A new type of four-bar linkage loading and unloading arm for liquid chemical wharf

Abstract

This invention provides a novel four-bar linkage loading and unloading boom for liquid chemical terminals, comprising a support column, an inner boom assembly, and an outer boom assembly. The support column includes a column body and a pivot box, with the side wall of the pivot box connected to the middle and rear ends of the inner boom assembly. The front and rear ends of the inner boom support on the inner boom assembly are hinged to the outer boom support and the lower swing beam on the outer boom assembly, respectively. The front and rear ends of the outer boom tie rod on the outer boom assembly are hinged to the outer boom support and the lower swing beam, respectively. The lower swing beam is hinged to the pivot box via an outer boom drive cylinder. This invention, through the synergistic effect of the four-bar linkage and dual drive cylinders, uses a rigid connection instead of traditional wire rope transmission, effectively solving the technical problems of frequent maintenance and significant safety hazards associated with traditional equipment. It has the advantages of high structural strength, safe operation, and convenient maintenance, and can meet the design requirements of large-diameter / large-tonnage terminals.

Description

Technical Field

[0001] This utility model relates to the technical field of loading and unloading equipment for liquid chemical terminals, and in particular to a novel four-bar linkage loading and unloading arm for liquid chemical terminals. Background Technology

[0002] Currently, most major dock loading and unloading booms in China adopt an independently supported rotary balance structure. The outer boom and counterweight are driven by a rope pulley system, which involves a wire rope transmission structure between the upper and lower pulleys. Due to long-term use, the wire rope can elongate, causing it to deviate from the pulley grooves, posing a significant safety hazard of equipment loss of control. Therefore, this structure requires regular tightening. Furthermore, maintenance personnel frequently need to climb to heights, increasing operational difficulty and posing safety risks – these are typical drawbacks of this structure.

[0003] To address the shortcomings of traditional wire rope drive loading booms, our R&D team independently designed and developed a self-supporting four-link system (patent number ZL 202510292772.5). However, this system still suffers from structural fragility and insufficient strength, making it unable to bear greater weight and failing to meet the operational needs of large wharves with capacities exceeding 300,000 tons. It also exhibits significant limitations in large-diameter pipeline applications. Existing self-supporting four-link loading boom equipment cannot meet design requirements and can only accommodate small-diameter equipment. Therefore, there is an urgent need for a loading boom solution that can simultaneously address issues of structural strength, operational safety, and ease of maintenance. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a new type of four-bar linkage loading and unloading arm for liquid chemical terminals, which adopts an independent support structure, does not use wire rope drive, and is suitable for low-temperature environments in the north.

[0005] To solve the above-mentioned technical problems, this utility model adopts the following technical solution:

[0006] A novel four-link loading boom for liquid chemical terminals includes a support column, an inner boom assembly, and an outer boom assembly, wherein:

[0007] The support column includes a column body and a pivot box disposed on the top of the column body. The side wall of the pivot box is hinged to the middle and rear end of the inner arm assembly through a bearing with a seat.

[0008] The front and rear ends of the inner arm support on the inner arm assembly are respectively hinged to the outer arm support and the lower swing beam on the outer arm assembly, and the front end is hinged to the pivot box via an inner arm drive cylinder; and

[0009] The front and rear ends of the upper arm tie rod of the upper arm assembly are respectively hinged to the upper arm support and the lower swing beam, and form a four-bar linkage with the inner arm support on the inner side. The lower swing beam is hinged to the pivot box through the upper arm drive cylinder.

[0010] Preferably, the column body is a hollow columnar structure with a liquid phase pipe passing through its inner cavity. The bottom is fixed to the ground by a mounting base plate. The lower side wall is provided with a locking mechanism that cooperates with the lower end of the inner arm support. A vertically arranged first hand ladder is installed on the side wall.

