Flange for electrical bushing and electrical bushing

Abstract

A flange (2) for an electrical bushing (1) is specified, the flange comprising a lower part (21) and an upper part (22) configured to be mechanically fixed to each other, wherein - the lower part and the upper part are arranged one above the other in an axial direction of the flange, and - one of the lower part and the upper part surrounds a part of the other of the lower part and the upper part in a plurality of regions in a radial direction, thereby forming a rigid connection (24) against a relative movement of the upper part with respect to the lower part in a non-axial direction of the flange. Furthermore, an electrical bushing (1) is specified.

Description

Technical Field

[0001] This application relates to a flange for an electrical bushing, such as a flange configured to allow large installation angles or seismic loads relative to vertical orientation, and to an electrical bushing. Background Technology

[0002] Electrical bushings are used to insulate and conduct electrical power through planes with different potentials, such as the grounded transformer housing. The structure and dimensions of such bushings depend on the specific requirements, and most types of bushings are manufactured according to specific application needs and parameter ranges. Document EP 3 579 252 A1 describes an electrical bushing having a flange comprising an upper portion and a lower portion.

[0003] Currently, earthquake-compatible flanges are typically configured as single-piece cast or forged flanges to withstand strong mechanical loads. Depending on the application of the bushing, the diameter of the flange face and the number of bolt holes on the corresponding flange face for connection to appliances such as transformers vary considerably.

[0004] However, adapting these one-piece flanges to specific customer needs requires redesign and may necessitate new or modified tools for casting or forging. Summary of the Invention

[0005] The purpose of this application is to provide a flange for an electrical bushing that is mechanically robust and easily adaptable to specific customer requirements.

[0006] This objective is achieved, in particular, by the electric bushing according to the independent claim and the method for producing the electric bushing. Further development and advantages are the subject of other claims.

[0007] A flange for an electrical bushing is specified. For example, the flange includes an opening extending through the flange in an axial direction, such that a conductor can be guided through the opening to an electrical appliance, such as a transformer housing, a switchgear, or a reactor.

[0008] According to at least one embodiment, the flange includes a lower portion and an upper portion configured to be mechanically fixed to each other. Therefore, the upper and lower portions of the flange can be manufactured separately and then fixed to each other, for example, using screws. The means for fixing the two portions of the flange to each other can include, but are not limited to, bolts, screws, rivets, and clamps. Thus, the flange exhibits a modular design. The upper and lower portions can be formed of the same material, such as a metal like aluminum or stainless steel. However, different materials can also be used for the portions if advantageous.

[0009] The terms "lower portion of the flange" and "upper portion of the flange" do not imply any limitation on the actual spatial location of these components. For example, the lower portion is the part of the flange that provides a mounting surface for attaching the sleeve to an electrical appliance.

[0010] According to at least one embodiment, the lower portion and the upper portion are arranged such that one is above the other in the axial direction of the flange. For example, the lower portion and the upper portion are directly abutting each other along the axial direction in at least a plurality of regions. The interface between the upper portion and the lower portion may span a connecting plane. The connecting plane may extend parallel to the mounting surface and / or extend in a radial direction perpendicular to the axis.

[0011] In this context and hereinafter, the terms “parallel” and “perpendicular” also include slight deviations, such as a deviation of up to 15°, unless otherwise stated.

[0012] According to at least one embodiment, one of the lower portion and the upper portion correspondingly surrounds a portion of the other of the upper portion and the lower portion in at least a plurality of regions in the radial direction. For example, the lower portion surrounds a portion of the upper portion. For example, one of the flange portions may surround a portion of another flange portion along its entire circumference. For example, a portion of the upper portion may be inserted into the lower portion in the axial direction. The lower portion and the upper portion may be directly adjacent to each other in at least a plurality of regions in the radial direction.

[0013] According to at least one embodiment, a rigid connection is formed between the upper portion and the lower portion, wherein shape locking or rigid connection refers to relative movement of the upper portion relative to the lower portion in a non-axial direction of the flange. The mating surface for the rigid connection may extend parallel to the axial direction or at an acute angle to the axial direction. Alternatively or additionally, the mating surface may extend perpendicularly or obliquely relative to the connecting plane.

[0014] In the axial direction, the upper portion and the lower portion are held together by a mechanical device for fixing the upper portion and the lower portion to each other.

[0015] In at least one embodiment, a flange for an electrical bushing includes a lower portion and an upper portion configured to be mechanically fixed to each other, wherein the lower portion and the upper portion are arranged such that one is above the other in the axial direction of the flange. One of the lower portion and the upper portion surrounds a portion of the other in at least a plurality of regions in the radial direction, thereby forming a rigid connection resisting relative movement of the upper portion relative to the lower portion in the non-axial direction of the flange. For example, the lower portion also includes a seat configured to mechanically support a core of the bushing.

