range extends from 1 kV up to and including 52 kV, and a second range that covers voltages greater than 52 kV and is referred to as high voltage.

[0009] For "mechanical" DC circuit breakers, especially for medium- and high-voltage applications, a mechanical interrupter unit is used as the core component. Due to the excellent switching and insulation properties of vacuum interrupters, medium-voltage vacuum interrupters are used in such DC circuit breakers. Previous designs were based on medium-voltage vacuum interrupters for AC applications. In AC applications, switching times in the range of 10 to 50 ms are achieved. However, significantly shorter switching times are required for DC applications.

[0010] In vacuum switching tubes in AC applications, a metal vapor arc discharge (electric arc) can occur through the 2023PF 12576 when the contacts are galvanically isolated.

[0011] 2

[0012] Current is generated. The current flows through this metal vapor plasma until the next zero crossing. The arc extinguishes at the current zero crossing, and the remaining metal vapor loses its conductivity within a few microseconds, thus very quickly re-solidifying the switching path. With a re-solidification rate of approximately 5 kV per microsecond, the vacuum interrupter can immediately handle the applied voltages again. When switching off small operating currents, it can happen that the current breaks down before the natural zero crossing. To prevent impermissible switching overvoltages during this switching, the breakover current must be limited to small values. When using a special contact material, the breakover current for a vacuum interrupter, for example, is between two and three amperes.The contact material used in vacuum switching tubes for AC applications is therefore a specific compromise, where on the one hand the lowest possible contact resistance can be achieved in the closed state and on the other hand the break-up currents can be minimal in the switching case.

[0013] Using different contact geometries or contact systems, an arc can be controlled by an axial or radial magnetic field, ensuring reliable interruption at current zero crossing. The macroscopic effect of the magnetic fields, in the radial or axial direction, on the arc behavior after contact separation is in the range of 2 to 5 ms.

[0014] One object of the present invention is to design a vacuum switching tube which is designed for DC voltage applications and which has a more efficient, in particular faster, switching time with regard to DC voltage applications, especially compared to AC vacuum switching tubes.

[0015] This problem is solved by a vacuum switching tube according to claim 1. Meaningful further developments arise from the dependent claims.

[0016] One aspect of the invention relates to a vacuum switching tube for establishing or disconnecting an electrical connection between two DC voltage terminals, comprising:

[0017] - a first connection side and a second connection side, wherein the first connection side is electrically connectable to a first DC voltage terminal of the DC voltage terminals and the second connection side is electrically connectable to a second DC voltage terminal of the DC voltage terminals, 2023PF 12576

[0018] 3

[0019] - a tube housing,

[0020] - a first switching contact movably arranged in the tube housing, which is electrically connected to the first terminal side, wherein the first switching contact has a ground,

[0021] - a second switching contact arranged in the tube housing, which is electrically connected to the second terminal side, wherein the first switching contact and the second switching contact are spaced apart from each other in the tube housing, and

[0022] - a switching unit which is designed to establish or disconnect an electrical connection between the first and second switching contacts on the basis of a mechanical switching actuation, whereby the electrical connection between the connection sides can be established or disconnected, wherein

[0023] - the mass of the first switching contact corresponds to a proportion in the range of 1% to 40% of the total mass of the vacuum switching tube.

[0024] The proposed vacuum switching tube enables the realization of a switching unit, particularly an interrupter unit, for DC applications. Specifically, the vacuum switching tube according to the invention is designed for DC applications. In particular, the proposed vacuum switching tube can be used for medium and high voltage applications. To provide an efficient vacuum switching tube for DC applications, especially in the medium and high voltage range, the proposed vacuum switching tube is designed to be manufactured more efficiently, with less installation space and at a lower cost.With regard to the requirements of medium- and high-voltage applications in the DC range, the proposed vacuum switching tube is more compact, smaller, and especially lighter compared to known vacuum switching tubes and, in particular, compared to AC vacuum switching tubes. The weight of vacuum switching tubes is primarily determined by the mass of the contacts. For switching operations, the moving contact of a vacuum switching tube is often made of copper and, in terms of service life and the number of switching operations to be performed, is usually the main weight-driving factor of a vacuum switching tube. 2023PF 12576.

[0025] 4

[0026] Accordingly, the proposed vacuum switching tube offers weight savings and, in particular, space savings, since the moving contact—in this case, the movable first switching contact—accounts for between 1% and 40% of the total mass of the vacuum switching tube. Thus, the mass of the first switching contact can be at least 1% and at most 40% of the total mass. By reducing the weight of the first switching contact, the switching time of the vacuum switching tube can be reduced, as the lower weight of the first switching contact allows for a more efficient and faster movement. Consequently, improved, and especially faster, switching times can be achieved, which is particularly advantageous for DC applications.

