Mechanical protection device of unequal-diameter submarine cable joint

Abstract

The invention discloses a mechanical protection device for an unequal-diameter submarine cable connector, relates to the field of submarine cable connector protection, and aims to solve the problems that at present, the unequal-diameter submarine cable connector is prone to mechanical stress concentration, uneven stress and the like due to unbalanced structural weight. The device comprises an unequal-diameter overall fixing assembly, the middle of a through hole formed by splicing the unequal-diameter overall fixing assembly is provided with a taper hole matched with a connector variable-diameter inclined face, and the two ends of the taper hole extend to form a small-diameter hole section and a large-diameter hole section which are matched with a small-diameter submarine cable and a large-diameter submarine cable respectively; the two rigid supporting and fixing assemblies are arranged on the two sides of the overall fixing assembly respectively, radial rigid supporting pieces are arranged on the inner circumferential walls of the rigid supporting and fixing assemblies, and the inner ends of the supporting pieces are connected with submarine cables on the corresponding sides; the two flexible connecting pieces are arranged on the outer side of the rigid supporting and fixing assembly, are elastic pieces and wrap the corresponding submarine cables. According to the technical scheme, the mechanical protection reliability of the joint area in laying and operation is remarkably improved through a three-stage cooperative structure that the taper hole supports the reducing area, the rigid supporting piece anchors the submarine cable and the flexible connecting piece buffers stress.

Description

Technical Field

[0001] The present invention relates to the field of submarine cable joint protection, and in particular to a mechanical protection device for unequal diameter submarine cable joints. Background Art

[0002] In recent years, with the development of offshore wind power and island power supply projects, the number of submarine cable lines has steadily increased. Submarine cable lines typically reach lengths of tens or even dozens of kilometers, and the vast majority of these cables are buried below sea level or beneath the seabed. This section is called the mid-sea section. The landing section of a submarine cable line typically gradually emerges from the sea surface along the coastline, reaching land. This section generally includes the intertidal zone (submerged at high tide and exposed at low tide) and the onshore section. The ambient temperature and heat dissipation conditions surrounding the cable in the mid-sea section differ significantly from those in the landing section. Research and test data show that the landing channel environment is complex, with high ambient temperatures in the landing section significantly affected by seawater and air temperatures. Furthermore, heat dissipation in the landing section is significantly affected and poor, making it a bottleneck for the current carrying capacity of the entire cable line. When designing the current carrying capacity of a submarine cable line and determining the emergency current carrying capacity requirements during operation, the temperature rise and transmission capacity of the cable in the landing section are primarily considered.

[0003] Improving the current-carrying capacity of the landing section of a submarine cable line is the key to improving the current-carrying capacity and safe operation of the entire submarine cable line. If the conductor cross-section of the entire submarine cable is designed based on the requirements of the transmission load, the landing section will be the main standard, which will lead to excess current-carrying capacity in the mid-sea section of more than ten kilometers, increasing the investment of the entire submarine cable line and reducing the cost-effectiveness of the submarine cable line. Therefore, the use of unequal-diameter submarine cable technology can increase the conductor cross-section of the landing section of the submarine cable, thereby directly increasing the current-carrying capacity of the landing section. However, due to the problem of inconsistent outer diameters at the unequal-diameter connection of unequal-diameter submarine cables due to their own structure, during installation and long-term operation, this unequal-diameter form will cause stress concentration problems due to its own structural and weight imbalance, resulting in abnormal local stress. Therefore, it is necessary to combine the structural characteristics of unequal-diameter submarine cable joints and adopt appropriate methods and devices to improve the mechanical protection of the unequal-diameter submarine cable joint area. Summary of the Invention

[0004] The technical problem to be solved and the technical task proposed by the present invention are to improve and perfect the existing technical solutions and provide a mechanical protection device for unequal diameter submarine cable joints to improve the mechanical protection of the unequal diameter submarine cable joint area. To this end, the present invention adopts the following technical solutions.