[0016] Due to its modular design, the flange can be more easily adapted to specific customer needs. For example, the lower portion can be modified to be compatible with a new appliance without having to redesign the upper portion of the flange.

[0017] Furthermore, it has been found that the mechanical robustness of the flange can be significantly improved by a rigid connection that provides a loading path for forces acting on the flange in a non-axial direction, especially compared to a flat lower portion that does not surround the upper portion. For example, it reduces the load on mechanical fasteners (e.g., bolts) between flange components, allowing for larger installation angles (e.g., 30° or greater) and / or seismic loads relative to the vertical orientation in space.

[0018] According to at least one embodiment, the lower portion of the flange includes a mounting surface configured for mounting the flange to an appliance. Devices for mounting the sleeve to the electrical appliance include, but are not limited to, bolts, rivets, and clamps.

[0019] According to at least one embodiment, the upper portion and the lower portion are fixed to each other along a connecting plane extending parallel to the mounting surface, wherein the lower portion includes a raised portion. In other words, when viewed from the mounting surface, the raised portion extends beyond the connecting plane in the axial direction. The raised portion may form a neck of the lower portion. The raised portion facilitates a rigid connection between the lower portion and the upper portion. For example, the raised portion surrounds the upper portion or the upper portion surrounds the raised portion. In the first case, the raised portion may form an inner wall of the lower portion of the flange facing the upper portion of the flange. In the second case, the raised portion may form an outer wall of the lower portion of the flange facing the upper portion of the flange.

[0020] According to at least one embodiment, the raised portion includes an annular portion extending along the upper portion. For example, the raised portion extends around the upper portion. Alternatively, the upper portion may extend around the raised portion. For example, the annular portion may have a rectangular or trapezoidal cross-section.

[0021] According to at least one embodiment, the raised portion further includes a plurality of ribs that mechanically support the annular portion on the side of the annular portion opposite to the upper portion of the flange. The ribs further improve the mechanical robustness of the flange against forces acting in a non-axial direction.

[0022] According to at least one embodiment, the upper portion overlaps with the raised portion when viewed along the axial direction. For example, the upper portion may cover the interface between the mating surfaces of the rigid connection. For example, the upper portion includes a circumferential portion that forms an undercut when viewed along the axial direction toward the mounting surface.

[0023] According to at least one embodiment, the rigid connection is configured as a clearance fit or a transition fit. The clearance fit is preferably a sliding fit or a positioning fit to ensure that the lower portion prevents radial movement of the upper portion caused by non-axial forces acting on the flange.

[0024] According to at least one embodiment, the rigid connection is configured as an interference fit, also known as a press fit or friction fit. Assembly of the flange portions can be performed using mechanical pressure. Alternatively or additionally, before or during assembly, the flange portion surrounding the other flange portion in the finished flange is held at a higher temperature than the other flange portion, for example, by heating or cooling one of the flange portions. Therefore, when both flange portions reach the same temperature, the pressure between the upper and lower portions increases after assembly. The interference fit ensures a reliable load path from the upper portion of the flange to the lower portion of the flange when non-axial forces act on the flange.

[0025] According to at least one embodiment, the upper portion is configured to receive an insulator. For example, the upper portion includes an indentation at one end portion configured to receive the insulator. The insulator may, for example, comprise: a polymeric material, such as a silicone shed or fiber-reinforced plastic in the case of direct molding; or a ceramic, such as porcelain. The insulator can form a closed seal with the flange. This prevents the ingress of water or contaminants. However, depending on the application of the sleeve, such an insulator may be omitted.

[0026] According to at least one embodiment, at least one of the upper portion and the lower portion is configured to receive at least one gasket for a sealing connection between the lower portion and the upper portion. For example, both the lower portion and the upper portion are configured to achieve a sealing connection. For example, one of the upper portion and the lower portion provides a recess, such as a groove, to receive the gasket, and the other of the flange portions has a surface finish at a location opposite the recess to facilitate a sealing connection. For example, the gasket may be an O-ring. Alternatively or additionally, the lower portion is configured to receive at least one gasket at the mounting surface.

[0027] According to at least one embodiment, the flange is configured to receive a wiper that extends around the upper portion and covers at least a portion of the lower portion when viewed along the axial direction. For example, the wiper covers the mating surface of the rigid connection when viewed along the axial direction. The wiper allows the sleeve to adapt to extreme environmental conditions, such as in desert, coastal, and marine environments.