[0027] Above all, this makes it possible to achieve switching times in the single-digit millisecond range.

[0028] The tube housing has a first and a second connection. These can be located, in particular, on opposite sides of the tube housing. Depending on the current switching state, the first switching contact, in particular, can be set in motion by means of a mechanical switching actuation initiated from outside the tube housing, especially in a linear motion, so that either the first switching contact is physically and electrically connected to the second switching contact or physically and electrically disconnected.

[0029] In one embodiment, the mass of the first switching contact is provided to represent a proportion in the range of 1% to 30%, particularly in the range of 1% to 20%, and especially in the range of 1% to 10%, of the total mass of the vacuum switching tube. For example, depending on the requirements for the DC voltage application of the vacuum switching tube, the first switching contact can be designed accordingly. In this context, the material, dimensions, and / or shape of the switching contact can be modified to achieve the desired weight reduction.

[0030] In other words, the mass of the first switching contact can be 40%, in particular 35%, 30%, 25%, 20%, 15%, 10%, 5%, or 1% of the total mass of the vacuum switching tube. 2023PF 12576

[0031] 5

[0032] The vacuum interrupter, and in particular the first switching contact, can be designed to meet specific requirements for DC applications. In particular, the vacuum interrupter according to the invention is designed to handle a DC rated current of up to 4 kA. Furthermore, the vacuum interrupter is designed to manage and switch a DC fault current of up to 20 kA. Most importantly, the weight-saving first switching contact enables the vacuum interrupter to achieve switching times in the range of 1 ms to 3 ms.

[0033] In one embodiment, the first and second switching contacts are arranged at a distance from each other in an electrically isolated state, such that a predetermined distance exists between the two switching contacts, whereby the distance can be specified based on a voltage requirement and / or a switching time requirement. Thus, the vacuum switching tube can be designed and, in particular, manufactured or produced accordingly, depending on the application area, e.g., for medium-voltage or high-voltage applications.

[0034] Depending on the intended DC application of the vacuum interrupter, the two switching contacts can be designed to maintain a specific distance between them when there is no electrical connection. For example, this distance can range from 1 mm to 15 mm, and in particular, 10 mm. DC voltage requirements may refer to specific levels of DC voltage applied to the vacuum interrupter. Similarly, DC voltage requirements may specify the rated DC current and / or DC fault current. Switching time requirements may refer to a specific switching time, such as a switching time of 2 ms.Thus, depending on the DC voltage application for which the vacuum switching tube is to be used, it can be designed, conceived and manufactured accordingly.

[0035] In one embodiment, the vacuum switching tube is further provided to have an insulator, wherein the insulator is made of an insulating material. Specifically 2023PF 12576

[0036] 6. The insulator can be designed to suit the application area and, in particular, the DC voltage application of the vacuum switching tube. Depending on which DC voltages and / or DC currents may occur in the application area of ​​the vacuum switching tube, a suitable insulating material can be used. Examples of insulating materials include aluminum oxides, chromium oxides, and barium titanates. The use of glass as an insulating material is also conceivable. Ceramics, such as insulating oxide ceramics, can be used as insulating materials. The insulator can be designed as a single piece or in multiple parts.

[0037] In one embodiment, the insulator is arranged on an outer surface of the tube housing that extends parallel to a longitudinal axis of the vacuum switching tube. This allows the tube housing to be electrically insulating. Both the insulator and the tube housing can be cylindrical. In particular, the insulator can be designed as a hollow cylinder. Thus, the insulator can be arranged circumferentially on the outer surface of the tube housing. Specifically, the insulator can be positioned abutting the outer surface of the tube housing.

[0038] In particular, the tube housing can be cylindrical, i.e., tubular. Thus, the tube housing can have a cylindrical ceramic, i.e., a cylindrical insulator.

[0039] This allows the outer surface of the tube casing to be electrically insulating. In other words, the insulator can form an outer shell for the tube casing, thus providing electrical insulation. Specifically, the outer surface, or shell, serves to electrically insulate the vacuum interrupter tube.

[0040] The longitudinal axis extends along a rotational axis of the vacuum switching tube, which is particularly cylindrical in design. Specifically, the two switching contacts are arranged opposite each other along the longitudinal axis.