[0011] Preferably, a first turntable base is installed at the bottom of the shaft box, and a second turntable base is installed at the bottom of the first turntable base, wherein:

[0012] The first turntable base and the second turntable base are arranged symmetrically from left to right, and are respectively hinged to the first horizontal drive cylinder and the second horizontal drive cylinder installed on the top of the column body, so as to drive the shaft box and the four-bar linkage installed on it to rotate horizontally.

[0013] Preferably, the pivot box is provided with a first inner arm cylinder support and a first outer arm cylinder support arranged in a staggered manner, wherein:

[0014] The first inner arm cylinder support is hinged to the cylinder body of the inner arm drive cylinder, and the first outer arm cylinder support is hinged to the cylinder body of the outer arm drive cylinder, respectively used to install the inner arm drive cylinder and the outer arm drive cylinder.

[0015] Preferably, the inner arm assembly includes an inner arm support and an inner arm drive cylinder, wherein:

[0016] The inner arm support is provided with a second inner arm cylinder support at the middle front end. The two ends of the inner arm drive cylinder are respectively hinged to the second inner arm cylinder support and the first inner arm cylinder support on the shaft box.

[0017] Preferably, a second ladder is provided on the outer side wall of the inner arm support along its length, and a maintenance platform is provided at the top of the second ladder.

[0018] Preferably, the rear end of the inner arm support is detachably provided with a counterweight, and its rear end is detachably connected to the locking mechanism on the lower side wall of the column body.

[0019] Preferably, the boom assembly includes a boom tie rod, a boom support, a lower swing beam, and a boom drive cylinder, wherein:

[0020] The front end of the outer arm tie rod is hinged to the rear end of the outer arm support via a bearing, and its rear end is hinged to the top of the lower swing beam via a bearing.

[0021] The middle and rear ends of the outer arm support and the bottom end of the lower swing beam are respectively connected to the inner arm support through corresponding bearing seats, forming a parallelogram-shaped four-bar linkage mechanism.

[0022] Preferably, a second outer arm cylinder support is provided at the lower middle end of the lower swing beam, and the two ends of the outer arm drive cylinder are respectively hinged to the second outer arm cylinder support and the first outer arm cylinder support on the pivot box.

[0023] Preferably, the novel four-bar linkage loading and unloading arm further includes a liquid phase pipeline, a gas phase pipeline, and a three-dimensional joint, wherein:

[0024] The lower end of the liquid phase pipeline passes through the hollow cavity of the column body, and the upper end is flexibly installed on the inner arm support and the outer arm support in sequence, for pumping liquefied natural gas from the LNG ship.

[0025] The lower end of the gas phase pipe is flexibly installed on the outer side wall of the column body, and its upper end is flexibly installed on the inner arm support and the outer arm support in sequence, in order to maintain the LNG pressure balance inside the LNG ship.

[0026] The three-dimensional joint is flexibly installed at the front end of the outer arm support and is connected to the liquid phase pipeline and the gas phase pipeline respectively, and can be detachably connected to the LNG ship.

[0027] The present invention adopts the above technical solution and has the following technical effects compared with the prior art:

[0028] This utility model provides a novel four-bar linkage loading and unloading boom for liquid chemical terminals. It mainly consists of a support column, an inner arm assembly, an outer arm assembly, a liquid phase pipeline, a gas phase pipeline, and a three-dimensional joint. The outer arm tie rod, outer arm support, lower swing beam, and inner arm support form a parallelogram-shaped four-bar linkage mechanism, which is mechanically driven by the inner arm drive cylinder and the outer arm drive cylinder. Through the synergistic effect of the four-bar linkage mechanism and the dual drive cylinders, it adopts a rigid connection to replace the traditional wire rope transmission, effectively solving the technical problems of frequent maintenance and high safety hazards of traditional equipment. It has the advantages of high structural strength, safe operation, and convenient maintenance, and can meet the design requirements of large-diameter / large-tonnage terminals. Attached Figure Description

[0029] Figure 1 This is a front view structural diagram of a novel four-bar linkage loading and unloading arm of this utility model in its unfolded use state;

[0030] Figure 2 This is a front view schematic diagram of the structure of a novel four-bar linkage loading and unloading arm of this utility model in a retracted and folded state;

[0031] Figure 3This is a side view of the structure of a novel four-bar linkage loading and unloading arm of this utility model in a retracted and folded state.