[0028] In addition, an electrical sleeve including a flange is specified. The flange may exhibit one or more of the features mentioned above.

[0029] According to at least one embodiment, the sleeve is a capacitance-grading sleeve, such as a condenser core sleeve. In a condenser core sleeve, a core comprising several layers of discontinuous conductive and dielectric films is arranged around a central conductor, thereby controlling the distribution of the electric field through capacitance gradation. Typically, the core extends through the flange and into the volume of the electrical appliance.

[0030] According to at least one embodiment, the electrical bushing is configured for voltages between 3.6kV and 1200kV, for example, between 245kV and 550kV. Attached Figure Description

[0031] Other embodiments and developments of the flange and the sleeve will become apparent from the exemplary embodiments described below in conjunction with the accompanying drawings. Features illustrated or described as part of one embodiment may be used in or in combination with any other embodiment to produce yet another embodiment. This disclosure is intended to include these modifications and variations.

[0032] In the attached diagram:

[0033] Figure 1 A schematic perspective cross-sectional view of a flange according to an exemplary embodiment is shown;

[0034] Figure 2A schematic cross-sectional view of an electrical bushing according to an exemplary embodiment is shown;

[0035] Figure 3 A schematic cross-sectional view of an electrical bushing according to another exemplary embodiment is shown; and

[0036] Figure 4 A schematic cross-sectional view of an electrical bushing according to another exemplary embodiment is shown.

[0037] In the exemplary embodiments and drawings, similar or analogous components are given the same reference numerals. Generally, only the differences with respect to the various embodiments are described. Unless otherwise stated, the description of a part or aspect of one embodiment also applies to the corresponding part or aspect of another embodiment.

[0038] The elements illustrated in the accompanying figures and their relative sizes are not necessarily true proportions. Instead, for better representation and / or for better understanding, the thicknesses of individual elements or layers may be represented by exaggerated sizes. Detailed Implementation

[0039] exist Figure 1 In the figure, an exemplary embodiment of flange 2 is illustrated in a perspective sectional view. Flange 2 includes a lower portion 21 and an upper portion 22. The lower portion 21 forms a mounting surface 20 for mounting flange 2 to an appliance (e.g., a corresponding flange of the appliance).

[0040] The flange 2 (e.g., lower portion 21 and upper portion 22) can be made of metal or metal alloy, such as aluminum alloy or stainless steel.

[0041] The lower portion 21 and the upper portion 22 of the flange are in the axial direction of the flange ( Figure 1 y direction in, Figures 2 to 4 One is arranged on the axis 10 above the other.

[0042] The lower portion 21 surrounds a portion of the upper portion 22 of the flange 2, thereby forming a rigid connection 24 that resists relative movement of the upper portion 22 relative to the lower portion 21 in a non-axial direction of the flange 2.

[0043] Along the axial direction, the lower portion 21 and the upper portion 22 are directly abutting each other at a connecting plane 25 extending parallel to the mounting surface 20. A bolted engagement is formed between the lower portion 21 and the upper portion 22 at the connecting plane 25, which is preferably also a sealed engagement. When viewed axially toward the mounting surface 20, the upper portion 22 does not extend beyond the connecting plane 25 at any position.

[0044] Relative to the connecting plane 25, the lower portion 21 includes a raised portion 23. In the illustrated exemplary embodiment, the raised portion 23 is formed by an annular portion 231. The axial extension of the raised portion 23 is preferably less than the axial extension of the upper portion 22, for example, at most 30% or at most 20% and / or at least 1% or at least 5%.

[0045] The inner wall 271 of the raised portion 23 is directly adjacent to the outer wall 272 of the upper portion 22 to form a rigid connection 24.

[0046] The lower portion 21 with the raised portion 23 is preferably formed as a single piece. For example, the lower portion 21 and / or the upper portion 22 can be formed by casting.

[0047] The lower portion 21 also includes ribs 232 arranged on the side of the annular portion 231 facing away from the inner wall 271. Of course, the shape of the protrusion 23 can be modified in a wide range to achieve a rigid connection with respect to the upper portion 22 that allows for non-axial movement. For example, the ribs 232 can be omitted. The radial extent of the protrusion 23 can also vary. For example, the protrusion 23 can extend to the outer edge of the lower portion 21, making the surface of the lower portion 21 opposite the mounting surface 20 completely flat next to the upper portion 22.

[0048] In the axial direction, the lower portion 21 and the upper portion 22 are held together by a connecting device 4 such as a screw or bolt (see...). Figure 2 ).

