Terminal bushing sealing element

Patent metadata

Field	Value
Publication number	US-9396875-B2
Application number	US-201314888589-A
Country	US
Kind code	B2
Filing date	Jun 14, 2013
Priority date	Jun 14, 2013
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

A terminal bushing sealing element is adapted to be fitted between a terminal bushing and a barrier element. The sealing element is elastic, has an annular shape, and includes a wall with an inner surface and an outer surface. A first opening is provided at a first end of the sealing element and a second opening is provided at a second end of the sealing element, which is opposite to the first end and the wall extends between the first end and the second end. The wall includes a first wall portion that is inclined such that a diameter of the sealing element increases from the first end in the direction towards the second end. The sealing element provides for improved sound attenuation while maintaining a long creepage distance and may be used in sound attenuation casings that are included in power capacitor arrangements.

First claim

The invention claimed is:

1. A terminal bushing sealing element, adapted to be fitted between a terminal bushing and a barrier element, which sealing element is elastic, has an annular shape, and comprises a wall with an inner surface and an outer surface,
wherein a first opening is provided at a first end of the sealing element and a second opening is provided at a second end of the sealing element, which is opposite to the first end, the wall extending between the first end and the second end,
wherein the wall comprises a first wall portion that is inclined such that a diameter of the sealing element increases from the first end in the direction towards the second end, and
wherein the first wall portion adjacently to the first end of the sealing element is provided with a radially inwardly extending circumferential protrusion and the protrusion is arc shaped and extends essentially in the direction away from the first end towards the second end and forms a circumferential open channel with the first wall portion.

2. The sealing element according to claim 1 , wherein the first wall portion is inclined with an angle in relation to a centre line of the sealing element, wherein the angle is between 1°-45°.

3. The sealing element according to claim 1 , wherein a spherical sealing protrusion is integrated with the first end, forming a convex inner surface of the first end.

4. The sealing element according to claim 1 , wherein a first, radially outwardly extending circumferential flange is provided at the first end and a second radially outwardly extending circumferential flange is provided at a distance from the first flange, the flanges forming a first outer groove with the first wall portion.

5. The sealing element according to claim 4 , wherein the second flange is tapered in a direction radially outwards from the wall.

6. The sealing element according to claim 1 , wherein the wall comprises a second wall portion that extends beyond the first wall portion in the direction away from the first end, wherein the second wall portion comprises at least one radially outwardly directed circumferential flange means and a second outer groove.

7. The sealing element according to claim 6 , wherein a slit is provided in the wall separating the second wall portion and the first wall portion.

8. A sound attenuation casing for a capacitor unit, comprising the sealing element according to claim 1 , wherein the sound attenuation casing forms the barrier element, the sound attenuation casing being provided with at least one opening through which the terminal bushing extends, wherein the sealing element is adapted to be fitted in the at least one opening.

9. The sound attenuation casing according to claim 8 , wherein the at least one opening is conical and has a larger diameter towards an outer surface of the casing, wherein conicity of the opening corresponds to the inclination of the first wall portion of the sealing element.

10. The sound attenuation casing according to claim 8 , wherein the sound attenuation casing comprises a base and four side walls extending perpendicular to the base and surrounding the base, wherein the base comprises the at least one opening.

11. The sound attenuation casing according to claim 10 , further comprising a sealing gasket, which is adapted to be fitted between the side walls of the sound attenuation casing and a capacitor unit.

12. A capacitor sound attenuation arrangement, comprising the sound attenuation casing according to claim 8 .

13. The capacitor sound attenuation arrangement according to claim 12 , further comprising a sound attenuation enclosure enclosing the sound attenuation casing, the sound attenuation enclosure having at least one opening through which the terminal bushing extends.

14. The capacitor sound attenuation arrangement according to claim 13 , wherein the case where the sealing element comprises a second outer groove, the second outer groove is adapted to be fitted to the at least one opening of the sound attenuation enclosure.

15. A power capacitor arrangement comprising a capacitor unit and the capacitor sound attenuation arrangement according to claim 12 .

16. The power capacitor arrangement according to claim 15 , wherein the capacitor unit comprises at least one terminal bushing and the sealing element is arranged in abutment with a shed of the terminal bushing, which shed is the shed closest to the capacitor unit.

17. The power capacitor arrangement according to claim 16 , wherein the radially inwardly extending circumferential protrusion of the sealing element is arranged in abutment with the shed.

18. The power capacitor arrangement according to claim 15 , wherein the first end of the sealing element is arranged in abutment with a base of the terminal bushing.

Assignees

• Abb Technology Ltd

Inventors

• Gustavsson Roger
• Johansson Petter

Classifications

• H01G2/103 Primary

  Sealings, e.g. for lead-in wires; Covers · CPC title

• H01G4/224

  Housing; Encapsulation · CPC title

• H01G4/236

  leading through the housing, i.e. lead-through · CPC title

• G10K11/16

  Methods or devices for protecting against, or for damping, noise or other acoustic waves in general (G10K11/36 takes precedence) · CPC title