Patent ID: 12237135

DETAILED DESCRIPTION

Aspects of the present disclosure provide an improved concept for a vacuum interrupter by means of which the vacuum interrupter is shielded from the disruptive influence of a surrounding external magnetic field and safe operation of the tap changer is ensured.

Aspects of the present disclosure are based on the idea of equipping the vacuum interrupter with a metal shield against external magnetic fields.

According one aspect, a vacuum interrupter for a tap changer is provided which comprises a metal shield against external magnetic fields and a holder.

The metal shield has a hollow cylindrical design and is arranged at least around a part of a cylindrical outer surface of the vacuum interrupter. The hollow cylindrical shield is preferably arranged centrally on the vacuum interrupter, at least over half the height of the cylindrical outer surface of the vacuum interrupter and in the axial direction of the latter. The shield can be designed as a single part or as multiple parts and is made, for example, from soft iron.

The holder is arranged on the outside of the metal shield and the vacuum interrupter and surrounds the metal shield and the vacuum interrupter at least partially coaxially. The vacuum interrupter is preferably surrounded coaxially by the holder over at least 240 degrees.

The holder furthermore has a plurality of holding elements which hold the metal shield in position relative to the vacuum interrupter.

According to at least one embodiment, the holding elements comprise at least two radially inward projecting protrusions which form a stop for a first end and a second end of the metal shield.

As a result, the metal shield is positioned on the vacuum interrupter in the axial direction of the latter, preferably centrally.

According to at least one further embodiment, at least one of the protrusions comprises a spacer which is arranged between the metal shield and the vacuum interrupter.

The spacer is designed as a wedge-shaped raised portion which is arranged radially inside on the at least one protrusion and extends in the axial direction of the vacuum interrupter. When the holder is mounted, the spacer is arranged between the shield and the vacuum interrupter and prevents the shield from bearing directly against the cylindrical outer surface of the vacuum interrupter.

According to at least one embodiment, the holding elements also comprise at least one radially inward projecting stud which projects in form-fitting fashion, i.e. so that it fits precisely, into an opening in the metal shield.

As a result, the shield is held in position and counteracts twisting of the shield relative to the vacuum interrupter.

According to at least one embodiment, the holder comprises at a first end and at a second end in each case at least one inward facing shoulder which bears in form-fitting fashion against the vacuum interrupter.

The shoulder can be formed radially on the circumference of the ends of the holder and/or be radially segmented, i.e. consisting of individual shoulders which are arranged spaced apart from one another and radially on the ends of the holder.

According to at least one embodiment, the holder comprises at the first end and at the second end in each case a plurality of radially inward extending braces which bear in form-fitting fashion against the vacuum interrupter. The holder is fixed in the axial direction of the vacuum interrupter by means of the braces.

According to at least one further embodiment, the holder consists of at least two segments which are designed in an identical fashion and each have a plurality of cross struts and longitudinal struts. The segments are preferably arranged so that they are rotated horizontally and vertically relative to each other by 180 degrees.

According to at least one further embodiment, the vacuum interrupter comprises a fastening ring which is mechanically connected to the holder in detachable fashion in such a way that the fastening ring can be pushed into the holder and can be locked therein by twisting.

The fastening ring is supported on its end side against the vacuum interrupter and fixes the holder in the axial direction of the vacuum interrupter by means of the locking mechanism.

According to the improved concept, a tap changer, in particular an on-load tap changer, is moreover provided which comprises at least one vacuum interrupter according to the improved concept.

According to at least one embodiment of the tap changer, the tap changer contains a diverter switch which comprises the vacuum interrupter, or a selector switch which comprises the vacuum interrupter.

Aspects of the present disclosure will be explained in detail below with the aid of exemplary embodiments with reference to the drawings. Components which are identical or functionally identical or have an identical effect can be provided with identical reference symbols. Identical components or components with an identical function are in some circumstances explained only with regard to the Figure in which they first appear. The explanation is not necessarily repeated in the subsequent Figures.

FIGS.1and2show a perspective illustration and an illustration in longitudinal section of an exemplary embodiment of a vacuum interrupter according to the improved concept of the present disclosure.

The vacuum interrupter1has a housing with a switching chamber8which is made, for example, from ceramic and has two walls9, for example made from metal, which are each arranged at the ends. The switching chamber8has a hollow cylindrical design and has a cylindrical outer surface. The walls9adjoin the ends of the switching chamber8and seal the latter airtightly.

