A submarine cable

Abstract

The application relates to the technical field of submarine cables, in particular to a submarine cable. The submarine cable comprises a plurality of power core units, the power core units being used for power transmission; an optical fiber unit, the optical fiber unit being twisted with the plurality of power core units to form a cable core, the optical fiber unit being used for signal transmission; a buffer layer, the buffer layer being wrapped outside the cable core; a first armor layer, the first armor layer comprising a plurality of first armor pieces, the plurality of first armor pieces being sequentially spliced along the circumference of the buffer layer; and a second armor layer, the second armor layer comprising a plurality of second armor pieces, the plurality of second armor pieces being sequentially spliced along the circumference of the first armor layer, the splicing gaps of the second armor pieces and the splicing gaps of the first armor pieces being staggered, so that the second armor layer can transmit force to the first armor layer in the radial direction when being pressed and can lock the first armor layer and the buffer layer, thereby improving the compression resistance and structural stability of the submarine cable.

Description

Technical Field

[0001] This application relates to the field of submarine cable technology, and more particularly to a submarine cable. Background Technology

[0002] Deep-sea wind energy resources are abundant and have huge development potential, making them a direction for new energy development. As the offshore wind power industry expands to deep-sea, long-distance, and ultra-high-voltage fields, photovoltaic composite submarine cables (hereinafter referred to as "submarine cables") are equipment that simultaneously transmits electrical energy and fiber optic signals. As a carrier of energy transmission and information communication, they are immersed in the environment of deep-sea high pressure, ocean current scouring, seabed towing and bending, and seawater penetration and corrosion for a long time. They must ensure the stable transmission of power and optical signals, and rely on multi-layer protective structures to resist the damage of complex external forces in the ocean. The pressure-bearing and impact-resistant capabilities of submarine cables directly determine the reliability of marine engineering power supply and communication systems.

[0003] Existing submarine cables consist of optical fiber units and multiple power line core units. The optical fiber units and multiple power line core units are twisted together and covered with a buffer layer. The buffer layer is equipped with metal wire armor to provide mechanical protection. The armor is covered with an outer sheath. The submarine cable relies on the armor to achieve pressure resistance and impact resistance.

[0004] However, the aforementioned metal wire armor is prone to axial slippage under the high pressure of the deep sea, which reduces the pressure-bearing and impact-resistant capacity of the submarine cable, resulting in insufficient pressure-bearing and impact-resistant strength. Summary of the Invention

[0005] This application provides a submarine cable to address the problem of insufficient pressure resistance and impact resistance.

[0006] This application provides a submarine cable, comprising:

[0007] Multiple power line core units, which are used for power transmission;

[0008] The fiber optic unit is twisted together with multiple power line core units to form a cable core. The fiber optic unit is used for signal transmission.

[0009] Buffer layer, the buffer layer is wrapped around the outside of the cable core;

[0010] The first armor layer includes multiple first armor components, which are sequentially spliced ​​together along the circumference of the buffer layer.

[0011] The second armor layer includes multiple second armor pieces, which are sequentially spliced ​​together along the circumference of the first armor layer. The splicing gaps of the second armor pieces and the splicing gaps of the first armor pieces are staggered.

[0012] The second armor layer is configured such that when subjected to external radial pressure, the second armor layer exerts force on the first armor layer, thereby locking the first armor layer and the buffer layer together.

[0013] In one possible embodiment, a chamfer is provided on the second armor member, the chamfer is provided at the end of the second armor member in the extension direction, and the chamfer is provided with the beveled surface facing the first armor layer;

[0014] The chamfered surface is configured such that when subjected to external radial pressure, the chamfered surface abuts against the outer wall of the first armor layer to exert force on the first armor layer.

[0015] In one possible embodiment, multiple second armor pieces are spliced ​​together circumferentially along the first armor layer to form a second armor segment, and multiple second armor segments are arranged axially along the first armor layer and connected sequentially.

[0016] In one possible embodiment, two adjacent second armor sections overlap, and the overlap length of two adjacent second armor sections is greater than or equal to 25% of the axial length of the second armor and less than or equal to 35% of the axial length of the second armor.

[0017] In one possible embodiment, multiple first armor pieces are spliced ​​together along the circumferential direction of the buffer layer to form a first armor segment, and multiple first armor segments are arranged along the axial direction of the buffer layer and connected in sequence.

[0018] And / or, a connecting part is provided on the first armor piece, and a positioning part is provided on the buffer layer, with the connecting part connected to the positioning part.

[0019] In one possible embodiment, both the first armor piece and the second armor piece are arc-shaped armor pieces, and the projection of the arc-shaped armor piece on the buffer layer is rectangular. The inner wall of the first armor piece abuts against the buffer layer, and the outer wall of the first armor layer abuts against the inner wall of the second armor piece.

[0020] In one possible embodiment, the power line core unit includes a conductor, a conductor shielding layer, an insulation layer, an insulation shielding layer, a semiconducting resistive water strip, a metal shielding layer, and a non-metallic sheath, with the conductor shielding layer, insulation layer, insulation shielding layer, semiconducting resistive water strip, metal shielding layer, and non-metallic sheath sequentially wrapped around the outside of the conductor.

[0021] In one possible embodiment, the non-metallic sheath includes a first sheath layer and a second sheath layer wrapped around the outside of the first sheath layer, the first sheath layer being wrapped around the outside of the metallic shielding layer.

[0022] In one possible embodiment, it also includes a covering tape and an outer sheath, the covering tape being wrapped around the outside of the second armor layer and the outer sheath being wrapped around the outside of the covering tape.

[0023] In one possible embodiment, a filler layer is also included, which is disposed between the cable core and the buffer layer.

[0024] This application provides a submarine cable that forms a cable core by twisting multiple power line core units and optical fiber units together. A buffer layer, a first armor layer formed by splicing multiple first armor components, and a second armor layer formed by splicing multiple second armor components with staggered splicing gaps to the first armor layer are sequentially arranged on the outside of the cable core. This allows the second armor layer to exert force on the first armor layer when subjected to external radial pressure, enabling the first armor layer and the buffer layer to lock together under external pressure, thereby improving the radial compressive strength and overall structural stability of the submarine cable. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0026] Figure 1 This is a schematic diagram of the structure of the submarine cable provided in this application;

[0027] Figure 2 for Figure 1 A structural diagram from another direction;

[0028] Figure 3 for Figure 2 Schematic diagram of the structure of the second armor piece;

[0029] Figure 4 for Figure 3 A structural diagram from another direction;

[0030] Figure 5 for Figure 2 A schematic diagram of the structure of the first armor layer and the buffer layer.

[0031] Explanation of reference numerals in the attached figures:

[0032] 100-Cable core;

[0033] 110 - Power line core unit; 111 - Conductor; 112 - Conductor shielding layer; 113 - Insulation layer; 114 - Insulation shielding layer; 115 - Semiconductor resistive water tape; 116 - Metallic shielding layer;

[0034] 117 - Non-metallic sheath; 1171 - First sheath layer; 1172 - Second sheath layer; 120 - Fiber optic unit;

[0035] 200 - Buffer layer; 210 - Positioning part; 220 - Covering tape; 230 - Outer layer; 240 - Filling layer;

[0036] 300 - First armor layer; 310 - First armor piece; 311 - Connecting part; 320 - First armor section;

[0037] 400 - Second armor layer; 410 - Second armor piece; 411 - Beveled chamfer; 4111 - Beveled surface;

[0038] 420 - Second Armor Section.

