Patent Description:
Submarine cable is a current-carrying device for power transmission under the sea, which is applicable in power supply for offshore drilling platforms, offshore islands, etc. Generally, the submarine cable includes a submarine cable section, a landing cable section and a joint connecting the submarine cable section and the landing cable section. The submarine cable section refers to a portion of the submarine cable located in deep water, and the landing cable section refers to a portion of the submarine cable located between the shallow water near the shore and a joint at the beach.

Due to the impact of environmental changes and human activities, the current-carrying capacity of the landing cable section is relatively low. Therefore, in order to solve the current-carrying capacity bottleneck problem of the landing cable section, it is generally designed that a cross-section of a conductor of the landing cable section is greater than that of a conductor of the submarine cable section and that the landing cable section is connected to the submarine cable section through a joint. The landing cable section and the submarine cable section are generally connected through a service joint. The service joint includes a crimping sleeve, a prefabricated insulating part, and a waterproof casing. For connecting the landing cable section and the submarine cable section through the service joint, the conductors of both the landing cable section and the submarine cable section are placed into the crimping sleeve so as to be connected by way of crimping.

However, the submarine cable presents poor bendability, flexibility and electrical performance when the landing cable section and the submarine cable section are connected through the service joint.

<CIT> relates to a connection method and structure for a submarine cable, which is used to reduce the cost by a satisfactory connection of cables having different conductor section areas.

<CIT> relates to an ultra-high-voltage submarine cable flexible joint, which comprises a conductor welding segment, a conductor shielding recovery layer, an insulation recovery layer, an insulation shielding recovery layer, a metal sheath recovery layer and an outer sheath recovery layer.

<CIT> discloses a flexible joint for 220kV crosslinked polyethylene submarine cables and a method for manufacturing the flexible j oint, which is suitable for manufacturing long 220kV submarine cables, meeting the clients' demand on integral long submarine cables.

In view of the above problems, embodiments of the present invention provide a submarine cable and a method for manufacturing the same, to improve the bendability, flexibility and electrical performance of the submarine cable.

In order to achieve the above purpose, embodiments of the present invention provide following technical solutions.

Embodiments of the present invention provide a submarine cable, including:.

The submarine cable provided by the embodiments of the present invention has following advantages:
the submarine cable provided by the embodiments of the present invention includes the submarine cable section and the landing cable section, the n first monofilament layers of the first conductor of the submarine cable section, from inside to outside in the radial direction of the submarine cable, are welded to the n second welding monofilament layers in the m second monofilament layers of the second conductor of the landing cable section in a one-to-one relationship. The h second winding monofilament layers in the m second monofilament layers are, sequentially from inside to outside in the radial direction of the submarine cable, wound outside the outermost layer of the n first monofilament layers. For any two adjacent second winding monofilament layers, a winding part of a second winding monofilament layer located outside covers a winding part of a second winding monofilament layer located inside, and the area in which the n first monofilament layers are connected to the m second monofilament layers forms the conductor welding area of the joint. With such arrangement, the first monofilament layers of the first conductor and the second monofilament layers of the second conductor are connected together by way of welding and winding, without using a crimping sleeve. This can improve the bendability and flexibility of the submarine cable, and in comparison to connecting the conductors of the landing cable section and the submarine cable section by crimping, connecting them by welding and winding offers a stronger bonding force between the conductors of the landing cable section and the submarine cable section, which results in less easy separation of the conductors of the landing cable section and the submarine cable section and thus improves the electrical performance of the submarine cable.

In the submarine cable as described above, a difference between a winding pitch of the winding part of each of the second winding monofilament layers and a stranding pitch of a stranding part of each of the second winding monofilament layers is less than a preset difference, and the stranding part refers to a portion of each of the second winding monofilament layers stranded outside an outermost layer of the second welding monofilament layers.

In the submarine cable as described above, for any two adjacent second welding monofilament layers, a second welding monofilament layer located outside covers a secondary welding area between a second welding monofilament layer located inside and a corresponding first monofilament layer;.

In the submarine cable as described above, the submarine cable section further includes a first conductor shielding layer, and the first conductor shielding layer covers part of the first conductor; the landing cable section further includes a second conductor shielding layer, and the second conductor shielding layer covers part of the second conductor; and the joint further includes a conductor shielding recovery layer, the conductor shielding recovery layer covers part of the first conductor, part of the second conductor, and the conductor welding area, and the conductor shielding recovery layer has one end connected to the first conductor shielding layer and the other end connected to the second conductor shielding layer.

In the submarine cable as described above, the submarine cable section further includes a first insulating layer, and the first insulating layer covers the first conductor shielding layer; the landing cable section further includes a second insulating layer, and the second insulating layer covers the second conductor shielding layer; and the joint further includes an insulating recovery layer, the insulating recovery layer covers the conductor shielding recovery layer, and the insulating recovery layer has one end connected to the first insulating layer and the other end connected to the second insulating layer.

In the submarine cable as described above, the submarine cable section further includes a first insulation shielding layer, and the first insulation shielding layer covers the first insulating layer; the landing cable section further includes a second insulation shielding layer, and the second insulation shielding layer covers the second insulating layer; and the joint further includes an insulation shielding recovery layer, the insulation shielding recovery layer covers the insulating recovery layer, and the insulation shielding recovery layer has one end connected to the first insulation shielding layer and the other end connected to the second insulation shielding layer.

In the submarine cable as described above, the submarine cable section further includes a first longitudinal water blocking layer, and the first longitudinal water blocking layer covers part of the first insulation shielding layer; the landing cable section further includes a second longitudinal water blocking layer, and the second longitudinal water blocking layer covers part of the second insulation shielding layer; and the joint further includes a longitudinal water-blocking recovery layer, the longitudinal water-blocking recovery layer covers part of the first insulation shielding layer, part of the second insulation shielding layer, and the insulation shielding recovery layer, and the longitudinal water-blocking recovery layer has one end connected to the first longitudinal water blocking layer and the other end connected to the second longitudinal water blocking layer.

In the submarine cable as described above, the submarine cable section further includes a first radial water blocking layer, and the first radial water blocking layer covers part of the first longitudinal water blocking layer; the landing cable section further includes a second radial water blocking layer, and the second radial water blocking layer covers part of the second longitudinal water blocking layer; and the joint further includes a radial water-blocking recovery layer, the radial water-blocking recovery layer covers part of the first longitudinal water blocking layer, part of the second longitudinal water blocking layer, and the longitudinal water-blocking recovery layer, and the radial water-blocking recovery layer has one end connected to the first radial water blocking layer and the other end connected to the second radial water blocking layer.

In the submarine cable as described above, the submarine cable section further includes a first non-metallic sheath layer, and the first non-metallic sheath layer covers part of the first radial water blocking layer; the landing cable section further includes a second non-metallic sheath layer, and the second non-metallic sheath layer covers part of the second radial water blocking layer; and the joint further includes a non-metallic sheath recovery layer, and the non-metallic sheath recovery layer covers part of the first radial water blocking layer, part of the second radial water blocking layer, and the radial water-blocking recovery layer, and the non-metallic sheath recovery layer has one end connected to the first non-metallic sheath layer and the other end connected to the second non-metallic sheath layer.