[0032] Figure 4 This is a schematic planar cross-sectional view of the transfer axle box of a novel four-link loading and unloading arm according to this utility model. Figure 1 ;

[0033] Figure 5 This is a schematic planar cross-sectional view of the transfer axle box of a novel four-link loading and unloading arm according to this utility model. Figure 2 ;

[0034] Figures 6 to 9 This is a schematic diagram of the working process structure of a novel four-bar linkage loading and unloading arm of this utility model when it is deployed and used.

[0035] The accompanying figures are labeled as follows:

[0036] 100-Support column, 101-Column body, 102-Spindle box, 103-First inner arm cylinder support, 104-First outer arm cylinder support, 105-First turntable base, 106-Second turntable base, 107-First horizontal drive cylinder, 108-Second horizontal drive cylinder, 109-Bearing with seat, 110-Locking mechanism, 111-First escalator;

[0037] 200-Inner arm assembly, 201-Inner arm support, 202-Inner arm drive cylinder, 203-Second inner arm cylinder support, 204-Second ladder, 205-Maintenance platform;

[0038] 300-Outer boom assembly, 301-Outer boom tie rod, 302-Outer boom support, 303-Lower swing beam, 304-Outer boom drive cylinder, 305-Second outer boom cylinder support;

[0039] 400 - Liquid phase pipeline;

[0040] 500 - Vapor phase pipeline;

[0041] 600-3D connector. Detailed Implementation

[0042] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0043] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0044] In existing technologies, liquid chemical terminal loading and unloading equipment has long relied on wire rope drive structures, using a sheave system to balance the outer arm and counterweight. This type of structure suffers from drawbacks such as the wire rope's tendency to elongate and deviate from the sheave groove, leading to high maintenance frequency and safety hazards. While the subsequently developed self-supporting four-bar linkage structure partially addresses these issues, its thin frame design makes it difficult to meet the load-bearing capacity requirements of large terminals and large-diameter pipelines, thus limiting its application in terminals with a capacity of 300,000 tons or more.

[0045] To address these issues, researchers discovered that the core failure of traditional wire rope systems lies in the uncontrollable physical properties of the flexible transmission components, while the insufficient strength of existing four-bar linkages stems from the dispersed support system. Based on this, the design approach shifted to constructing a rigid linkage mechanism with independent support capabilities, replacing indirect transmission with direct hydraulic cylinder drive, and employing a split structure to distribute the load. This process focused on integrating the rotating support point with the drive system to form a self-balancing parallelogram mechanism to enhance overall rigidity.

[0046] Therefore, as Figure 1 , Figure 2 , Figure 3 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, this application proposes a loading arm structure including a support column 100, an inner arm assembly 200, and an outer arm assembly 300. The support column 100 includes a column body 101 and a top pivot box 102. The side wall of the pivot box 102 is hinged to the middle and rear end of the inner arm assembly 200 via a seated bearing 109. The front and rear ends of the inner arm support 201 of the inner arm assembly 200 are hinged to the outer arm support 302 and the lower swing beam 303, respectively, and the middle and front ends are connected to the pivot box 102 via an inner arm drive cylinder 202. The outer arm tie rod 301 of the outer arm assembly 300 connects the outer arm support 302 and the lower swing beam 303, forming a four-bar linkage with the inner arm support 201. The lower swing beam 303 is hinged to the pivot box 102 via an outer arm drive cylinder 304.

