A deep sea floating multi-floater array rigid-flexible coupling connector

Abstract

The application provides a deep-sea floating multi-floater array rigid-flexible coupling connector, and belongs to the technical field of offshore energy. The deep-sea floating multi-floater array rigid-flexible coupling connector is used for connecting adjacent first and second floaters in a floater array, and comprises a connecting main body, a first connecting unit and a second connecting unit. The first connecting unit comprises four support legs in the form of space rods, one end of each support leg is hinged to the connecting main body, and the other end is connected to the first floater. The second connecting unit comprises two hydraulic cylinders, the cylinder body end of the hydraulic cylinder is connected to the second floater, and the piston rod end of the hydraulic cylinder is connected to the connecting main body through a ball hinge connection structure to provide multi-degree-of-freedom rotation capability, thereby solving the technical problem that the deep-sea floating multi-floater array connector cannot simultaneously consider rigid geometric constraints and flexible motion adaptation and cannot realize working condition self-adaptive adjustment.

Description

Technical Field

[0001] This invention belongs to the field of marine energy technology, and more specifically, relates to a rigid-flexible coupling connector for a deep-sea floating multi-buoy array. Background Technology

[0002] Deep-sea floating multi-buoy array technology, as an important development direction for marine engineering equipment, has received widespread attention in recent years in fields such as offshore photovoltaics, aquaculture, observation, and energy development. This technology deploys various functional platforms or structural units in deep-sea areas, utilizing the spatial resources and environmental conditions of open sea areas to achieve large-scale operations, while avoiding space occupation and ecological conflicts in nearshore areas. Deep-sea multi-buoy systems typically consist of large-scale arrays composed of multiple floating units. The floating units are mechanically connected and load-bearing is transferred between them via connectors, forming an integral structure to resist environmental loads such as wind, waves, and currents. As a key component of the array system, the performance of the connectors directly determines the geometric stability, structural safety, and operational reliability of the multi-buoy array.

[0003] Traditional deep-sea floating multi-buoy array connectors mainly employ either purely rigid or purely flexible connections. Purely rigid connectors typically use welded trusses, bolted flanges, or hinged rod structures. While providing good geometric constraints and load transfer capabilities, in the complex conditions of deep-sea environments, the six-degree-of-freedom relative motion between floats is excessively constrained. This leads to enormous inertial forces and impact loads at the connection points, easily causing weld fatigue cracking, bolt loosening, or rod buckling failure. Furthermore, rigid connections cannot effectively absorb wave energy, exacerbating the risk of vibration damage to upper structures and equipment. Purely flexible connectors often use cables, rubber pads, or simple hinge structures. While they can accommodate the relative motion of floats, they lack sufficient in-plane stiffness and torsional constraint capabilities. This causes the array to easily become overly clustered, dispersed, or torsional deformed under the influence of wind and waves, compromising the relative positional accuracy and operational coordination between floats. In severe cases, this can even lead to float collisions, cable entanglement, or structural instability. In addition, some existing technologies attempt to achieve flexible connections using a single hydraulic damping element, but they generally suffer from problems such as insufficient rotational freedom, fixed and unadjustable damping parameters, and lack of active control capabilities. They are difficult to adapt to the complex needs of the ever-changing sea conditions in the deep sea, and hydraulic components are prone to sealing failure and accelerated wear in seawater corrosion and biological adhesion environments, resulting in high maintenance costs. Summary of the Invention

[0004] In view of this, the present invention provides a rigid-flexible coupling connector for deep-sea floating multi-buoy arrays, which solves the technical problem that deep-sea floating multi-buoy array connectors are unable to simultaneously take into account rigid geometric constraints and flexible motion adaptation, and are unable to achieve adaptive adjustment under working conditions.

[0005] This invention is implemented as follows:

[0006] This invention provides a rigid-flexible coupling connector for a deep-sea floating multi-buoy array, used to connect adjacent first and second floats in a float array, comprising a connecting body, a first connecting unit, and a second connecting unit;

[0007] The first connecting unit includes four support legs distributed in a spatial rod shape. One end of each support leg is hinged to the connecting body, and the other end is connected to the first floating body. The four support legs form a spatial tetrahedral support frame structure, forming a statically indeterminate rigid support system.

[0008] The second connecting unit includes two hydraulic cylinders. The cylinder body of the hydraulic cylinder is connected to the second float, and the piston rod of the hydraulic cylinder is connected to the connecting body through a ball joint connection structure to provide multi-degree-of-freedom rotation capability. The hydraulic cylinder compensates for the displacement of the relative motion between the first float and the second float by the extension and retraction of the piston rod.

[0009] The technical advantages of the rigid-flexible coupling connector for deep-sea floating multi-buoy array provided by this invention are as follows: This rigid-flexible coupling connector, through a spatially statically indeterminate rigid support system composed of four support legs, effectively constrains the relative displacement between floats and provides multi-path load transfer capability, significantly enhancing the overall structural stiffness and torsional bearing capacity. At the same time, by utilizing the flexible connection unit formed by the combination of dual hydraulic cylinders and ball joints, it realizes multi-degree-of-freedom rotational self-adaptation and dynamic displacement compensation functions, effectively absorbing and dissipating the low-frequency large-amplitude dynamic impact energy caused by waves and wind loads in the deep-sea environment, avoiding stress concentration and fatigue damage problems caused by pure rigid connections. Thus, while maintaining the geometric stability of the multi-buoy array, it significantly improves the system's adaptability to complex sea conditions and structural durability.

[0010] Based on the above technical solution, the rigid-flexible coupling connector for deep-sea floating multi-buoy arrays of the present invention can be further improved as follows:

[0011] The connecting body includes a base, a transition unit, and a rotating unit. The base and the transition unit are fixedly connected by bolts. The rotating unit is hinged to the transition unit by a pin. The rotating unit can rotate relative to the transition unit around the pin axis. Each support leg of the first connecting unit is hinged to the base. The ball joint connection structure of the second connecting unit is connected to the rotating unit.