[0039] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0041] In the embodiments of this application, the terms "upper," "lower," "inner," "middle," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for better description of this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in the embodiments of this application according to the specific circumstances.

[0042] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0043] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those illustrated or described herein.

[0044] In this application, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0045] Unless otherwise stated, the term "multiple" means two or more.

[0046] Submarine cables are used in deep-sea power transmission and marine information communication scenarios, especially suitable for offshore wind farms, submarine energy transmission links, and marine engineering systems that require synchronous transmission of power and signals. Submarine cables need to maintain transmission stability and structural safety under high water pressure, ocean current impact, seabed undulation, and long-term dynamic stress conditions.

[0047] Existing submarine cables use a combination of power line cores and optical fiber units to form the cable core, with buffer structures and metal protective structures on the outside to improve resistance to pressure, impact, and external damage. However, the aforementioned metal wire armor is prone to axial slippage under the high pressure of the deep sea, which reduces the cable's pressure-bearing and impact-resistant capabilities, resulting in insufficient pressure-bearing and impact-resistant strength.

[0048] To address the aforementioned issues, a submarine cable is provided, comprising multiple power line core units, an optical fiber unit twisted together with the multiple power line core units to form a cable core, a buffer layer wrapped around the outside of the cable core, and a first armor layer and a second armor layer sequentially spliced ​​together circumferentially, wherein the splicing gap of the second armor layer is staggered with the splicing gap of the first armor layer.

[0049] Under external radial pressure, the second armor layer can exert force on the first armor layer, locking the first armor layer and the buffer layer together, thus forming a stable interlayer force-bearing relationship. This structural approach, combining the cable core, buffer layer, and double-layer spliced ​​armor, enhances the compressive strength and structural stability of the submarine cable.

[0050] Reference Figures 1 to 4 As shown, this application provides a submarine cable including multiple power line core units 110, which are used for power transmission; an optical fiber unit 120, which is twisted with the multiple power line core units 110 to form a cable core 100, which is used for signal transmission; and a buffer layer 200, which is wrapped around the outside of the cable core 100.

[0051] The first armor layer 300 includes a plurality of first armor pieces 310, which are sequentially spliced ​​together along the circumference of the buffer layer 200; the second armor layer 400 includes a plurality of second armor pieces 410, which are sequentially spliced ​​together along the circumference of the first armor layer 300, with the splicing gaps of the second armor pieces 410 and the splicing gaps of the first armor pieces 310 being staggered; the second armor layer 400 is configured such that when subjected to external radial pressure, the second armor layer 400 applies force to the first armor layer 300, thereby locking the first armor layer 300 and the buffer layer 200 together.

[0052] Multiple power line core units 110 refer to conductive components that constitute the power transmission channel of the cable. The power line core units 110 are used to carry electrical energy and transmit it along the cable axis to the target end during submarine power transmission or energy supply. Multiple power line core units 110 are stranded inside the cable core 100 at a predetermined pitch so as to form a composite transmission unit with a certain degree of flexibility together with the optical fiber unit. The power line core units 110 maintain a stable relative positional relationship with adjacent power line core units 110 or optical fiber units 120.

[0053] The power line core unit 110 can be made of any of copper conductors, aluminum conductors or copper alloy conductors, and can be selected according to current carrying capacity, quality requirements and corrosion resistance requirements. The power line core unit 110 can also be made into single stranded conductors or compacted round conductors to adapt to different voltage levels and laying radii.

[0054] The fiber optic unit 120 refers to a signal transmission component that is disposed within the cable core 100 and twisted together with multiple power line core units 110. The fiber optic unit 120 is used to transmit communication, monitoring, or control signals in submarine cables. The fiber optic unit 120 and multiple power line core units 110 together constitute the cable core 100, allowing power transmission and signal transmission to be arranged collaboratively within the same cable, thereby reducing the number of independently laid lines.

[0055] The fiber optic unit 120 is arranged in the gaps between the power line core units 110 or located in the central region of the cable core 100. It forms a stable geometric relationship with the power line core units 110 through a stranded structure, thereby reducing the impact of relative slippage and local compression between the fiber optic unit 120 and the power line core units 110 on the stability of the optical path. The fiber optic unit 120 can be any of a loose-tube type, a tight-tube type, or a bundled-tube type. Different sheathing methods can be selected based on bending radius requirements and long-term stress conditions during implementation.

[0056] The buffer layer 200 refers to the transition protective layer wrapped around the outside of the cable core 100. The buffer layer 200 is used to provide a buffer base, isolation, and interface conditioning between the cable core 100 and the external armor structure. After the buffer layer 200 is placed on the outer surface of the cable core 100, it can form a continuous wrapping of the power line core unit 110 and the optical fiber unit 120, so that the local pressure from the external armor layer can be diffused through the buffer layer 200, and the sharp contact or friction on the surface of the cable core 100 can be isolated.

[0057] The buffer layer 200 is tightly fitted to the outer periphery of the cable core 100, extends continuously along the cable axis, and cooperates with the inner wall of the first armor layer to form a stable interlayer contact interface. The buffer layer 200 can be any one of a non-woven fabric wrapping layer, a water-blocking material layer, or a polymer buffer coating layer; the buffer layer 200 can be made into a spiral wound tape or a continuously extruded layer; the thickness of the buffer layer 200 is less than the thickness of the armor layer, but should be sufficient to fill the irregular undulations on the surface of the cable core 100 and provide a uniform support surface for locking the first armor layer 300.

[0058] The first armor layer 300 refers to the basic protective layer set outside the buffer layer 200 and formed by sequentially splicing multiple first armor pieces 310 along the circumference. The first armor layer 300 is used to provide radial support, anti-compression and structural skeleton for submarine cables.

[0059] The inner wall of the first armor layer 300 abuts against the buffer layer 200. Multiple first armor pieces 310 form a ring structure around the buffer layer 200 in the circumferential direction. A splicing gap is formed between adjacent first armor pieces 310 to allow for a certain amount of local displacement and stress dispersion under pressure. The first armor pieces 310 can be any of the following: arc-shaped armor pieces, segmented metal scale armor pieces, or composite material armor pieces. The metal material can be steel, galvanized steel, stainless steel, or high-strength aluminum alloy, while the composite material can be fiber-reinforced resin-based material. The first armor pieces 310 can be arc-shaped, trapezoidal segmented, or curved sheet with overlapping edges. The circumferential arc length, thickness, and overlapping edge width of the first armor pieces 310 should be adapted to the outer diameter of the buffer layer 200 and the inner diameter of the second armor layer 400. The splicing gap between two adjacent first armor pieces 310 is generally maintained as an assembly gap that can accommodate thermal expansion and micro-displacement under pressure, so as to take into account both circumferential ring formation and deformation capacity under stress.