[0041] In one embodiment, the insulator is arranged on the upper side of the housing within which the first connection side extends, or the insulator is arranged on the lower side of the housing, 2023PF 12576

[0042] 7 within which the second connection side extends. Here, an upper and a lower area of ​​the housing can each be designed to be electrically insulating.

[0043] In particular, the insulator is designed as a disc insulator. This allows for a compact design of the vacuum switching tube.

[0044] The lower and upper surfaces of the housing are arranged opposite each other with respect to the longitudinal axis of the vacuum switching tube. The lower and upper surfaces of the housing are each positioned perpendicular to the longitudinal axis at their respective end regions of the housing.

[0045] It is also conceivable that a first insulator element of the insulator is arranged on the top of the housing and a second insulator element on the bottom of the housing. The first and second insulator elements can be designed as disc cylinders.

[0046] In one embodiment, a metallic wall element is arranged on an outer surface of the tube housing, extending parallel to a longitudinal axis of the vacuum switching tube. In other words, a metallic wall, such as the wall element, can be arranged along the outer surface of the cylindrical tube housing. The bottom and the top of the cylindrical tube housing can be equipped with the insulator.

[0047] In one embodiment, the first switching contact has a first contact disc and the second switching contact has a second contact disc, the two switching contacts being arranged such that, when an electrical connection is established between them, the two contact discs are in contact with each other. The contact discs are designed, in particular, to be flush against each other when the switching contacts have been moved to establish an electrical connection. Specifically, the contact discs can be plate-shaped or disc-shaped and, for a good electrical connection, should be as flat against each other as possible when the switching contacts have been moved to establish the electrical connection. In particular, the contact discs can be designed as plate contacts. 2023PF 12576

[0048] 8

[0049] Considering the direction of movement of the first switching contact, the contact disc of the first switching contact is located on the side of the first switching contact that faces the second switching contact. The same applies to the second contact disc of the second switching contact, which is also oriented towards the first switching contact.

[0050] Specifically, the contact discs can each be separate parts for the switching contacts.

[0051] Alternatively, the contact discs can be a fixed or integral part of the switching contacts. In other words, the first switching contact and the first contact disc can be designed as a single piece or a (common) unit. The second switching contact and the second contact disc can also be designed as a single piece or a (common) unit.

[0052] For example, the first contact disc can be positioned on a section of the first switching contact that faces the second switching contact. The second contact disc can be positioned on a section of the second switching contact that faces the first switching contact.

[0053] In one embodiment, the two contact discs are made of an electrically conductive or semiconducting material. This allows the electrical connection to be established so that the vacuum switching tube can conduct current between the first and second terminals. For example, electrically conductive materials such as copper, tungsten, stainless steel, iron, a precious metal, aluminum, or a combination of these can be used. Particularly suitable electrically conductive materials include copper-chromium (CuCr), tungsten carbide (Wc), tungsten carbide silver (WcAg), tungsten carbide copper (WcCu), silicon carbide (SiC), Inconel, silver, gold, platinum, or palladium. Copper-chromium is especially preferred because it exhibits good electrical conductivity and low wear when the two contact discs come into contact.Other suitable materials, mixtures of substances or material combinations are also conceivable.

[0054] In one embodiment, it is provided that the first movable switching contact has a first metal bellows, wherein the first metal bellows is attached to the first 2023PF 12576

[0055] 9

[0056] The first switching contact is arranged, or the first switching contact has a first spring steel element. For example, the first metal bellows can be arranged on the first switching contact in such a way that the mechanical switching actuation can be transferred to the first switching contact in order to move it. In particular, the movement can be introduced into the vacuum region, i.e., into the tube housing, using the first metal bellows or a bellows. In other words, the first metal bellows serves to move the first switching contact accordingly within the tube housing, either to connect or disconnect the first switching contact from the second switching contact.

[0057] If necessary, the first metal bellows or the first spring steel element can be used for power transmission.

[0058] For example, the first metal bellows can be formed around the first switching contact, which might be rod-shaped. In other words, the first metal bellows can at least partially enclose the first switching contact. For instance, the first metal bellows can have a bellows cap, which can be implemented as an end cap of the first metal bellows facing the second switching contact. Outside the first metal bellows is the contact disc of the first switching contact, which establishes the electrical connection.