[0012] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the modular design of the connecting body realizes the functional division and reliable transition between the rigid support system and the flexible compensation unit; the bolt detachable connection between the base and the transition unit facilitates on-site assembly and positioning and subsequent maintenance and disassembly; the pin hinge design between the rotating unit and the transition unit provides the second connecting unit with rotational freedom around a specific axis, ensuring that the hydraulic cylinder maintains good attitude adaptability during the complex spatial movement of the floating body, effectively reducing the constraint reaction force and wear risk at the connection interface, and improving the maintainability and life cycle economy of the system.

[0013] Furthermore, three of the four support legs are located in the same vertical plane, and the other support leg is located to the side of the vertical plane and arranged at a spatial angle to the vertical plane; adjacent support legs located in the same vertical plane are connected by a triangular connecting member and achieve a common node intersection, and the vertex of the triangular connecting member is hinged to the side wall of the base.

[0014] The beneficial effects of adopting the above-mentioned improved scheme are as follows: This spatial arrangement enables the support leg system to form a geometrically invariant statically determinate or hyperstatically indeterminate spatial truss system, which can effectively resist bending moments, torques and shear forces from different directions. The application of triangular connecting members concentrates the force flow of the members at the common node, optimizes the load transmission path and reduces the local stress concentration phenomenon at the connection point. At the same time, the in-plane common node design simplifies the connection interface with the base, improves the structural assembly accuracy and force transmission efficiency, and enhances the overall structural anti-tilting stability.

[0015] Furthermore, the triangular connecting member is a plate-type triangular structure or a truss-type triangular structure, with its three vertices connected to the rods of the two adjacent supporting legs and the sidewall of the base, respectively, and the plane of the triangular connecting member is coplanar with the axis of the rod of the supporting leg.

[0016] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the use of plate or truss triangular components allows for flexible selection of structural form according to load size, weight limitations and manufacturing process requirements. Plate structures are suitable for compact space requirements with high rigidity and lightweight, while truss structures are suitable for large-span heavy-load conditions to reduce the self-weight of the structure. The coplanar arrangement of the component plane and the axis of the supporting leg ensures that the force flow is directly transmitted in the plane, avoiding the additional bending moment and bending deformation of the node plate caused by spatial torque, improving the reliability of node connection and structural stability, and facilitating mass production and quality control.

[0017] Furthermore, the second connecting unit also includes an auxiliary support leg, which is located between or to the side of the two hydraulic cylinders. One end of the auxiliary support leg is hinged to the second float, and the other end is hinged to the rotating unit or the connecting body, for assisting in connecting the second float and the connecting body.

[0018] The beneficial effects of adopting the above-mentioned improved scheme are as follows: The auxiliary support leg enhances the connection redundancy between the second float and the connecting body, providing auxiliary rigid constraints while the hydraulic cylinder performs flexible compensation. This effectively shares the lateral load, torque, and lateral shear force borne by the hydraulic cylinder, preventing excessive relative displacement or structural instability caused by a single flexible connection under extreme sea conditions. By directly hinged the auxiliary support leg to the rotating unit, the auxiliary support leg can work in conjunction with the rotating unit to adapt to the complex spatial motion of the float, forming a composite rotation capability. This optimizes the load transfer path, avoids motion interference and additional constraints caused by direct connection with the fixed base, and improves the safety, reliability, and structural self-adaptability of the connector under severe sea conditions. At the same time, the hinged end of the auxiliary support leg and the rotating unit can rotate synchronously with the rotating unit, realizing dynamic coordination and balanced load distribution of the connection structure. Furthermore, the ball joint connection structure includes a ball head, a ball seat, and a lubrication assembly. The ball head is a spherical structure and is fixedly connected to the end of the piston rod of the hydraulic cylinder. The ball seat has a spherical cavity that matches the ball head. The ball head is embedded in the spherical cavity and forms a multi-degree-of-freedom rotary pair. The outer wall of the ball seat is hinged to the side wall of the rotating unit through a pin. The ball seat can rotate around the axis of the pin.

[0019] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the ball joint structure realizes the spatial universal rotation capability of the piston rod end of the hydraulic cylinder, effectively releases the angular displacement constraints caused by the relative motion of the float, avoids the piston rod bearing lateral bending moment and thus avoids uneven wear, bending deformation and sealing element failure. At the same time, the single-degree-of-freedom hinge design of the ball seat and the rotating unit further provides the rotation capability around a specific horizontal or vertical axis, forming a composite rotating pair, which significantly reduces the additional bending moment and lateral load of the hydraulic cylinder, extends the service life of hydraulic components and improves the reliability of the system.

[0020] Furthermore, the lubrication assembly is disposed on the side wall or top of the ball seat, and the ball seat has a lubricating oil cavity surrounding the spherical cavity inside. The lubricating oil cavity is connected to the surface of the spherical cavity through an oil passage, and is used to continuously lubricate the contact friction surface between the ball head and the ball seat.

[0021] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: the built-in lubrication system realizes active lubrication and continuous oil film maintenance of the ball joint friction pair, effectively reducing the friction coefficient and wear rate of the ball head and ball seat contact surface, reducing the frequency of regular maintenance and downtime, while the closed design of the lubrication oil cavity, together with the sealing element, effectively prevents the intrusion of corrosive media such as seawater and salt spray, and improves the durability, operational reliability and long-term operational stability of the connection structure in deep and highly corrosive marine environments.

[0022] Furthermore, the hydraulic cylinder is a parameter-adjustable hydraulic damping cylinder, whose damping characteristics and equivalent stiffness can be steplessly adjusted by adjusting the opening of the throttling element in its hydraulic circuit to adapt to the dynamic load response requirements under different sea conditions.

[0023] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: by adjusting the opening of the throttling element to change the damping characteristics and equivalent stiffness of the hydraulic cylinder, the connector can perform dynamic parameter matching and adaptive adjustment according to real-time sea conditions. In calm sea conditions, it provides a low-stiffness flexible connection to reduce constraint reaction force and structural stress, and in severe sea conditions, it provides high-stiffness and large damping to suppress excessive relative displacement and resonance response. It realizes the functions of working condition adaptive vibration control, energy dissipation and attitude stabilization, and significantly broadens the applicable sea condition range of the connector.