[0005] A mechanical protection device for an unequal diameter submarine cable joint, wherein the unequal diameter submarine cable joint is formed by butting a large diameter submarine cable with a small diameter submarine cable, wherein the diameter of one end of the unequal diameter submarine cable joint is greater than the diameter of the other end, and the mechanical protection device comprises: The unequal diameter integral fixing assembly comprises a first unequal diameter integral fixing assembly and a second unequal diameter integral fixing assembly, wherein the first unequal diameter integral fixing assembly and the second unequal diameter integral fixing assembly are assembled to form a through-hole compatible with the unequal diameter submarine cable joint; the middle portion of the through-hole is a tapered hole compatible with the unequal diameter submarine cable joint, and the two ends of the tapered hole extend to form a small diameter hole section and a large diameter hole section to respectively cooperate with the small diameter submarine cable and the large diameter submarine cable at the two ends of the unequal diameter submarine cable joint; Two rigid support and fixing assemblies are respectively located on both sides of the unequal diameter integral fixing assembly, each rigid support and fixing assembly includes a first rigid support and fixing splice and a second rigid support and fixing splice, and the first rigid support and fixing splice and the second rigid support and fixing splice form a hole that matches the diameter of the corresponding side submarine cable after splicing; a radial rigid support member is provided on the inner circumferential wall of the rigid support and fixing assembly, and the inner end of the rigid support member is connected to the corresponding side submarine cable; Two flexible connectors are respectively located on the outside of the two rigid support and fixing components. The flexible connector is a deformable elastic component, one end of which is connected to the corresponding rigid support and fixing component, and the other end extends outward to cover the corresponding submarine cable.

[0006] This technical solution improves the mechanical protection performance and structural reliability of unequal diameter submarine cable joints through the three-level collaborative design of "overall conical support + bilateral rigid anchoring + flexible transition at the end", directly targeting and effectively alleviating the "uneven mechanical force" and "stress concentration" problems caused by structural unequal diameters pointed out in the background technology. Specifically, in this technical solution, a tapered hole is used in the middle of the perforation of the unequal diameter overall fixing component to fit the inclined structure of the transition from small diameter to large diameter at the joint. The gaps or local compression generated by the traditional equal diameter sheath in the variable diameter area are eliminated, so that the joint body can obtain uniform and continuous support. The small diameter hole section and the large diameter hole section extending from both ends of the tapered hole are respectively matched with the small diameter submarine cable and the large diameter submarine cable to ensure that the submarine cable bodies on both sides of the joint are also effectively fixed; the joint and the submarine cables on both sides of it are constrained as a whole, which effectively disperses the local concentrated stress caused by structural differences and prevents the joint area from being deformed or damaged due to uneven force. Independent rigid support fixtures are installed on both sides of the unequal-diameter integral fixture (i.e., the small-diameter end and the large-diameter end) to ensure that the load on both sides of the joint transition zone can be effectively borne. The inner end of the radial rigid support member installed on the inner circumferential wall of each rigid support fixture is directly connected to the submarine cable on the corresponding side. This is equivalent to establishing multiple rigid anchor points in the key load-bearing layer of the submarine cable, firmly connecting the submarine cable body to the protective device, and achieving efficient transmission of mechanical loads from the submarine cable to the protective device body. This greatly enhances the joint area's ability to resist external forces such as stretching, extrusion, and bending, and prevents relative slippage between the submarine cable and the protective device. The flexible connector located on the outside of the rigid support fixture is made of a deformable elastic material and extends outward to cover the submarine cable on the corresponding side, forming a buffer zone. This technical solution achieves a smooth transition from the rigid support and fixing area to the fully flexible submarine cable body. The flexible connector absorbs and releases the stress concentration that may occur at the rigid fixed end (for example, caused by dynamic loads such as laying bending, operation vibration, and ocean current impact), effectively preventing the submarine cable structure near the rigid fixing point from being damaged due to fatigue or stress concentration, and improving the reliability of long-term operation.

[0007] As a preferred technical means: the first unequal diameter integral fixed assembly and the second unequal diameter integral fixed assembly are plastic parts, and after the first unequal diameter integral fixed assembly and the second unequal diameter integral fixed assembly are assembled, their outer diameters are equal.

