Switchgear arrangement

Abstract

Switchgear arrangement comprising an interrupter unit (2) with a first switching contact piece (7, 9) and a second switching contact piece (8, 10), which are movable relative to one another, and with a switching gas channel originating in a switching path that can be formed between the switching contact pieces (7, 8, 9, 10), which channel runs through the interrupter unit (2) and connects the switching path with the surroundings of the interrupter unit (2) and is delimited at least in sections by mutually encompassing elements in the manner of an annular channel, wherein a first body (17) clamped at the end in the manner of a pipe socket as an element with a free end projecting towards the switching path, characterized in that the first body (17) has at least one recess (19) on the shell side, which is covered by a cover (16) in the radial direction.

Description

The invention relates to a switching device arrangement comprising an interrupter unit having a first switching contact piece and a second switching contact piece, which can be moved relative to one another, and having a switching gas channel which originates in a switching path which can be formed between the switching contact pieces and runs through the interrupter unit and connects the switching path to the environment of the interrupter unit and is bounded at least in sections by mutually engaging elements in the manner of an annular channel.Such a switching device arrangement is known, for example, from the patent specification DE 102 21 580 B3. The switching device arrangement there has an interrupter unit with a switching section which can be formed between a first and a second switching contact piece. A switching gas channel emerges in the switching section. The switching gas channel extends through the interrupter unit and connects the switching section to an environment surrounding the interrupter unit. The switching gas channel is formed in sections from elements encompassing each other, whereby the switching gas channel is shaped in sections in the manner of an annular channel.In order to lengthen the flow path in the case of axial limitation, a change of direction of the switching channel is provided in the known arrangement. In order to effect the change of direction, different elements overlap one another, wherein in part in the region of the overlap a screwing and connection of the elements is provided in each case. This produces a torsionally rigid structure which gives the interrupter unit stability. However, the cross section of the switching gas channel is reduced in the connecting region. Thus, in the course of the switching gas channel, sections with an increased flow resistance are produced. At these points, jams of the outflowing switching gas occur, as a result of which back-pressure waves can develop within the interrupter unit. Such back pressure waves can fall back into the switching path, as a result of which the switching behavior of the switching device arrangement is influenced. Further switching device arrangements are known from EP 1 768 150 A1 and WO 2011 / 067 122 A1.It is therefore an object of the invention to provide a switching device arrangement which enables improved outflow of switching gas from the switching section.According to the invention, this is achieved in a switching device arrangement of the type mentioned at the beginning in that a first body is clamped at the end side in the manner of a pipe socket as an element with a free end protruding towards the switching section.An annular channel is a channel which provides a cross section for the flow of a gas, which cross section runs annularly around a central section in a closed manner. Such annular channels can have, for example, a circular ring-shaped cross section, but can also have strip-shaped closed cross sections of any other shape. Thus, an annular channel can also have, for example, an oval annular cross section, a polygonal annular cross section or other ring shapes in cross section. An annular channel makes it possible to provide a space centrally for receiving modules and to encase these modules on all sides with the switching gas channel, so that a cross section as large as possible is available for discharging switching gas from the switching section. The switching gas channel has an inlet opening in the region of the switching section in order to be able to absorb switching gas from the switching section. Switching gas flows through the inlet opening into the switching gas channel. An inlet opening can be bounded, for example, at least partially by one of the switching contact pieces.It is also possible to entangle the switching gas channel itself and, for example, by reversing the direction, to deflect the switching gas channel from a central region into the annular region and to achieve a flow path extension. It can also be provided that several successive annular sections of the switching gas channel engage around one another.Switching gases occurring in the switching section can be discharged via the switching gas channel during a switching process. The switching section is the section / space of the interrupter unit within which contact / disconnection of contact regions of the switching contact pieces movable relative to one another takes place. The switching section can be surrounded by a switching chamber, so