[0024] Furthermore, an accumulator is fixedly installed on the outer wall surface of the hydraulic cylinder. The accumulator is connected to the working chamber of the hydraulic cylinder through pipelines and a shut-off valve. The accumulator is pre-charged with compressed gas, and the pre-charge pressure is an adjustable parameter. By changing the pre-charge pressure, the equivalent stiffness and energy storage capacity of the second connecting unit can be adjusted.

[0025] The beneficial effects of adopting the above-mentioned improvement scheme are as follows: The integrated design of the accumulator provides the hydraulic system with the dual functions of an elastic element and an energy storage element. By adjusting the pre-charge pressure, the equivalent stiffness and energy buffering capacity of the system can be changed. It absorbs hydraulic energy instantaneously during wave impact and releases it slowly, effectively smoothing the peak impact force and pressure pulsation of the hydraulic cylinder. At the same time, as an auxiliary power source, it can replenish oil or absorb thermal expansion oil under specific working conditions, thereby improving the dynamic response characteristics, energy utilization efficiency and operational stability of the system.

[0026] Furthermore, the hydraulic cylinder is equipped with a hybrid active-passive adjustment system. In passive adjustment mode, the hydraulic cylinder dissipates energy through the viscous damping generated by the internal hydraulic oil flowing through the throttling element. In active adjustment mode, the hydraulic cylinder actively adjusts its output force or piston rod displacement through an external electro-hydraulic system to achieve active control of the relative motion between the first float and the second float.

[0027] The beneficial effects of adopting the above-mentioned improved scheme are as follows: This active-passive hybrid regulation system realizes the integration of passive energy consumption and vibration reduction with active control technology. In passive mode, basic energy dissipation and wide-band vibration suppression can be achieved without external energy, and it has good reliability and economy. In active mode, precise force or displacement output is achieved through an external control system, which can actively cancel, track or optimize the excitation of waves at specific frequencies, significantly improving the connector's adaptability, control accuracy and intelligence level in complex and changeable sea conditions, and realizing the technological leap from passive adaptation to active regulation.

[0028] Compared with existing technologies, the beneficial effects of the rigid-flexible coupling connector for deep-sea floating multi-buoy arrays provided by this invention are as follows: Through the synergistic design of rigid support and flexible compensation, the rigid-flexible coupling connector for deep-sea floating multi-buoy arrays provided by this invention significantly improves the performance and environmental adaptability of the array structure. The statically indeterminate rigid support system composed of four spatially distributed support legs effectively constrains the relative displacement between floats and provides multi-path load transfer, enhancing overall stiffness and torsional bearing capacity, and avoiding excessive deformation caused by purely flexible connections. The flexible connection unit formed by the combination of dual hydraulic cylinders and ball joints achieves multi-degree-of-freedom rotational adaptation and dynamic displacement compensation, effectively absorbing the dynamic impact energy caused by waves and wind loads, and eliminating the stress concentration and fatigue damage risks of purely rigid connections. The ball joint structure releases the angular displacement constraints caused by the relative motion of the floats, avoiding uneven wear and sealing failure caused by the piston rod bearing lateral bending moment. The built-in lubrication system reduces friction and wear and prevents seawater corrosion intrusion. The adjustable hydraulic cylinder parameter design alters damping characteristics and equivalent stiffness by adjusting the throttling element, allowing the connector to adaptively adjust according to sea conditions. It provides a low-stiffness, flexible connection in calm seas and a high-stiffness, high-damping connection in harsh seas, significantly broadening the applicable sea condition range. The integrated accumulator design changes the system's elasticity and buffering capacity by adjusting the pre-charge pressure, smoothing peak impact forces and improving operational stability. The hybrid active-passive control system integrates passive energy-saving vibration reduction and active control technologies. In passive mode, it achieves wide-band vibration suppression without external energy, while in active mode, it achieves precise force or displacement output through external control, actively canceling wave excitation at specific frequencies, improving control accuracy and intelligence. The modular connection body facilitates assembly and maintenance, while auxiliary support legs enhance connection redundancy, reducing overall life-cycle costs. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 This is a partially enlarged schematic diagram of the ball joint connection structure of the present invention;

[0031] Figure 3 This is a schematic diagram of the connection structure between the hydraulic cylinder and the accumulator of the present invention;

[0032] Figure 4 This is a schematic diagram of the left side structure of the connecting body of the present invention;

[0033] Figure 5 This is a schematic diagram of the right side structure of the connecting body of the present invention;

[0034] The attached diagram lists the components represented by each number as follows:

[0035] 1. Support leg; 3. Triangular component; 4. Base; 5. Transition unit; 6. Bolt; 7. Rotating unit; 8. Pin; 9. Ball seat; 10. Ball head; 11. Hydraulic cylinder; 12. Accumulator; 13. Shut-off valve; 16. Piston rod; 17. Lubrication assembly; 21. Triangular component; 22. Lubricating oil chamber; 23. Limiting mechanism. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0037] like Figures 1-5 The diagram shown is an example of a rigid-flexible coupling connector for a deep-sea floating multi-buoy array provided by the present invention, used to connect adjacent first and second floats in a float array, wherein it includes a connecting body, a first connecting unit and a second connecting unit;

[0038] The first connecting unit includes four support legs 1 arranged in a spatial rod shape. One end of each support leg 1 is hinged to the connecting body, and the other end is connected to the first floating body. The four support legs 1 form a spatial tetrahedral support frame structure, forming a statically indeterminate rigid support system.

[0039] The second connecting unit includes two hydraulic cylinders 11. The cylinder body end of the hydraulic cylinder 11 is connected to the second float, and the piston rod 16 end of the hydraulic cylinder 11 is connected to the connecting body through a ball joint connection structure to provide multi-degree-of-freedom rotation capability. The hydraulic cylinder 11 compensates for the displacement of the relative motion between the first float and the second float through the extension and retraction movement of the piston rod 16.