In the submarine cable as described above, the submarine cable further includes an armor inner cushion layer, an armor layer, and an armor outer coating layer, and the armor inner cushion layer covers the first non-metallic sheath layer, the second non-metallic sheath layer, and the non-metallic sheath recovery layer; and the armor layer covers the armor inner cushion layer, and the armor outer coating layer covers the armor layer.

Embodiments of the present invention further provide a method for manufacturing a submarine cable, including:.

The method for manufacturing the submarine cable provided by the embodiments of the present invention has following advantages:
in the method for manufacturing the submarine cable provided by the embodiments of the present invention, firstly the submarine cable section with part of the first conductor exposed and the landing cable section with part of the second conductor exposed are provided, secondly the n first monofilament layers of the first conductor of the submarine cable section, from inside to outside in the radial direction of the submarine cable, are welded to the n second welding monofilament layers in the m second monofilament layers of the second conductor of the landing cable section in a one-to-one relationship, and then the h second winding monofilament layers in the m second monofilament layers are, sequentially from inside to outside in the radial direction of the submarine cable, wound outside the outermost layer of the n first monofilament layers. For any two adjacent second winding monofilament layers, a winding part of a second winding monofilament layer located outside covers a winding part of a second winding monofilament layer located inside. Therefore, the area in which the n first monofilament layers are connected to the m second monofilament layers forms the conductor welding area of the joint. With the above steps, the first monofilament layers of the first conductor and the second monofilament layers of the second conductor can be connected together by way of welding and winding, without using a crimping sleeve. This can improve the bendability and flexibility of the submarine cable, and in comparison to connecting the conductors of the landing cable section and the submarine cable section by crimping, connecting them by welding and winding offers a stronger bonding force between the conductors of the landing cable section and the submarine cable section, which results in less easy separation of the conductors of the landing cable section and the submarine cable section and thus improves the electrical performance of the submarine cable.

In the method for manufacturing the submarine cable as described above, in a step of winding sequentially from inside to outside the h second winding monofilament layers outside the outermost layer of the n first monofilament layers, a difference between a winding pitch of the winding part of each of the second winding monofilament layers and a stranding pitch of a stranding part of each of the second winding monofilament layers is less than a preset difference; and
the stranding part refers to a portion of each of the second winding monofilament layers stranded outside an outermost layer of the second welding monofilament layers.

In the method for manufacturing the submarine cable as described above, a step of welding the n first monofilament layers to the n second welding monofilament layers in a one-to-one relationship further includes:.

In the method for manufacturing the submarine cable as described above, the step of winding, sequentially from inside to outside in the radial direction of the submarine cable, the h second winding monofilament layers outside the outermost layer of the n first monofilament layers further includes:
welding a winding end of the winding part of each of the second winding monofilament layers to the outermost layer of the first monofilament layers, and performing a polishing operation on a welding area between the winding end and the outermost layer of the first monofilament layers, so that a connection between the winding end and the outermost layer of the first monofilament layers is firm and smooth.

In the method for manufacturing the submarine cable as described above, following a step of forming the conductor welding area, the method for manufacturing the submarine cable further includes: covering, by way of winding or extrusion molding with a same material as a conductor shielding layer, the conductor welding area and a exposed portion of the first conductor and a exposed portion of the second conductor to form a conductor shielding recovery layer, and making the conductor shielding recovery layer have one end connected to a first conductor shielding layer of the submarine cable section and the other end connected to a second conductor shielding layer of the landing cable section.

In the method for manufacturing the submarine cable as described above, following a step of forming the conductor shielding recovery layer, the method for manufacturing the submarine cable further includes: cutting a first insulating layer of the submarine cable section to obtain a cone surface with a cone angle not greater than <NUM>°, and cutting a second insulating layer of the landing cable section to obtain a cone surface with a cone angle not greater than <NUM>°; and covering, by way of extrusion molding with a same material as the first insulating layer and the second insulating layer, the conductor shielding recovery layer to form an insulating recovery layer, and making the insulating recovery layer have one end connected to the first insulating layer and the other end connected to the second insulating layer.

In the method for manufacturing the submarine cable as described above, following a step of forming the insulating recovery layer, the method for manufacturing the submarine cable further includes: covering, with a same material as a first insulation shielding layer of the submarine cable section and a second insulation shielding layer of the landing cable section, the insulating recovery layer to form an insulation shielding recovery layer, and making the insulation shielding recovery layer have one end connected to the first insulation shielding layer and the other end connected to the second insulation shielding layer; covering, with a same material as a first longitudinal water blocking layer of the submarine cable section and a second longitudinal water blocking layer of the landing cable section, the insulation shielding recovery layer to form a longitudinal water-blocking recovery layer, and making the longitudinal water-blocking recovery layer have one end connected to the first longitudinal water blocking layer and the other end connected to the second longitudinal water blocking layer; and covering, with a same material as a first radial water blocking layer of the submarine cable section and a second radial water blocking layer of the landing cable section, the longitudinal water-blocking recovery layer to form a radial water-blocking recovery layer, and making the radial water-blocking recovery layer have one end connected to the first radial water blocking layer and the other end connected to the second radial water blocking layer.

In the method for manufacturing the submarine cable as described above, following a step of forming the radial water-blocking recovery layer, the method for manufacturing the submarine cable further includes: when a material of a first non-metallic sheath layer of the submarine cable section is same as that of a second non-metallic sheath layer of the landing cable section, covering, with a non-metallic sheath material same as that of the first non-metallic sheath layer and the second non-metallic sheath layer, the radial water-blocking recovery layer, and heating the non-metallic sheath material, to form a non-metallic sheath recovery layer with the non-metallic sheath recovery layer, the first non-metallic sheath layer and the second non-metallic sheath layer integrated; and when the material of the first non-metallic sheath layer of the submarine cable section is different from that of the second non-metallic sheath layer of the landing cable section, covering, with a non-metallic sheath material same as that of the first non-metallic sheath layer or the second non-metallic sheath layer, the radial water-blocking recovery layer, and heating the non-metallic sheath material, to form a non-metallic sheath recovery layer with the non-metallic sheath recovery layer, the first non-metallic sheath layer and the second non-metallic sheath layer integrated.

In the method for manufacturing the submarine cable as described above, following a step of when the material of the first non-metallic sheath layer of the submarine cable section is different from that of the second non-metallic sheath layer of the landing cable section, covering, by way of extrusion molding with the non-metallic sheath material same as that of the first non-metallic sheath layer or the second non-metallic sheath layer, the radial water-blocking recovery layer, and heating the non-metallic sheath material, to form the non-metallic sheath recovery layer, the method for manufacturing the submarine cable further includes: when the non-metallic sheath material is same as the material of the first non-metallic sheath layer, winding a cross-linked polyethylene tape at a junction between the non-metallic sheath recovery layer and the second non-metallic sheath layer, and heating the cross-linked polyethylene tape to integrate the cross-linked polyethylene tape, the non-metallic sheath recovery layer, and the second non-metallic sheath layer; and when the non-metallic sheath material is same as the material of the second non-metallic sheath layer, winding a cross-linked polyethylene tape at a junction between the non-metallic sheath recovery layer and the first non-metallic sheath layer, and heating the cross-linked polyethylene tape to integrate the cross-linked polyethylene tape, the non-metallic sheath recovery layer, and the first non-metallic sheath layer.

