EP1933347B1 - High voltage insulator with glue coupling - Google Patents

Description

TECHNICAL AREA

The present invention relates to a high-voltage insulator according to the preamble of claim 1. Such an insulator has an axially symmetrical insulating body and two brackets, which are attached to form an electrical insulating section on the insulating body. One of the two holders is fixed with an adhesive layer on the insulating body. This adhesive layer is disposed between a portion of an outer surface of the insulating body and a portion of an inner surface of a connecting sleeve of the holder or between a portion of an inner surface of the insulating body and a portion of an outer surface of a connecting bolt of the holder.

Such an insulator is typically used in high-voltage engineering in apparatus engineering as a switching rod, post insulator or quenching chamber insulator.

STATE OF THE ART

A high voltage insulator of the type mentioned is described in CH 633651 A5 , This designed as a hollow profile component insulator consists of a mechanically supporting, glass fiber reinforced plastic pipe, both ends of which carry conical metal fasteners. The outer or inner surface of one end of the plastic tube is in each case as inner ( Fig.1 ) or as outer cone ( Fig.2 ) educated. On the inner or outer cone of the plastic tube is an outer or inner cone of the fastener. An adhesive layer applied to the co-operating conical surfaces and / or an incision cut into this surface conical thread sets the associated fastener to the plastic tube. If the plastic pipe has a small wall thickness, then it can be glued to the side facing away from the fastening element with a support ring. The conical adhesive and / or screw connection on the one hand achieves a good introduction of force into the plastic pipe and, with simultaneous coating of the pipe with polymer-impregnated polyester fibers, ensures protection of the glass fibers from fission products of SF ₆ gas which is produced when the high-voltage insulator is used in a gas-insulated apparatus occur.

EP 899764 A2 shows a designed as an insulating tie rod high-voltage insulator with an insulating tube and two metal brackets, which are respectively disposed at one end of the insulating tube. The brackets each contain an outer sleeve and an inserted into the pipe end inner fitting. The holder is fixed by spreading, by press fit or by gluing on the insulating tube.

PRESENTATION OF THE INVENTION

The invention, as indicated in the claims, the object is to provide a high-voltage insulator of the type mentioned, which can be exposed over a long period of high mechanical and thermal stress.

In the high-voltage insulator according to the invention in an end of a connecting sleeve or a connecting bolt fixed to an insulating holder arranged in a transverse contraction of the insulating body elastically deformable annular body, which is connected via an insulating section facing an end portion of an adhesive layer with the insulating body.

When using the high-voltage insulator in an electrical apparatus or in an electrical system as a result of heating occurring transverse contraction of the insulator passes due to the elastic deformability of the annular body no strong mechanical forces in the end portion of the adhesive connection one. Therefore, in this end portion acting perpendicular to the layer tensile and compressive forces are largely suppressed and so the formation of undesirable peeling and splitting forces is avoided. The high-voltage insulator according to the invention is therefore characterized by good long-term behavior even under high mechanical and thermal loads.

Further advantageous effects of the high-voltage insulator according to the invention will become apparent from the following description part.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig.1

eine Aufsicht auf einen längs einer Achse geführten Schnitt durch einen rechts der Achse gelegenen Teil einer ersten Ausführungsform des Hochspannungsisolators nach der Erfindung mit einem verkürzt dargestellten, als Rohr ausgebildeten Isolierkörper und mit zwei am Isolierkörper befestigten Halterungen, bei der die untere der beiden Halterungen eine Verbindungshülse und einen Verbindungsbolzen enthält,

Fig.2

eine Aufsicht gemäss Fig.1 auf eine zweite Ausführungsform des Hochspannungsisolators nach der Erfindung, bei der lediglich die untere Halterung dargestellt ist, welche wie die entsprechende Halterung gemäss Fig.1 eine Verbindungshülse und einen Verbindungsbolzen aufweist,

Fig.3

eine Aufsicht gemäss Fig.1 auf eine dritte Ausführungsform des Hochspannungsisolators nach der Erfindung, bei der die dargestellte untere Halterung lediglich eine Verbindungshülse enthält, und

Fig.4

eine Aufsicht gemäss Fig.1 auf eine vierte Ausführungsform des Hochspannungsisolators nach der Erfindung, bei der die dargestellte untere Halterung lediglich einen Verbindungsbolzen enthält.