[0059] In one embodiment, the second switching contact is movably arranged within the tube housing. Based on the mechanical actuation, the first and second switching contacts are movable to establish or break the electrical connection between them. In other words, depending on the requirements of the DC application of the vacuum switching tube, both switching contacts can be designed to be movable. This allows for even faster switching of the contacts, as both can be moved towards or away from each other, particularly synchronously. In this embodiment, the first and second switching contacts together can represent a maximum of 80%, particularly 60%, and preferably 40% of the total mass of the vacuum switching tube.This means specifically that the mass of the second switching contact corresponds to a proportion in the range of 1% to 40% of the total mass of the vacuum switching tube. For example, in a particular embodiment, the combined masses of the two switching contacts can correspond to a maximum of 40% of the vacuum switching tube. In particular, the first and second switching contacts can be identical. 2023PF 12576.

[0060] 10

[0061] In one embodiment, the second movable switching contact has a second metal bellows, with the second metal bellows being arranged on the second switching contact, or the second switching contact has a second spring steel element. In particular, the second metal bellows can be designed analogously to the first metal bellows. For example, the second metal bellows can be arranged on the second switching contact such that the mechanical actuation can be transferred to the second switching contact to move it. In particular, the movement can be introduced into the vacuum region, i.e., into the tube housing, using the second metal bellows or a bellows. In other words, the second metal bellows serves to move the second switching contact within the tube housing to either connect or disconnect the first switching contact from the second.If necessary, the second metal bellows or the second spring steel element can be used for power transmission.

[0062] The invention also includes combinations of the features of the described embodiments.

[0063] The embodiments described below are preferred embodiments of the invention. In these embodiments, the described components each represent individual features of the invention that can be considered independently of one another. Each of these features further develops the invention independently and can therefore be considered part of the invention individually or in a combination other than that shown. Furthermore, the described embodiments can also be supplemented by other features of the invention already described.

[0064] In the figures, functionally identical elements are each provided with the same reference symbols.

[0065] The following figures illustrate this in:

[0066] FIG 1 shows a schematic representation of a vacuum switching tube, which has a movable and a fixed switching contact; 2023PF 12576

[0067] 11

[0068] FIG 2 shows another schematic representation of the vacuum switching tube from FIG 1;

[0069] FIG 3 shows a schematic representation of an embodiment of the vacuum switching tube from FIG 1, where a disc-shaped insulator is used;

[0070] FIG 4 shows a schematic representation of another embodiment of the vacuum switching tube from FIG 1, wherein a hollow cylindrical insulator is used and a spring steel element is arranged in the area of ​​the movable switching contact;

[0071] FIG 5 shows a schematic representation of another embodiment of the vacuum switching tube from FIG 4, wherein a metal bellows is arranged in the area of ​​the movable switching contact;

[0072] FIG 6 shows a schematic representation of another embodiment of the vacuum switching tube from FIG 4, wherein two movable switching contacts are used, both switching contacts having a spring steel element or a metal bellows;

[0073] FIG 7 shows a schematic representation of an arrangement of a shielding of the vacuum switching tube, in which shielding elements are arranged opposite each other;

[0074] FIG 8 shows a schematic representation of an alternative arrangement of the shielding of the vacuum switching tube, in which the shielding elements are arranged overlapping each other;

[0075] FIG 9 shows a schematic representation of an arrangement of a spring steel element of a movable switching contact of the vacuum switching tube; and

[0076] FIG 10 shows a schematic representation of an arrangement of a metal bellows and a flange of a movable switching contact of the vacuum switching tube. 2023PF 12576

[0077] 12

[0078] Figure 1 shows an exemplary and, in particular, illustrative representation (in a sectional view) of a vacuum interrupter 1 as an interrupting unit of, for example, a DC voltage switch. The vacuum interrupter 1 can be electrically connected to the, for example, DC voltage switch via connection sides 2, 3.

[0079] The vacuum switching tube 1 can be equipped such that, depending on a mechanical switching actuation 4, an electrical connection between the terminal sides 2 and 3 can be established. For this purpose, the vacuum switching tube 1 can have a first switching contact 6 movably arranged in a tube housing 5 of the vacuum switching tube 1. A vacuum can be present in the tube housing 5. The movable, and in particular electrical, first switching contact 6 can be moved such that it establishes or breaks a galvanic contact and thus a galvanic connection with a correspondingly opposite second switching contact 7, i.e., a mating contact. The mechanical switching actuation 4, which serves to switch the vacuum switching tube 1, can be provided or generated by a drive unit, in particular a switching unit 8.

[0080] For example, the first connection side 2 can be formed by an end region of the first switching contact 6, which is oriented opposite to the second switching contact 7. It would also be conceivable that the end region of the first switching contact extends within the first connection side 2 as a separate part.