In the method for manufacturing the submarine cable as described above, following a step of forming the non-metallic sheath recovery layer, the method for manufacturing the submarine cable further includes: arranging, by using an armoring tool, an armor layer outside the non-metallic sheath recovery layer, the first non-metallic sheath layer, and the second non-metallic sheath layer, where the armoring tool includes a hydraulic cylinder, a pressure sensor, an inner mould layer, and an outer mould layer, the inner mould layer is located within the outer mould layer, the hydraulic cylinder is connected with the inner mould layer for controlling the inner mould layer to be tightened or loosened, and the pressure sensor is in signal connection with the inner mould layer and the hydraulic cylinder, respectively for controlling a movement of the hydraulic cylinder according to a pressure on the inner mould layer.

To illustrate the technical solutions in the embodiments of the present invention or in the prior art more clearly, the drawings required for describing the embodiments or the prior art will be briefly introduced below. Apparently, the accompanying drawings described below show some embodiments of the present invention, and persons of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

In the related art, a landing cable section and a submarine cable section are generally connected through a service j oint. The service joint includes a crimping sleeve. For connecting the landing cable section and the submarine cable section through the service joint, conductors of both the landing cable section and the submarine cable section are placed into the crimping sleeve so as to be connected by way of crimping. However, when the landing cable section and the submarine cable section are connected through the service joint, the submarine cable presents poor bendability and flexibility due to the crimping sleeve incapable of being bent, and the bonding force between the conductors of the landing cable section and of the submarine cable section is relatively weak as the conductors are connected by way of crimping, which results in easy separation of the conductors of the landing cable section and of the submarine cable section and thus poor electrical performance of the submarine cable.

In view of the above problems, a submarine cable provided by an embodiment of the present invention includes a submarine cable section and a landing cable section, n first monofilament layers of the submarine cable section, from inside to outside in a radial direction of the submarine cable, are welded to n second welding monofilament layers in m second monofilament layers of the landing cable section in a one-to-one relationship, and h second winding monofilament layers that are extra layers in the m second monofilament layers relative to the n first monofilament layers are, sequentially from inside to outside in the radial direction of the submarine cable, wound outside an outermost layer of the n first monofilament layers. With such arrangement, the first monofilament layers of a first conductor and the second monofilament layers of a second conductor are connected together by way of welding and winding, without using a crimping sleeve. This can improve the bendability and flexibility of the submarine cable, and in comparison to connecting the conductors of the landing cable section and the submarine cable section by crimping, connecting them by welding and winding offers a stronger bonding force between the conductors of the landing cable section and the submarine cable section, which results in less easy separation of the conductors of the landing cable section and the submarine cable section and thus improves the electrical performance of the submarine cable.

To make the above objectives, features, and advantages of the embodiments according to the present invention clearer and understandable, the following clearly and completely describes the technical solutions in the embodiments according to the present invention with reference to the accompanying drawings in the embodiments according to the present invention. Apparently, the described embodiments are only some but not all of the embodiments according to the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments according to the present invention without creative efforts shall fall within the protection scope of the present invention.

As shown in <FIG>, a submarine cable provided by an embodiment of the present invention includes a submarine cable section <NUM> and a landing cable section <NUM>. The submarine cable section <NUM> refers to a portion of the submarine cable located in deep water, and the landing cable section <NUM> refers to a portion of the submarine cable located between the shallow water near the shore and a joint at the beach.

The submarine cable section <NUM> includes a first conductor <NUM>, and the first conductor <NUM> includes n first monofilament layers <NUM> sequentially arranged from inside to outside in a radial direction of the submarine cable. The landing cable section <NUM> includes a second conductor <NUM>, and the second conductor <NUM> includes m second monofilament layers <NUM> sequentially arranged from inside to outside in the radial direction of the submarine cable. The m second monofilament layers <NUM> are sequentially divided from inside to outside in the radial direction of the submarine cable into n second welding monofilament layers <NUM> and h second winding monofilament layers <NUM>, where m and n are both positive integers, and m≥n, h=m-n. Each of the first monofilament layers <NUM> and of the second monofilament layers <NUM> may include multiple monofilaments, and the monofilaments may be copper monofilaments, or aluminum monofilaments, etc..

The first conductor <NUM> and the second conductor <NUM>, which may be multi-layer tightly-compressed stranded circular copper conductors or multi-layer tightly-compressed stranded circular aluminum conductors, are each a water-blocking conductor with a water-blocking material that may be one or more of a water-blocking tape, a water-blocking yarn, water-blocking glue, and water-blocking powder. The first conductor <NUM> and the second conductor <NUM> may have a same or different cross-sectional area. In this embodiment, the first conductor <NUM> has a smaller cross-sectional area than the second conductor <NUM>.

As shown in <FIG>, the n first monofilament layers <NUM> are, from inside to outside in the radial direction of the submarine cable, welded to the n second welding monofilament layers <NUM> in a one-to-one relationship, and the h second winding monofilament layers <NUM> are, sequentially from inside to outside in the radial direction of the submarine cable, wound outside an outermost layer of the n first monofilament layers <NUM>. For any two adjacent second winding monofilament layers <NUM>, a winding part of a second winding monofilament layer <NUM> located outside covers a winding part of a second winding monofilament layer <NUM> located inside. The winding part refers to a portion of each of the second winding monofilament layers <NUM> wound outside the outermost layer of the first monofilament layers <NUM>. An area where the n first monofilament layers <NUM> are connected to the m second monofilament layers <NUM> forms a conductor welding area of a joint.

In some embodiments, from inside to outside in the radial direction of the submarine cable, first monofilament layers <NUM> and second welding monofilament layers <NUM> within same layers have the same number of monofilaments. At this point, corresponding welding of the first monofilament layers <NUM> and the second welding monofilament layers means that, from inside to outside in the radial direction of the submarine cable, monofilaments of the first monofilament layers <NUM> and monofilaments of the second welding monofilament layers <NUM> within the same layers are welded in a one-to-one relationship.

It should be noted that winding of each of the second winding monofilament layers <NUM> outside the outermost layer of the first monofilament layers <NUM> does not mean that each of the second winding monofilament layers <NUM> along its whole length is wound outside the outermost layer of the first monofilament layers <NUM>, but instead a portion of each of the second winding monofilament layers <NUM>, which is beyond a welding area between the first monofilament layers <NUM> and the second monofilament layers <NUM>, such as a section a and a section b in <FIG>, is wound outside the outermost layer of the first monofilament layers <NUM>. Furthermore, in some embodiments, a portion of each of the second winding monofilament layers <NUM>, which is not beyond the welding area between the first monofilament layers <NUM> and the second monofilament layers <NUM> is stranded outside an outermost layer of the second welding monofilament layers <NUM>.