With reference to drawings, embodiments of the invention will be explained in more detail below. Hereby shows:

Fig.1

a plan view of a guided along an axis section through a right part of the axis of a first embodiment of the high voltage insulator according to the invention with a shortened, designed as a pipe insulator and two fastened to the insulator brackets, wherein the lower of the two brackets a connecting sleeve and contains a connecting bolt,

Fig.2

a supervision according to Fig.1 to a second embodiment of the high-voltage insulator according to the invention, in which only the lower holder is shown, which as the corresponding holder according to Fig.1 a connecting sleeve and a connecting bolt,

Figure 3

a supervision according to Fig.1 to a third embodiment of the high voltage insulator according to the invention, in which the illustrated lower holder contains only a connecting sleeve, and

Figure 4

a supervision according to Fig.1 to a fourth embodiment of the high voltage insulator according to the invention, in which the illustrated lower holder only contains a connecting bolt.

WAYS FOR CARRYING OUT THE INVENTION

In all figures, like reference numerals refer to like acting parts and repeated reference numerals may be omitted. An in Fig.1 illustrated high-voltage insulator has an axially symmetrical, hollow insulator 1, which is evidently designed as a tube, but may optionally also be a hollow cylinder or a ring. The insulating body 1 is generally made of a fiber-reinforced polymer, such as a glass and / or plastic-reinforced epoxy. Spaced apart along the symmetry axis 2, two holders 3 and 4 made of metal, in particular aluminum or steel, are fastened to the insulating body 1. The insulating body 1 in this case ensures a defined insulation distance A between the two brackets 3 and 4 safe. The holder 3 may be at ground potential and may then be electrically connected to a drive or with a metal housing, whereas the holder 4 are at high voltage potential and may then be connected to a contact arrangement of a high voltage switch. The high-voltage insulator can transmit in the formation of the insulating body 1 as a pipe or optionally as a rod driving force for actuating the contact assembly, and can absorb in the formation of the insulating body 1 as a hollow cylinder or as a ring support forces for supporting a contact assembly receiving quenching chamber of the high voltage switch in a insulating gas filled Housing needed. If the insulating body 1 is formed as a tube or as a ring, the high-voltage insulator can also form the housing of the quenching chamber.

The lower 3 of the two brackets 3, 4 is glued to the insulating body 1 temperature resistant, wherein as an adhesive generally a two-component adhesive based on epoxy is used. Obviously, this holder contains a connection sleeve 10, which is connected via an adhesive layer 11 with the insulating body 1. The adhesive layer 11 is arranged between a portion of the outer surface of the insulating body 1 and a portion of the inner surface of the connecting sleeve 10. A guided into the interior of the insulating body 1 connecting pin 20 is fixed with an adhesive layer 21 on the insulating body 1. The adhesive layer 21 is between a Section of the outer surface of the connecting pin 20 and a portion of the inner surface of the insulating body 1 is arranged.

In one of the insulating section A facing the end of the connecting sleeve 10, an elastically deformable annular body 12 is arranged, which is connected via an insulating section A facing end portion 111 of the adhesive layer 11 with the insulating body 1. In a corresponding manner, in the insulating section A facing the end of the connecting bolt 20, an elastically deformable annular body 22 is arranged, which is connected via one of the insulating section A facing end portion 211 of the adhesive layer 21 with the insulating body 1. The elastic deformability of the annular body 12 and 22 is determined by choosing the wall thickness of the predominantly hollow cylindrical annular body so that in a transverse contraction of the insulating body 1, the end portions 111 and 211 of the adhesive layers 11 and 21 are loaded with forces significantly compared to a rigid holder are reduced. Such forces are mainly tensile and compressive forces and peeling and splitting forces acting perpendicular to the adhesive layers 11 and 21.

