JPH0412760Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention connects the intermediate connection part of the existing OF cable.
Reinforced to enable radial flow cooling.
This invention relates to a cooling cable connection.

[Conventional technology] FIG. 3 is an example of a normal connection part.

10 is a hollow oil passage.

12 is a cable conductor.

14 is a cable insulator.

16 is aluminum covered.

18 is the sheath side oil passage.

Reference numeral 20 denotes a reinforcing insulating layer, which is usually formed using wide oil-impregnated paper.

22 is a stiff layer, for example, first wrap crepe carbon paper 24 around the stress cone portion 21 of the reinforcing insulating layer 20, wrap a lead tape 26 over it, and tightly wrap a tin-plated copper wire 28 over it. It is formed by

30 indicates an external copper tube.

By the way, in the radial flow method forced cooling, insulating oil (which also serves as refrigerant oil) flows not only in the longitudinal direction in the hollow oil passage 10 of the cable but also in the radial direction in the cable insulator 14. . This cooling method has the effect of reducing the thermal resistance of the cable insulator 14 in addition to the cooling effect of the insulating oil.

[Problems to be Solved by the Invention] When wide oil-impregnated paper is used for the reinforcing insulating layer 20 as described above, a butt gap inevitably occurs due to the width of the wide oil-impregnated paper.

However, OF with radial flow forced cooling
In the cable, the pressure in the hollow oil passage 10 is always higher than that in the sheath side oil passage 18, and therefore a force that tends to widen the butt gap is always exerted.

However, the connecting portion of the above structure is not designed to withstand such forces. for that,
In some cases, the butt gap may widen and even lead to dielectric breakdown.

Therefore, it has a connection part with such a structure.
It is difficult to apply radial flow forced cooling to OF cable lines.

This invention solves the above problem and prevents the reinforcing insulating layer from being deformed or destroyed by hydraulic pressure.

[Means for Solving the Problems] As shown in FIG. 1, (1) The stress cone portions 21 at both ends of the reinforcing insulating layer 20 are formed so that the inner surface is in contact with the surface of the stress cone, and there is a gap between the inner and outer surfaces. A two-split presser 32 having a large number of small holes 36 passing through it.
(2) tighten the halves 32a and 32b of the presser 32, and (3) tighten the connecting rod 46 between the pressers 32 at both ends.
It is characterized by connecting with.

[Example] 32 is a two-piece presser (Figure 2).

This has a wrapper shape and has a flange 34 near the opening on the thick side.
The inner surface is shaped to fit into the stress cone portion 21. Further, a large number of small holes 36 are provided throughout the entire surface, penetrating between the inner and outer surfaces. These are for radial flow of oil.

The material of this presser 32 is stainless steel.
Non-magnetic metal such as aluminum or FRP
High-strength plastics such as

A two-piece presser 32 is placed on the left and right stress cone portions 21 which have been subjected to the normal heat treatment.
Attach the flanges 34 of the halves 32a and 32b.
For example, a bolt 4 with a spring 40 inserted between the
2 to fix the reinforcing insulating layer 20 and the cable insulating paper to form a shield layer 22.

Then, connect the connecting rod 4 containing the spring 44 between the flanges 34 of the left and right halves of the holding tool 32.
6 (for example, a through bolt). Connecting rod 4
The material 6 is a non-magnetic metal such as stainless steel or a high-strength plastic such as FRP.

This connecting rod 46 is connected to the left and right two-split presser 3.
It serves to mechanically connect the two and prevent them from being pushed and moved in the axial direction of the cable by hydraulic pressure.

48 is a reinforcing band. This is a cylinder made of stainless steel or the like, which is divided into two parts, and is attached to the center of the reinforcing insulating layer 20 at appropriate intervals, and then tightened with a band 50.
Fixed.

This reinforcing band 48 is for preventing the wide oil-impregnated paper from swelling in the radial direction due to hydraulic pressure.

[Effects of the invention] (1) Stress cones at both ends of the reinforcing insulating layer,
A two-split presser whose inner surface is in contact with the surface of the stress cone is placed on top of each other, and the two halves of the presser are tightened, and the pressers at both left and right ends are connected using a connecting rod. Therefore, by applying the radial flow method, even if strong hydraulic pressure is applied to the wide oil-impregnated paper of the reinforcing insulating layer to widen the butt gap, it can resist that force. This prevents the insulating layer from deforming in the length direction.

(2) Furthermore, since the bifurcated presser has many small holes penetrating between the inner and outer surfaces, the insulating oil can easily flow out to the outside of the reinforcing insulating layer.

(3) Therefore, when applied to an existing OF cable, a radial flow connection with good hydraulic resistance can be obtained without changing the structure of the reinforcing insulating layer.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention, FIG. 2 is a perspective view of a presser 32, and FIG. 3 is an explanatory diagram of a conventional power cable connection section. 10... Hollow oil passage, 14... Cable insulator, 18... Sheath side oil passage, 20... Reinforcement insulating layer, 22... Shallow layer, 32... Holder, 32
a, 32b...Two halves of the presser, 46...
...Connecting rod.

Claims (1)

[Claims for Utility Model Registration] In a connecting portion of a radial flow power cable in which a reinforcing insulating layer is formed by butting and winding wide oil-impregnated paper, the stress cone portions at both ends of the reinforcing insulating layer have inner surfaces that are exposed to the stress. A two-split presser, which is formed so as to be in contact with the surface of the cone and has a large number of small holes penetrating between the inner and outer surfaces, is placed on each of the cones, and the two halves of the presser are tightened, and the pressers at both ends are tightened. A connecting part of a power cable, characterized in that the parts thereof are connected by a connecting rod.