The vacuum interrupter1has a fixed contact11and a contact12which can move axially relative to the vacuum interrupter. The contacts11,12are arranged in the switching chamber8. The vacuum interrupter1can be opened and closed by actuating the movable contact12.

A hollow cylindrical, metal shield12is arranged around a part of the vacuum interrupter1, to be more precise around a part of the cylindrical outer surface of the switching chamber8, along an axis A centrally with respect to the height of the switching chamber8.

A holder4surrounds the outside of the vacuum interrupter1and the shield2coaxially over approximately 240 degrees. The remainder of the vacuum interrupter1and the shield2are not affected by the holder4.

At the first end41and a second end42of the holder4, in each case a plurality of braces44are arranged which extend radially inward and, in the mounted state of the holder4, bear in form-fitting fashion against the vacuum interrupter1or the end-side walls9and consequently fix the holder4with respect to the axis A.

The holder4consists of two segments which have an identical design and have a plurality of cross struts13and longitudinal struts14. The two segments are arranged so that they are rotated horizontally and vertically relative to each other by 180 degrees.

FIG.3shows a perspective illustration of such a segment of the holder4in detail.

The holder4or the segments have holding elements by means of which they bear against the vacuum interrupter1or the switching chamber8and the walls9, as well as against the shield2.

A plurality of radially inward projecting protrusions5are arranged at the level of a first end21and a second end22of the shield2, on the radially arranged longitudinal struts14. They form an upper and a lower stop for the shield2and fix them with respect to the axis A.

Some of the adjacent protrusions5which are arranged at the level of the second end22of the shield2on the longitudinal struts14are connected to each other in such a way that additional partial struts15are formed. Spacers16are provided on the protrusions5which are connected to each other via partial struts15. They are designed as wedge-shaped raised portions which extend in the axial direction of the vacuum interrupter1, taper in the direction of the first end41of the holder4, and are arranged radially on the inside of the partial struts15of the protrusions5. In the mounted state of the holder4, the wedge-shaped raised portions are arranged between the shield2and the vacuum interrupter1, to be more precise the switching chamber8, in such a way that the shield2does not bear directly against the cylindrical outer surface of the shield2.

A further holding element represents a radially inward projecting stud6which is arranged centrally on one of the longitudinal struts14of the holder4. This stud6interacts in form-fitting fashion with an opening23in the shield2. Twisting of the shield2relative to the vacuum interrupter1is prevented as a result.

The segments of the holder4have in each case at the first end41and the second end42an inner collar43with a shoulder7which is arranged so that it faces radially and inward. The vacuum interrupter1or the end-side walls9of the vacuum interrupter1bears or bear against the shoulders7.

In order to stabilize the holder4on the vacuum interrupter1, a cable tie17is furthermore arranged in each case at the level of the collar43at the first end41and the second end42(cfFIG.1).

FIG.4shows a perspective detailed view of a further exemplary embodiment of a vacuum interrupter according to an improved concept of the present disclosure.

A fastening ring3, which is supported on the end-side wall9at the first end41, is arranged at the first end41of the holder4. The fastening ring3is mechanically connected to the holder4in detachable fashion using the principle of a bayonet lock in such a way that the fastening ring3can be pushed into the collar43at the first end41of the holder4and can be locked therein by twisting. The holder4is fixed with respect to the axis A in this way.

It is assumed that the present disclosure and many of its accompanying advantages are to be understood from the above description. It is moreover evident that various changes can be made to the shape, structure, and arrangement of the components without departing from the disclosed subject or without foregoing all the material advantages. The embodiments described are purely explanatory and such changes are encompassed by the claims below. It should furthermore be understood that the invention is defined by the claims below.

While subject matter of the present disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. Any statement made herein characterizing the invention is also to be considered illustrative or exemplary and not restrictive as the invention is defined by the claims. It will be understood that changes and modifications may be made, by those of ordinary skill in the art, within the scope of the following claims, which may include any combination of features from different embodiments described above.

The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.

REFERENCE SYMBOLS

1vacuum interrupter2shield3fastening ring4holderprotrusion6stud7shoulder8switching chamber9end-side wall11fixed contact12movable contact13cross strut14longitudinal strutpartial strut16spacer17cable tie21,22first end and second end of223opening of241,42first end and second end of443collar of444braces of4