[0081] Optionally, the second connection side 3 can be formed by an end section of the second switching contact 7, which is oriented opposite to the first switching contact 6. It would also be conceivable for the end section of the second switching contact to extend within the second connection side 3 as a separate part.

[0082] The first switching contact 6 can be moved in a corresponding direction 9 based on the mechanical switching actuation 4. The direction of movement 9 can, for example, be parallel to a longitudinal axis L or a main extension plane of the vacuum switching tube 1. Thus, the two switching contacts 6, 7 are arranged opposite each other parallel to the longitudinal axis.

[0083] With respect to the longitudinal axis L, the vacuum switching tube optionally has the greatest extent. 2023PF 12576

[0084] 13

[0085] As schematically shown in FIG. 1, the two switching contacts 6, 7 are arranged opposite each other. An electrical connection between the two switching contacts 6, 7 can be established by moving the first switching contact 6.

[0086] As shown by way of example in FIG. 1, the switching contacts 6, 7 can be designed as contact bars or contact rods, which can in particular be rod-shaped or tubular. It is also conceivable that they are designed as current paths or current path elements.

[0087] Furthermore, the tube housing 5 can have one or more electrical shields 10. Thus, shielding can be provided for the tube housing 5. The shields 10 are, in particular, electrically conductive components.

[0088] The vacuum interrupter 1 can be designed, in particular in terms of shape, dimensions, size, and / or mass, to handle a rated current of up to 4 kA, a fault current of up to 20 kA, and switching times of around 2 ms. To meet these DC voltage requirements, the movable, heaviest switching contact 6 is specifically designed accordingly. Compared to previous vacuum interrupters, especially AC switching tubes, this contact is significantly lighter. Specifically, the movable first switching contact 6 has a mass, or weight, of its own. The mass of the first switching contact 6 corresponds to, or is in the range of 1% to 40% of, the total mass of the vacuum interrupter 1. This lower mass of the movable first switching contact 6 allows switching operations to be performed more efficiently, and in particular faster, since a much smaller mass needs to be moved.A ratio of 1 to 3, 1 to 6, preferably 1 to 10, between the mass of the first switching contact 6 and the total mass of the vacuum switching tube 1 is particularly advantageous.

[0089] Due to the lower mass of the first switching contact 6, the movements or strokes based on the mechanical switching actuation 4 can be carried out more quickly, since the mass to be moved is smaller. 2023PF 12576

[0090] 14

[0091] For rapid switching, the two switching contacts 6, 7 are arranged such that, in an electrically isolated state, they are positioned at a predetermined distance 11 from each other. This distance 11 is predetermined based on voltage and / or switching time requirements for the DC application of the vacuum interrupter 1. Because the vacuum interrupter 1 is used as a DC switching tube for DC applications, the return voltage upon separation of the switching contacts 6, 7 is lower, depending on the topology of the DC circuit breaker used, thus allowing for a smaller stroke of the first switching contact 6. The tube housing 5 has, in particular, an outer surface 12.

[0092] The outer surface 12 serves in particular as electrical insulation or as an electrical insulator for the vacuum switching tube 1. The vacuum switching tube 1, and in particular the tube housing 5, are designed to be cylindrical or tubular, so that the outer surface 12 can be formed as a cylindrical ceramic or cylindrical insulator. The outer surface 12 can be made of an electrical insulating material. For example, insulating ceramics can be used. In particular, an insulator 19 can be arranged on the outer surface 12.

[0093] For efficient current transmission between the contacted switching contacts 6, 7, the two switching contacts 6, 7 have electrical contact discs 13, 14. These can be plate-shaped, i.e., plate contacts. To establish the electrical connection, the first switching contact 6 is moved towards the second switching contact 7 until the two contact discs 13, 14 touch. This creates a planar connection. To achieve good electrical contact and simultaneously minimize wear when the contact discs 13, 14 come into contact or separate, the contact discs can be made of an electrically conductive material such as copper, tungsten, stainless steel, iron, or a precious metal, or a combination thereof.

[0094] In a further embodiment of the vacuum switching tube 1, in addition to the first switching contact 6, the second switching contact 7 can also be designed to be movable. Thus, based on the mechanical switching actuation 4 with the direction of movement 9 2023PF 12576

[0095] 15 Both switching contacts 6, 7 are moved to connect both switching contacts 6, 7 electrically and physically to each other or to cause an electrical and physical separation.

[0096] Furthermore, the vacuum switching tube 1 can have a first flange 15. This flange can be disc-shaped and / or cylindrical, depending on the design of the tube. The first flange 15 primarily serves for the nominal current transmission.