For ease of understanding, the n first monofilament layers <NUM> are divided sequentially from inside to outside in the radial direction of the submarine cable into layers a<NUM>, a<NUM>, a<NUM>,. , and an, the n second welding monofilament layers <NUM> are divided sequentially from inside to outside in the radial direction of the submarine cable into layers b<NUM>, b<NUM>, b<NUM>,. , and bn, and the h second winding monofilament layers <NUM> are divided sequentially from inside to outside in the radial direction of the submarine cable into layers c<NUM>, c<NUM>, c<NUM>,. , and ch, where layer c<NUM> is located outside layer bn.

The n first monofilament layers <NUM> are, from inside to outside in the radial direction of the submarine cable, welded to the n second welding monofilament layers <NUM> in a one-to-one relationship, that is, the layers a<NUM>, a<NUM>, a<NUM>,. , and an are welded to the layers b<NUM>, b<NUM>, b<NUM>,. , and bn in a one-to-one relationship, that is, layer a<NUM> is welded to layer b<NUM>, layer a<NUM> is welded to layer b<NUM>, layer a<NUM> is welded to layer b<NUM>,. , layer an is welded to layer bn.

The h second winding monofilament layers <NUM> are, sequentially from inside to outside in the radial direction of the submarine cable, wound outside the outermost layer of the n first monofilament layers <NUM>; and for any two adjacent second winding monofilament layers <NUM>, a winding part of a second winding monofilament layer <NUM> located outside covers a winding part of a second winding monofilament layer <NUM> located inside. The winding part refers to a portion of each of the second winding monofilament layers <NUM> wound outside the outermost layer of the first monofilament layers <NUM>. This means that layer c<NUM> is wound outside layer an first, and a portion of layer c<NUM> wound outside layer an is the winding part of layer c<NUM>, and then layer c<NUM> is wound outside layer an, and a portion of layer c<NUM> wound outside layer an is the winding part of layer c<NUM>, and the winding part of layer c<NUM> covers the winding part of layer c<NUM>. By analogy, finally, layer ch is wound outside layer an, and a portion of layer ch wound outside layer an is the winding part of layer ch, and the winding part of layer ch covers the winding part of layer ch-<NUM>.

When m is equal to n, taking a value of both m and n equal to <NUM> as an example, the first monofilament layers <NUM> are layers a<NUM>, a<NUM> and a<NUM> sequentially from inside to outside, and the second monofilament layers <NUM> are layers by, b<NUM> and b<NUM> sequentially from inside to outside. At this point, within the submarine cable, layer a<NUM> is welded to layer b<NUM>, layer a<NUM> is welded to layer b<NUM>, and layer a<NUM> is welded to layer b<NUM>.

As shown in <FIG>, when m is greater than n, taking the value of m equal to <NUM> and the value of n equal to <NUM> as an example, the first monofilament layers <NUM> are layers a<NUM>, a<NUM> and a<NUM> sequentially from inside to outside, and the second monofilament layers <NUM> are layers b<NUM>, b<NUM>, b<NUM>, c<NUM>, and c<NUM> sequentially from inside to outside. At this point, within the submarine cable, layer a<NUM> is welded to layer b<NUM>, layer a<NUM> is welded to layer b<NUM>, layer a<NUM> is welded to layer b<NUM>, layer c<NUM> is wound outside layer a<NUM>, layer c<NUM> is wound outside layer a<NUM> and a portion of layer c<NUM> wound outside layer a<NUM> covers a portion of layer c<NUM> wound outside layer a<NUM>.

With such arrangement, the first monofilament layers <NUM> of the first conductor <NUM> and the second monofilament layers <NUM> of the second conductor <NUM> are connected together by way of welding and winding, without using a crimping sleeve. This can improve the bendability and flexibility of the submarine cable, and in comparison to connecting the conductors of the landing cable section <NUM> and the submarine cable section <NUM> by crimping, connecting them by welding and winding offers a stronger bonding force between the conductors of the landing cable section and the submarine cable section, which results in less easy separation of the conductors of the landing cable section and the submarine cable section and thus improves the electrical performance of the submarine cable.

Further, when the cross-sectional area of the second conductor <NUM> differs from the cross-sectional area of the first conductor <NUM> by more than one standard size, joints of the factory in the related art fail to connect the first conductor <NUM> to the second conductor <NUM>. However, in this embodiment, by winding the second winding monofilament layers <NUM> in the second monofilament layers <NUM>, on the outermost layer of the first monofilament layers <NUM>, extra monofilament layers of the second conductor <NUM> relative to the first conductor <NUM> can be connected to the first monofilament layers <NUM> by way of winding, which thereby solves the technical problem that the first conductor <NUM> cannot be connected to the second conductor <NUM> when the cross-sectional area of the second conductor <NUM> differs from the cross-sectional area of the first conductor <NUM> by more than one standard size. In addition, for any two adjacent second winding monofilament layers <NUM>, a winding part of a second winding monofilament layer <NUM> located outside covers a winding part of a second winding monofilament layer <NUM> located inside. Such arrangement enables protection of the winding part located inside, and an outer surface of a conductor welding area <NUM> of the joint can be smoother by layer upon layer covering.

It should be noted that, in a specific embodiment, respective standard sizes of the cross-sectional areas of the first conductor <NUM> and the second conductor <NUM>, in ascending order, are <NUM>-<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> (unit: square millimeters).

According to the invention, a difference between a winding pitch of the winding part of each of the second winding monofilament layers <NUM> and a stranding pitch of a stranding part of each of the second winding monofilament layers <NUM> is less than a preset difference. The stranding part refers to a portion of each of the second winding monofilament layers <NUM> stranded outside the outermost layer of the second welding monofilament layers <NUM>, and the preset difference is <NUM>% of the stranding pitch of the stranding part of each of the second winding monofilament layers. This means that the difference between the winding pitch of the winding part of layer ci from aforementioned layers c<NUM>, c<NUM>, c<NUM>,. , and ch wound outside layer an and the stranding pitch of the stranding part of layer ci stranded outside layer bn is less than <NUM>% of the stranding pitch of the stranding part of layer ci stranded outside layer bn. Here, ci may be any one of layers c<NUM>, c<NUM>, c<NUM>,. With such arrangement, the winding part of layer ci wound outside layer an and the part of layer ci stranded outside the outermost layer of the second welding monofilament layers <NUM> are similar in size, so that the conductor welding area <NUM> of the joint <NUM> formed by the connection of the first conductor <NUM> and the second conductor <NUM> presents a smooth transition.

Further, for any two adjacent second welding monofilament layers <NUM>, a second welding monofilament layer <NUM> located outside covers a secondary welding area <NUM> between a second welding monofilament layer <NUM> located inside and a first monofilament layer <NUM>. An innermost layer of the second winding monofilament layers <NUM> covers a secondary welding area <NUM> between the outermost layer of the first monofilament layers <NUM> and the outermost layer of the second welding monofilament layers <NUM>. The secondary welding area <NUM> is an area where a first monofilament layer <NUM> and a second monofilament layer <NUM> are welded. Such arrangement enables protection of the welding area and prevention of two adjacent secondary welding areas <NUM> from contacting each other, thereby improving the electrical performance of the submarine cable.