[0060] The second armor layer 400 refers to an outer protective structure disposed outside the first armor layer 300, formed by sequentially splicing multiple second armor pieces 410 along the circumference. The second armor layer 400 is used to apply radial constraint to the first armor layer 300 under external radial pressure and form interlayer locking. The second armor layer 400 is coaxially arranged with the first armor layer 300, and the splicing gaps of the multiple second armor pieces 410 are staggered with the splicing gaps of the first armor pieces 310, so that the weak splicing parts of the second armor layer 400 are not directly aligned with the weak splicing parts of the first armor layer 300, thereby distributing the external load circumferentially to the armor pieces and gap areas at different locations.

[0061] The second armor piece 410 can be any of the following: an arc-shaped metal armor piece, a segmented metal scale armor piece, or a composite material armor piece. The material can be the same as that of the first armor layer 300, or a material with high hardness or high fatigue performance can be selected according to wear resistance requirements. The thickness, curvature, and splicing length of the second armor piece 410 match the curvature of the outer surface of the first armor layer 300, and by cooperating with the first armor layer 300, the second armor piece 410 can generate effective radial force transmission when under pressure.

[0062] The staggered splicing relationship between the second armor layer 400 and the first armor layer 300 means that the splicing gap of the second armor piece 410 avoids the splicing gap of the first armor piece 310 in the circumferential direction, so that the opening positions of the two armor layers do not coincide, thus forming a staggered support structure. The staggered splicing gap relationship of the two armor pieces ensures that the radial pressure, when passing through the splicing position of the second armor layer 400, is not directly concentrated and transmitted to the same weak point of the first armor layer 300, but is distributed step by step through the bearing surfaces of adjacent second armor pieces 410, the bearing surfaces of first armor pieces 310, and the continuous support surfaces of the buffer layer 200.

[0063] The misalignment of the splicing gap can be determined based on the number of armored parts, the circumferential arc length, and the construction assembly direction to ensure that the pressure path of each circumferential area is different but continuous. The splicing gap width of the second armored part 410 is coordinated with the splicing gap width of the first armored part 310 to avoid the splicing opening being too large, resulting in insufficient local support, while maintaining the necessary assembly tolerance and bending compliance.

[0064] Based on the above analysis, it can be seen that the submarine cable provided in this application provides a power transmission channel by setting multiple power line core units 110, and the optical fiber unit 120 is twisted with multiple power line core units 110 to maintain the stability of the signal transmission path. The buffer layer 200 forms a continuous covering on the outer surface of the cable core 100, so that the internal power line core units 110 and optical fiber units 120 can obtain transition support when bearing external mechanical loads.

[0065] When the cable is subjected to deep-sea hydrostatic pressure, seabed compression, dragging disturbance, or local contact load, the external radial pressure first acts on the second armor layer 400. The second armor piece 410 is subjected to overall pressure under the constraint of the circumferential splicing structure and transmits the load along the arc surface to the adjacent second armor piece 410 and the first armor layer 300. Since the splicing gaps of the second armor piece 410 and the splicing gaps of the first armor piece 310 are staggered, the pressure will not be directly concentrated at the same interlayer opening position, but will diffuse circumferentially through the staggered pressure-bearing path.

[0066] As the pressure continues to increase, the second armor layer 400 exerts radial pressure on the first armor layer 300, causing the first armor piece 310 to press inward against the buffer layer 200. The buffer layer 200 is further compacted and fills the irregular interface on the outer periphery of the cable core 100, thereby forming a tight surface contact and friction constraint between the first armor layer 300 and the buffer layer 200, thus achieving interlayer locking and preventing the armor piece from loosening, gap enlargement, or local collapse when the first armor layer 300 is under local stress. Furthermore, since the load is distributed step by step through the double-layer staggered splicing structure, the radial deformation of the cable periphery can be limited to a certain range, and the pressure state of the internal cable core 100 is also more uniform.

[0067] Furthermore, when the cable undergoes bending, sag, or repeated laying deformation, the staggered splicing relationship between the first armor layer 300 and the second armor layer 400 provides a dispersion channel for circumferential micro-displacement, while the buffer layer 200 transitions the contact interface, preventing the continuous accumulation of local stress at a single splicing position. This allows the cable to maintain its parallel power and signal transmission functions while achieving stable compressive support, interlayer synergistic stress distribution, and long-term service reliability. It should be understood that the above examples are merely illustrative and not limiting; relevant parameters can be adjusted according to application conditions without departing from the technical concept defined in this application.

[0068] Reference Figure 3 and Figure 4 As shown, in one possible implementation, a chamfer 411 is provided on the second armor member 410. The chamfer 411 is located at the end of the second armor member 410 in the extending direction, and the chamfer 4111 is oriented toward the first armor layer 300. The chamfer 4111 is configured such that when it receives external radial pressure, the chamfer 4111 abuts against the outer wall of the first armor layer 300 to exert force on the first armor layer 300.

[0069] In this application, the chamfer 411 on the second armor piece 410 is a beveled transition structure formed at the end of the second armor piece 410 along the extension direction. The function of the chamfer 411 is to enable the second armor piece 410 to transfer the load to the first armor layer 300 in a wedge-type contact manner when subjected to radial pressure from the seabed, thereby enhancing the pressure exerted by the second armor layer 400 on the first armor layer 300 and the interlayer locking stability.

[0070] In one possible embodiment, the chamfer 411 is disposed at the end of the second armor member 410 facing the first armor layer 300, and is arranged circumferentially with the second armor member 410 along the first armor layer 300, so that adjacent second armor members 410 form a continuous circumferential force boundary at the splice. When the cable is under deep-sea hydrostatic pressure, seabed compression, or external impact conditions, the second armor member 410 undergoes slight elastic deformation or radial displacement, and the chamfered surface 4111 preferentially contacts the outer wall of the first armor layer 300 and forms a surface contact, so that the first armor layer 300 is subjected to an additional clamping force in the direction of the buffer layer 200. Based on the above analysis, it can be seen that the chamfer 411 not only serves as a transition of the end structure, but also acts as a force-guiding surface to improve the synergistic locking effect between the first armor layer 300 and the second armor layer 400.

[0071] In terms of specific structure, the chamfer 411 can be defined as the chamfered area formed by the oblique cutting of the end of the second armor piece 410 from the inner wall to the outer wall. The oblique cutting surface 4111 is arranged facing the first armor layer 300, so that the oblique cutting surface 4111 becomes a working surface that abuts against the outer wall of the first armor layer 300 under pressure.

[0072] The chamfer 411 is formed at the end of the second armor piece 410 in the axial extension direction and is adjacent to the splicing end face of the second armor piece 410, so as to ensure that after multiple second armor pieces 410 are spliced ​​together in the circumferential direction, each chamfer 411 area can form a continuous or nearly continuous force transmission path in the circumferential direction.

[0073] Since the second armor piece 410 and the first armor piece 310 constitute different splicing layers, the chamfer 411 helps to establish a stable contact geometry between the second armor layer 400 and the first armor layer 300, so that the external pressure is preferentially borne by the second armor layer 400 and further applied to the first armor layer 300, avoiding local stress concentration only on a single splicing edge.