[0097] In this embodiment according to FIG. 1, the flange 15 serves specifically to attach or arrange the first switching contact 6 on the tube housing 5. In particular, the first flange 15 can have a corresponding opening through which the rod-shaped first switching contact 6 can be passed.

[0098] For example, the vacuum switching tube 1 can also be a first metal bellows.

[0099] 16 or bellows. This bellows, for example, as shown by way of example in FIG. 1, partially encloses the first switching contact 6, in particular exclusively the contact disc 13. With the aid of the metal bellows 16, the movement caused by the mechanical switching actuation 4 can be introduced into the vacuum region, i.e., into the tube housing 5. In particular, the metal bellows 16 can have a bellows cap 17, which encloses the bellows in particular towards the contact disc 13.

[0100] As an alternative to the metal bellows 16, a spring steel element 18 (see FIG 9) can be used.

[0101] The spring steel element 18 can assume a stable and a metastable, i.e., a bistable, state. The movement is introduced by actuating the spring steel element 18. This utilizes the principle of a "clicking frog." A clicking frog is a spring made from a strip of spring steel. The steel is shaped in such a way that it exhibits both a stable and a metastable state. Through the application of force, by the mechanical actuation 4, it is bent until it suddenly bulges and enters the metastable state. Thus, with minimal effort, the movement can be transferred to the first switching contact 6, in order to connect or disconnect the switching contact 6 from the second switching contact 7. 2023PF 12576

[0102] 16

[0103] In addition, current transmission can be carried out, for example, via the metal bellows 16 as well as via the spring steel element 18.

[0104] Figure 3 shows a schematic representation of another embodiment of the vacuum switching tube 1. Here, only one side of the vacuum switching tube 1 is shown as an example with respect to an axis of rotation R of the vacuum switching tube 1.

[0105] The axis of rotation R is directed parallel to the longitudinal axis L.

[0106] In this embodiment of the vacuum switching tube 1, the insulator 19 can be designed as a disc insulator 20, in particular a disc-shaped one. The disc insulator can be arranged on a lower housing 21 of the housing 5, within which the second terminal 3 extends. The disc insulator 20 can be arranged perpendicular to the axis of rotation R. Here, the disc insulator 20 can additionally be used to attach or fix the second switching contact 7, which in this embodiment is designed as a fixed, immovable contact, to the housing. In other words, in this example, the insulation can be provided perpendicular to the axis of rotation R. Furthermore, in this embodiment, a metallic wall element 22 can be arranged, in particular abutting, on the outer surface 12 of the tube housing 5, which extends parallel to a longitudinal axis L of the vacuum switching tube 1.In a cylindrical design of the tube housing 5, the metallic wall element 22 or a wall is in contact with an outer surface of the cylindrical tube housing 5. For example, the wall element can be at least partially formed by the first flange 15 of the first switching contact 6.

[0107] The screens 10 can be configured here as steam screens 26. Optionally, the screens 10 can be electrically connected to the first flange 15.

[0108] The spring steel element 18 for the first switching contact 6 is arranged on a housing top 23 opposite the housing bottom 21, within which the first connection side 2 can extend.

[0109] Figure 4 shows a schematic representation of another embodiment of the vacuum switching tube 1. Here, only one side of the vacuum switching tube 1 is shown as an example with respect to an axis of rotation R of the vacuum switching tube 1. 2023PF 12576

[0110] 17

[0111] In this embodiment of the vacuum switching tube 1, the insulator 19 is arranged on the outer surface 12 of the tube housing 5, which extends parallel to a longitudinal axis L of the vacuum switching tube 1. Here, the insulator 19 is designed as a hollow cylinder 24. The hollow cylinder 24 can partially, and in particular completely, enclose the outer surface of the cylindrical tube housing 5. Thus, the hollow cylinder 24 can form an outer, and in particular electrically insulating, termination (viewed from the outside) of the tube housing 5. The spring steel element 18 for the first switching contact 6 can again be arranged on the upper surface 23 of the housing, within which the first terminal side 2 can extend.

[0112] In addition to the shields 10, a special bellows shield 25 can be provided for the spring steel element 18. This can also be used for the metal bellows 16. The shields 10 can be arranged opposite each other, as shown, for example, in FIG. 7. Alternatively, the shields can also be arranged to overlap each other, at least partially, as shown, for example, in FIG. 8.