that an arc, which may burn in the switching section, is surrounded by a wall.A switching operation is initiated by a relative movement of the switching contact pieces with respect to one another. The switching contact pieces are movable relative to one another, for example, in order to interrupt a current path or to establish a current path. For this purpose, the switching contact pieces are removed from one another for interrupting an existing galvanic contacting and moved towards one another for switching on until there is sufficient galvanic contacting of the switching contact pieces. During a switching process, an arc can be ignited. The switching contact pieces can preferably be designed as power contact pieces. Power contact pieces are switching contact pieces which are configured to conduct an arc on their surfaces, wherein the material selection for the switching contact pieces is carried out in such a way that a thermal effect of the arc is as resistant as possible. For example, it can be provided that the switching contact pieces are designed as so-called arc contact pieces, which are arranged electrically parallel to rated current contact pieces. The arc contact pieces have the task of contacting each other before the rated current contact pieces during an activation process and separating from each other after the rated current contact pieces during an deactivation process. This ensures that, during an activation process, an activation arc occurs preferably on the arc contact pieces / switching contact pieces, and deactivation arcs that occur during an deactivation process are likewise preferably guided on the arc contact pieces / switching contact pieces.An arc / switching arc heats its environment. Overheating and expansion of gases and / or evaporation of solid or liquids can occur. The heated medium is called switching gas and is preferably discharged from the switching section via the switching gas channel. The switching gas channel discharges the switching gas from the interior of the interrupter unit into the environment of the interrupter unit. This ensures that the switching gas, which may also contain combustion products, soot particles and other undesirable impurities, does not precipitate as desired in the interior of the interrupter unit. Preferably, a large proportion, as far as possible the entire switching gas, is led out of the interrupter unit. For this purpose, the switching gas channel is arranged within the interrupter unit.For example, it can be provided that the switching contact pieces are surrounded by an electrically insulating fluid. For example, insulating liquids such as oils and esters, but also insulating gases such as sulfur hexafluoride gas and nitrogen gas, can be used. Advantageously, the fluid which washes around the switching contact pieces can be under an overpressure. The excess pressure can additionally increase the electrical strength of the electrically insulating fluid. It can be provided that the interrupter unit is surrounded by an encapsulating housing, within which the electrically insulating fluid is enclosed. Thus, uncontrolled volatilization of the electrically insulating fluid from the interrupter unit is made more difficult.The environment of the breaker unit is bounded by the encapsulating housing, i.e. the breaker unit itself is arranged inside the encapsulating housing. The electrically insulating fluid washes around and washes through the interrupter unit. Between the interrupter unit and the encapsulating housing there is an insulation section which acts in an electrically insulating manner by the electrically insulating fluid. The region for receiving the fluid between interrupter unit and encapsulating housing is the environment of the interrupter unit. It is thus possible to lead the contaminated switching gas out of the interrupter unit into its surroundings via the switching gas channel and to enable swirling and mixing there with electrically insulating fluid located there. As a result, weakening of the electrical insulation of the interrupter unit can be reduced to a permissible extent.Due to the tubular connection-like configuration of a first body which is clamped at the end, the latter can project with its free end as self-supporting as possible and free of further attachments with its free end in the direction of the switching section. This creates a wall along which the switching gas can flow with as little resistance as possible on the inside and / or on the outside shell side. Clamping at the end is provided when the body is clamped and held on one side outside a central region, with respect to a longitudinal axis. The first body is supported and supported via the restraint. Preferably, the first body is positioned exclusively via an end clamping. Holding of the first body is preferably effected at an end face. Thus, the pipe socket-like first body can freely project into a volume which is flooded with electrically insulating fluid, for example. If the first body bears exclusively itself, this can contribute only to a limited extent to a mechanical stabilization or stiffening of the interrupter unit. The body can provide a wall inside the interrupter unit for delimiting the switching gas channel. The resistance of the first body is to be designed in such a way that there is sufficient resistance force with respect to the incoming or incoming