[0074] The chamfer 411 can be processed into any one or a combination of a planar bevel chamfer, a rounded transition chamfer 411, or a multi-segment polygonal chamfer, to adapt to different armor material and manufacturing processes. For example, the second armor 410 can be a curved metal part, and the chamfer can be obtained through machining, stamping, molding, or subsequent grinding. It should be understood that the above examples are merely illustrative and not limiting.

[0075] The axial length, depth of cut, and width of the chamfer 411 can be proportionally designed according to the thickness and outer diameter of the second armor 410 to balance processing strength, splicing stability, and force transmission effect. For example, the chamfer angle of the chamfer 411 can be set between approximately 30° and 60°, preferably close to 45°, so that the external radial pressure generates a balanced normal locking force on the chamfer 4111; the axial length of the chamfer 411 can account for 5% to 20% of the axial length of the second armor 410, the width of the chamfer 4111 can be adapted to the wall thickness of the second armor 410, and the depth of cut can be controlled within a range that ensures sufficient residual strength at the chamfer end.

[0076] For submarine cables of different specifications, the specific dimensions of the chamfer 411 can be adjusted according to the thickness of the second armor 410, the splicing gap and the target contact pressure. For example, in thick-walled armor, the chamfer length can be appropriately increased to improve the contact conduction effect, while in thin-walled armor, the chamfer cutting depth should be reduced to avoid weakening the end bearing capacity.

[0077] When a submarine cable is laid, in service, or subjected to external pressure, the external radial pressure first acts on the circumferential splicing structure of the second armor layer 400. Since the chamfer 411 at the end of the second armor piece 410 is arranged with the chamfer 4111 facing the first armor layer 300, when the second armor layer 400 undergoes a slight radial compression or relative displacement, the chamfer 4111 will preferentially abut against the outer wall of the first armor layer 300 and convert the external pressure into a compressive component along the chamfer 4111.

[0078] As radial pressure increases, the contact area between the chamfered surface 4111 and the first armor layer 300 expands, and the force exerted by the second armor layer 400 on the first armor layer 300 increases, causing the first armor layer 300 to press further against the outside of the buffer layer 200, thus forming a stable locking fit with the buffer layer 200. Because the chamfered angle 411 provides a wedge-shaped force-guiding path at the end of the second armor member 410, external loads will not only remain at the splicing edge of the second armor member 410, but will be gradually transmitted and dispersed to the first armor layer 300 through the chamfered surface 4111. This reduces local stress concentration, suppresses the opening of splicing gaps and edge warping, and improves the compressive stability and long-term service reliability of the submarine cable under deep-sea high pressure, impact, and repeated bending conditions. It should be understood that the above examples are for demonstration purposes only and are not limiting. Without departing from the spirit of this application, the chamfer 411 can also be replaced by a stepped end face, a conical end face, an arc end face, or a composite wedge end face, as long as it can effectively abut against the first armor layer 300 and apply force to the first armor layer 300 after being compressed.

[0079] Reference Figure 2As shown, in one possible implementation, multiple second armor pieces 410 are spliced ​​together along the circumference of the first armor layer 300 to form a second armor segment 420, and multiple second armor segments 420 are arranged along the axial direction of the first armor layer 300 and connected in sequence.

[0080] In this application, the second armor section 420 refers to a circumferential protective unit formed by sequentially splicing multiple second armor components 410 around the first armor layer 300 in a circumferential direction. The second armor section 420 is used to form a segmented continuous covering structure on the outside of the first armor layer 300. The function of the second armor section 420 is to prevent the second armor layer 400 from covering the outer periphery of the first armor layer 300 in the form of a single long continuous layer, but instead to divide it into several adjacent second armor sections 420 along the axial direction. Each second armor section 420 can apply radial constraint to the first armor layer 300 in the corresponding axial section, and retain a cooperative space between two adjacent second armor sections 420 to accommodate cable bending and laying deformation, thereby taking into account both external pressure protection and overall flexibility.

[0081] In one possible embodiment, the second armor section 420 can be a full-circle segmented structure, that is, multiple second armor pieces 410 are spliced ​​together end to end to form a closed loop; it can also be a semi-circle spliced ​​structure, that is, it is divided into several semi-ring units along the circumference and then spliced ​​together to form a complete loop; it can also be a multi-lobed encircling structure, that is, it is formed by three, four or more arc-shaped pieces to form a circumferential protective unit.

[0082] The second armor section 420 is located outside the first armor layer 300 and is connected sequentially in multiples along the axial direction of the first armor layer 300. The sections can be connected by end-to-end contact, partial overlap, or lap joint transition to ensure the axial continuity of the outer protection. To meet different laying radii and dynamic bending requirements, the axial length of a single second armor section 420 can be set to an integer or approximately integer multiple of the axial length of multiple second armor components 410. The appropriate size can be selected based on the cable diameter, target bending radius, and protection level, so that adjacent second armor sections 420 form a structural relationship that can transmit external pressure without inhibiting bending deformation. It should be understood that the above example is for demonstration purposes only and is not limiting. The specific number of splices, section length, and material combination of the second armor sections 420 can be adjusted according to the water depth, external load level, and construction conditions of the submarine cable.

[0083] In one possible embodiment, when the submarine cable is in a high-pressure deep-sea environment or a localized seabed compression environment, the radial pressure acting on the outside of the cable is initially borne by multiple second armor sections 420. Since the second armor sections 420 are arranged sequentially along the axial direction, adjacent second armor sections 420 can disperse the local load axially and transfer it to adjacent circumferential areas, thereby reducing stress concentration at a single location. As the external pressure continues to increase, the second armor sections 420, formed by multiple second armor components 410, will form a stable covering constraint on the first armor layer 300, and further transfer the pressure to the first armor layer 300 and the buffer layer 200, creating a tight fit between the layers.

[0084] Meanwhile, multiple sequentially connected second armor sections 420 along the axial direction can coordinate slight relative rotation and axial compensation when the cable bends, is dragged, or sags, preventing the second armor layer 400 from experiencing local warping or gap instability due to excessive overall rigidity. Thus, the second armor sections 420 can provide continuous external support under pressure and maintain necessary compliance under bending conditions, making the stress distribution between the first armor layer 300 and the buffer layer 200 more uniform, reducing the risk of local deformation and fatigue damage accumulation, and thereby improving the long-term mechanical reliability and service life of the submarine cable in complex marine environments.

[0085] Reference Figure 2 As shown, in one possible implementation, two adjacent second armor sections 420 overlap, and the overlap length of two adjacent second armor sections 420 is greater than or equal to 25% of the axial length of the second armor 410 and less than or equal to 35% of the axial length of the second armor 410.

[0086] In this application, the overlapping of two adjacent second armor sections 420 refers to a connection method in which the preceding second armor section 420 and the following second armor section 420, arranged sequentially along the axial direction of the submarine cable, overlap and cover each other in the end region. By making the two adjacent second armor sections 420 have a common coverage area in the axial direction, the continuous protective performance of the second armor layer 400 in the axial direction is maintained. The function of the overlapping of two adjacent second armor sections 420 is to enhance the load transfer continuity between adjacent second armor sections 420 when the submarine cable is subjected to bending, dragging, impact, or external radial pressure, and to reduce the probability of gaps, end warping, relative misalignment, and local fatigue damage between adjacent second armor sections 420. This allows the second armor layer 400 to stably apply force to the first armor layer 300 and work together to lock and protect the buffer layer 200 and the cable core 100.