[0040] The connectors are installed between adjacent floating photovoltaic floats. One end of the four support legs of the first connecting unit is connected to the connecting body through a spatial hinge node, and the other end is anchored to the reinforcing structure or embedded part of the first float, forming a spatial truss force transmission system to bear the main static load. The end of the hydraulic cylinder of the second connecting unit is fixedly connected to the rigid frame of the second float through a flange or lug. The end of the piston rod is connected to the connecting body through a ball joint structure. When the float is excited by waves and generates six degrees of freedom relative motion, the piston rod of the hydraulic cylinder reciprocates under the action of pressure difference. The mechanical energy is buffered, stored and dissipated through the controllable flow of hydraulic oil between the cylinder chambers. At the same time, the ball joint structure allows the end of the piston rod to swing freely within the spatial cone angle range, effectively eliminating the additional bending moment generated by lateral constraints.

[0041] In the above technical solution, the connecting body includes a base 4, a transition unit 5 and a rotating unit 7. The base 4 and the transition unit 5 are fixedly connected by bolts 6. The rotating unit 7 is hinged to the transition unit 5 by a pin 8. The rotating unit 7 can rotate relative to the transition unit 5 around the axis of the pin 8. Each support leg 1 of the first connecting unit is hinged to the base 4. The ball joint connection structure of the second connecting unit is connected to the rotating unit 7.

[0042] The base 4 adopts a box-type welded structure or an integral casting structure. Its bottom plate is fastened to the top plate or side plate of the transition unit 5 by high-strength bolts according to the predetermined preload requirements, forming a rigid transition section to transfer the concentrated load of the first connecting unit. The end of the transition unit 5 is provided with a fork-shaped ear plate or a single ear plate structure. The rotating unit 7 has a through hole at the corresponding position. By inserting an alloy steel pin 8 and cooperating with a wear-resistant bushing, axial baffle and cotter pin, a rotating pair is formed. During installation, the base and the transition unit 5 are first fixedly connected by bolts 6 and hoisted as a whole to the side of the first floating body. Then, the rotating unit 7 is hinged and positioned with the transition unit 5. Finally, the hydraulic cylinder is connected to the rotating unit 7, and the rotation flexibility is ensured by adjusting the shims.

[0043] Furthermore, in the above technical solution, three of the four support legs 1 are located in the same vertical plane, and the other support leg 1 is located to the side of the vertical plane and is arranged at a spatial angle to the vertical plane; adjacent support legs 1 located in the same vertical plane are connected by a triangular connecting member and achieve common node intersection, and the vertex of the triangular connecting member is hinged to the side wall of the base 4.

[0044] The three supporting legs are in the same plane and are connected by triangular member 3 to achieve a common node. The remaining supporting leg is arranged in a spatially opposite direction to the other three, which further enhances the load-bearing capacity of the statically indeterminate structure. All four supporting legs are connected to the connecting body and the first floating body by hinge, forming a stable statically indeterminate rigid connection structure to ensure the overall stiffness and fatigue resistance of the array structure.

[0045] The hinge base points of the first, second, and third support legs are located in the same vertical plane. The fourth support leg is arranged in a horizontal direction perpendicular to the plane or in an oblique direction according to the design angle to form spatial support. The middle sections of adjacent support legs located in the same plane are welded together by triangular steel plates or truss-type node plates to form a common node. The third vertex of the triangular member 3 is connected to the ear plate on the side wall of the base 4 by a pin or ball joint. During installation, the spatial angle of the four support legs is first adjusted to meet the design configuration, and then the fasteners of each hinge node are tightened to ensure that the main plane of the triangular member 3 coincides with the plane where the axis of the support leg is located.

[0046] Furthermore, in the above technical solution, the triangular connecting member is a plate-type triangular structure or a truss-type triangular structure, with its three vertices connected to the rods of the two adjacent support legs 1 and the side wall of the base 4, and the plane of the triangular connecting member is coplanar with the axis of the rods of the support legs 1.

[0047] The plate-type triangular component 3 is cut or precision cast from a single piece of alloy steel plate, with connection holes or welding bevels at its three corner points; the truss-type triangular component 3 is formed by welding three angle steels, channel steels, or round pipes through node plates to form a triangular frame structure; during installation, the two ends of the component are connected to the middle of the adjacent support leg by high-strength bolts or full penetration welding process, and the third end is connected to the hinge support of the base side wall by a pin. During the assembly process, a theodolite or total station is used for calibration to ensure that the main plane of the component is strictly coplanar with the axis of the support leg to avoid installation eccentricity.

[0048] Furthermore, in the above technical solution, the second connecting unit also includes an auxiliary support leg, which is located between or to the side of the two hydraulic cylinders 11. One end of the auxiliary support leg is hinged to the second float, and the other end is hinged to the rotating unit 7 or the connecting body, for assisting in connecting the second float and the connecting body.

[0049] The auxiliary support leg is made of seamless steel pipe, H-beam, or composite material rod, with perforated lugs or ball joints welded to both ends. Its position is determined according to the spacing between the floats and the arrangement of the hydraulic cylinders. It can be located on the perpendicular bisector of the line connecting the two hydraulic cylinders or at a laterally offset position to optimize force transmission. During installation, one end is hinged to the embedded part or reinforcing rib plate at the bottom of the second float via a pin, and the other end is hinged to the side wall lug of the rotating unit via a pin, forming a compound kinematic chain that rotates synchronously with the rotating unit. The axis of the pin is spatially perpendicular to or at an optimized angle to the axis of the hinge pin of the rotating unit and the transition unit. After the ball joint connection and positioning of the hydraulic cylinder and the rotating unit are completed first, the length of the auxiliary support leg is adjusted and the hinge nodes at both ends are locked to ensure that it is in the designed pre-tightened state or stress-free state, and that the motion plane of the auxiliary support leg is coordinated with the rotation axis of the rotating unit. During the rotation, the angle change range between the auxiliary support leg and the hydraulic cylinder is controlled within ±15 degrees to avoid structural interference and additional bending moment during the movement.

[0050] Furthermore, in the above technical solution, the ball joint connection structure includes a ball head 10, a ball seat 9, and a lubrication assembly 17. The ball head 10 is a spherical structure and is fixedly connected to the end of the piston rod 16 of the hydraulic cylinder 11. The ball seat 9 has a spherical cavity that matches the ball head 10. The ball head 10 is embedded in the spherical cavity and forms a multi-degree-of-freedom rotating pair. The outer wall of the ball seat 9 is hinged to the side wall of the rotating unit through a pin. The ball seat 9 can rotate around the axis of the pin.