In some embodiments, a winding end of the winding part of each of the second winding monofilament layers <NUM> is welded to the outermost layer of the first monofilament layers <NUM>, so that a connection between each of the second winding monofilament layers <NUM> and the outermost layer of the first monofilament layers <NUM> is firmer. Further, a polishing operation may be performed on the welding area between the winding end and the outermost layer of the first monofilament layers <NUM> so as to make the connection between the winding end and the outermost layer of the first monofilament layers <NUM> smoother. Here, the winding end refers to an end of a part, wound on the outermost layer of the first monofilament layers <NUM>, of each monofilament in each of the second winding monofilament layers <NUM>.

The submarine cable provided by the embodiments of the present invention may be different types of submarine cables such as a single-core submarine cable and a three-core submarine cable, etc., and when the submarine cable provided by the embodiments of the present invention is a three-core submarine cable, a distance between any two joints <NUM> is greater than <NUM> meters, so that the mechanical performance of the submarine cable can be improved.

As shown in <FIG>, in a specific embodiment, the submarine cable section <NUM> further includes a first conductor shielding layer <NUM>, and the first conductor shielding layer <NUM> covers part of the first conductor <NUM>. The landing cable section <NUM> further includes a second conductor shielding layers <NUM>, and the second conductor shielding layer <NUM> covers part of the second conductor <NUM>. The joint <NUM> further includes a conductor shielding recovery layer <NUM>, and the conductor shielding recovery layer <NUM> covers part of the first conductor <NUM>, part of the second conductor <NUM>, and the conductor welding area <NUM>, and has one end connected to the first conductor shielding layer <NUM> and the other end connected to the second conductor shielding layer <NUM>. External interference can be shielded by arranging the first conductor shielding layer <NUM>, the second conductor shielding layer <NUM>, and the conductor shielding recovery layer <NUM>.

Each of the first conductor shielding layer <NUM> and the second conductor shielding layer <NUM> may be formed by covering by way of extrusion molding with a semi-conductive polyethylene shielding material, or by covering by way of winding with a water-blocking tape combined with covering by way of extrusion molding with semi-conductive polyethylene. The conductor shielding recovery layer <NUM>, the first conductor shielding layer <NUM>, and the second conductor shielding layer <NUM> are of a same material. Such arrangement can strengthen the bonding force between the conductor shielding recovery layer <NUM> and the first conductor shielding layer <NUM>, and that between the conductor shielding recovery layer <NUM> and the second conductor shielding layer <NUM>.

As shown in <FIG>, the submarine cable section <NUM> further includes a first insulating layer <NUM>, and the first insulating layer <NUM> covers the first conductor shielding layer <NUM>. The landing cable section <NUM> further includes a second insulating layer <NUM>, and the second insulating layer <NUM> covers the second conductor shielding layer <NUM>. The joint <NUM> further includes an insulating recovery layer <NUM>. The insulating recovery layer <NUM> covers the conductor shielding recovery layer <NUM>, and has one end connected to the first insulating layer <NUM> and the other end connected to the second insulating layer <NUM>. Such arrangement can insulate the first conductor <NUM>, the second conductor <NUM> and the conductor welding area <NUM> from the outside.

Each of the first insulating layer <NUM> and the second insulating layer <NUM> may be formed by covering by way of extrusion molding with cross-linked polyethylene. The insulating recovery layer <NUM>, the first insulating layer <NUM> and the second insulating layer <NUM> are of a same material. Such arrangement can strengthen the bonding force between the insulating recovery layer <NUM> and the first insulating layer <NUM>, and between the insulating recovery layer <NUM> and the second insulating layer <NUM>.

As shown in <FIG>, the submarine cable section <NUM> further includes a first insulation shielding layer <NUM>, and the first insulation shielding layer <NUM> covers the first insulating layer <NUM>. The landing cable section <NUM> further includes a second insulation shielding layer <NUM>, and the second insulation shielding layer <NUM> covers the second insulating layer <NUM>. The joint <NUM> further includes an insulation shielding recovery layer <NUM>. The insulation shielding recovery layer <NUM> covers the insulating recovery layer <NUM>, and has one end connected to the first insulation shielding layer <NUM> and the other end connected to the second insulation shielding layer <NUM>. Such arrangement can further shield external interference and improve insulating property of the first conductor <NUM>, the second conductor <NUM>, and the conductor welding area <NUM> against the outside.

Each of the first insulation shielding layer <NUM> and the second insulation shielding layer <NUM> may be formed by covering by way of extrusion molding with a semi-conductive polyethylene shielding material. The insulation shielding recovery layer <NUM>, the first insulation shielding layer <NUM> and the second insulation shielding layer <NUM> are of a same material. Such arrangement can strengthen the bonding force between the insulation shielding recovery layer <NUM> and the first insulation shielding layer <NUM>, and between the insulation shielding recovery layer <NUM> and the second insulation shielding layer <NUM>.

As shown in <FIG>, the submarine cable section <NUM> further includes a first longitudinal water blocking layer <NUM>, and the first longitudinal water blocking layer <NUM> covers part of the first insulation shielding layer <NUM>. The landing cable section <NUM> further includes a second longitudinal water blocking layer <NUM>, and the second longitudinal water blocking layer <NUM> covers part of the second insulation shielding layer <NUM>. The joint <NUM> further includes a longitudinal water-blocking recovery layer <NUM>. The longitudinal water-blocking recovery layer <NUM> covers part of the first insulation shielding layer <NUM>, part of the second insulation shielding layer <NUM> and the insulation shielding recovery layer <NUM>, and has one end connected to the first longitudinal water blocking layer <NUM> and the other end connected to the second longitudinal water blocking layer <NUM>. Such arrangement can prevent external moisture from penetrating into the interior of the submarine cable along a longitudinal direction.

Each of the first longitudinal water blocking layer <NUM> and the second longitudinal water blocking layer <NUM> may be formed by covering by way of winding with a semi-conductive water-blocking tape. The longitudinal water-blocking recovery layer <NUM>, the first longitudinal water blocking layer <NUM> and the second longitudinal water blocking layer <NUM> are of a same material. Such arrangement can strengthen the bonding force between the longitudinal water-blocking recovery layer <NUM> and the first longitudinal water blocking layer <NUM>, and between the longitudinal water-blocking recovery layer <NUM> and the second longitudinal water blocking layer <NUM>.

As shown in <FIG>, the submarine cable section <NUM> further includes a first radial water blocking layer <NUM>, and the first radial water blocking layer <NUM> covers part of the first longitudinal water blocking layer <NUM>. The landing cable section <NUM> further includes a second radial water blocking layer <NUM>, and the second radial water blocking layer <NUM> covers part of the second longitudinal water blocking layer <NUM>. The joint <NUM> further includes a radial water-blocking recovery layer <NUM>. The radial water-blocking recovery layer <NUM> covers part of the first longitudinal water blocking layer <NUM>, part of the second longitudinal water blocking layer <NUM> and the longitudinal water-blocking recovery layer <NUM>, and has one end connected to the first radial water blocking layer <NUM> and the other end connected to the second radial water blocking layer <NUM>. Such arrangement can prevent external moisture from penetrating into the interior of the submarine cable in the radial direction.