[0087] Two adjacent second armor sections 420 are usually positioned axially adjacent to the first armor layer 300 and arranged sequentially along the outer circumferential surface of the first armor layer 300. The overlapping area is located at the end joint of the two second armor sections 420, and the overlapping area cooperates with the aforementioned circumferential splicing structure, so that the second armor layer 400 forms a continuous force path in both the circumferential and axial directions.

[0088] The overlapping area can adopt a straight overlapping structure, an oblique overlapping structure, or a stepped overlapping structure. In one possible embodiment, the second armor section 420 can be composed of an arc-shaped steel part, an arc-shaped aluminum alloy part, or a composite metal armor plate, and the end overlapping surface can be machined to form a flat fitting surface, an oblique fitting surface, or a fitting surface with limiting steps, so as to improve the fitting degree during assembly and the stability after being subjected to force.

[0089] The overlap length of the adjacent second armor section 420 is limited to 25% to 35% of the axial length of the second armor piece 410, for example, it can be set to about 30%, so that the overlap area has sufficient coverage length to ensure connection strength, without increasing structural stiffness, self-weight and material consumption due to excessive coverage. It should be understood that the above example is only for demonstration and not a limitation. The specific ratio can be adapted and adjusted according to the cable outer diameter, armor material strength, laying radius and target service water depth.

[0090] In one possible embodiment, the second armor section 420 can be understood as an axial segmented unit formed by splicing multiple second armor pieces 410 along the circumference of the first armor layer 300. The length of each segment can be determined based on the manufacturing winding conditions, laying tension, and bending performance of the submarine cable, while the overlap length is the overlapping part of two adjacent segments in the cable axial direction.

[0091] The overlapping structure allows adjacent second armor sections 420 to share the load under external loads through the overlapping coverage area. When the cable undergoes axial tension or bending deformation, the second armor sections 420 within the overlapping area can undergo slight relative slippage or coordinated rotation to release local stress concentration and avoid sharp stress peaks at the ends. When the cable is subjected to external radial pressure, the overlapping area can maintain continuous end coverage to prevent the formation of obvious weak points. Since the overlap length is controlled within the range of 25% to 35% of the axial length of the second armor 410, it can ensure effective interlocking and continuous force transmission between the second armor sections 420, while avoiding excessive overlap that would restrict circumferential rotation, cause excessive bending stiffness, or increase laying resistance. This allows the submarine cable to maintain good protective stability and bending adaptability under conditions of high water pressure, ocean current impact, and complex seabed undulations in deep sea. Based on the above analysis, it can be seen that the overlapping method of the second armor section 420 can improve the synergy and locking reliability of the second armor layer 400 without increasing the outer diameter and material usage, which is conducive to extending the long-term service life of the submarine cable and improving the cable's resistance to pressure, fatigue and misalignment. It should be understood that the above example is only for demonstration and not a limitation.

[0092] Reference Figure 2 and Figure 5 As shown, in one possible implementation, multiple first armor pieces 310 are spliced ​​together circumferentially along the buffer layer 200 to form a first armor segment 320, and multiple first armor segments 320 are arranged along the axial direction of the buffer layer 200 and connected in sequence; and / or, a connecting part 311 is provided on the first armor piece 310, a positioning part 210 is provided on the buffer layer 200, and the connecting part 311 is connected to the positioning part 210.

[0093] In this application, the first armor section 320 is a protective unit formed by sequentially splicing multiple first armor pieces 310 around the outer periphery of the buffer layer 200 in a circumferential direction. The first armor section 320 is used to form a continuous basic armor frame on the outside of the buffer layer 200. The multiple first armor sections 320 are arranged along the axial direction of the buffer layer 200 and connected in sequence, which means that several first armor sections 320 are connected end to end along the length of the cable, so that multiple first armor sections 320 form a continuous protective structure covering a long axial range.

[0094] The connecting part 311 is a structural part provided on the first armor 310 for assembly guidance, limiting and connection. The positioning part 210 is a structural part provided on the buffer layer 200 for receiving and cooperating with the connecting part 311. After the connecting part 311 and the positioning part 210 are connected, the first armor 310 can be circumferentially positioned and axially limited relative to the buffer layer 200.

[0095] Based on the above structure, in one possible embodiment, the first armor piece 310 may be in the form of an arc-shaped piece, an arc-shaped scale, an arc-shaped steel plate, or an arc-shaped composite reinforcing plate. The shape of the first armor piece 310 matches the outer circumferential curvature of the buffer layer 200 so as to form a continuous circumferential covering surface after splicing. The connecting part 311 may be configured as a tenon, a buckle, a hanging ear, a tongue, or an opening structure. The positioning part 210 may be configured as a groove, a positioning hole, a positioning slot, or a boss structure. The two can be connected by plugging, snapping, embedding, or limiting fit. They can also be connected by screws, rivets, welding positioning, or magnetic limiting connection according to the manufacturing process.

[0096] The connecting part 311 and the positioning part 210 are preferably integrally formed, but can also be a subsequently attached structure. The fit between the connecting part 311 and the positioning part 210 can be designed as a small clearance fit or an interference fit to improve positioning stability while ensuring assembly feasibility. The specific thickness, width, and overlap length can be adjusted according to the target sea depth and external pressure level. It should be understood that the above example is only for demonstration and is not a limitation.

[0097] Multiple first armor pieces 310 are first spliced ​​sequentially at predetermined circumferential positions on the outer periphery of the buffer layer 200. Initial positioning is achieved by the insertion, snapping, or limiting cooperation between the connecting part 311 and the positioning part 210, so that each first armor piece 310 is evenly arranged in the circumferential direction and forms multiple continuous first armor segments 320 along the axial direction. After the first armor segments 320 are sequentially connected along the axial direction of the buffer layer 200, the structure of the first armor layer 300 forms a continuous force path in the direction of cable length.

[0098] Since the connecting part 311 and the positioning part 210 can circumferentially guide and axially constrain the first armor 310, they can prevent the first armor 310 from radially shifting or misaligning adjacent parts during installation and service, thereby enabling the first armor layer 300 to be stably attached to the outside of the buffer layer 200 and maintain a reliable interlayer contact relationship with the buffer layer 200.

[0099] When external radial pressure is applied to the second armor layer 400, the load is transferred to the first armor layer 300 via the second armor layer 400. The connecting portions 311 of the multiple first armor components 310 bear the functions of local compression and circumferential support, and evenly distribute the pressure to the buffer layer 200, making the covering state of the cable core 100 by the buffer layer 200 more stable. Therefore, the modular axial continuous arrangement of the first armor section 320 and the cooperative connection between the connecting portions 311 and the positioning portions 210 can improve the assembly efficiency and positioning accuracy of the first armor components 310, reduce circumferential splicing errors, and enhance the bonding stability and stress coordination between the first armor layer 300 and the buffer layer 200 under deep-sea high pressure, dragging loads, and repeated bending conditions, thereby improving the overall compressive strength, structural reliability, and long-term service stability of the submarine cable. It should be understood that the above example is for demonstration purposes only and is not limiting.