The transverse contraction can occur under heavy mechanical stresses of the high voltage insulator due to axially induced tensile or compressive forces or due to bending forces, but is primarily caused by temperature changes occurring during operation of a high voltage switch or other high voltage insulator containing the high voltage insulator. Since the coefficient of thermal expansion of the insulating body 1 is generally considerably greater than that of the connecting sleeve 10, respectively. of the connecting bolt 20, is pressed together with a temperature increase of the insulating body in a rigidly formed by a connecting sleeve 10 and a rigidly formed connecting pin 20 annular space of the holder, whereas the insulating outside the annulus, ie in the region of the insulating stretch, can expand unhindered. This resulting stresses in the insulating act in the adhesive layers primarily as a radially directed compressive force in the end portions of the adhesive layers but also as a predominantly radially directed tensile force, which generates peeling and splitting forces.

Characterized in that the adhesive layers 11 and 21 are connected at their the insulating section A facing end portions 111 and 211 with the elastically deformable annular bodies 12 and 22, the insulating body 1 can expand at the temperature increase in the region of the end portions 111 and 211, without being inadmissible high voltages occur. Therefore, in the end portions 111 and 211, high local shear and tensile forces and thus peeling or splitting of the adhesive layers 11 and 21 in the end portions are avoided.

The ring body 12 has a section formed in the manner of a hollow cylinder 121. At the end of the hollow cylinder 121 facing the insulating section A, a field control element designed in the manner of a torus 122 with a width exceeding the wall thickness of the hollow cylinder is arranged in the radial direction. The inner surface of the hollow cylinder 121 is connected to the end portion 111 of the adhesive layer 11. The wall thickness of the hollow cylinder 121 is chosen so that the elastic deformability of the annular body 11 is ensured in the region of the end portion 111. The width of the torus 122, however, is chosen so that the torus homogenized during operation of the high voltage insulator electric field in the Isolierstrecke so that electrical flashovers are avoided. The torus 122 has a small distance from the insulating body 1, so that the transverse contraction of the insulating body 1 can be compensated by this distance. In addition, axially and radially aligned slots 123 can be provided in the torus 122, which reduce the mechanically effective wall thickness of the torus 122 and thus facilitate its elastic deformation.

When ring body 22, the wall thickness decreases for Isolierstrecke A out. As a result, the elastic deformability of the annular body 22 is continuously increased towards the insulating section and thus the forces caused by transverse contraction in the adhesive layer 21 in its end section 211 are continuously reduced. The annular body 22 can be produced in a simple manner by an annular pin 23 arranged in the connecting bolt 20, which limits the annular body inwards.

To support the holding force of one of the two adhesive layers 11 and 21, the connecting sleeve 10 or the connecting bolt 20 and the insulating body 1 may be additionally connected by a thread. For the additional connection of bolt 20 and body 1 is characterized by a reference numeral 24 thread Fig.1 seen.

In the embodiment of the high voltage insulator after Fig.2 has the annular groove 23 in manufacturing technology advantageous form in contrast to the embodiment Fig.1 only a small depth up. The annular body 22 is then extended in the axial direction only over a small distance, but this small embedding is sufficient to reduce in the critical end portion 211 of the adhesive layer 21, the effect of the transverse contraction of the insulating body 1 on the holder 3 by elastic deformation of the annular body 22 and so to reduce the effect of undesirable peeling and splitting forces. As can be seen, the hollow cylinder 121 extends to an end remote from the insulating section A end of the connecting sleeve 10 and connected to this end via the adhesive layer 11 with the insulating body 1. By these measures, a good elastic deformability of the connecting sleeve 10 along the entire adhesive layer 11 is ensured, so that the adhesive layer 11 is largely protected from the action of peel and splitting forces and is also characterized by a high shear strength.