Each of the first radial water blocking layer <NUM> and the second radial water blocking layer <NUM> may be formed by covering by way of extrusion molding with a lead alloy sheath. The radial water-blocking recovery layer <NUM>, the first radial water blocking layer <NUM> and the second radial water blocking layer <NUM> are of a same material. Such arrangement can strengthen the bonding force between the radial water-blocking recovery layer <NUM> and the first radial water blocking layer <NUM>, and between the radial water-blocking recovery layer <NUM> and the second radial water blocking layer <NUM>.

As shown in <FIG>, the submarine cable section <NUM> further includes a first non-metallic sheath layer <NUM>, and the first non-metallic sheath layer <NUM> covers part of the first radial water-blocking layer <NUM>. The landing cable section <NUM> further includes a second non-metallic sheath layer <NUM>, and the second non-metallic sheath layer <NUM> covers part of the second radial water blocking layer <NUM>. The joint <NUM> further includes a non-metallic sheath recovery layer <NUM>. The non-metallic sheath recovery layer <NUM> covers part of the first radial water blocking layer <NUM>, part of the second radial water blocking layer <NUM> and the radial water-blocking recovery layer <NUM>, and has one end connected to the first non-metallic sheath layer <NUM> and the other end connected to the second non-metallic sheath layer <NUM>. Such arrangement can protect the submarine cable structure located in the non-metallic sheaths.

The first non-metallic sheath layer <NUM> and the second non-metallic sheath layer <NUM> may be of a same or different material. In a specific embodiment, the first non-metallic sheath layer <NUM> may be formed by covering by way of extrusion molding with semi-conductive polyethylene, and the second non-metallic sheath layer <NUM> may be formed by covering by way of extrusion molding with insulating polyethylene. With such arrangement, the submarine cable section <NUM> with the first non-metallic sheath layer <NUM> can avoid an underwater induced voltage problem, and the landing cable section <NUM> with the second non-metallic sheath layer <NUM> can meet insulation requirements. The material of the non-metallic sheath recovery layer <NUM> may be insulating polyethylene or semi-conductive polyethylene.

As shown in <FIG>, the submarine cable further includes an armor inner cushion layer <NUM>, an armor layer <NUM>, and an armor outer coating layer <NUM>. The armor inner cushion layer <NUM> covers the first non-metallic sheath layer <NUM>, the second non-metallic sheath layer <NUM> and the non-metallic sheath recovery layer <NUM>. The armor layer <NUM> covers the armor inner cushion layer <NUM>, and the armor outer coating layer <NUM> covers the armor layer <NUM>. Such arrangement can increase mechanical strength of the submarine cable.

The armor inner cushion layer <NUM> and the armor outer coating layer <NUM> are formed by winding with a polypropylene PP rope, and the armor layer <NUM> may adopt round steel wire armor, flat steel wire armor, round copper wire armor or flat copper wire armor.

The embodiments of the present invention further provide a method for manufacturing a submarine cable, including:.

With the above steps, the first monofilament layers of the first conductor and the second monofilament layers of the second conductor can be connected together by way of welding and winding, without using a crimping sleeve. This can improve the bendability and flexibility of the submarine cable, and in comparison to connecting the conductors of the landing cable section and the submarine cable section by crimping, connecting them by welding and winding offers a stronger bonding force between the conductors of the landing cable section and the submarine cable section, which results in less easy separation of the conductors of the landing cable section and the submarine cable section and thus improves the electrical performance of the submarine cable.

Further, when the cross-sectional area of the second conductor differs from the cross-sectional area of the first conductor by more than one standard size, joints of the factory in the related art fail to connect the first conductor to the second conductor. However, in this embodiment, by winding the second winding monofilament layers in the second monofilament layers, on the outermost layer of the first monofilament layers, extra monofilament layers of the second conductor relative to the first conductor can be connected to the first monofilament layers by way of winding, which thereby solves the technical problem that the first conductor cannot be connected to the second conductor when the cross-sectional area of the second conductor differs from the cross-sectional area of the first conductor by more than one standard size. In addition, for any two adjacent second winding monofilament layers, a winding part of a second winding monofilament layer located outside covers a winding part of a second winding monofilament layer located inside. Such arrangement enables protection of the winding part located inside, and an outer surface of a conductor welding area of the joint can be smoother by layer upon layer covering.

Exemplarily, reference for this embodiment may be made to the above-mentioned device embodiments, and they are similar in principles and technical effects which are therefore not repeated here.

In a specific embodiment, after the submarine cable section and the landing cable section are provided, cutting off part of an end to be connected, of the submarine cable section and cutting off part of an end to be connected, of the landing cable section are further included, so that the parts with poor quality caused by damp, oxidation and other factors in the end to be connected of the submarine cable section and in the end to be connected of the landing cable section are removed, and the electrical performance of the submarine cable is thereby improved.

A length of the removed part of the end of the submarine cable section and a length of the removed part of the end of the landing cable section may be arranged according to actual conditions. In this embodiment, both the length of the removed part of the end of the submarine cable section and the length of the removed part of the end of the landing cable section are <NUM>.

After part of the end of the submarine cable section and part of the end of the landing cable section are cut off, the following is further included:
stripping off the first non-metallic sheath layer and the second non-metallic sheath layer both of which have a first preset length, and stripping off the first radial water blocking layer and the second radial water blocking layer both of which have a second preset length, where the first preset length is greater than the second preset length. Such arrangement facilitates a subsequent operation of connecting the submarine cable section and the landing cable section. In a specific embodiment, the first preset length is <NUM>, and the second preset length is <NUM>.

After the first non-metallic sheath layer and the second non-metallic sheath layer both of which have the first preset length are stripped off and the first radial water blocking layer and the second radial water blocking layer both of which have the second preset length are stripped off, the following is further included:
heating to straighten the first conductor and the second conductor. A deviation in a subsequent welding process can be reduced though the straightening by means of heating, thus improving the reliability of the submarine cable. Further, an internal stress of the submarine cable can be reduced through the straightening by means of heating, thus making the connection between the submarine cable section and the landing cable section more stable.

After the straightening by means of heating, the following is further included:
removing a covering layer outside the first conductor at the end to be connected of the submarine cable section, and removing a covering layer outside the second conductor at the end to be connected of the landing cable section, so as to expose the first conductor and the second conductor. The first conductor and the second conductor may have a same exposed length. In this embodiment, both the first conductor and the second conductor have an exposed length of about <NUM>.

After the step of exposing the first conductor and the second conductor, and before the step of forming the conductor welding area of the joint by the area where the n first monofilament layers and the m second monofilament layers are connected, the following is further included:
aligning a center of an innermost layer of the n first monofilament layers with a center of an innermost layer of the m second monofilament layers. Such arrangement can reduce an error in a welding process.