[0100] Reference Figure 2 and Figure 3 As shown, based on the aforementioned embodiments, both the first armor piece 310 and the second armor piece 410 are arc-shaped armor pieces. The projection of the arc-shaped armor piece onto the buffer layer 200 is rectangular. The inner wall of the first armor piece 310 abuts against the buffer layer 200, and the outer wall of the first armor layer 300 abuts against the inner wall of the second armor piece 410.

[0101] During operation, when the submarine cable is under deep-water external pressure, towing load, or seabed contact compression, the external pressure first acts on the arc-shaped armor of the second armor layer 400. The arc-shaped structure causes the load to be distributed along the curved surface and transmitted through the inner wall of the second armor 410 to the outer wall of the first armor layer 300. Then, the arc-shaped armor of the first armor layer 300 further distributes the pressure evenly to the surface of the buffer layer 200.

[0102] Since both the first armor piece 310 and the second armor piece 410 are arc-shaped armor pieces and fit and abut against the buffer layer 200 and the first armor layer 300 respectively, the interlayer contact area is increased, and local point contact is replaced by surface contact, thereby reducing the peak contact stress and making the external pressure form a continuous force transmission path in the circumferential direction.

[0103] The projection of the arc-shaped armor on the buffer layer 200 is rectangular, which enables the first armor 310 or the second armor 410 to maintain a stable axial coverage length and circumferential enclosure width after splicing, thereby reducing weak areas caused by assembly gaps; when the cable is bent or slightly twisted, the arc-shaped armor can undergo slight rotation or elastic deformation within the allowable range, which maintains contact with adjacent layers and avoids stress concentration caused by excessive rigidity.

[0104] Based on the above force application and transmission process, it can be seen that the second armor layer 400 can effectively apply external radial pressure to the first armor layer 300 and promote a stable locking fit between the first armor layer 300 and the buffer layer 200, thereby improving the compressive strength, interlayer stability, and structural reliability of the submarine cable during long-term service. It should be understood that the above example is merely illustrative and not limiting.

[0105] Reference Figure 1 As shown, in one possible implementation, the power line core unit 110 includes a conductor 111, a conductor shielding layer 112, an insulation layer 113, an insulation shielding layer 114, a semiconducting resistance water tape 115, a metal shielding layer 116, and a non-metallic sheath 117. The conductor 111 is wrapped with the conductor shielding layer 112, the insulation layer 113, the insulation shielding layer 114, the semiconducting resistance water tape 115, the metal shielding layer 116, and the non-metallic sheath 117 in sequence.

[0106] In this application, each layer is coaxially wrapped around the outer periphery of the conductor 111 in order from the inside to the outside. The conductor shielding layer 112 is disposed close to the outer surface of the conductor 111. The insulating layer 113 is wrapped around the outside of the conductor shielding layer 112. The insulating shielding layer 114 is disposed around the outer periphery of the insulating layer 113. The semiconducting resistive water tape 115 is wrapped around the outside of the insulating shielding layer 114. The metallic shielding layer 116 is disposed outside the semiconducting resistive water tape 115. The non-metallic sheath 117 is located at the outermost layer and forms an overall wrapping of the inner layer structure.

[0107] Conductor 111 can be a multi-strand stranded copper conductor, aluminum conductor, or copper-clad aluminum conductor; conductor shielding layer 112 can be a semi-conductive shielding material layer, preferably a semi-conductive polymer material, a semi-conductive cross-linked material, or a composite semi-conductive adhesive layer; insulation layer 113 can be a cross-linked polyethylene insulation layer, a water-resistant resin insulation layer, or an elastomer insulation layer, or can be a modified polyolefin material, silicone rubber material, or ethylene propylene rubber material; insulating shielding layer 114 can be a semi-conductive polymer layer, a peelable semi-conductive layer, or a co-extruded semi-conductive layer; semi-conductive resistive water tape 115 can be a material with longitudinal resistance... The water-resistant wrapping tape can be made of expandable water-blocking fiber tape, composite semi-conductive water-resistant tape 115, or strip-shaped water-absorbing resin composite material; the metal shielding layer 116 can be copper wire shielding, copper strip shielding, or metal composite tape shielding, or can be made of tin-plated copper wire braided layer, overlapping wrapped copper strip layer, or copper-aluminum composite tape layer according to different voltage levels; the non-metallic sheath 117 can be polyethylene sheath, polypropylene sheath, or cross-linked polyolefin sheath, or can be made of modified polyolefin, thermoplastic elastomer, or high-density polyethylene material according to the requirements of wear resistance, seawater resistance, and low temperature resistance.

[0108] Because each layer is arranged coaxially from the inside out, the electric field distribution, water-blocking path, and mechanical protection path can work together in the same structure. This allows the power conductor unit 110 to maintain stable power transmission, reliable insulation, and environmental adaptability during long-term service of the submarine cable, while also maintaining good durability under the combined effects of deep-sea pressure, repeated bending, and water intrusion. It should be understood that the above example is merely illustrative and not limiting. Without departing from the technical concept of this application, the materials, thickness, and structural form of each layer can be equivalently replaced and adjusted according to the specific voltage level, laying method, and marine conditions.

[0109] Reference Figure 1 As shown, based on the aforementioned embodiments, the non-metallic sheath 117 further includes a first sheath layer 1171 and a second sheath layer 1172 wrapped around the outside of the first sheath layer 1171, with the first sheath layer 1171 wrapped around the outside of the metallic shielding layer.

[0110] The first sheath layer 1171, as the inner sheath, is directly wrapped around the outside of the metal shielding layer. The function of the first sheath layer 1171 is to adhere and fix the metal shielding layer and to establish a basic barrier interface between the metal shielding layer and the external medium, so as to reduce the risk of corrosion of the metal shielding layer by seawater, salt spray and microbial corrosion.

[0111] The second sheath layer 1172 wraps around the outside of the first sheath layer 1171. The function of the second sheath layer 1172 is to improve the wear resistance, impact resistance and seawater corrosion resistance of the outer surface of the power conductor unit 110, and to provide additional buffer for the internal structure during cable laying, dragging and long-term service.

[0112] The first sheath layer 1171 and the second sheath layer 1172 are coaxially wrapped. The first sheath layer 1171 can be directly wrapped onto the outer surface of the metal shielding layer by extrusion molding. The second sheath layer 1172 can be formed by secondary extrusion, co-extrusion, or lamination after the first sheath layer 1171 has been cured or shaped, so as to ensure that the two sheaths have a stable interfacial bonding strength.

[0113] When the first sheath layer 1171 is in direct contact with the metal shielding layer, it can suppress the relaxation and deformation of the metal shielding layer and maintain the roundness of the cross-section of the power conductor unit 110. The second sheath layer 1172 is located on the outermost side of the power conductor unit 110 and can withstand the direct mechanical loads caused by falling objects and construction traction.