switching gas. This switching gas can have a temperature increase of several 100° C. and also collide with the first body with an overpressure.The first body can have, for example, a hollow cylindrical structure, wherein a cylinder axis corresponds to the longitudinal axis of the body. The first body may be formed of electrically conductive material. Preferably, the body can be configured rotationally symmetrically cylindrically, so that it substantially corresponds to a hollow cylinder with a circular ring cross section, which is clamped at the end and protrudes freely into a space as a connecting piece. Preferably, a pipe socket can define the path of the switching gas channel both on the inner jacket side and on the outer jacket side. A flow through a hollow cylindrical body can be provided on the inner jacket side and on the outer jacket side with opposite direction (for example along a cylinder axis). In addition, in contrast to a cylindrical shape, any other shape of the body can also be provided, wherein the body extends along an axis from its clamping in the direction of the switching path and an annular channel of any cross section is bounded between the first body and an encircling element or an encircling element.A further advantageous embodiment can provide that the first body is surrounded by a cap acting as an element, which extends over the free end of the first body.A cap engages around and covers the first body on the outer jacket side, so that the first body is protected from direct access from the outside. Advantageously, the projection should delimit the outer contour of the interrupter unit at least in sections, wherein the switching gas channel opens out in the vicinity of the interrupter unit. The cap engages around a longitudinal axis of the first body. The projection protrudes beyond at least the free end of the first body in the axial direction. In particular, the projection can completely project / span the first body in the axial direction. The projection can be designed in particular advantageously in the shape of a bell, so that a further radial extension of the projection is provided in a base region than at an opposite, tapered end, so that the projection covers the first body on the one hand on the casing side and on the other hand at the tapered end at least partially on the end side. The projection can have a conical contour. In addition, the base region can have a radially widening protrusion. The projection can be formed substantially rotationally symmetrically and can be aligned substantially coaxially with respect to a longitudinal axis of the interrupter unit. The projection can serve, for example, to let the switching gas channel open out in the vicinity of the interrupter unit. An opening opening of the switching gas channel can be arranged on the cap in such a way that the opening opening has a shape, for example, which is substantially annular or ring segment-shaped. The opening can preferably be aligned coaxially with the longitudinal axis of the interrupter unit. Switching gas should preferably escape into the environment in the direction of the longitudinal axis. Advantageously, the first body and the projection should be formed rotationally symmetrically. By coaxial arrangement of the first body and the cap, a uniform shaping of the cross section of the switching gas channel can thus be effected. At the free end of the first body, which is overlapped, for example, by the projection in both the axial and radial directions, it is possible to deflect the switching gas channel in its direction and to carry out a deflection by, for example, twice 90°. For example, the switching gas channel can run essentially along a longitudinal axis, wherein an extension of the switching gas channel can be provided alternately with different directional directions along the longitudinal axis. For example, meandering of the switching gas channel can be effected. It can also be provided, in particular in the case of a coaxial configuration of the structures, to initially have the switching gas channel run centrally and to force a radial jumping of the switching gas channel with a change of direction, so that, starting from a center, for example, a plurality of hollow cylindrical sections of the switching gas channel are arranged successively in the form of a shell. Thus, for example, the wall of the first body can advance the switching gas channel in a first direction (for example in the direction of the longitudinal axis) on the inner jacket side and on the outer jacket side, wherein the switching gas channel runs with the opposite direction direction on the inner jacket side and on the outer jacket side.A further advantageous embodiment can provide that a second body acting as an element is clamped on the projection, which body projects like a pipe socket with a free end in the direction of the first body.A second body, which is likewise designed like a pipe socket, makes it possible to clamp the first body and the second body on each end, with free ends of the first and second body projecting toward one another. It is thus possible to configure a shell-like, radially widening switching gas channel. The walls of the first and of the second body, which serve to subdivide the interior of the projection into different travel paths of the switching gas duct, can thus freely project relative to one