[0008] Plastics can effectively resist corrosion from marine environments such as seawater and salt spray, extending the service life of protective devices in harsh environments. Compared to metal, plastics have a lower density, significantly reducing the overall weight of protective devices. This reduces the additional burden on submarine cable joints, facilitates installation operations, and reduces additional mechanical stress on submarine cables during long-term operation. Plastics can be easily processed into complex shapes (such as internal tapered holes, small-diameter hole sections, and large-diameter hole sections) through processes such as injection molding, ensuring that they match the contours of unequal-diameter joints, improving support and sealing. When there is a large gap between the joint and the plastic part, it can be filled with rubber pads or glue injection. Plastics are excellent electrical insulating materials, avoiding the introduction of unnecessary conductive paths or the risk of short circuits near metal submarine cable structures. They also avoid the risks of eddy current loss heating, hysteresis loss heating, and contact resistance heating that can occur with metal materials, thereby improving the thermal stability and overall reliability of submarine cable joints during long-term operation. After the two parts are combined, their outer diameters are consistent, forming a regular cylindrical outer surface, which provides a guarantee for the subsequent socketing or installation of the rigid support fixing components on the outside, ensures the reliability of the installation of the rigid part and the stability of the overall structure, and ensures the uniformity and reliability of the force transmission between the two.

[0009] As a preferred technical approach, the joints of the first and second unequal-diameter integrally fixed components extend outward to form first positioning portions, which are connected by a connector to facilitate assembly. This facilitates installation and improves efficiency by relocating the connection points and stress-bearing areas (bolt holes, fastening surfaces) to dedicated positioning portions, avoiding the need for holes or concentrated stress in the main structure of the components. This maintains the integrity and strength of the main structure and reduces the risk of damage to the main structure due to connection operations or prolonged stress.

[0010] As a preferred technical means: the first rigid support fixing assembly and the second rigid support fixing assembly are metal parts; the first rigid support fixing assembly and the second rigid support fixing assembly both include a semi-cylindrical protective sleeve and a plurality of rigid support members arranged on the inner circumferential wall of the protective sleeve; the outer end of the rigid support member is fixedly connected to the protective sleeve, and the inner end is used to be fixedly connected to the armor layer of the corresponding submarine cable; the rigid support members are arranged in multiple rows along the axial direction of the protective sleeve, and the number of rigid support members in each row is not less than 3.

[0011] This technical solution uses rigid support fixtures to anchor the submarine cables on either side of the unequal-diameter joint to the main body of the protective device. This effectively resists various complex mechanical loads and prevents deformation, slippage, or damage to the joint area caused by insufficient rigidity or uneven force. This provides crucial rigidity for the safe operation of the unequal-diameter cable joint. Specifically, the rigid supports are arranged in multiple rows along the axial direction of the protective sleeve, effectively creating multiple reinforcement rings along the length of the submarine cable on both sides of the joint, increasing the number of connection points with the cable armor. Each row contains at least three rigid supports, ensuring at least three stable circumferential supports on each axial section. The uniform or uneven distribution of the rigid supports around the circumference effectively prevents deflection or twisting of the cable within the protective sleeve and ensures that loads (tension, compression, and bending) are more evenly transferred from the cable armor to the rigid sleeve. The protective sleeve is made of high-strength and high-rigidity metal and directly integrates multiple rigid supports to form a strong, rigid frame structure. The "multiple axial rows" design with "no fewer than three cables per row" creates a distributed, high-density rigid support network within the entire rigid support fixture assembly. This disperses significant mechanical stresses (such as laying tension, water flow impact, and seabed pressure) across numerous supports and over a longer axial distance. This suppresses local stress concentration and prevents deformation or fracture of the protective sleeve or supports themselves due to overload. This enhances the assembly's overall restraint and stabilization of both sides of the submarine cable joint, creating a sturdy "skeleton." The supports and armor layers can be connected by welding or other methods. The numerous rigid connection points significantly enhance resistance to this harmful relative motion, reducing the risk of loosening, wear, or even failure due to long-term micro-motion, and ensuring the long-term reliability and durability of the anchor connection.

[0012] As a preferred technical means: one end of the protective sleeve facing the unequal diameter integral fixing component is sleeved on the outer periphery of the unequal diameter integral fixing component, and one end of the protective sleeve facing the flexible connector is sleeved on the outer periphery of the flexible connector.

[0013] One end of the protective sleeve is sleeved onto the outer periphery of the unequal-diameter integral fixing component, and the other end is sleeved onto the outer periphery of the flexible connector, making the metal protective sleeve the key physical bridge connecting the unequal-diameter integral fixing component and the flexible connector. This ensures that the unequal-diameter integral fixation, rigid support fixation, and flexible connection are physically closely connected to form a coherent, seamless rigid support skeleton, avoiding structural weakening caused by loosening or displacement between modules. In addition, the sleeve interface itself forms a large-area mechanical contact surface. When the submarine cable joint is subjected to axial tension, pressure, or bending moment, the load can be transferred from the unequal-diameter integral fixing component to the rigid protective sleeve through this contact surface, and then transferred to the flexible connector at the other end through the protective sleeve, and then dispersed to a longer submarine cable section.