[0113] A second flange 27, particularly for the second switching contact 7, can be arranged on the underside 21 of the housing. The second flange 27 can be arranged perpendicular to the axis of rotation R. The second flange 27 can be used to attach or fix the second switching contact 7, which in this embodiment is designed as a fixed, immovable contact, to the tube housing 5. The second flange 27 can be cylindrical and / or disc-shaped.

[0114] The second flange 27 can serve as the bottom of the vacuum switching tube 1. The first flange 15 can serve as the cover of the vacuum switching tube 1.

[0115] The second switching contact 7 can have a first sub-section 28, which may be rod-shaped, and a second sub-section 29 immediately adjoining it. In this sectioned view with respect to the axis of rotation R, the two sub-sections 28, 29 can together form an L-shape. In the complete sectional view, as shown, for example, in FIG. 2, the switching contacts 6, 7 have a T-shape in their sectional view. 2023PF 12576

[0116] 18

[0117] The first sub-section 28 includes, in particular, the portion of the second switching contact 7 that extends to the second terminal side. The second sub-section 29 extends in the area of ​​the second contact disc 14. With respect to the axis of rotation R, the second sub-section 29 has a larger extent (i.e., perpendicular to the axis of rotation R). A gap 31 may exist between a side 30 of the second sub-section, which is arranged perpendicular to the second sub-section 28, and the second flange 27. This gap 31 may also be omitted.

[0118] Figure 5 shows a schematic representation of another embodiment of the vacuum switching tube 1. Here, only one side of the vacuum switching tube 1 is shown as an example, with respect to an axis of rotation R of the vacuum switching tube 1. Starting from the embodiment in Figure 4, the first metal bellows 16 is used for the first switching contact 6 instead of the spring steel element 18, as already explained with reference to Figure 1. A schematic representation of the design of the first metal bellows 16 in combination with the first flange 15 for the first switching contact 6 is shown in Figure 10.

[0119] Figure 6 shows a schematic representation of another embodiment of the vacuum switching tube 1. Here, only one side of the vacuum switching tube 1 is shown as an example, with respect to an axis of rotation R of the vacuum switching tube 1. Here, the second switching contact 7 can also be movable. The switching unit 8 allows the second switching contact 7 to be moved based on the mechanical switching actuation 4. In particular, both switching contacts 6 and 7 can be moved synchronously or simultaneously based on the mechanical switching actuation 4. In contrast to the embodiment in Figure 4, a second spring steel element 32 can be arranged on the underside 21 of the housing instead of the second flange 27. The second spring steel element 32 can be designed analogously to the first spring steel element 18. The second spring steel element 32 can, for example, have a bellows shield 33 as a shield.The explanations regarding the components of the first switching contact 6 can be applied analogously to the second switching contact if it is designed to be movable, as shown here.

[0120] To establish the electrical connection between terminals 2 and 3, the first switching contact 6 can be moved towards the second switching contact 7. The second switching contact 7 can be moved in the opposite direction to the first switching contact 6. For establishing and disconnecting the electrical connection, see 2023PF 12576.

[0121] 19

[0122] For the connection, the two movable switching contacts 6, 7 must be moved in opposite directions. The second switching contact 7 can be moved in a movement 34 opposite to the direction of movement 9. For example, in this embodiment, a metal bellows can be used instead of the two spring steel elements 18, 32.

[0123] With the vacuum switching tube 1 according to the preceding descriptions, a compact DC vacuum switching tube can be provided which can handle some fault switching cases with high short-circuit currents and many load switching operations with

[0124] can perform nominal current tests.