another. The interior of the cap remains free of holding and supporting elements. Thus, the switching gas channel between the end-side clampings of the first and second bodies can be formed with correspondingly low flow resistance. The clamping of the second body serves for supporting and positioning the second body on the cover. This is advantageously the only holder for the second body. The end constraints may be positioned at opposite ends of the two bodies. In particular when using rotationally symmetrical structures for the first and the second body, the two bodies can be aligned coaxially with respect to one another, so that holding and positioning of the two bodies is provided on ends facing away from one another on the first body and on the second body. The space located between the end-side holding points of the first and second bodies can thus be filled with walls for shaping the switching gas duct in an almost freely selectable manner. The configuration of the second body is not limited to a pipe socket. For example, only a portion of the second body can be formed in the manner of a pipe socket, wherein the pipe socket-like portion of the second body protrudes free from the clamping into the space. Furthermore, further add-on portions can also be provided on the second body. The same applies to the first body. The second body, like the first body, may be electrically conductive. Bodies made of cast metal have proven to be advantageous.A further advantageous embodiment can provide that mutually protruding free ends of the first and second bodies overlap one another.If the free ends of the first and second bodies overlap one another, an additional extension of the travel distance of the switching gas channel inside the interrupter unit is made possible in a simple manner. For example, the second body can be surrounded on the outer jacket side by the first body. However, it can also be provided that the first body is surrounded on the outer jacket side by the second body. In the axial direction, the two bodies overlap, so that a section can be formed here, in which the switching gas channel is bounded between the first and second bodies in the manner of an annular channel. Advantageously, it should be provided that both the first body and the second body as well as the projection are arranged in a spatially invariable manner relative to each other. As a result, the geometry of the switching gas channel is maintained and switching gas can be discharged along the switching gas channel from the switching section into the environment of the interrupter unit.Overlapping of the two bodies can be more or less pronounced as required, so that an annular channel-shaped section of the switching gas channel between the first and second bodies can be embodied to be more or less long in the axial direction.A further advantageous embodiment can provide that the projection is supported on the first body.Supporting the collar makes it possible to support the first body itself in an electrically insulated manner, for example, wherein the collar is in turn supported on the first body. Thus, the fastening of the first body and the fastening of the cover can take place in each case on the same end-side region of the cover or of the first body. The cap and the first body may have the same electrical potential. An opening opening of the switching gas channel can be provided in the region of the support of the projection on the first body. Advantageously, the mouth opening can be arranged between the first body and the projection to be limited by the latter. Advantageously, the collar can be supported exclusively on the first body and supported by the latter.Furthermore, it can advantageously be provided that the second body carries a contact piece.The second body can advantageously serve as a contact carrier for switching contact pieces, so that the switching path, i.e. the region in which a switching path is located between the switching contact pieces, can extend as far as / into the first body and can be bounded by the first body. The second body, like the projection, can be part of the current path to be switched by the switching device arrangement. A switching contact piece carried by the second body can be designed as a rated current contact piece, arc contact piece, etc.Supporting the second body on the collar makes it possible to use the collar as a supporting structure for the second body, wherein the collar itself is mounted in a fixed position. For example, it is thus possible to connect the projection at one end to the first body, to clamp it on opposite ends (relative to a longitudinal axis) of the projection, and to connect and clamp the second body at the other opposite end of the projection to the projection. The projection can thus form a section of the interrupter unit as an outer enveloping contour. The projection can serve as a supporting structure for the second body and furthermore provide a wall for forming the switching gas channel.Furthermore, it is provided that the first body has on the jacket side at least one recess covered by the projection in the radial direction.By introducing at least one recess into the first body, it is possible to arrange bypasses in the course of the switching gas channel, so that parts of the switching gas passing through the switching gas channel are conducted over shortened travel