[0047] The support column 100 is a vertical support structure that bears the main load of the equipment. It can be implemented using hollow columnar steel components, with its top pivot box 102 serving as a multi-directional hinge node, providing an installation foundation for each drive component. The inner boom assembly 200 is a transition structure connecting the support column 100 and the outer boom assembly 300. It can be a conventionally known triangular or rectangular cross-section steel frame structure, mainly composed of steel, connected by welding or bolts to form a frame or truss structure, thus creating a force transmission path through the front and rear double hinge points. The outer boom assembly 300 is the end effector that performs loading and unloading operations. It can be implemented using a parallel four-bar linkage layout to ensure the outer boom maintains a predetermined trajectory when extended. The four-bar linkage is a planar linkage device composed of the inner boom support 201, outer boom support 302, outer boom tie rod 301, and lower swing beam 303, achieving parallelogram-shaped movement.

[0048] Specifically, the pivot box 102 forms a stable rotation fulcrum with the inner arm assembly 200 via the seated bearing 109, eliminating the radial clearance of the traditional rope pulley structure. The inner arm drive cylinder 202 acts directly on the front end of the inner arm support 201, driving the inner arm to rotate around the hinge point through hydraulic pressure. In the outer arm assembly 300, the linkage between the outer arm tie rod 301 and the lower swing beam 303 ensures that the outer arm support 302 always maintains parallel movement. Combined with the pulling action of the outer arm drive cylinder 304 on the lower swing beam 303, precise control of the outer arm deployment angle is achieved. The coordinated work of the two sets of cylinders enables the four-bar linkage to produce controllable deformation, replacing the passive transmission method of the wire rope.

[0049] Compared to existing technologies, traditional solutions rely on the elastic deformation of steel wire ropes to transmit motion, while this solution controls the motion trajectory through the geometric constraints of rigid linkages. Existing four-bar linkage structures use integral supports, leading to stress concentration; this solution distributes the load to the column body 101 via the shaft box 102. Traditional drive methods require maintaining the alignment of the sheave group; this solution's direct-drive hydraulic cylinder eliminates intermediate links in the transmission chain.

[0050] Through the above technical solution, this application effectively solves the problem of difficult maintenance of wire rope systems, achieving maintenance-free transmission through a rigid four-bar linkage. The increased structural strength allows the equipment to be adapted to large-diameter pipelines, meeting the loading and unloading needs of large docks. The direct-drive hydraulic cylinder improves motion control accuracy and avoids positioning deviations caused by wire rope slack in traditional structures.

[0051] In some of these embodiments, such as Figure 2 and Figure 3 As shown, this application further proposes that the column body 101 adopts a hollow columnar structure, with a liquid phase pipe 400 passing through its inner cavity, and the bottom is fixed to the ground by a mounting base plate. The lower side wall is provided with a locking mechanism 110 that cooperates with the rear end of the inner arm support 201, and the side wall is equipped with a vertically arranged first hand ladder 111.

[0052] The hollow columnar structure refers to the cavity formed inside the column body 101, which provides internal installation space for the liquid phase pipeline 400 while bearing the weight of the equipment. The mounting base plate is a steel plate base welded to the bottom of the column body, which can be fixed to a concrete foundation using pre-embedded bolts to securely anchor the column body 101 to the ground. The locking mechanism 110 is a mechanical locking device located on the lower side wall of the column body 101, which can be a conventional pin-type or snap-fit ​​structure, used to fix its position when the inner arm assembly 200 retracts. The first escalator 111 is a climbing structure arranged longitudinally along the side wall of the column body 101, which can be a stepped passage formed by welding a steel frame, providing a vertical passage for operators.

[0053] Specifically, the lower end of the liquid phase pipeline 400 is completely enclosed within the cavity of the column body 101, preventing corrosion or physical damage from the external environment. The mounting base plate distributes the load by increasing the contact area, ensuring the stability of the column body under the weight of the equipment and operational loads. The locking mechanism 110 mechanically interlocks with the lower end of the inner arm support 201 when the inner arm assembly 200 is not in operation, preventing component displacement due to external forces or vibrations. The first escalator 111 extends vertically along the side wall of the column body, allowing maintenance personnel to reach higher parts of the equipment without the need for external tools.