[0051] The ball joint connection structure is equipped with a limit mechanism 23 to limit the maximum rotation angle of the ball head relative to the ball seat 9, so as to avoid affecting the sealing performance or causing structural damage.

[0052] The ball head is fixed to the end of the piston rod by precision thread connection or welding, and is made of high-strength alloy steel with quenching treatment to improve surface hardness. The ball seat 9 is a split or integral casting structure with a high-precision spherical cavity machined inside and inlaid with wear-resistant copper alloy bushings or coatings. After the ball head is inserted, it is limited by the end cap, pressure ring and fastening bolts to prevent it from falling out. The outer walls of the ball seat 9 extend symmetrically from both sides, and are hinged to the fork-shaped structure of the rotating unit through transverse pins to form a single-degree-of-freedom pair that can rotate around the horizontal or vertical axis. During assembly, the ball head is first installed into the ball seat 9 and the clearance is adjusted, and then the whole assembly is connected to the rotating unit through the pin to ensure flexible rotation without jamming.

[0053] Furthermore, in the above technical solution, the lubrication component is disposed on the side wall or top of the ball seat 9, and the ball seat 9 is provided with a lubricating oil cavity 22 surrounding the spherical cavity. The lubricating oil cavity 22 is connected to the surface of the spherical cavity through an oil passage, and is used to continuously lubricate the contact friction surface between the ball head and the ball seat 9.

[0054] The ball seat 9 has an oil filling hole on its side wall or top and is fitted with a grease nipple, oil cup or sealing oil filling joint. The inside has annular, spiral or radial oil chambers, which are connected to the surface of the spherical cavity through radial or oblique oil passages. The oil passage outlets are distributed in the main contact bearing area of ​​the ball head. During use, seawater corrosion resistant extreme pressure lithium-based grease or high viscosity lubricating oil is periodically injected into the oil filling hole through an oil gun or automatic lubrication pump. Under pressure, the lubricating medium is evenly distributed on the friction interface through the oil passages to form an elastic fluid dynamic pressure lubrication film. After use, the oil chamber is kept sealed by a sealing cap or one-way valve.

[0055] Furthermore, in the above technical solution, the hydraulic cylinder is a parameter-adjustable hydraulic damping cylinder, whose damping characteristics and equivalent stiffness can be steplessly adjusted by adjusting the opening of the throttling element in its hydraulic circuit to adapt to the dynamic load response requirements under different sea conditions.

[0056] The rodless chamber and rod chamber of the hydraulic cylinder are connected by an external high-pressure pipeline. A manually adjustable flow valve, a proportional throttle valve, or a servo throttle valve are connected in series on the pipeline. The flow area of ​​the valve port is changed by manually adjusting the handle, electric actuator, or hydraulic motor. During the adjustment process, the hydraulic oil generates a throttling pressure drop that is proportional to the square of the flow velocity when flowing between the chambers, thereby changing the speed-force characteristic curve of the piston movement and the equivalent stiffness of the system. After installation, the initial opening is set according to environmental monitoring data, the motion response of the float, or empirical formulas. During operation, it can be manually adjusted locally or remotely controlled by electricity to adapt to changes in sea state.

[0057] Furthermore, in the above technical solution, an accumulator 12 is fixedly installed on the outer wall surface of the hydraulic cylinder. The accumulator 12 is connected to the working chamber of the hydraulic cylinder through a pipeline and a shut-off valve 13. The accumulator 12 is pre-charged with compressed gas and the pre-charge pressure is an adjustable parameter. The equivalent stiffness and energy storage capacity of the second connecting unit can be adjusted by changing the pre-charge pressure.

[0058] The accumulator adopts a bladder, piston, or diaphragm structure, and is connected in parallel to the rodless chamber or two-chamber pipeline of the hydraulic cylinder via a high-pressure hose or rigid pipe through a shut-off valve and a check valve. Before installation, nitrogen or inert gas is charged into the accumulator bladder or air chamber side to the set pre-charge pressure through a dedicated charging valve. During operation, the pre-charge pressure is changed through a pressure reducing valve or charging device according to the sea state, buoy mass, or control strategy, or the connection between the accumulator and the hydraulic cylinder is cut off / connected by operating the shut-off valve to achieve stepped or stepless adjustment of the system stiffness. In daily maintenance, the air-side pressure is checked regularly to ensure the stability of the pre-charge pressure.

[0059] Furthermore, in the above technical solution, the hydraulic cylinder is equipped with a hybrid active and passive adjustment system. In passive adjustment mode, the hydraulic cylinder dissipates energy through the viscous damping generated by the internal hydraulic oil flowing through the throttling element. In active adjustment mode, the hydraulic cylinder actively adjusts its output force or piston rod displacement through an external electro-hydraulic system to achieve active control of the relative motion between the first float and the second float.

[0060] Specific implementation methods: In passive working mode, the hydraulic cylinder relies on internal or external fixed throttling orifices, adjustable flow valves, and damping orifices to achieve throttling of hydraulic oil, converting the mechanical energy of the relative motion of the float into heat energy, which is dissipated through the oil and cylinder wall; In active working mode, the hydraulic cylinder is connected to an external electro-hydraulic power station (including hydraulic pump, oil tank, filter, and cooler) through a high-precision servo valve or proportional directional valve. Displacement sensors, acceleration sensors, or force sensors collect the motion signal of the float in real time and transmit it to the controller. The controller calculates the optimal control force or displacement command based on a preset control algorithm (such as optimal control, fuzzy control, or neural network control), and drives the servo valve to adjust the flow and pressure entering the two chambers of the hydraulic cylinder, so as to realize the active extension and retraction of the piston rod or the precise output of a specific damping force; The two modes are switched through electromagnetic reversing valves, logic valves, or manual switching valves, or the operating mode is automatically switched according to preset triggering conditions (such as wave height, period, or structural response amplitude).