distances from the switching path in the direction of the opening opening of the switching gas channel of the interrupter unit. It is thus possible, for example, to swirl and displace electrically insulating gas present within the switching gas channel with the outflowing switching gas as quickly as possible over a large length of the switching gas channel before a switching action occurs. The casing-side recess can extend through the first body, for example, in the form of an elongated hole or a circular recess, wherein, due to the arrangement of the projection in the radial direction, i.e., in the direction of passage of the switching gas through the recess, the recess is covered at a distance from the projection. This results in a deflection and deflection of the switching gas and prevents a direct radial outflow of the switching gas into the environment.A further advantageous embodiment can provide that the first body is supported in an electrically insulated manner on a housing surrounding the interrupter unit.Supporting the first body on a housing surrounding the interrupter unit makes it possible to position further assemblies starting from the first body. Thus, for example, the collar can be supported on the first body, wherein the second body is again supported on the collar. This results in a chain of support points which, although spaced apart from one another, are arranged angularly fixed to one another via one and the same common support mechanism. For electrically insulated support, the use of an insulating body can be provided. For example, a pillar-shaped support insulator may be used. The housing can be, for example, an encapsulating housing which encapsulates and hermetically seals a fluid which flushes and flushes the interrupter unit. The electrically insulating insulator extends through the environment of the interrupter unit, which is located between interrupter unit and encapsulating housing and is filled with the electrically insulating fluid.Furthermore, it can advantageously be provided that the projection is supported in an electrically insulated manner on a housing surrounding the interrupter unit.The projection can be supported directly on the surrounding housing. The projection can be supported directly on the housing. However, indirect support of the projection on the housing can be provided. For example, the projection can be formed as part of a current path for supplying an electric current to the switching contact pieces, wherein the projection is connected in an angularly fixed manner to further current path sections which are in turn supported on the encapsulating housing. The cap can thus also be supported indirectly in an electrically insulated manner with respect to the housing via further assemblies.An exemplary embodiment of the invention is shown schematically in a drawing below and described in more detail below.The figure showsFIG. shows a section through a switching device arrangement with a breaker unit.The switching device arrangement has a housing 1. The housing 1 is designed in the present case as a hermetically sealable encapsulating housing which accommodates a switch unit 2 in its interior. The housing 1 is designed in the present case as a metallic cast housing which provides a fluid-tight wall. The interior of the housing 1 is filled with an electrically insulating fluid, for example an electrically insulating gas, such as sulfur hexafluoride or nitrogen. Preferably, the housing 1 should be designed as a pressure vessel, so that the fluid located inside can also be placed under an overpressure. The housing 1 has a first connector 3 and a second connector 4. It is possible to introduce a first and a second current path section 5 a, 5 b,in each case electrically insulated and spaced apart from the housing 1, into the interior of the housing 1 by means of the stubs 3, 4. The current path sections 5 a, 5 bmay be electrically contacted to one another via the interrupter unit 2 of the switching device arrangement, or a connection between the two current path sections 5 a, 5 bmay be interrupted by means of the interrupter unit 2. Not shown in the figure is the fluid-tight termination of the housing 1 with respect to the current path sections 5 a, 5 b. For example, the stubs 3, 4 can be closed by means of electrically insulating assemblies (which are each penetrated by the current path sections 5 a, 5 b), so that the interior of the housing 1 is hermetically sealed. As electrically insulating assemblies, free air feedthroughs can be provided, for example, which allow integration of the switching device arrangement, for example, into a free air switching system.The housing 1 is charged with ground potential and supported on a foundation via support feet. The interrupter unit 2 is arranged in the interior of the housing 1. The interrupter unit 2 extends along a longitudinal axis 6. The first switching contact piece 7 is presently designed bolt-shaped and aligned substantially coaxially to the longitudinal axis 6. The second switching contact piece 8 is shaped like a socket and is also arranged coaxially to the longitudinal axis 6. The contact regions of the first and second switching contact pieces 7, 8 face each other, wherein the dimensioning of the first and second switching contact pieces 7, 8 is selected such that, in the event of a relative movement of the two switching