[0054] In some of these embodiments, such as Figure 3 , Figure 4 and Figure 5 As shown, this application further proposes to install a first turntable base 105 at the bottom of the pivot box 102 and a second turntable base 106 at the bottom of the first turntable base 105. The first turntable base 105 and the second turntable base 106 are arranged symmetrically from left to right and are respectively hinged to the first horizontal drive cylinder 107 and the second horizontal drive cylinder 108 installed on the top of the column body 101 to drive the pivot box 102, the inner arm assembly 200 and the outer arm assembly 300 to rotate horizontally.

[0055] The first turntable base 105 refers to the annular support structure installed at the bottom of the shaft box 102. Specifically, it can be a conventionally known turntable load-bearing rotating base, used to distribute the torque load generated during the rotation of the shaft box. The second turntable base refers to the auxiliary support structure nested below the first turntable base. It can also be a conventionally known turntable load-bearing rotating base, used to form a two-stage torque transmission path. The left-right symmetrical arrangement means that the central axes of the two turntable bases are mirror-symmetrical with the longitudinal axis of the column body 101, thus constructing a stable torque couple structure. The first horizontal drive cylinder 107 and the second horizontal drive cylinder 108 are hydraulic actuators installed on the top bracket of the column body 101. Specifically, they can be implemented using double-rod synchronous cylinders, with synchronous control achieved through an electro-hydraulic proportional valve.

[0056] Specifically, the first turntable base 105 and the second turntable base 106 are rigidly connected by bolts, and their axis of symmetry coincides with the longitudinal axis of the column body 101. When the piston rod of the first horizontal drive cylinder 105 extends and the piston rod of the second horizontal drive cylinder 106 retracts synchronously, the shaft box 102 is driven to rotate around the column axis. The synchronous control of the two cylinders is achieved through a closed-loop feedback system, which adjusts the displacement of the two cylinders in real time to ensure that the rotation angle deviation of the shaft box 102 is controlled within the set range.

[0057] In some of these embodiments, such as Figure 3 and Figure 5 As shown, this application further proposes that the pivot box 102 is provided with a first inner arm cylinder support 103 and a first outer arm cylinder support 104 arranged vertically and horizontally. The first inner arm cylinder support 103 is hinged to the cylinder body of the inner arm drive cylinder 202, and the first outer arm cylinder support 104 is hinged to the cylinder body of the outer arm drive cylinder 304, which are respectively used to install the inner arm drive cylinder 202 and the outer arm drive cylinder 304.

[0058] The first inner arm cylinder support 103 is a metal connector fixed to the shaft box 102. Specifically, it can be fixed to the top area of ​​the shaft box 102 by welding or bolting, providing a mounting point for the inner arm drive cylinder body 202. The first outer arm cylinder support 104 is a metal connector fixed to the shaft box 102. Specifically, it can be a cantilever structure welded to the side wall of the shaft box 102, providing an independent mounting position for the outer arm drive cylinder 304. The staggered arrangement means that the two cylinder supports form a height difference in the vertical direction. This can be achieved by adjusting the machining height difference of the support mounting surfaces, resulting in spatial layering of the mounting axes of the two drive cylinders.

[0059] Specifically, the cylinder body of the inner arm drive cylinder 202 forms a revolute joint with the first inner arm cylinder support 103 via a pin, while the cylinder body of the outer arm drive cylinder 304 forms an independent revolute joint with the first outer arm cylinder support 104 via another set of pins. When the inner arm drive cylinder 202 performs the extension / retraction action, its cylinder body swings around the hinge point of the first inner arm cylinder support, while the cylinder body of the outer arm drive cylinder 304 swings independently below. Due to the vertically staggered arrangement of the two cylinder supports, the swing trajectory of the inner arm drive cylinder 202 and the swing plane of the outer arm drive cylinder 304 are spatially isolated, preventing collisions between the cylinder bodies during movement. Simultaneously, the installation positions of the first inner arm cylinder support 103 and the first outer arm cylinder support 104 correspond to the force directions of the inner arm assembly 200 and the outer arm assembly 300, respectively, ensuring that the thrust transmission paths of the two drive systems do not intersect, thus guaranteeing the smooth deployment and synchronous retraction of the four-bar linkage.