[0061] To better understand and implement this invention, the following is an example of a specific application scenario: A deep-sea floating photovoltaic project with a planned installed capacity of 50 MW is deployed in open waters approximately 60 nautical miles offshore, with a water depth ranging from 35 to 45 meters, an average annual wave height of 2.5 meters, a maximum wave height of 12 meters, and a wave period ranging from 6 to 14 seconds. The project adopts a modular truss-type floating structure, with each floating body having a planar dimension of 30 meters × 24 meters, a draft of 2.8 meters, and a displacement of approximately 1800 tons. 720 standard photovoltaic modules are arranged on each floating body. The floating body array is arranged in 8 rows × 12 columns, with a longitudinal spacing of 35 meters and a lateral spacing of 28 meters. Adjacent floating bodies are mechanically connected and load-bearing is transferred via the rigid-flexible coupling connector of this invention.

[0062] Based on the sea conditions and dynamic response analysis of the floating bodies, the rigid-flexible coupling connector for deep-sea floating multi-buoy arrays described in this invention was selected. The connectors are arranged along the longitudinal mating edges of adjacent floating bodies, with two sets of connectors installed at each mating interface, located on either side of the longitudinal centerline of the floating body, symmetrically spaced 8 meters apart. The first connecting unit of the connector connects to the upstream floating body (first floating body), and the second connecting unit connects to the downstream floating body (second floating body), forming a series-connected flexible array structure.

[0063] The first step is to prefabricate and install the support legs of the first connecting unit. The four support legs are made of high-strength seamless steel pipes with an outer diameter of 219 mm and a wall thickness of 12 mm. The material is Q355NHD marine engineering steel, and the surface is treated with a hot-spray zinc-aluminum coating followed by an epoxy heavy-duty anti-corrosion coating, with a total coating thickness of 350 micrometers. The first, second, and third support legs are located in the same vertical plane, while the fourth support leg is arranged horizontally perpendicular to this plane, forming a 35-degree angle with the vertical plane. The lengths of the support legs are determined based on the spacing between the floats and the installation height, with designed lengths of 4850 mm, 5120 mm, 4980 mm, and 5230 mm, respectively.

[0064] During the floating body construction phase, a connecting base is pre-embedded at a predetermined position on the longitudinal docking edge of the first floating body. The base adopts a box-type welded structure with external dimensions of 1200 mm × 800 mm × 600 mm and a plate thickness of 20 mm. It is reinforced internally with longitudinal and transverse baffles. The base plate is fixed to the main truss of the floating body by fillet welds with a weld leg size of 10 mm. The top plate has a pre-drilled array of M24 bolt holes with a hole spacing of 150 mm. The hinge joint between the support leg and the base adopts a double-ear plate structure with an ear plate thickness of 25 mm. The pin shaft has a diameter of 60 mm, is made of 40Cr, and is heat-treated to a hardness of HRC28-32. It is used with a ZCuAl10Fe3 self-lubricating copper alloy bushing with a wall thickness of 8 mm.

[0065] After the floating hull is launched and positioned, the support legs are installed on-site. A 200-ton floating crane is used to hoist the prefabricated support legs to the designed position. Temporary positioning fixtures are used to adjust the spatial angles to ensure that the parallelism deviation between the vertical plane of the three coplanar support legs and the longitudinal centerline of the floating hull is ≤2 mm, and the horizontal deviation of the fourth support leg is controlled within ±1.5 degrees. One end of the support leg is hinged to the base lug plate by a pin and locked with a GB / T91 6.3×40 cotter pin. The other end is bolted to the embedded part on the side wall of the first floating hull by a flange. 24 M24 10.9 grade high-strength bolts are used and tightened in three stages at 50%, 75%, and 100% of the design preload of 300 N·m. After installation, a triangular connecting component is installed in the middle of the adjacent support legs. The component adopts an integrally cast plate triangular structure with a side length of 650 mm and a thickness of 30 mm. The material is ZG270-500. The three corner points are respectively hinged to the two support leg rods and the side wall of the base, forming a common node intersection. The main plane of the component is strictly coplanar with the axis of the support leg, and the flatness deviation is controlled within 1 mm.

[0066] The main connecting body is modularly assembled in the onshore workshop. The base and transition unit are fixedly connected by a set of 24 M30 10.9 grade high-strength bolts, with a design preload of 400 N·m applied in three stages. The transition unit adopts a box-beam structure with a cross-sectional dimension of 600 mm × 400 mm, a length of 1800 mm, and a plate thickness of 16 mm. The ends are equipped with fork-shaped lugs with a lug spacing of 280 mm and a thickness of 30 mm. The rotating unit is an integrally cast fork-shaped structure, with its external dimensions adapted to the ends of the transition unit. It is hinged by a transversely penetrating alloy steel pin with a diameter of 80 mm, made of 35CrMo, with a tempered hardness of HRC30-35. It is fitted with a GCr15 wear-resistant steel sleeve and a Q235 axial baffle. After installation, manual inspection ensures that the rotation is flexible and free of jamming, with a single-sided rotation clearance ≤0.3 mm.

[0067] The assembled connecting body is hoisted to the converging end of the support legs of the first connecting unit, and hinged to the vertex of the triangular connecting member via a 70 mm diameter pin, forming a complete rigid support system. A Leica TS16 total station is used for measurement and adjustment to ensure that the horizontal deviation between the centerline of the connecting body and the longitudinal centerline of the floating body does not exceed 5 mm, and the elevation deviation does not exceed 8 mm.

[0068] The hydraulic cylinder of the second connecting unit adopts a double-acting piston structure, with a cylinder inner diameter of 125 mm, a piston rod diameter of 90 mm, a stroke of ±350 mm, a rated working pressure of 25 MPa, and a test pressure of 37.5 MPa. The end of the hydraulic cylinder body is fixedly connected to the rigid frame of the second float via a 400 mm diameter flange, with the installation position 1200 mm from the longitudinal mating edge of the float. The two hydraulic cylinders are symmetrically arranged on both sides of the transverse centerline of the float, with a spacing of 4 meters. The piston rod end is machined with M80×2 external threads, which are connected to the ball head through precision threads and Loctite 243 threadlocker is applied. The ball head is made of 42CrMo alloy steel with quenching treatment, a surface hardness of HRC58-62, and a ball diameter of 160 mm.