[0014] As a preferred technical means: the joints of the first rigid support and fixed assembly piece and the second rigid support and fixed assembly piece extend outward to form an axial second connecting portion, and the second connecting portions are connected by a connecting piece to achieve the splicing of the first rigid support and fixed assembly piece and the second rigid support and fixed assembly piece.

[0015] A second connecting portion extends axially outward from the joint of each component, creating a dedicated "connection platform" outside the component body for connection operations. This allows connection operations (such as bolt tightening) to be performed entirely outside the main contour of the component, eliminating the difficulty of operating on narrow or complex curved surfaces, simplifying the on-site installation process, and improving assembly efficiency and precision. When the connecting portions of the two components are tightly pulled together using connecting members (such as bolts), these extended connecting portions together form a solid "reinforcement rib" and "flange" structure on both sides of the joint, enhancing the rigidity and bending resistance of the entire rigid support and fixing assembly (composed of the two components) at the joint. This ensures that the joint is less likely to open, misalign, or deform when subjected to forces (such as axial tension, lateral pressure, and torsional torque), maintaining the integrity of the protective cover.

[0016] As an optimal technical means: the protective sleeve is provided with a snap ring at one end facing the flexible connector, the flexible connector is provided with a groove matching the snap ring, and the snap ring of the protective sleeve is embedded in the groove of the flexible connector to limit the axial displacement of the flexible connector relative to the protective sleeve.

[0017] The snap ring is embedded in the slot to form a physical interlock, forming a hard barrier in the axial direction, which can effectively prevent the flexible connector from moving in two axial directions relative to the protective sleeve. Ensure that the flexible connector is firmly fixed to the end of the protective sleeve to avoid accidental disengagement or axial slippage caused by water flow impact, changes in the weight of the submarine cable, vibration or bending stress, and ensure the structural integrity of the rigid-flexible transition zone. During assembly, just align the slot of the flexible connector with the snap ring of the protective sleeve and apply radial pressure to complete a quick "snap" connection. When disassembling, the reverse operation can be performed to separate. Compared with bolt connection, welding or gluing, it eliminates the process of tightening bolts, welding operations or waiting for adhesives to cure, significantly improving the efficiency of on-site installation and subsequent maintenance, and reducing operational complexity.

[0018] As a preferred technical means: the flexible connector is a split structure or an integral structure. Different structures can be selected according to actual conditions to match different installation environments and maintenance requirements.

[0019] The split structure can be composed of a first flexible splicing part and a second flexible splicing part (such as two symmetrical semi-cylinders). The material can be a corrosion-resistant elastomer (such as nitrile rubber, chloroprene rubber or polyurethane); during assembly, the first and second flexible splicing parts are radially aligned from both sides of the submarine cable and wrapped around the outer surface of the submarine cable. The splicing surface is fixed by a locking mechanism (such as bolt connection, snap connection or bonding) to form a complete cylindrical body; the spliced flexible connector is then connected to the end of the protective sleeve of the rigid support and fixing component (such as a clamping ring-slot). When it is an integral structure, it can be a complete cylindrical elastomer (without splicing seams). During assembly, the integral flexible connector is inserted along the axis of the cable and slid to the set position; its end is connected to the end of the protective sleeve of the rigid support and fixing component.

[0020] As a preferred technical means: the split-structure flexible connector is composed of a first flexible splicing piece and a second flexible splicing piece.

[0021] The split structure allows for direct installation from both radial sides while the submarine cable joint is fixed, such as on-site maintenance of an already laid submarine cable (without cutting the cable or removing the joint), solving the installation space requirement of the integral structure that must be "axially inserted". The first / second flexible splice is an independent semi-cylinder, smaller than a monolithic cylinder of the same specification, facilitating processing and reducing costs.

[0022] As a preferred technical means: the first flexible splicing piece and the second flexible splicing piece are one group or multiple groups; when there are multiple groups, the multiple groups of the first flexible splicing pieces and the second flexible splicing pieces are axially arranged in series to form a flexible connecting piece with adjustable length; the two adjacent groups of flexible connecting pieces are bendably connected.