contact pieces 7, 8 along the longitudinal axis 6, the bolt-shaped first switching contact piece 7 can be moved into the socket-shaped second switching contact piece 8.The two switching contact pieces 7, 8 are formed as arcing contact pieces of the switching device arrangement. Accordingly, the first switching contact piece 7 is supplemented by a first rated current contact piece 9. The second switching contact piece 8 is supplemented by a second rated current contact piece 10. The first switching contact piece 7 and the first rated current contact piece 9 and the second switching contact piece 8 and the second rated current contact piece 10 are galvanically contacted with one another, so that mutually associated contact pieces permanently carry the same electrical potential. In the present case, the rated current contact pieces 9, 10 are of tubular configuration and are aligned coaxially with respect to the longitudinal axis 6, wherein the switching contact pieces 7, 8 are surrounded on the outer shell side by their respectively assigned rated current contact piece 9, 10. In the case of an activation process, it is provided that first the switching contact pieces 7, 8 contact one another, whereupon the two rated current contact pieces 9, 10 contact one another subsequently. In the case of a disconnection process, firstly a disconnection of the rated current contact pieces 9, 10 is provided, whereupon a disconnection of the switching contact pieces 7, 8 takes place in chronological succession. During an activation process, the switching contact pieces 7, 8 lead in relation to the rated current contact pieces 9, 10. During a disconnection process, the switching contact pieces 7, 8 retract relative to the two rated current contact pieces 9, 10. The switching contact pieces 7, 8 and the rated current contact pieces 9, 10 are each held electrically insulated at a distance from the housing 1.The second rated current contact piece 10 is mounted in a sliding bushing 11 such that it can be displaced along the longitudinal axis 6. The sliding bushing 11 is electrically conductively connected to the second rated current contact piece 10. The sliding bushing 11 is equipped with a circular cylindrical cross section and is arranged coaxially to the longitudinal axis 6. On the outer jacket side, a first support insulator 12 ais attached to the sliding bushing 11, which insulator holds the sliding bushing 11 on the jacket side in an electrically insulated manner with respect to the housing 1. The second rated current contact piece 10 and the second switching contact piece 8 are arranged at an angle fixed with respect to one another. Accordingly, a movement of the second rated current contact piece 10 is accompanied by a movement of the second switching contact piece 8.In order to couple a movement into the interior of the housing 1 and to bring about a relative movement between the two switching contact pieces 7, 8, a shaft 13 passes through a wall of the housing 1 in a fluid-tight manner. The shaft 13 is rotatably mounted, so that a drive movement can be transmitted fluid-tightly into the interior of the housing 1 via a drive device arranged on the outer side of the encapsulating housing 1. On the shaft 13, a pivot lever 14 is arranged on the inner wall side. By means of the pivot lever 14, a rotational movement of the shaft 13 can be converted by means of a connecting rod 15 into a linear movement along the longitudinal axis 6. The connecting rod 15 is connected to the second rated current contact piece 10. It is thus possible for the second rated current contact piece 10 and the second switching contact piece 8 to be displaced guided in the sliding bushing 11 along the longitudinal axis 6. A contact region is arranged on the sliding bushing 11 in order to electrically conductively contact the second current path section 5 bto the second rated current contact piece 10 or the second switching contact piece 8 via the sliding bushing 11.For positioning the first rated current contact piece 9 and the first switching contact piece 7, a projection 16 is provided. The projection 16 has a bell-shaped structure, wherein the projection base expands radially at its end facing away from the second rated current contact piece 10 or the second switching contact piece 8. On the jacket side, a contact region is arranged on the projection 16, into which the first current path section 5 aprotrudes, such that the projection 16 can be electrically contacted. The projection 16 thus becomes part of a current path to be switched. The projection 16 is formed substantially rotationally symmetrically, wherein the axis of rotation is arranged congruently with the longitudinal axis 6.Furthermore, a second support insulator 12 bis provided, which in the present case is designed as a rotationally symmetrical hollow support and is arranged coaxially to the longitudinal axis 6. A first body 17 is attached to the second support insulator 12 b, wherein the first body 17 is shaped substantially rotationally symmetrically and is aligned coaxially with the longitudinal axis 6. The cover 16 is again attached to the first body 17. The cap 16 engages around the first body 17 on the outer jacket side. The collar 16 can also be supported directly on the second support insulator 12 aand the first body 17 can be supported on the collar 16. It is also possible for both the collar 16 