[0069] The ball joint connector features a split-cast structure made of ZG35CrMo material. The internal spherical cavity has a radius of 82 mm, with a clearance between the ball joint and the ball head controlled between 0.08 mm and 0.15 mm. A ZCuSn10P1 wear-resistant copper alloy bushing with a thickness of 10 mm is embedded within. Symmetrical lugs extend from both sides of the ball joint's outer wall, hinged to the fork-shaped structure of the rotating unit via a 60 mm diameter pin. The pin axis is spatially perpendicular to the hinge pin axes of the rotating unit and the transition unit, forming a composite rotating pair. An M10×1 grease nipple is located on the top of the ball joint, containing a 20 mm × 15 mm annular lubrication chamber. This chamber is connected to the spherical cavity surface via six 4 mm diameter radial oil channels. After installation, 150 grams of Shell Gato S3 V220C extreme pressure lithium-based grease are injected.

[0070] The auxiliary support leg is made of seamless steel pipe with an outer diameter of 168 mm and a wall thickness of 10 mm. The material is Q355NHD, and its length is 3850 mm, determined by actual measurement based on the installation location. The auxiliary support leg is located on the perpendicular bisector of the line connecting the two hydraulic cylinders. One end is hinged to the pre-embedded lug plate at the bottom of the second float via a 50 mm diameter pin, and the other end is hinged to the hinge support at the bottom of the rotating unit. During installation, the hydraulic cylinder connection is completed first, then the length of the auxiliary support leg is adjusted. A fine-tuning process using an M48×3 adjustable screw structure is employed until a stress-free state is achieved, after which the M48 nuts at both ends are tightened with a preload of 150 N·m.

[0071] An NXQ-A-10 / 31.5-LY bladder-type accumulator with a capacity of 10 liters and a pre-charged nitrogen pressure of 8 MPa is fixedly mounted on the outer wall of the hydraulic cylinder. It is connected in parallel to the rodless chamber pipeline of the hydraulic cylinder via a 15 mm diameter high-pressure hose and a QF-10 shut-off valve. The hose's working pressure is 31.5 MPa, and its burst pressure is 126 MPa. The two chambers of the hydraulic cylinder are connected to the hydraulic power unit located within the floating body compartment via a 20 mm diameter external high-pressure pipeline. A 4WRZE16W8-150-7X / 6EG24N9ETK31 / F1V proportional throttle valve is connected in series on the pipeline as an adjustable damping element. A HYDAC HDA4745-A-250-000 pressure sensor, a PT100 temperature sensor, and a KRACHT VC0.2F1PS flow meter are also included.

[0072] System commissioning was conducted in phases. First, passive mode commissioning was performed: the accumulator shut-off valve was closed, and the proportional throttle valve opening was adjusted to its initial value of 15%. Wave-generating tests were conducted in the seaworthiness tank of the China Ship Scientific Research Center, simulating regular waves with a wave height of 2.0 meters and a period of 8 seconds, and irregular waves with a wave height of 4.0 meters and a period of 10 seconds. The pitch amplitude of the float and the pressure pulsation of the hydraulic cylinder were monitored. The throttle valve opening was optimized to achieve a system damping coefficient of 850 kN·s / m and an equivalent stiffness of 12 MN / m, matching the target sea state, and the optimal parameter combination was recorded. Subsequently, accumulator parameter optimization was performed: the shut-off valve was opened, and the pre-charge pressure was adjusted to 6 MPa, 8 MPa, and 10 MPa respectively. The changes in system stiffness and energy buffering effect were observed. It was determined that at a pre-charge pressure of 8 MPa, the system dynamic stiffness decreased to 8.5 MN / m, and the energy absorption rate increased by 23%, balancing comfort and safety. Finally, active mode debugging was performed: the proportional throttle valve was switched to servo control mode, the MTS 661.31F-03 float motion attitude sensor and SIMATIC S7-1500 controller were connected, the sampling frequency was 100 Hz, and the control force command was calculated in real time based on the linear quadratic Gaussian optimal control algorithm to drive the servo valve to adjust the hydraulic cylinder output. The active cancellation effect on wave excitation with a period of 8 seconds and a wave height of 3 meters was verified. The float pitch amplitude was reduced by 42%, and the trajectory tracking accuracy was ±25 mm.

[0073] After the connectors are put into operation, a regular inspection system should be established. Quarterly, check the wear of the pins at each hinge node, using calipers to measure diameter wear ≤0.5 mm. Check the preload reduction of M24 and M30 bolts, ensuring the retightening torque is not less than 90% of the design value. Every six months, add 80 grams of grease through the grease fitting, check the integrity of the ball joint seal and the smoothness of the lubrication system, and perform magnetic particle testing on the ball head surface to detect cracks. Annually, perform ISO 4406 oil cleanliness testing on the hydraulic system, requiring a grade of 18 / 16 / 13. Replace two high-pressure filters and two return oil filters each. Use a nitrogen charging tool to calibrate the accumulator precharge pressure; if the error exceeds ±0.5 MPa, recharge. Use a FLUKE 754 to calibrate the pressure sensor and displacement sensor, ensuring an accuracy error ≤0.5% of full scale. Specialized tests are conducted before and after extreme sea conditions (wave height > 8 meters) to assess structural damage and parameter drift. If necessary, the passive and active modes are switched or the damping parameters are adjusted through a remote communication system to ensure that the connector maintains its performance within its designed service life of 25 years, thus guaranteeing the safe and stable operation of the deep-sea floating photovoltaic array.