In a specific embodiment, in the step of welding the n first monofilament layers to the n second welding monofilament layers in the m second monofilament layers in a one-to-one relationship, ends of the n first monofilament layers are welded to ends of the n second welding monofilament layers of the m second monofilament layers in a one-to-one relationship.

In a step of winding sequentially from inside to outside the h second winding monofilament layers outside the outermost layer of the n first monofilament layers, a difference between a winding pitch of the winding part of each of the second winding monofilament layers and a stranding pitch of a stranding part of each of the second winding monofilament layers is less than a preset difference, where the preset difference is <NUM>% of the stranding pitch of the stranding part of each of the second winding monofilament layers, and the stranding part refers to a portion of each of the second winding monofilament layers stranded outside the outermost layer of the second welding monofilament layers. With such arrangement, the conductor welding area of the joint formed by the area where the first conductor and the second conductor are connected can present a smooth transition.

In a possible embodiment, the step of welding the n first monofilament layers to the n second welding monofilament layers in a one-to-one relationship further includes: covering, by a second welding monofilament layer located outside, a secondary welding area between a second welding monofilament layer located inside and a corresponding first monofilament layer, where the secondary welding area is an area where the individual first monofilament layers and the individual second monofilament layers are welded. In the step of winding, sequentially from inside to outside in the radial direction of the submarine cable, the h second winding monofilament layers outside the outermost layer of the n first monofilament layers, an innermost layer of the second winding monofilament layers covers a secondary welding area between the outermost layer of the first monofilament layers and the outermost layer of the second welding monofilament layers.

Further, the step of winding, sequentially from inside to outside in the radial direction of the submarine cable, the h second winding monofilament layers outside the outermost layer of the n first monofilament layers further includes:
welding a winding end of the winding part of each of the second winding monofilament layers to the outermost layer of the first monofilament layers, and performing a polishing operation on a welding area between the winding end and the outermost layer of the first monofilament layers, so that a connection between the winding end and the outermost layer of the first monofilament layers is firm and smooth.

In order to better understand the solution, the following description is given taking a value of m equal to <NUM> and a value of n equal to <NUM> as an example. The first monofilament layers are a<NUM>, a<NUM> and a<NUM> sequentially from inside to outside, and the second monofilament layers are layers b<NUM>, b<NUM>, b<NUM>, c<NUM>, and c<NUM> sequentially from inside to outside. At this point, a sequence of welding and winding for the first monofilament layers and the second monofilament layers is:.

The conductor welding area of the joint can be formed by the above steps.

Further, after the conductor welding area is formed, the following is further included:
polishing an outer surface of the conductor welding area with a polishing tool, and wiping and smoothing the outer surface of the conductor welding area with fine sandpaper, so as to ensure that the surface of the conductor welding section is smooth, burr-free, and oxidation-free.

Further, after the conductor welding area is formed, the method for manufacturing the submarine cable further includes:
covering, by way of winding or extrusion molding with a same material as a conductor shielding layer, the conductor welding area and a exposed portion of the first conductor and a exposed portion of the second conductor, to form a conductor shielding recovery layer, and making the conductor shielding recovery layer have one end connected to a first conductor shielding layer of the submarine cable section and the other end connected to a second conductor shielding layer of the landing cable section.

With such arrangement, the first conductor shielding layer and the second conductor shielding layer can be connected. After the conductor shielding recovery layer is formed, the quality of the surface of the conductor shielding recovery layer may further be checked to ensure that there are no defects such as bubbles or cracks.

Exemplarily, reference for the materials used for each layer in this embodiment and technical effects thereof may be made to the above-mentioned device embodiments, which are not repeated here.

After the conductor shielding recovery layer is formed, the method for manufacturing the submarine cable further includes:
cutting the first insulating layer <NUM> of the submarine cable section <NUM> to obtain a cone surface with a cone angle not greater than <NUM>°, and cutting the second insulating layer <NUM> of the landing cable section <NUM> to obtain a cone surface with a cone angle not greater than <NUM>°, as shown in <FIG>. Such arrangement facilitates subsequent connection of the first insulating layer <NUM> and the second insulating layer <NUM>.

After the first insulating layer <NUM> of the submarine cable section <NUM> is cut to obtain a cone surface with a cone angle not greater than <NUM>° and the second insulating layer <NUM> of the landing cable section <NUM> is cut to obtain a cone surface with a cone angle not greater than <NUM>°, the following is further included:
covering, by way of extrusion molding with a same material as the first insulating layer <NUM> and the second insulating layer <NUM>, the conductor shielding recovery layer <NUM>, to form an insulating recovery layer <NUM>, and making the insulating recovery layer <NUM> have one end connected to the first insulating layer <NUM> and the other end connected to the second insulating layer <NUM>. During actual operation, an insulating extruder may be used to extrude the material of the insulating recovery layer <NUM> to cover the conductor shielding recovery layer <NUM>.

With such arrangement, the first insulating layer <NUM> and the second insulating layer <NUM> can be connected. Reference for the materials used for each layer in this embodiment and technical effects thereof may be made to the above-mentioned device embodiments, which are not repeated here.

After the insulating recovery layer <NUM> is formed, the insulating recovery layer <NUM> may further be fully crosslinked by a crosslinking machine to ensure that there are no bubbles, pits or cracks on the surface of the insulating recovery layer. The thickness, eccentricity, and the presence or absence of visible pores, protrusions or impurities of the insulating recovery layer <NUM> are detected by an X-ray machine. The insulating recovery layer <NUM> is polished with an abrasive belt to ensure that the surface of the insulating recovery layer <NUM> is smooth and its outer diameter is larger than that of the first insulating layer <NUM> and of the second insulating layer <NUM>, and a difference between the outer diameter of the insulating recovery layer <NUM> and the larger outer diameter in the outer diameter of the first insulating layer <NUM> and the outer diameter of the second insulating layer <NUM> is about <NUM>.

After the insulating recovery layer <NUM> is formed, the method for manufacturing the submarine cable further includes:.

With such arrangement, the first insulation shielding layer <NUM> and the second insulation shielding layer <NUM>, the first longitudinal water blocking layer <NUM> and the second longitudinal water blocking layer <NUM>, and the first radial water blocking layer <NUM> and the second radial water blocking layer <NUM> can be connected respectively. Reference for the materials used for each layer in this embodiment and technical effects thereof may be made to the above-mentioned device embodiments, which are not repeated here.

After the radial water-blocking recovery layer <NUM> is formed, the method for manufacturing the submarine cable further includes:.

With such arrangement, the first non- metallic sheath layer <NUM> and the second non- metallic sheath layer <NUM> can be connected. Reference for the materials used for each layer in this embodiment and technical effects thereof may be made to the above-mentioned device embodiments, which are not repeated here.