and the first body 17 to be supported directly on the second support insulator 12 a. The first body 17 is designed in the manner of a pipe socket, the pipe socket being fastened at the end and projecting freely with its free end into the interior of the projection 16 in the direction of the switching path which is formed between the switching contact pieces 7, 8 or the rated current contact pieces 9, 10. The first body 17 is closed at the end in the region of its clamping. With respect to the longitudinal axis 6, a support of a second body 18 on the cover 16 is provided at the end opposite the connection of the cover 16 to the first body 17. The cap 16 engages around the second body 18 on the outer jacket side, wherein the second body 18 is formed in sections as a pipe socket. The second body 18 or the pipe socket has an inlet opening of the switching gas channel. In the present case, the inlet opening is at least partially delimited by the rated current contact piece 9. The second body 18 is clamped on the cap 16, so that a pipe socket-like section is fixed. The pipe socket-like section of the second body 18 projects with a free end in the direction of the free end of the first body 17.The second body 18 serves as a support for at least one contact piece. In the present case, the first switching contact piece 7 and the second rated current contact piece 9 are supported on the second body 18. The second body 18 positions elastically deformable contact fingers so as to form a contact area of the first rated current contact piece 9. Correspondingly, the second body 18 is part of a current path of the switching device arrangement to be switched. The two bodies 17, 18 overlap each other with their ends of their pipe socket-like sections which are free from their clamping points. It is provided here that the second body 18 protrudes into the first body 17 and is surrounded on the outer jacket side by the first body 17. The second body 18 encompasses a switching gas channel which leads away from the switching section and projects into the interior of the first body 17. In the region of the overlap of the two bodies 17, 18, a deflection of the switching gas channel is provided, wherein between the two bodies 17, 18 the switching gas channel has a section with an annular channel-shaped structure. Furthermore, between the outer jacket of the second body 18 and the inner jacket of the cap 16, a further section of the switching gas channel is formed, which is formed in the shape of an annular channel. In the further course of the switching gas channel, a section of the switching gas channel is formed between the outer jacket of the first body 17 and the inner jacket of the cap 16, which section likewise has an annular channel-shaped structure. In the region of the fastening of the first body 17 to the second support insulator 2 b, an opening opening of the switching gas channel into the environment of the interrupter unit 2 is provided. The opening opening of the switching gas channel is preferably formed in the shape of a circular ring and is preferably aligned coaxially with the longitudinal axis 6. Instead of a circular ring-shaped structure, one or more segments of a circular ring can also be used as the orifice opening.The first body 17 has a plurality of recesses 19 on the casing side. The recesses 19 are aligned substantially radially with respect to the longitudinal axis 6, so that a radial outflow direction for switching gas exiting through the recesses 19 is defined. The recesses 19 are each covered on the outer jacket side by the projection 16, so that switching gas passing through the recesses 19 impinges against the projection 16 and is swirling and deflected there.The second switching contact piece 8 is surrounded on the outer jacket side by an insulating nozzle 20. The insulating nozzle 20 is in turn surrounded on the outer jacket side by the second rated current contact piece 10. The insulating nozzle 20 has an insulating nozzle channel into which the first switching contact piece 7 can be moved in order to be able to come into contact with the socket-shaped contact region of the second switching contact piece 8. In the present case, it is provided that both the first and the second switching contact piece 7, 8 are mounted in a spatially variable manner in order to bring about a relative movement of the switching contact pieces 7, 8 with respect to one another. In the case of the rated current contact pieces 9, 10, on the other hand, only a movable mounting of the second rated current contact piece 10 is provided, whereas the first rated current contact piece 9 is fixed in a fixed position on the projection 16. For driving the first switching contact piece 7, a reversing gear 21 is provided which is connected to the nozzle 20 of insulating material via a coupling rod 22. A movement of the second rated current contact piece 10 leads to a movement of the coupling rod 22, and a movement of the coupling rod 22 is transmitted to the first switching contact piece 7 via a coupling gear 21. The linkage 21 reverses the direction of movement of the linkage 22. The first switching contact piece 7 moves in the opposite direction to the second switching contact piece 8, and by using an insulating nozzle 20 which can be moved together with the second rated current contact piece 10 and the second switching contact piece 8, a movement