[0074] Specifically, the principle of this invention is as follows: The technical principle of this invention is based on the statically indeterminate support theory of structural mechanics and the damping energy dissipation mechanism of fluid mechanics. The first connecting unit adopts four spatially distributed support legs to form a spatial tetrahedral statically indeterminate system. The degree of constraint is greater than the degree of freedom, effectively resisting multi-directional bending moments, torques and shear forces, and dispersing stress through multi-path load transfer; the hinged connection design releases the bending moment at the rod end so that the rod mainly bears the axial force, and the triangular connecting component optimizes the convergence of force flow and reduces stress concentration. The second connecting unit is based on the principle of hydraulic transmission, using the pressure difference on both sides of the piston to drive the flow of oil, and converting mechanical energy into heat energy dissipation through the resistance of the throttling element to achieve vibration suppression; the ball joint structure is based on the principle of spatial kinematics, the spherical pair realizes universal rotation, and the pin hinge provides single-degree-of-freedom rotation, combined to form a multi-degree-of-freedom kinematic chain to adapt to the complex attitude of the floating body and eliminate additional internal forces. The adjustable hydraulic cylinder parameters are based on throttling speed regulation theory, changing the flow area of ​​the valve orifice to adjust flow rate and pressure loss, thereby altering the speed-force characteristics and equivalent stiffness. The accumulator, based on the principle of gas compression energy storage, adjusts the pre-charge pressure to change the system's elasticity and buffering capacity, absorbing pressure pulsations and stabilizing the working pressure. The hybrid active-passive regulation integrates the reliability of passive control with the precision of active control. The passive mode relies on fluid damping and natural dissipation to achieve wideband suppression, while the active mode, based on modern control theory, uses sensors to collect motion information in real time, and the controller calculates optimal commands to drive the electro-hydraulic servo system to adjust output characteristics, achieving active cancellation or optimal tracking at specific frequencies. The two modes can be switched or superimposed according to sea conditions. The overall solution ensures geometric stability through rigid support, adapts to environmental excitation through flexible compensation, and achieves adaptive operation and intelligent regulation through adjustable parameters and active control, forming a complete rigid-flexible coupling connection technology system for deep-sea floating photovoltaic arrays.

[0075] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A rigid-flexible coupling connector for a deep-sea floating multi-buoy array, used to connect adjacent first and second floats in a float array, characterized in that, It includes a connecting body, a first connecting unit, and a second connecting unit; The first connecting unit includes four support legs distributed in a spatial rod shape. One end of each support leg is hinged to the connecting body, and the other end is connected to the first floating body. The four support legs form a spatial tetrahedral support frame structure, forming a statically indeterminate rigid support system. The second connecting unit includes two hydraulic cylinders. The cylinder body of the hydraulic cylinder is connected to the second float, and the piston rod of the hydraulic cylinder is connected to the connecting body through a ball joint connection structure to provide multi-degree-of-freedom rotation capability. The hydraulic cylinder compensates for the displacement of the relative motion between the first float and the second float by the extension and retraction of the piston rod.

2. The deep-sea floating multi-buoy array rigid-flexible coupling connector according to claim 1, characterized in that, The connecting body includes a base, a transition unit, and a rotating unit. The base and the transition unit are fixedly connected by bolts. The rotating unit is hinged to the transition unit by a pin. The rotating unit can rotate relative to the transition unit around the pin axis. Each support leg of the first connecting unit is hinged to the base. The ball joint connection structure of the second connecting unit is connected to the rotating unit.

3. A deep-sea floating multi-buoy array rigid-flexible coupling connector according to claim 2, characterized in that, Three of the four support legs are located in the same vertical plane, and the other support leg is located to the side of the vertical plane and is arranged at a spatial angle to the vertical plane; adjacent support legs located in the same vertical plane are connected by a triangular connecting member and achieve a common node intersection, and the vertex of the triangular connecting member is hinged to the side wall of the base.

4. A deep-sea floating multi-buoy array rigid-flexible coupling connector according to claim 3, characterized in that, The triangular connecting member is a plate-type triangular structure or a truss-type triangular structure, with its three vertices connected to the rods of the two adjacent supporting legs and the side wall of the base, respectively, and the plane of the triangular connecting member is coplanar with the axis of the rod of the supporting leg.

5. A deep-sea floating multi-buoy array rigid-flexible coupling connector according to claim 4, characterized in that, The second connecting unit also includes an auxiliary support leg, which is located between or to the side of the two hydraulic cylinders. One end of the auxiliary support leg is hinged to the second float, and the other end is hinged to the rotating unit or the connecting body, for assisting in connecting the second float and the connecting body.

6. A deep-sea floating multi-buoy array rigid-flexible coupling connector according to claim 5, characterized in that, The ball joint connection structure includes a ball head, a ball seat, and a lubrication assembly. The ball head is a spherical structure and is fixedly connected to the end of the piston rod of the hydraulic cylinder. The ball seat has a spherical cavity that matches the ball head. The ball head is embedded in the spherical cavity and forms a multi-degree-of-freedom rotary pair. The outer wall of the ball seat is hinged to the side wall of the rotating unit through a pin. The ball seat can rotate around the axis of the pin.

7. A deep-sea floating multi-buoy array rigid-flexible coupling connector according to claim 6, characterized in that, The lubrication assembly is disposed on the side wall or top of the ball seat. The ball seat has a lubricating oil cavity surrounding the spherical cavity. The lubricating oil cavity is connected to the surface of the spherical cavity through an oil passage, and is used to continuously lubricate the contact friction surface between the ball head and the ball seat.

8. A deep-sea floating multi-buoy array rigid-flexible coupling connector according to claim 7, characterized in that, The hydraulic cylinder is a parameter-adjustable hydraulic damping cylinder. Its damping characteristics and equivalent stiffness can be steplessly adjusted by adjusting the opening of the throttling element in its hydraulic circuit to adapt to the dynamic load response requirements under different sea conditions.

9. A deep-sea floating multi-buoy array rigid-flexible coupling connector according to claim 8, characterized in that, An accumulator is fixedly installed on the outer wall surface of the hydraulic cylinder. The accumulator is connected to the working chamber of the hydraulic cylinder through pipelines and a shut-off valve. The accumulator is pre-charged with compressed gas, and the pre-charge pressure is an adjustable parameter. The equivalent stiffness and energy storage capacity of the second connecting unit can be adjusted by changing the pre-charge pressure.

10. A deep-sea floating multi-buoy array rigid-flexible coupling connector according to claim 9, characterized in that, The hydraulic cylinder is equipped with a hybrid active-passive adjustment system. In passive adjustment mode, the hydraulic cylinder dissipates energy through the viscous damping generated by the internal hydraulic oil flowing through the throttling element. In active adjustment mode, the hydraulic cylinder actively adjusts its output force or piston rod displacement through an external electro-hydraulic system to achieve active control of the relative motion between the first float and the second float.

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