[0023] This technical solution can extend the total coverage length of the flexible connector as needed by increasing the number of series groups (e.g. 1 group → 3 groups). For example, short lengths can be used for flat seabeds and low-stress areas. Long lengths: used for complex terrain (slopes, undulations), high mechanical stress areas, and enhanced buffer distances. This technical solution can use the same set of basic components to meet the protection length requirements of different engineering scenarios, avoiding customized design. By increasing or decreasing the number of groups, different total lengths can be assembled, eliminating the need to manufacture and store integral parts of various lengths, which helps reduce costs. Limited angles of relative deflection are allowed between adjacent groups, which helps increase terrain conformity. When the submarine cable passes through slopes, reefs or curved grooves, the series structure can bend locally to fit the path, eliminating rigid pulling or stress concentration caused by sudden changes in terrain, and avoiding local suspension failure.

[0024] Beneficial effects: This technical solution improves the mechanical protection performance and structural reliability of unequal-diameter submarine cable joints in harsh marine environments through the three-level collaborative design of "overall conical support + bilateral rigid anchoring + flexible transition at the end", and effectively alleviates the problems of "uneven mechanical force" and "stress concentration" caused by unequal structural diameters.

[0025] 1. In this technical solution, a tapered hole is used in the middle of the perforation of the unequal-diameter integral fixing component to fit the inclined structure of the transition from small diameter to large diameter at the joint. This eliminates the gaps or local pressure generated by traditional equal-diameter sheaths in the variable-diameter area, allowing the joint body to obtain uniform and continuous support. The small-diameter hole section and large-diameter hole section extending from both ends of the tapered hole respectively cooperate with the small-diameter submarine cable and the large-diameter submarine cable to ensure that the submarine cable bodies on both sides of the joint are also effectively fixed; the joint and the submarine cables on both sides are constrained as a whole, effectively dispersing the local concentrated stress caused by structural differences and preventing the joint area from deformation or damage due to uneven force.

[0026] 2. Independent rigid support fixtures are installed on both sides of the unequal-diameter integral fixture assembly to ensure that the loads on both sides of the joint transition zone can be effectively borne. The radial rigid support members installed on the inner circumferential wall of each rigid support fixture assembly are directly connected to the corresponding submarine cable at their inner ends. This is equivalent to establishing multiple rigid anchor points in the key load-bearing layer of the submarine cable, firmly connecting the submarine cable body to the protective device, achieving efficient transfer of mechanical loads from the submarine cable to the protective device body, greatly enhancing the joint area's ability to resist external forces such as tension, compression, and bending, and preventing relative slippage between the submarine cable and the protective device.

[0027] 3. The flexible connector, located outside the rigid support assembly, is made of a deformable elastic material and extends outward to wrap around the corresponding cable, forming a buffer zone. This creates a smooth transition from the rigid support area to the fully flexible cable body. The flexible connector absorbs and releases stress concentration that may occur at the rigid end, effectively preventing damage to the cable structure near the rigid fixing point due to fatigue or stress concentration, thereby improving long-term operational reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the present invention.

[0029] Figure 2 It is a schematic diagram of the top structure of the present invention.

[0030] Figure 3 It is a schematic cross-sectional structural diagram of the present invention.

[0031] Figure 4 It is a schematic diagram of the blasting structure of the present invention.

[0032] Figure 5 It is a schematic structural diagram of the unequal diameter integral fixing assembly of the present invention.

[0033] Figure 6 It is a structural schematic diagram of the rigid support fixing assembly of the present invention.

[0034] In the figure: 1, unequal diameter integral fixing assembly; 11, first unequal diameter integral fixing assembly; 12, second unequal diameter integral fixing assembly; 13, first positioning portion; 2. Rigid support fixing assembly; 21. First rigid support fixing assembly; 22. Second rigid support fixing assembly; 23. Rigid support member; 24. Second connecting portion; 25. Snap ring; 3. Flexible connector; 31. Card slot; 4. Unequal diameter submarine cable joint; 5. Large diameter submarine cable; 6. Small diameter submarine cable. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Since the embodiments disclosed in the present invention can be set in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0037] Example 1: like Figures 1-6 As shown, the unequal diameter submarine cable joint 4 is formed by connecting a large diameter submarine cable 5 with a small diameter submarine cable 6. The diameter of one end of the unequal diameter submarine cable joint 4 is larger than the diameter of the other end. In this embodiment, the mechanical protection device includes: 1. The unequal-diameter integral fixing assembly 1 includes a first unequal-diameter integral fixing assembly 11 and a second unequal-diameter integral fixing assembly 12. These 11 and 12 combine to form a through-hole compatible with the unequal-diameter submarine cable connector 4. The center of the through-hole is a tapered hole compatible with the unequal-diameter submarine cable connector 4, with the angle of the tapered hole matching the taper of the unequal-diameter connector. The ends of the tapered hole extend to form a small-diameter hole section and a large-diameter hole section, respectively, to accommodate the small-diameter submarine cable 6 and the large-diameter submarine cable 5 at the ends of the unequal-diameter submarine cable connector 4.