[0114] In one possible embodiment, the first sheath layer 1171 may be made of a thermoplastic material, cross-linked polyolefin material, or elastomer material compatible with the metal shielding layer, and the second sheath layer 1172 may be made of high abrasion-resistant polyethylene, seawater corrosion-resistant polymer, or reinforced sheath composite material. The two can be formed by co-extrusion, coating, extrusion compounding, or lamination. The material of the first sheath layer 1171 is generally preferred to have good adhesion, molding stability, and electrical insulation properties so as to form a reliable bond with the metal shielding layer, while the material of the second sheath layer 1172 is generally preferred to have a higher abrasion resistance coefficient, tear resistance, and environmental aging resistance to adapt to underwater towing, transportation, and long-term immersion conditions.

[0115] For example, the first sheath layer 1171 can be any one of medium-density polyethylene, cross-linked polyethylene, or thermoplastic elastomer, and the second sheath layer 1172 can be any one of high-density polyethylene, modified polyolefin, polyurethane, or fiber-reinforced composite material; in another possible implementation, the first sheath layer 1171 and the second sheath layer 1172 can also be respectively set as material combinations with different hardness levels to take into account both the inner layer's adhesion and the outer layer's wear resistance.

[0116] During power transmission, the heat, mechanical vibration, and external seawater pressure generated by the power core unit 110 will act on the outer structure of the cable. At this time, the first sheath layer 1171 first adheres to the surface of the metal shielding layer to maintain stable coverage, and restricts seawater penetration inward through its own insulation and interface constraint. The second sheath layer 1172 bears the direct external load from seabed friction, construction drag and local collisions on the outermost layer, and transmits part of the stress to the first sheath layer 1171 and the inner structure with a large contact area, thereby avoiding the metal shielding layer from directly bearing external wear.

[0117] Because the first sheath layer 1171 and the second sheath layer 1172 form a layered protective structure, the inner layer can continue to provide basic isolation when the outer layer is damaged. Furthermore, the inner layer can maintain its overall roundness under pressure or localized deformation thanks to the constraint of the outer layer. Therefore, under deep-sea high pressure, long-term immersion, and repeated bending conditions, the corrosion resistance, wear resistance, and impact resistance of the non-metallic sheath 117 can be improved, as well as the service stability of the metallic shielding layer and the mechanical reliability and service life of the entire submarine cable. It should be understood that the above example is for illustrative purposes only and is not limiting.

[0118] Reference Figure 1 As shown, in one possible implementation, it also includes a covering strip 220 and an outer sheath 230, with the covering strip 220 wrapped around the outside of the second armor layer 400 and the outer sheath 230 wrapped around the outside of the covering strip 220.

[0119] In this application, the covering tape 220 can be understood as an intermediate constraint layer located between the second armor layer 400 and the outer layer 230. The function of the covering tape 220 is to continuously or intermittently wrap and cover the outer periphery of the second armor layer 400 to prevent the second armor piece 410 from warping, misaligning or spreading out during pressure, bending or dragging, and to form a relatively flat transition interface between the second armor layer 400 and the outer layer 230.

[0120] The outermost protective layer 230 covers the outside of the covering tape 220 and is used to directly withstand seawater erosion, seabed friction, mud and sand scraping and mechanical collisions during the laying process, thereby improving the wear resistance, corrosion resistance and long-term service stability of the submarine cable.

[0121] In one possible embodiment, the covering tape 220 may be one or more of non-woven tape, polyester tape, aramid tape, semi-conductive tape, or water-blocking tape to balance covering strength, flexibility, and dielectric / water-blocking properties; the outer sheath 230 may be one or more of polyethylene outer sheath, polypropylene sheath, thermoplastic elastomer sheath, or abrasion-resistant composite outer layer to meet the protection requirements under different sea area water pressure, abrasion, and temperature conditions.

[0122] When the covering tape 220 is wrapped around the outside of the second armor layer 400, it can be spirally wound along the cable axis or longitudinally wrapped to form a continuous cover. Both methods can achieve the binding and covering of the second armor layer 400. The outer sheath 230 can be formed on the outside of the covering tape 220 by extrusion molding, winding molding, or composite wrapping molding, and is tightly attached to the covering tape 220 to form a layered protective structure that transitions from the inside to the outside. Based on the above structure, a stable attachment relationship can be formed between the covering tape 220 and the second armor layer 400. The outer sheath 230 undergoes elastic or plastic deformation simultaneously when bent, dragged, or in contact with the seabed, thereby dispersing the external force over a wider area and reducing local stress concentration.

[0123] In one possible embodiment, the sheathing tape 220 can be defined as a flexible strip or band material for constraining and protecting the outer periphery of the armor layer. Its width can be set according to the outer diameter of the second armor layer 400 and overlap requirements, allowing it to form at least a partial overlap after wrapping. The outer sheath 230 can be defined as a continuous outer protective structure formed outside the sheathing tape 220, providing the final outer mechanical protection and environmental isolation for the submarine cable.

[0124] The two components are positioned such that the sheathing tape 220 is directly attached to the outer periphery of the second armor layer 400, and the outer sheath layer 230 then covers the outer periphery of the sheathing tape 220, thereby surrounding the second armor layer 400 with the sheathing tape 220 and encapsulating it with the outer sheath layer 230. The sheathing tape 220 can limit the radial migration of the second armor layer 400 during the molding of the outer sheath layer 230 and its subsequent service, while the outer sheath layer 230 isolates the sheathing tape 220 and its inner structure from external water, corrosive media, and friction particles.

[0125] The materials selected for the covering tape 220 and the outer sheath 230 can be flexibly adjusted according to the marine environment. For example, in highly abrasive conditions, high-strength polyester tape combined with a high-density polyethylene sheath is preferred. When additional water-blocking performance is required, water-blocking tape combined with a thermoplastic elastomer sheath can be used. In deep-sea overhanging sections where flexibility is required, aramid tape combined with a wear-resistant composite outer sheath 230 can be used. It should be understood that the above materials, shapes, and dimensions are only illustrative and not limiting. Anything that can achieve the covering and fixing of the second armor layer 400 and form a protective outer layer on its outside can fall within the protection scope of this application.

[0126] When the submarine cable is subjected to external radial pressure, seabed compression, or laying drag, the second armor layer 400 first bears the main local load through the splicing structure, while the covering strip 220 located on the outside of the second armor layer 400 binds the second armor layer 400, so that each second armor component 410 maintains a relatively stable circumferential position, reducing the warping of the ends of the second armor components 410, expansion of the splicing seam, or interlayer movement caused by external forces.

[0127] Meanwhile, the sheathing tape 220 disperses the localized stress from the second armor layer 400 to a larger circumferential range and provides a relatively flat forming base for the outer sheath 230, enabling the outer sheath 230 to bear the external load more evenly when subjected to friction, impact, or repeated bending in the external environment. After the outer sheath 230 wraps around the sheathing tape 220, it not only provides external support for the sheathing tape 220 but also provides a continuous wear-resistant and corrosion-resistant barrier for the submarine cable, making it difficult for seawater, silt, and impurities to directly penetrate the surface of the second armor layer 400, thereby reducing wear and fatigue damage to the armor components and their joints.

