Electrical bushing and methods of producing an electrical bushing

1. An electrical bushing, comprising:

a flange comprising a lower part and an upper part affixed to one another,

a core surrounded by the flange, and

a volume of a joint between the flange and the core, the volume of the joint delimited by a flange step transition and by a core diameter transition,

wherein:

the flange is affixed to the core by a locking compound disposed in the volume of a joint, and

the volume of the joint further comprises a compressible material, the compressible material being configured to compress or expand in response to a change in the volume of the joint.

2. The electrical bushing according to claim 1 , wherein the core has a first section with a diameter that is larger than a diameter of a second section and a diameter of a third section, wherein the first section is arranged between the second section and the third section along an axial direction of the bushing, wherein the flange forms a seat for a first transition between the first section and the second section and wherein the volume of the joint is located at a second transition between the first section and the third section.

3. The electrical bushing according to claim 2 , wherein the seat is located at the lower part of the flange and the joint is located at least in part at the upper part of the flange or vice versa.

4. The electrical bushing according to claim 1 , wherein the compressible material is compressible by at least 10% with respect to its unloaded volume.

5. The electrical bushing according to claim 1 , wherein the compressible material comprises at least one of: an elastomer, a gel, a compressible filler, expancels.

6. The electrical bushing according to claim 1 , wherein the joint is an annular joint spanning a circumference of the core.

7. The electrical bushing according to claim 1 , wherein the locking compound is an Epoxy-type resin, an Epoxy-type adhesive, a Silicone-type adhesive or a Polyurethane-type adhesive.

8. The electrical bushing according to claim 1 , wherein the bushing is a capacitance graded bushing.

9. A method for producing an electrical bushing, the method comprising:

providing a core and a flange with a lower part and an upper part;

arranging the upper part and the lower part of the flange around the core;

affixing the upper part and the lower part to one another;

forming a joint delimited by a flange step transition and by a core diameter transition between the flange and the core, comprising the steps of:

injecting a locking compound filling a second portion of the volume of the joint, wherein a compressible material is provided in a first portion of the volume of the joint, and

curing the locking compound while it is in contact with the compressible material.

10. The method according to claim 9 , wherein the locking compound is injected into the joint after affixing the upper part and the lower part to one another.

11. The method according to claim 10 , wherein the injection is performed with hand-held equipment or mixing equipment, and wherein the joint is sealed after injection.

12. The method according to claim 9 , wherein the locking compound is hardened by heating it to a temperature of at least 50° C.

13. The method according to claim 9 , wherein a bushing is produced comprising:

a flange comprising a lower part and an upper part affixed to one another, and

a core surrounded by the flange,

wherein:

the flange is affixed to the core by a locking compound disposed in a volume of a joint between the flange and the core, and

the volume of the joint further comprises a compressible material, the compressible material being configured to compress or expand in response to a change in the volume of the joint.

14. The method according claim 13 , wherein the bushing is a capacitance graded bushing.

15. The method according to claim 13 , wherein the locking compound is an Epoxy-type resin, an Epoxy-type adhesive, a Silicone-type adhesive or a Polyurethane-type adhesive.

16. The method according to claim 13 , wherein the joint is an annular joint spanning a circumference of the core.

17. The method according to claim 13 , wherein the compressible material comprises at least one of: an elastomer, a gel, a compressible filler, expancels.

18. The method according to claim 13 , wherein the compressible material is compressible by at least 10% with respect to its unloaded volume.

19. An electrical bushing, comprising:

a flange comprising a lower part and an upper part affixed to one another, and

a core surrounded by the flange,

wherein:

the flange is affixed to the core by a locking compound disposed in a volume of a joint between the flange and the core, and the volume of the joint further comprises a compressible material, the compressible material being configured to compress or expand in response to a change in the volume of the joint,

wherein the core has a first section with a diameter that is larger than a diameter of a second section and a diameter of a third section,

wherein the first section is arranged between the second section and the third section along an axial direction of the bushing, wherein the flange forms a seat for a first transition between the first section and the second section and wherein the volume of the joint is delimited by a second transition between the first section and the third section,

wherein the seat is located at the lower part of the flange and the joint is located at least in part at the upper part of the flange or vice versa,

wherein the compressible material comprises at least one of: an elastomer, a gel, a compressible filler, expancels, and

wherein the locking compound is an Epoxy-type resin, an Epoxy-type adhesive, a Silicone-type adhesive or a Polyurethane-type adhesive.

20. The electrical bushing according to claim 19 , wherein the bushing is a capacitance graded bushing.