[0038] To improve the thermal stability and overall reliability of the submarine cable joint in long-term operation, the first unequal diameter integral fixed splice 11 and the second unequal diameter integral fixed splice 12 are plastic parts. The plastic parts can be made of corrosion-resistant ABS or nylon.

[0039] To facilitate connection with the rigid support fixing assembly 2 , the first unequal diameter integral fixing assembly 11 and the second unequal diameter integral fixing assembly 12 are assembled to form a complete cylinder having the same outer diameter.

[0040] The joints of the first unequal-diameter integral fixed assembly 11 and the second unequal-diameter integral fixed assembly 12 extend outward to form a first positioning portion 13. A corresponding number of bolt holes are provided on the first positioning portion 13. Bolts are passed through the bolt holes and fastened with nuts to achieve a rigid connection between the first unequal-diameter integral fixed assembly 11 and the second unequal-diameter integral fixed assembly 12.

[0041] When there is a large gap between the unequal diameter integral fixing assembly 1 and the unequal diameter submarine cable joint 4, an elastic rubber pad can be inserted and fixed with adhesive. The elastic rubber pad fills the gap between the assembly and the submarine cable, preventing wear caused by rigid contact and absorbing vibration stress.

[0042] 2. Two rigid support and fixing components 2 are respectively located on both sides of the unequal diameter integral fixing component 1. Each rigid support and fixing component 2 includes a first rigid support and fixing splice 21 and a second rigid support and fixing splice 22. The first rigid support and fixing splice 21 and the second rigid support and fixing splice 22 are spliced to form a hole that matches the diameter of the corresponding side submarine cable; a radial rigid support member 23 is provided on the inner circumferential wall of the rigid support and fixing component 2, and the inner end of the rigid support member 23 is connected to the corresponding side submarine cable.

[0043] To improve the connection strength, in this embodiment, the first rigid support and fixing assembly 21 and the second rigid support and fixing assembly 22 are corrosion-resistant metal parts, such as stainless steel.

[0044] Both the first rigid support and fixing assembly 21 and the second rigid support and fixing assembly 22 comprise a semi-cylindrical protective sleeve and a plurality of rigid support members 23 disposed on the inner circumferential wall of the protective sleeve. The rigid support members 23 are arranged in three rows along the axial direction of the protective sleeve, with five members evenly distributed circumferentially in each row. Their outer ends are welded to the inner wall of the protective sleeve, and their inner ends are also welded to the armor layer of the submarine cable.

[0045] To facilitate connection, the joints of the first and second rigid support and fixing components 21, 22 extend outward to form an axial second connecting portion 24. Bolt holes are provided in the second connecting portion 24, through which bolts pass through the bolt holes in the first and second rigid support and fixing components 21, 22 and connect with nuts to achieve the connection between the first and second rigid support and fixing components 21, 22.

[0046] To improve the strength of the connection, one end of the protective sleeve facing the unequal diameter integral fixing component 1 is sleeved on the outer periphery of the unequal diameter integral fixing component 1 , and one end of the protective sleeve facing the flexible connector 3 is sleeved on the outer periphery of the flexible connector 3 .

[0047] 3. Two flexible connectors 3 are located on the outside of the two rigid support and fixing components 2 respectively. The flexible connector 3 is a deformable elastic component, such as neoprene, one end of which is connected to the corresponding rigid support and fixing component 2, and the other end extends outward to cover the corresponding submarine cable.

[0048] The flexible connector 3 is formed by combining a first flexible assembly and a second flexible assembly, and is semi-cylindrical in shape. After assembly, the inner diameter matches the outer diameter of the submarine cable.