When the material of the first non-metallic sheath layer <NUM> is different from that of the second non-metallic sheath layer <NUM>, and the non-metallic sheath material is the same as the material of the first non-metallic sheath layer <NUM>, the method for manufacturing the submarine cable further includes:
Winding a cross-linked polyethylene tape at a junction of the non-metallic sheath recovery layer <NUM> and the second non-metallic sheath layer <NUM>, and heating the cross-linked polyethylene tape to integrate the cross-linked polyethylene tape, the non-metallic sheath recovery layer <NUM>, and the second non-metallic sheath layer <NUM>.

When the material of the first non-metallic sheath layer <NUM> is different from that of the second non-metallic sheath layer <NUM>, and the non-metallic sheath material is the same as the material of the second non-metallic sheath layer <NUM>, the method for manufacturing the submarine cable further includes:
winding a cross-linked polyethylene tape at a junction of the non-metallic sheath recovery layer <NUM> and the first non-metallic sheath layer <NUM>, and heating the cross-linked polyethylene tape to integrate the cross-linked polyethylene tape, the non-metallic sheath recovery layer <NUM>, and the first non-metallic sheath layer <NUM>.

Tools such as heat guns may be used in a process of heating the non-metallic sheath material and the cross-linked polyethylene. A problem of weak connection occuring when the material of the non-metallic sheath recovery layer <NUM> is different from that of the first non-metallic sheath layer <NUM> or of the second non-metallic sheath layer <NUM> can be solved by the above steps.

In view of further improving the mechanical strength of the submarine cable, an outer diameter of the joint <NUM> of the submarine cable is greater than an outer diameter of the submarine cable section <NUM> and an outer diameter of the landing cable section <NUM>, and an outer diameter of the armor layer <NUM> of the joint <NUM> generally exceeds the outer diameter of the joint <NUM> by <NUM>, the method for manufacturing the submarine cable provided by the embodiment of the present invention, after the non-metallic sheath recovery layer <NUM> is formed, further includes:
arranging, with an armoring tool, an armor layer outside the non-metallic sheath recovery layer <NUM>, the first non-metallic sheath layer <NUM>, and the second non-metallic sheath layer <NUM>. Here, reference for the material of the armor layer <NUM> may be made to the above-mentioned device embodiments, which is not repeated here.

As shown in <FIG>, the armoring tool includes a hydraulic cylinder <NUM>, a pressure sensor <NUM>, an inner mould layer <NUM> and an outer mould layer <NUM>. The inner mould layer <NUM> is located within the outer mould layer <NUM>. The hydraulic cylinder <NUM> is connected with the inner mould layer <NUM>, for controlling the inner mould layer <NUM> to be tightened or loosened. The pressure sensor <NUM> is in signal connection with the inner mould layer <NUM> and the hydraulic cylinder <NUM> respectively for controlling a movement of the hydraulic cylinder <NUM> according to a pressure on the inner mould layer <NUM>.

In a specific embodiment, the inner mould layer <NUM> includes <NUM> arc-shaped parts <NUM>, and corresponding centers of the <NUM> arc-shaped parts <NUM> are at a same point during the tightening and loosening process of the mould. Such arrangement can improve the uniformity of the armor layer <NUM>.

An inner diameter of the inner mould layer <NUM> is <NUM>-<NUM> larger than the outer diameter of the armor layer <NUM>. During a process of arranging the armor layer <NUM>, the submarine cable passes through the inner mould layer <NUM> gradually. When a pressure value measured by the pressure sensor <NUM> exceeds a first tightening force that is set, the pressure sensor <NUM> controls an action of the hydraulic cylinder <NUM>, so that the hydraulic cylinder <NUM> releases the inner mould layer <NUM> until the pressure value is less than or equal to the first tightening force that is set. When the pressure value is less than a second tightening force that is set, the pressure sensor <NUM> controls the action of the hydraulic cylinder <NUM>, and the hydraulic cylinder <NUM> tightens the inner mould layer <NUM> until the pressure value is equal to the second tightening force that is set. Generally, an outer diameter of the first non-metallic sheath layer <NUM> of the submarine cable section <NUM> < an outer diameter of the second non-metallic sheath layer <NUM> < an outer diameter of the non-metallic sheath recovery layer <NUM>. Therefore, the first tightening force can be a pressure applied to the inner mould layer <NUM> when the joint <NUM> passes through the inner mould layer <NUM>, and the second tightening force can be a pressure applied to the inner mould layer <NUM> when the submarine cable section <NUM> passes through the inner mould layer <NUM>. With such arrangement, there is no need to replace the mould in the process of armoring the submarine cable of which the outer diameter varies, which simplifies the armoring process of the submarine cable.

Embodiments or implementations in the present specification are described in a progressive manner. Description of each embodiment focuses on a difference from other embodiments, and references may be made to each other for same or similar parts among respective embodiments.

Those skilled in the art should understand that in the disclosure of the present invention, terms such as "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer", etc. refer to orientations or positional relationships based on orientations or positional relationships illustrated in the accompanying drawings, which are only to facilitate and simplify descriptions of the present invention, rather than to indicate or imply that the system or element referred to must be of a particular orientation, or must be constructed and operated in a particular orientation, and therefore the above terms should not be construed as limiting the present invention.

Claim 1:
A submarine cable, comprising:
a submarine cable section (<NUM>) which comprises a first conductor (<NUM>), wherein the first conductor (<NUM>) comprises n first monofilament layers (<NUM>) sequentially arranged from inside to outside in a radial direction of the submarine cable; and
a landing cable section (<NUM>) which comprises a second conductor (<NUM>), wherein the second conductor (<NUM>) comprises m second monofilament layers (<NUM>) sequentially arranged from inside to outside in the radial direction of the submarine cable, and the m second monofilament layers (<NUM>) are sequentially divided from inside to outside in the radial direction of the submarine cable into n second welding monofilament layers (<NUM>) and h second winding monofilament layers (<NUM>), wherein m and n are both positive integers, and m≥n, h=m-n, h≥<NUM>;
wherein the n first monofilament layers (<NUM>), from inside to outside in the radial direction of the submarine cable, are welded to the n second welding monofilament layers (<NUM>) in a one-to-one relationship;
wherein the h second winding monofilament layers (<NUM>) are, sequentially from inside to outside in the radial direction of the submarine cable, wound outside an outermost layer of the n first monofilament layers (<NUM>); and for any two adjacent second winding monofilament layers (<NUM>), a winding part of a second winding monofilament layer (<NUM>) located outside covers a winding part of a second winding monofilament layer (<NUM>) located inside; wherein the winding part refers to a portion of each of the second winding monofilament layers (<NUM>) wound outside the outermost layer of the first monofilament layers (<NUM>); and
wherein an area in which the n first monofilament layers (<NUM>) are connected to the m second monofilament layers (<NUM>) forms a conductor welding area (<NUM>) of a joint (<NUM>);
wherein a difference between a winding pitch of the winding part of each of the second winding monofilament layers (<NUM>) and a stranding pitch of a stranding part of each of the second winding monofilament layers (<NUM>) is less than a preset difference; and
wherein the stranding part refers to a portion of each of the second winding monofilament layers (<NUM>) stranded outside an outermost layer of the second welding monofilament layers (<NUM>), and the preset difference is <NUM>% of the stranding pitch of the stranding part of each of the second winding monofilament layers.