[0125] 2023PF 12576

[0126] 20

[0127] Reference symbol list

[0128] 1 vacuum switching tube

[0129] 2 first connection side

[0130] 3 second connection side

[0131] 4 mechanical switch actuation

[0132] 5 tube housings

[0133] 6 movable first switching contact

[0134] 7 second switching contact

[0135] 8 switching unit

[0136] 9 Direction of movement

[0137] 10 umbrellas

[0138] 11 distance

[0139] 12 Outside

[0140] 13 first contact disc

[0141] 14 second contact disc

[0142] 15 first flange

[0143] 16 first metal bellows

[0144] 17 Bellows cap

[0145] 18 first spring steel element

[0146] 19 Insulator

[0147] 20 disc insulators

[0148] 21 Underside of housing

[0149] 22 metallic wall element

[0150] 23 Top of case

[0151] 24 hollow cylinders

[0152] 25 Bellows screen

[0153] 26 vapor shield

[0154] 27 second flange

[0155] 28 first sub-area

[0156] 29 second sub-area

[0157] Page 30

[0158] 31 distance

[0159] 32 second spring steel element

[0160] 33 Bellows screen

[0161] 34 opposite direction of movement 2023PF 12576

[0162] 21

[0163] L Longitudinal axis

[0164] R axis of rotation

Claims

2023PF 12576 22 Patent claims 1. Vacuum switching tube (1) for making or breaking an electrical connection between two DC voltage terminals, comprising: - a first connection side (2) and a second connection side (3), wherein the first connection side (2) is electrically connectable to a first DC voltage terminal of the DC voltage terminals and the second connection side (3) is electrically connectable to a second DC voltage terminal of the DC voltage terminals, - a tube housing (5), - a first switching contact (6) movably arranged in the tube housing (5), which is electrically connected to the first connection side (2), wherein the first switching contact (6) has a ground, - a second switching contact (7) arranged in the tube housing (5), which is electrically connected to the second terminal side (3), wherein the first switching contact (6) and the second switching contact (7) are spaced apart from each other in the tube housing (5), and - a switching unit (8) which is configured to establish or disconnect an electrical connection between the first and second switching contacts (6, 7) on the basis of a mechanical switching actuation (4), whereby the electrical connection between the connection sides (2, 3) can be established or disconnected, characterized in that - the mass of the first switching contact (6) corresponds to a proportion in the range of 1% to 40% of the total mass of the vacuum switching tube (1).

2. Vacuum switching tube (1) according to claim 1 , characterized in that the mass of the first switching contact (6) corresponds to a proportion in the range of 1% to 30%, in particular in the range of 1% to 20%, of the total mass of the vacuum switching tube (1).

3. Vacuum switching tube (1) according to claim 1 or 2, characterized in that the first and second switching contacts (6, 7) are arranged spaced apart from each other in an electrically isolated state such that a predetermined distance (11) exists between the two switching contacts (6, 7), wherein the distance (11) can be predetermined on the basis of a voltage requirement and / or a switching time requirement. 2023PF 12576 23 4. Vacuum switching tube (1) according to one of the preceding claims, characterized in that the vacuum switching tube (1) has an insulator (19), wherein the insulator (19) is made of an insulating material, in particular the insulating material consists of aluminium oxide, chromium oxide, barium titanate, further insulating oxide ceramics or glass.

5. Vacuum switching tube (1) according to claim 4, characterized in that the insulator (19) is arranged on an outer side (12) of the tube housing (5), which extends parallel to a longitudinal axis (L) of the vacuum switching tube (1), in particular the insulator (19, 24) is cylindrical.

6. Vacuum switching tube (1) according to claim 4, characterized in that the insulator (19) is arranged on a housing top (23) of the tube housing (5) within which the first connection side (2) extends, or the insulator (19) is arranged on a housing bottom (21) of the tube housing (5) within which the second connection side (3) extends, in particular the insulator (19) is designed as a disc insulator (20).

7. Vacuum switching tube (1) according to claim 6, characterized in that a metallic wall element (22) is arranged on an outer side (12) of the tube housing (5), which extends parallel to a longitudinal axis (L) of the vacuum switching tube (1).

8. Vacuum switching tube (1) according to one of the preceding claims, characterized in that the first switching contact (6) has a first contact disc (13) and the second switching contact (7) has a second contact disc (14), wherein the two switching contacts (6, 7) are designed such that when an electrical connection is established between the two switching contacts (6, 7) the two contact discs (13, 14) are arranged abutting each other.

9. Vacuum switching tube (1) according to claim 8, characterized in that the two contact discs (13, 14) are made of an electrically conductive material, in particular the electrically conductive material consists of copper, chromium, carbon, tungsten, stainless steel, iron, a precious metal, aluminium, silicon or a combination of these materials. 2023PF 12576 24 10. Vacuum switching tube (1) according to one of the preceding claims, characterized in that the first movable switching contact (6) has a first metal bellows (16), wherein the first metal bellows (16) is arranged on the first switching contact (6), or the first switching contact (6) has a first spring steel element (18).

11. Vacuum switching tube (1) according to one of the preceding claims, characterized in that the second switching contact (7) is movably arranged in the tube housing (5), wherein, based on the mechanical switching actuation (4), the first and second switching contacts (6, 7) are movable in order to establish or disconnect the electrical connection between the two switching contacts (6, 7).

12. Vacuum switching tube (1) according to claim 11, characterized in that the second movable switching contact (7) has a second metal bellows, wherein the second metal bellows is arranged at the second switching contact (7), or the second switching contact (7) has a second spring steel element (32).

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