[0049] In order to improve the reliability of the connection, a snap ring 25 is provided at one end of the protective sleeve facing the flexible connector 3, and the flexible connector 3 is provided with a groove 31 that cooperates with the snap ring 25. The snap ring 25 of the protective sleeve is embedded in the groove 31 of the flexible connector 3 to limit the axial displacement of the flexible connector 3 relative to the protective sleeve.

[0050] Assembly process: 1. The first stage: installation of unequal diameter integral fixing components 1 Step 1.1 Pre-assemble the parts The first unequal diameter integral fixed assembly 11 and the second unequal diameter integral fixed assembly 12 are aligned from both radial sides of the submarine cable joint so that the tapered hole is in close contact with the inclined surface of the joint.

[0051] Make sure the bolt holes of the first positioning portion 13 are aligned.

[0052] Step 1.2 Fastening and sealing Pass the bolts through the positioning part and tighten them step by step in diagonal order.

[0053] Detect the gap between the inner wall of the component and the joint: If the gap is large, fill it with glue or other methods; If the gap is small, go directly to the next step.

[0054] 2. Phase 2: Installing rigid support fixing components 2 Step 2.1 Attach the protective cover The first rigid support and fixing assembly 21 and the second rigid support and fixing assembly 22 are aligned radially from the submarine cable so that the right end of the protective sleeve is sleeved on the outer periphery of the assembly.

[0055] Step 2.2 Welding the rigid support 23 The surface of the armor layer is polished and cleaned, and then the inner end of the rigid support member 23 is welded to the armor layer of the submarine cable.

[0056] Step 2.3 Fasten the rigid support fixing assembly 2 The second connection portion 24 is tightened with bolts to connect the first rigid support and fixing component 21 and the second rigid support and fixing component 22 into a whole.

[0057] 3. The third stage: installation of flexible connector 3 3.1 Split flexible connector 3 The first flexible splicing piece and the second flexible splicing piece are aligned radially from the submarine cable and fixed on the submarine cable.

[0058] The fastening can be done by snaps or screws.

[0059] The clamping ring 25 is inserted into the clamping groove 31 at the right end of the flexible connector 3 , and then the clamping ring 25 and the protective cover are welded and fixed to achieve the fixed connection between the flexible connector 3 and the rigid support fixing assembly 2 .

[0060] 4. The fourth stage: final quality inspection and protective treatment Pull the flexible connector 3 laterally to confirm that there is no axial displacement; Bend the submarine cable and check if there are any cracks in the rigid-flexible transition zone.

[0061] Spray a protective layer on metal parts such as protective sleeves, bolts, etc.

[0062] Example 2: This embodiment differs from the first embodiment in that multiple groups of flexible connectors 3 are provided, each group consisting of a first flexible component and a second flexible component. Adjacent groups can be connected via a ball joint structure, allowing for ±15° deflection. The coverage length can be adjusted by increasing or decreasing the number of groups.

[0063] During assembly, first assemble the groups, then insert the ball head of the ball joint structure into the next group of ball sockets; then fit the first group's slots 31 into the snap rings 25 to achieve the fixed connection between the flexible connector 3 and the rigid support fixing assembly 2.

[0064] In this embodiment, a single group of flexible connectors 3 can be made of a material with certain strength and rigidity. After multiple groups of flexible connectors 3 are connected in series, a flexible connector 3 that can bend within a certain range is formed.

[0065] Example 3: The difference from the first embodiment is that the flexible connector 3 is an integral flexible connector 3 .

[0066] Before assembly, first insert it axially and slide it along the coastal cable to the designed position; finally, insert the clamping ring 25 into the annular clamping groove 31 to achieve the fixed connection between the flexible connector 3 and the rigid support fixing component 2.

[0067] The mechanical protection device for the unequal-diameter submarine cable joint shown above is a specific embodiment of the present invention, which has embodied the substantial features and progress of the present invention. According to actual use needs and under the guidance of the present invention, equivalent modifications in shape, structure, etc. can be made to it, which are all within the scope of protection of this solution.