can be transmitted to the first switching contact piece 7 in an electrically insulated manner. During an activation process, the second rated current contact piece 10 and the second switching contact piece 8 are moved in the direction of the first rated current contact piece 9 or the first switching contact piece 7. A movement with the opposite direction is transmitted to the first switching contact piece 7 via the nozzle 20, the coupling rod 22 and the reversing gear 21, so that an increase in the contacting speed of the two switching contact pieces 7, 8 takes place. This ensures that the switching contact pieces 7, 8 touch one another at a time before the rated current contact pieces 9, 10, so that inrush arcs are preferably guided on the switching contact pieces 7, 8. During a disconnection process, the second rated current contact piece 10 and the second switching contact piece 8 and the insulating material nozzle 20 fastened thereto move away from the first switching contact piece 7 and the first rated current contact piece 9. In this case, firstly the two rated current contact pieces 9, 10 are separated from one another and then the two switch contact pieces 7, 8 are separated from one another in time. A switching-off current is commutated accordingly from the rated current contact pieces 9, 10 to the switching contact pieces 7, 8, and any igniting arc is conducted between the switching contact pieces 7, 8. Due to the configuration of the insulating nozzle 20, an arc is preferably held within this insulating nozzle 20.Switching gas that is produced preferably flows away in the direction of the first switching contact piece 7. The switching gas is flowed into the switching gas channel which is initially delimited by the second body 18. The switching gas is radiated in the direction of the longitudinal axis 6. By means of an overpressure still prevailing in the switching section, a return flow of the switching gas is prevented. The switching gas then flows along the path of the switching gas channel against a closed end face of the first body 17 and is deflected and, on the one hand, is directed radially outwards through the recesses 19 of the first body 17. On the other hand, however, it is also pressed through the annular channel-shaped overlap region between the first and the second body 17, 18. From there, the switching gas flows further through the annular channel-shaped section which is formed between the outer circumferential surface of the second body 18 and the inner circumferential surface of the cap 16, in order to flow from this region, again with reversal of the direction, through an annular channel-shaped section of the switching gas channel which is bounded between the outer circumferential surface of the first body 17 and the inner circumferential surface of the cap 16. Finally, after the direction has been changed a number of times, the switching gas flows out of the interrupter unit 2 and flows into the environment of the interrupter unit 2, wherein the switching gas can be further mixed and fluidized with electrically insulating fluid located in the environment of the interrupter unit 2.

Claims

Switching device arrangement having an interrupter unit (2) with a first switching contact piece (7, 9) and a second switching contact piece (8, 10) which can be moved relative to one another, and with a switching gas channel which originates in a switching section which can be formed between the switching contact pieces (7, 8, 9, 10) and runs through the interrupter unit (2) and connects the switching section to the environment of the interrupter unit (2) and is bounded at least in sections by elements which engage around one another in the manner of an annular channel, wherein a first body (17), clamped at the end in the manner of a pipe socket, projects towards the switching section with a free end as an element, characterized in that the first body (17), on the casing side, has at least one recess (19) which is covered in the radial direction by a projection (16).Switching device arrangement according to Claim 1, characterized in that the first body (17) is surrounded by a cap (16) which acts as an element and which spans the free end of the first body (17).Switching device arrangement according to Claim 1 or 2, characterized in that a second body (18) acting as an element is clamped on the projection (16), said second body projecting in the manner of a pipe stub with a free end in the direction of the first body (17).Switching device arrangement according to Claim 3, characterized in that mutually projecting free ends of the first and second bodies (17, 18) overlap one another.Switching device arrangement according to one of Claims 2 to 4, characterized in that the projection (16) is supported on the first body (17).Switching device arrangement according to one of Claims 3 to 5, characterized in that the second body (18) carries a contact piece (7, 9).Switching device arrangement according to Claims 1 to 6, characterized in that the first body (17) is supported in an electrically insulated manner on a housing (1) surrounding the interrupter unit (2).Switching device arrangement according to Claims 2 to 7, characterized in that the projection (16) is supported in an electrically insulated manner on a housing (1) surrounding the interrupter unit (2).

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