Cold shrinkable termination for an electric power cable

Patent metadata

Field	Value
Publication number	US-9716378-B2
Application number	US-201514682216-A
Country	US
Kind code	B2
Filing date	Apr 9, 2015
Priority date	Oct 9, 2012
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

A cold shrinkable termination has an electric power cable, an insulation body, and a stress control tube. The electric power cable has a conductor core, an insulation layer covering the conductor core, and a conductive shielding layer covering the insulation layer. The insulation body has a first end portion and an opposite second end portion. The stress control tube is disposed in the insulation body adjacent to the second end portion of the insulation body. The stress control tube has a first tube portion directly overlapped on the insulation layer of the electric power cable, and a second tube portion directly overlapped on the conductive shielding layer of the electric power cable and extending a predetermined length thereon when the cold shrinkable termination is mounted on the electric power cable.

First claim

What is claimed is:

1. A cold shrinkable termination comprising:
an electric power cable having
a conductor core,
an insulation layer covering the conductor core, and
a conductive shielding layer covering the insulation layer;

an insulation body having a first end portion and an opposite second end portion; and
a stress control tube molded to and integrally formed with the insulation body adjacent to the second end portion of the insulation body, and having
a first tube portion directly overlapped on the insulation layer of the electric power cable, and
a second tube portion directly overlapped on the conductive shielding layer of the electric power cable and extending a predetermined length thereon when the cold shrinkable termination is mounted on the electric power cable, an end surface of the second tube portion protruding from an inner wall of the insulation body.

2. The cold shrinkable termination according to claim 1 , wherein the conductive shielding layer is made of metal.

3. The cold shrinkable termination according to claim 2 , wherein the conductive shielding layer is copper wire or copper tape.

4. The cold shrinkable termination according to claim 1 , wherein the electric power cable further comprises a semi-conductive shielding layer positioned between the insulation layer and the conductive shielding layer.

5. The cold shrinkable termination according to claim 4 , wherein the stress control tube further comprises a third tube portion positioned between the first tube portion and the second tube portion.

6. The cold shrinkable termination according to claim 5 , wherein the second tube portion has an inner diameter larger than or equal to that of the first tube portion.

7. The cold shrinkable termination according to claim 6 , wherein when the cold shrinkable termination is mounted on the electric power cable, the third tube portion of the stress control tube directly overlaps on the semi-conductive shielding layer of the electric power cable.

8. The cold shrinkable termination according to claim 7 , wherein the electrical power cable further comprises an outermost sheath layer covering the conductive shielding layer; and the second end portion of the insulation body is sealed on the sheath.

9. The cold shrinkable termination according to claim 8 , wherein the end surface of the second tube portion abuts a cut end surface of the sheath.

10. The cold shrinkable termination according to claim 1 , further comprising a metal connecting terminal connected to the conductor core of the electrical power cable;
and a sealing compound disposed on the inner wall of the first end portion of the insulation body, sealing the first end portion of the insulation body positioned on the insulation layer of the electrical power cable, and the metal connection terminal when the cold shrinkable termination is mounted on the electrical power cable.

11. The cold shrinkable termination according to claim 10 , wherein the sealing compound is disposed on the inner wall of the first end portion of the insulation body by a pre-expansion tube before the cold shrinkable termination is mounted on the electric power cable.

12. The cold shrinkable termination according to claim 1 , further comprising a pre-expansion tube having:
a first expanding section having a first outer diameter, and being positioned in the stress control tube and holding the first tube portion of the stress control tube and the first end portion of the insulation body in a radially expanded state; and
a second expanding section having a second outer diameter larger than or equal to the first outer diameter, and being positioned in the stress control tube, and holding the second tube portion of the stress control tube and the second end portion of the insulation body in a radially expanded state.

13. The cold shrinkable termination according to claim 12 , wherein when the pre-expansion tube is positioned in the stress control tube, the cold shrinkable termination is held in a radially pre-expanded state prior to being mounted on the electric power cable.

14. The cold shrinkable termination according to claim 1 , wherein the stress control tube is made of a semi-conductive silicon rubber.

15. The cold shrinkable termination according to claim 14 , wherein the semi-conductive silicon rubber has a resistivity of 2 ohm cm to 5000 ohm cm.

16. The cold shrinkable termination according to claim 1 , wherein the insulation body is made of an insulation silicon rubber.

17. The cold shrinkable termination according to claim 16 , wherein the insulation silicon rubber has a resistivity of 1010 ohm cm to 1018 ohm cm.

18. The cold shrinkable termination according to claim 1 , wherein a plurality of ribbed protrusions are positioned on an outer wall of the insulation body, and extend radially outward.

19. The cold shrinkable termination according to claim 1 , wherein the electric power cable is used to transmit a high voltage of 110 kV or less.

20. The cold shrinkable termination according to claim 1 , wherein the second tube portion of the stress control tube has a length larger than 2 mm and less than 200 mm.

21. The cold shrinkable termination according to claim 20 , wherein a total length of the first and second tube portions of the stress control tube is larger than or equal to 30 mm.

22. A method of producing a cold shrinkable termination, comprising the steps of:
providing a first portion of a stress control tube;
placing the first portion of the stress control tube in a mold and injecting an insulation material into the mold to form an insulation body integrally formed with the first portion of the stress control tube as one piece;
spraying a second portion of the stress control tube on an inner wall of the insulation body to form an insulation body integrally formed with the second portion of the stress control tube as one piece;
providing a pre-expansion tube;
placing a sealing compound on an end of a pre-expansion tube; and
inserting the pre-expansion tube, on which the sealing compound has been placed, into the integrally formed stress control tube and insulation body to radially expand the integrally formed stress control tube and insulation body.

23. The method of producing a cold shrinkable termination of claim 22 , wherein the end of the pre-expansion tube having the sealing compound is disposed on an end portion of the integrally formed stress control tube and insulation body opposite to the stress control tube.

Assignees

• Tyco Electronics Shanghai Co Ltd
• Tyco Electronics Corp
• Te Connectivity Corp
• Tyco Electronics Shanghai Co Ltd

Inventors

• Wu Jing
• Sang Wenlei
• Yaworski Harry George
• Yang Lizhang
• Xie Xiongchun

Classifications

• H01B9/02

  with screens or conductive layers, e.g. for avoiding large potential gradients · CPC title

• H02G1/14

  for joining or terminating cables · CPC title

• Y10T29/49178

  by shrinking of cover · CPC title

• H02G15/068

  connected to the cable shield only (H02G15/072 takes precedence) · CPC title

• H02G15/046 Primary

  with bores or protruding portions allowing passage of cable conductors · CPC title