Claims

1. A mechanical protection device for an unequal diameter submarine cable joint, wherein the unequal diameter submarine cable joint is formed by butting a large diameter submarine cable with a small diameter submarine cable, wherein the diameter of one end of the unequal diameter submarine cable joint is larger than the diameter of the other end, characterized in that: The mechanical protection device comprises: The unequal diameter integral fixing assembly comprises a first unequal diameter integral fixing assembly and a second unequal diameter integral fixing assembly, wherein the first unequal diameter integral fixing assembly and the second unequal diameter integral fixing assembly are assembled to form a through-hole compatible with the unequal diameter submarine cable joint; the middle portion of the through-hole is a tapered hole compatible with the unequal diameter submarine cable joint, and the two ends of the tapered hole extend to form a small diameter hole section and a large diameter hole section to respectively cooperate with the small diameter submarine cable and the large diameter submarine cable at the two ends of the unequal diameter submarine cable joint; Two rigid support and fixing assemblies are respectively located on both sides of the unequal diameter integral fixing assembly, each rigid support and fixing assembly includes a first rigid support and fixing splice and a second rigid support and fixing splice, and the first rigid support and fixing splice and the second rigid support and fixing splice form a hole that matches the diameter of the corresponding side submarine cable after splicing; a radial rigid support member is provided on the inner circumferential wall of the rigid support and fixing assembly, and the inner end of the rigid support member is connected to the corresponding side submarine cable; Two flexible connectors are respectively located on the outside of the two rigid support and fixing components. The flexible connector is a deformable elastic component, one end of which is connected to the corresponding rigid support and fixing component, and the other end extends outward to cover the corresponding submarine cable.

2. The mechanical protection device for unequal diameter submarine cable joints according to claim 1, characterized in that: The first unequal diameter integral fixed assembly piece and the second unequal diameter integral fixed assembly piece are plastic pieces. After the first unequal diameter integral fixed assembly piece and the second unequal diameter integral fixed assembly piece are assembled, their outer diameters are equal.

3. The mechanical protection device for an unequal diameter submarine cable joint according to claim 2, characterized in that: The joints of the first unequal diameter integral fixed assembly and the second unequal diameter integral fixed assembly extend outward to form a first positioning portion, and the first positioning portions are connected by a connecting piece to achieve the joint of the first unequal diameter integral fixed assembly and the second unequal diameter integral fixed assembly.

4. The mechanical protection device for unequal diameter submarine cable joints according to claim 1, characterized in that: The first rigid support fixing assembly and the second rigid support fixing assembly are metal parts; the first rigid support fixing assembly and the second rigid support fixing assembly each include a semi-cylindrical protective cover and a plurality of rigid support members arranged on the inner circumferential wall of the protective cover; the outer end of the rigid support member is fixedly connected to the protective cover, and the inner end is used to be fixedly connected to the armor layer of the corresponding submarine cable; the rigid support members are arranged in multiple rows along the axial direction of the protective cover, and the number of rigid support members in each row is not less than 3.

5. The mechanical protection device for unequal diameter submarine cable joints according to claim 4, characterized in that: One end of the protective sleeve facing the unequal diameter integral fixing component is sleeved on the outer periphery of the unequal diameter integral fixing component, and one end of the protective sleeve facing the flexible connector is sleeved on the outer periphery of the flexible connector.

6. The mechanical protection device for unequal diameter submarine cable joints according to claim 5, characterized in that: The joints of the first rigid support and fixed assembly and the second rigid support and fixed assembly extend outward to form an axial second connection portion, and the second connection portions are connected by a connection piece to achieve the splicing of the first rigid support and fixed assembly and the second rigid support and fixed assembly.

7. The mechanical protection device for unequal diameter submarine cable joints according to claim 6, characterized in that: The protective sleeve is provided with a snap ring at one end facing the flexible connector, and the flexible connector is provided with a groove matching the snap ring. The snap ring of the protective sleeve is embedded in the groove of the flexible connector to limit the axial displacement of the flexible connector relative to the protective sleeve.

8. The mechanical protection device for unequal diameter submarine cable joints according to claim 1, characterized in that: The flexible connector is a split structure or an integral structure.

9. The mechanical protection device for unequal diameter submarine cable joints according to claim 8, characterized in that: The split-structure flexible connector is composed of a first flexible splicing piece and a second flexible splicing piece.

10. The mechanical protection device for unequal diameter submarine cable joint according to claim 9, characterized in that: The first flexible splicing parts and the second flexible splicing parts are one group or multiple groups. When there are multiple groups, the multiple groups of the first flexible splicing parts and the second flexible splicing parts are axially arranged in series to form a flexible connecting part with adjustable length. The two adjacent groups of flexible connecting parts are bendably connected.

Images