In the embodiment according to Figure 3 force is introduced only via the connecting sleeve 10 and the adhesive layer 11 in the insulating body 1 or taken over the adhesive layer 11 of the sleeve 10 in the holder 3 of the connecting bolt 20. Instead of a hollow, in particular tubular, hollow cylindrical or annular, insulating body 1, an insulating body 1 can be used in this embodiment of the invention, which is designed as a solid cylinder. This manufacturing advantageous embodiment is to be used especially if the shear forces occurring in the power transmission, parallel to the single adhesive layer 11 acting shear forces are relatively small.

This also applies to the embodiment according to Figure 4 in which the connecting sleeve 10 is omitted in the holder 3. Force will then only over the Connecting bolts 20 and the adhesive layer 21 introduced into the insulating body 1 or taken over the adhesive layer 21 from the bolt 20. The field controlling torus 122 is then integrated into the ring body 22.

LIST OF REFERENCE NUMBERS

1

insulator

2

axis

3, 4

brackets

10

connecting sleeve

11, 21

adhesive layers

12, 22

ring body

20

connecting bolts

23

ring groove

24

thread

111, 211

End portions of the adhesive layers

121

hollow cylinder

122

Torus, field control

123

slots

A

insulating gap

Claims (12)

1. High-voltage insulator having an insulating body (1) and having two holders (3, 4) which are attached to the insulating body forming an electrical isolation gap (A), with one of the two holders (3) being fixed to the insulating body (1) by means of an adhesive layer (11, 21), which layer is arranged between a section of an outer surface of the insulating body (1) and a section of an inner surface of a connection sleeve (10) of the holder (3), or between a section of an inner surface of the insulating body (1) and a section of an outer surface of a connection bolt (20) for the holder (3), characterized in that an annular body (12, 22) which can be deformed elastically during lateral contraction of the insulating body (1) and is connected to the insulating body (1) via an end section, (111, 211), facing the isolation gap (A), of the adhesive layer (11, 21) is arranged in an end, facing the isolation gap (A), of the connection sleeve (10) or of the connection bolt (20).
2. High-voltage insulator according to Claim 1, characterized in that a field control element which is in the form of a torus (122) and has a width which is greater than the wall thickness of the hollow cylinder (121) is arranged at the end of a section of the annular body (12, 22) which is in the form of a hollow cylinder (121).
3. High-voltage insulator according to Claim 2, characterized in that the torus (122) has slots (123).
4. High-voltage insulator according to one of Claims 2 or 3, characterized in that the wall thickness of the hollow cylinder (121) is predominantly constant.
5. High-voltage insulator according to Claim 4, characterized in that the hollow cylinder (121) extends to an end, remote from the isolation gap (A), of the connection sleeve (10).
6. High-voltage insulator according to one of Claims 1 to 5, characterized in that the annular body (12) is part of the connection (10), and in that there is no connection bolt (20).
7. High-voltage insulator according to one of Claims 1 to 5, characterized in that the annular body (22) is part of the connection bolt (20).
8. High-voltage insulator according to Claim 7, characterized in that the annular body (22) is bounded on the inside by an annular groove (23) which is arranged in the connection bolt (20).
9. High-voltage insulator according to one of Claims 7 or 8, characterized in that the wall thickness of the annular body (22) decreases towards the isolation gap (A).
10. High-voltage insulator according to one of Claims 7 to 9, characterized in that there is no connection sleeve (20).
11. High-voltage insulator according to one of Claims 1 to 5 or 7 to 9, characterized in that a first adhesive layer (11) fixes the connection sleeve (10), and a second adhesive layer (21) fixes the connection bolt (20), to the insulating body (1).
12. High-voltage insulator according to one of Claims 1 to 11, characterized in that the connection sleeve (10) or the connection bolt (20) and the insulating body (1) are additionally connected by means of a thread (24).

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