[0128] Thus, a synergistic relationship of "constraint-isolation-protection" is formed between the sheathing tape 220, the outer sheath 230, and the second armor layer 400. This improves the overall stability and environmental adaptability of the submarine cable without weakening its bending adaptability, and helps reduce the accumulation of local damage during long-term service, thereby extending the service life of the submarine cable. It should be understood that the above example is merely illustrative and not limiting. Without departing from the technical concept of this application, the specific materials, forming methods, and thickness parameters of the sheathing tape 220 and the outer sheath 230 can be adjusted according to the actual marine conditions.

[0129] Reference Figure 1 As shown, in one possible implementation, a filling layer 240 is also included, which is disposed between the cable core 100 and the buffer layer 200.

[0130] In one possible embodiment, the filler layer 240 is a gap filling and support structure used to fill the gap between the outer periphery of the cable core 100 and the inner wall of the buffer layer 200. The function of the filler layer 240 is to compensate for the gap between the cable core 100 and the buffer layer 200, so that the cable core 100 maintains a good roundness after cabling, and provides transition support under external radial compression or bending load, thereby reducing the risk of local collapse, eccentricity and structural distortion.

[0131] The filling layer 240 is arranged on the outside of the cable core 100 and inside the buffer layer 200. It is continuously or segmentally distributed around the circumference of the cable core 100 and forms a coaxial arrangement with the cable core 100 and the buffer layer 200. It can be set on the outer periphery of the cable core 100 first and then covered by the buffer layer 200 so that the filling layer 240 fully fits the outer contour of the cable core 100 in the radial direction and forms a uniform contact surface with the inner wall of the buffer layer 200.

[0132] In accordance with the structural purpose of this application, the filling layer 240 can be made of water-blocking filling rope, non-woven filling strip, fiber bundle filling material, foamed polymer material or semi-conductive filling material, or it can be formed by spiral winding filling, strip filling or extrusion filling according to the process conditions.

[0133] When submarine cables are subjected to deep-sea hydrostatic pressure, laying tension, or seabed contact compression, the filling layer 240 located between the cable core 100 and the buffer layer 200 first occupies and constrains the local gaps around the cable core 100, thereby correcting the shape of the cable core 100 formed by twisting the power line core unit 110 and the optical fiber unit 120, and enabling the buffer layer 200 to withstand the load transmitted from the outer armor structure in a more uniform contact state after being covered.

[0134] Because the filler layer 240 has a certain compressibility and elastic recovery capability, it can undergo slight compression, rebound and relative displacement when the cable is bent or compressed, thereby absorbing local stress peaks and reducing hard contact and gap impact between the cable core 100 and the buffer layer 200. At the same time, when the filler layer 240 adopts a water-blocking material or a composite water-blocking structure, it can also form a longitudinal water-blocking channel with the outside of the cable core 100 to block the risk of seawater intruding longitudinally along the gap.

[0135] Based on the above analysis, it can be seen that the filling layer 240 can not only improve the roundness and coaxiality of the cable cross section, but also enhance the support continuity between the cable core 100 and the buffer layer 200, reduce local deformation, fatigue damage and protective gap instability, thereby improving the mechanical reliability and long-term service stability of submarine cables under complex deep-sea conditions.

[0136] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. The above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A submarine cable, characterized in that, include: Multiple power line core units (110) are used for power transmission; An optical fiber unit (120) is twisted together with a plurality of power line core units (110) to form a cable core (100), and the optical fiber unit (120) is used for signal transmission; A buffer layer (200) is wrapped around the outside of the cable core (100); The first armor layer (300) includes a plurality of first armor pieces (310), which are sequentially spliced ​​together along the circumferential direction of the buffer layer (200); The second armor layer (400) includes a plurality of second armor pieces (410), which are sequentially spliced ​​together along the circumference of the first armor layer (300), and the splicing gaps of the second armor pieces (410) and the splicing gaps of the first armor pieces (310) are staggered. The second armor layer (400) is configured such that when subjected to external radial pressure, the second armor layer (400) applies force to the first armor layer (300), thereby locking the first armor layer (300) with the buffer layer (200).

2. The submarine cable according to claim 1, characterized in that, The second armor piece (410) is provided with a chamfer (411), the chamfer (411) is provided at the end of the second armor piece (410) in the extension direction, and the chamfer (4111) is provided with the chamfer (4111) facing the first armor layer (300); The chamfered surface (4111) is configured such that when it receives radial pressure from the outside, the chamfered surface (4111) abuts against the outer wall of the first armor layer (300) to exert force on the first armor layer (300).

3. The submarine cable according to claim 2, characterized in that, Multiple second armor pieces (410) are spliced ​​together along the circumference of the first armor layer (300) to form a second armor segment (420), and multiple second armor segments (420) are arranged along the axial direction of the first armor layer (300) and connected in sequence.

4. The submarine cable according to claim 3, characterized in that, Two adjacent second armor sections (420) overlap, and the overlap length of two adjacent second armor sections (420) is greater than or equal to 25% of the axial length of the second armor (410) and less than or equal to 35% of the axial length of the second armor (410).

5. The submarine cable according to claim 4, characterized in that, Multiple first armor pieces (310) are spliced ​​together circumferentially along the buffer layer (200) to form a first armor segment (320), and multiple first armor segments are arranged along the axial direction of the buffer layer (200) and connected in sequence; And / or, a connecting part (311) is provided on the first armor (310), and a positioning part (210) is provided on the buffer layer (200), and the connecting part (311) is connected to the positioning part (210).

6. The submarine cable according to claim 5, characterized in that, Both the first armor piece (310) and the second armor piece (410) are arc-shaped armor pieces. The projection of the arc-shaped armor piece on the buffer layer (200) is rectangular. The inner wall of the first armor piece (310) abuts against the buffer layer (200), and the outer wall of the first armor layer (300) abuts against the inner wall of the second armor piece (410).

7. The submarine cable according to any one of claims 1-6, characterized in that, The power line core unit (110) includes a conductor (111), a conductor shielding layer (112), an insulation layer (113), an insulation shielding layer (114), a semiconducting resistance water tape (115), a metal shielding layer (116), and a non-metallic sheath (117). The conductor (111) is wrapped with the conductor shielding layer (112), the insulation layer (113), the insulation shielding layer (114), the semiconducting resistance water tape (115), the metal shielding layer (116), and the non-metallic sheath (117) in sequence.

8. The submarine cable according to claim 7, characterized in that, The non-metallic sheath (117) includes a first sheath layer (1171) and a second sheath layer (1172) wrapped around the outside of the first sheath layer (1171), wherein the first sheath layer (1171) is wrapped around the outside of the metallic shielding layer (116).

9. The submarine cable according to claim 8, characterized in that, It also includes a covering strip (220) and an outer layer (230), the covering strip (220) being wrapped around the outside of the second armor layer (400), and the outer layer (230) being wrapped around the outside of the covering strip (220).

10. The submarine cable according to claim 9, characterized in that, It also includes a filling layer (240) disposed between the cable core (100) and the buffer layer (200).

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