[0049] If a non-axial mechanical load is applied to the upper portion 22, the rigid connection 24 counteracts the movement of the upper portion 22 relative to the lower portion 21. Therefore, the mechanical load on the connecting device 4 is significantly reduced. Furthermore, the contact between the lower portion 21 and the upper portion 22 at the connecting plane 25 is significantly improved. Thus, the rigid connection 24 prevents the formation of gaps between the flange portions under mechanical loads. This allows the flange to be used in applications requiring high mechanical robustness, such as due to large installation angles relative to vertical orientation in space or due to seismic loads.

[0050] For example, simulations have shown that the short neck of the lower portion 21 formed by the protrusion 23 significantly increases the mechanical stability of the flange 2 compared to the lower portion 21 configured as a flat plate without any protrusions at the connecting plane.

[0051] The rigid connection 24 can be configured as a clearance fit, transition fit, or interference fit. For example, an interference fit is suitable because it ensures a strong mechanical connection between the lower portion 21 and the upper portion 22 at the mating surfaces of the rigid connection 24. For example, at least one of the flange portions can be subjected to mechanical pressure and / or heating or cooling to achieve an interference fit.

[0052] The upper portion 22 also includes a recess 26 facing the opening 29 of the flange. The recess 26 is configured to receive one end portion of the insulator 3. However, depending on the type of bushing, an insulator is not necessarily required.

[0053] The lower portion 21 also includes a seat 211 configured to mechanically support the core of the sleeve. For example, the seat 211 is a tapered portion in which the diameter of the opening 29 gradually decreases in the axial direction when viewed toward the mounting surface 20.

[0054] In the illustrated exemplary embodiment, the lower portion 21 surrounds the upper portion 22 to form a rigid connection between the flange portions in a non-axial direction. However, this arrangement can also be reversed, such that the upper flange portion 22 surrounds the lower flange portion 21. This also applies to the following exemplary embodiments.

[0055] exist Figure 2 Examples are given of combinations such as Figure 1 The described flange 2 has an electrical sleeve 1. A core 7 is inserted into the opening 29 of the flange 2 and extends into the appliance 9. The electrical sleeve 1 is mounted to the appliance 9 at the mounting surface 20 of the flange 2. For example, the core 7 is a machined resin-impregnated paper condenser core.

[0056] Figure 2 Possible locations of the recess 5 are also illustrated, which is configured to receive a gasket such as an O-ring to obtain a sealing connection between the lower portion 21 and the upper portion 22 and / or between the flange 2 and the appliance 9.

[0057] The lower portion 21 of the flange 2 also includes a mounting hole 6, which is configured to mate with a threaded hole or through hole provided in the appliance 9 to obtain a mechanical connection using a mounting device 61 (e.g., a screw).

[0058] Due to the modular configuration of the flange 2, including the lower portion 21 and the upper portion 22, the lower portion 21 can be adapted to the electrical appliance 9, for example, with respect to the diameter of the mounting surface and / or the required location and / or number of mounting holes, without having to redesign the entire flange 2, such as the upper portion 22. Therefore, customer requirements can be met by machining and casting the lower portion 21. For bushing voltage and current ratings, the upper portion 22 and the insulator 3 can be identical, independent of the user interface. This helps reduce costs and delivery time.

[0059] exist Figure 3 Another exemplary embodiment of the electric bushing 1 is illustrated below. This exemplary embodiment essentially corresponds to the combination of Figure 2 The described embodiment differs in that the upper portion 22 of the flange 2 includes a circumferential portion 28 that, when viewed in the axial direction, covers at least a portion of the ridge 23 of the lower portion. The circumferential portion 28 can form a “top” that helps prevent moisture or dust from reaching the opening 29 along the interface between the lower portion 21 and the upper portion 22.

[0060] like Figure 2 As illustrated, a recess 5 can be provided to achieve a sealed connection between the raised portion 23 of the lower portion 21 and the circumferential portion 28 of the upper portion.

[0061] exist Figure 2 and Figure 3 In the exemplary embodiment shown, the recess 5 is provided in the lower flange 21. However, such a recess may alternatively or additionally be provided in the upper flange portion 22 and / or the appliance 9.

[0062] exist Figure 4 Another exemplary embodiment of the sleeve is illustrated below. This exemplary embodiment essentially corresponds to the combination... Figure 2 The described implementation scheme.

[0063] In this exemplary embodiment, flange 2 is configured to receive wiper 8. Wiper 8 helps prevent contaminants from entering at the interface between the upper portion 22 and the lower portion 21 of flange. Wiper 8 extends around the upper portion 22 and covers a portion of the lower portion 21 when viewed along axis 10. Of course, such a wiper can also be provided in previous exemplary embodiments.

[0064] Sleeve 1 has been described in conjunction with the condenser core sleeve, but the inventive concept can also be applied to any other type of electrical sleeve, such as a solid sleeve, also known as a bulk type sleeve. Those skilled in the art will recognize that the flange and sleeve components can be made from a variety of available materials and compounds, such that references to a particular material should not be construed as limiting. For example, the sleeve core 7 can be made from any suitable material or compound, such as resin-impregnated paper, resin-impregnated composites, resin-impregnated nonwoven fabric, or solid epoxy resin.

[0065] This application claims priority to EP application 20203662.0, the disclosure of which is incorporated herein by reference.

[0066] Based on the description of the exemplary embodiments, the invention is not limited to the exemplary embodiments. Rather, the invention includes any new features and any combination of features, particularly any combination of features in the patent claims and any combination of features in the exemplary embodiments, even if such feature or combination is not expressly specified in the patent claims or exemplary embodiments.

[0067] List of reference numerals

[0068] 1 casing

[0069] 10 axis lines

[0070] 2 flanges

[0071] 20 mounting surfaces

[0072] 21 Lower part of the flange

[0073] 211 seats

[0074] 22 Upper part of the flange

[0075] 23 raised parts

[0076] 231 Circular section

[0077] 232 Ribs

[0078] 24 rigid connections

[0079] 25 Connecting planes

[0080] 26 dents

[0081] 271 The inner wall of the lower part

[0082] 272 Outer wall of the upper part

[0083] 28 circumference parts

[0084] 29 openings

[0085] 3 Insulators

[0086] 4. Connecting device

[0087] 5 recesses

[0088] 6 mounting holes

[0089] 61 Installation device

[0090] 7 cores

[0091] 8 wipers

[0092] 9 utensils

Claims

1. An electrical sleeve (1) comprising a flange (2) and a core (7) extending through said flange (2), wherein - The flange (2) includes a lower portion (21) and an upper portion (22) configured to be mechanically fixed to each other. - The lower portion (21) provides a mounting surface (20) and mounting holes (6) for mounting the sleeve (1) to the electrical appliance. - The lower portion (21) includes a seat (211) configured to mechanically support the core (7). - The lower portion and the upper portion are arranged such that one is above the other in the axial direction of the flange, and - One of the lower portion and the upper portion surrounds a portion of the other in at least a plurality of regions in the radial direction, thereby forming a rigid connection (24) that resists relative movement of the upper portion relative to the lower portion in the non-axial direction of the flange. The electric sleeve (1) is a condenser core sleeve, and the core (7) comprises several discontinuous conductive and dielectric films.

2. The electrical sleeve (1) according to claim 1. The lower portion of the flange includes a mounting surface (20) configured to mount the flange to an appliance (9).

3. The electrical sleeve (1) according to claim 2. The upper portion and the lower portion are fixed to each other along a connecting plane (25) extending parallel to the mounting surface, wherein the lower portion includes a raised portion (23), wherein the raised portion surrounds the upper portion or the upper portion surrounds the raised portion on the side of the connecting plane opposite to the mounting surface.

4. The electrical sleeve (1) according to claim 3. The raised portion includes an annular portion (231) extending along the upper portion.

5. The electrical sleeve (1) according to claim 4. The raised portion further includes a plurality of ribs (232) that mechanically support the annular portion on the side of the upper portion of the annular portion opposite to the flange.

6. The electrical sleeve (1) according to claim 4. When viewed along the axial direction, the upper portion overlaps with the raised portion.

7. The electrical sleeve (1) according to any one of claims 1 to 5. The rigid connection is configured as a clearance fit or a transition fit.

8. The electrical sleeve (1) according to any one of claims 1 to 5. The rigid connection is configured as an interference fit.

9. The electrical sleeve (1) according to any one of claims 1 to 5. The upper portion includes a recess (26) configured to receive an end portion of an insulator.

10. The electrical sleeve (1) according to any one of claims 1 to 5. At least one of the upper portion and the lower portion is configured for a sealing connection between the lower portion and the upper portion.

11. The electrical sleeve (1) according to any one of claims 1 to 5. The flange is configured to receive a wiper (8) that extends around the upper portion and covers at least a portion of the lower portion when viewed along the axial direction.

12. The electrical bushing according to any one of claims 1 to 5, The bushing mentioned above is a capacitor-grade bushing.

13. The electrical bushing according to any one of claims 1 to 5, The aforementioned electrical bushing is configured for voltages between 3.6kV and 1200kV.

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