[0060] In some of these embodiments, such as Figure 1 , Figure 2 and Figure 3 As shown, this application further proposes an inner arm assembly 200 including an inner arm support 201 and an inner arm drive cylinder 202. The inner arm support 201 has a second inner arm cylinder support 203 at its middle front end. The two ends of the inner arm drive cylinder 202 are respectively hinged to the second inner arm cylinder support 203 and the first inner arm cylinder support 103 on the pivot box 102.

[0061] The second inner arm cylinder support 203 refers to the cylinder mounting base located in the front section of the inner arm support 201. It can be implemented using a welded or bolted metal plate structure to change the fulcrum position in the traditional end-drive layout. The hinged connection refers to a rotating pair structure that engages with the cylinder support via a pin, allowing the drive cylinder to maintain its degree of freedom during the movement of the four-bar linkage.

[0062] Specifically, when the inner arm drive cylinder 202 extends or retracts, its two ends act on the second inner arm cylinder support 203 and the first inner arm cylinder support 103 on the pivot box 102, respectively, forming a triangular force transmission path with the two hinge points as vertices. During the extension or retraction of the four-bar linkage, the hinged connection allows the cylinder to automatically adjust its posture according to the swing angle of the inner arm support, avoiding motion interference.

[0063] In some of these embodiments, such as Figure 3 As shown, this application further proposes to provide a second escalator 204 along its length direction on the outer side wall of the inner arm support 201, and to provide a maintenance platform 205 at the top of the second escalator 204.

[0064] The second escalator 204 refers to a ladder-shaped structure installed on the outer wall of the inner arm support 201. Specifically, it can be implemented by welding segmented anti-slip steps to the side wall, extending along the length of the inner arm support 201 to form a continuous climbing path, providing a safe access route for maintenance personnel. The maintenance platform 205 refers to the horizontal working area located at the top of the second escalator 104. Specifically, it can be implemented using a combination of mesh steel plates and guardrails, fixedly connected to the outer wall of the inner arm support, providing a stable working space for maintenance personnel.

[0065] Specifically, the second escalator 104 is rigidly connected to the inner arm support 201 through a segmented step structure, allowing maintenance personnel to move vertically along the escalator to reach the area located above the inner arm support 201. The maintenance platform 205 is fixed to the side wall of the inner arm support 201 and the second escalator 104 through its bottom support frame, forming an enclosed space that can accommodate one person for work. During operation, the personnel load borne by the platform is transferred to the main structure of the inner arm support 201 through the support frame.

[0066] In some of these embodiments, such as Figure 1 and Figure 3 As shown, this application further proposes that the rear end of the inner arm support 201 is detachably provided with a counterweight block, and its rear end is detachably connected to the locking mechanism 110 on the lower side wall of the column body 101.

[0067] The detachable counterweight refers to a modular mass block fixed by bolts or clips. Specifically, it can be implemented using a split cast iron block with locating pins. Its function is to adjust the balancing torque according to the center of gravity position of the inner arm assembly 200. The detachable locking mechanism 110 refers to a mechanical clamp with a quick-release function. Specifically, it can be implemented using hydraulic pins or pneumatic calipers. Its function is to fix the unfolding of the inner arm support 201 through rigid constraint.

[0068] Specifically, in the non-working state, the weight of the counterweight is configured to counteract the gravitational torque at the front end of the inner arm assembly 200, keeping the overall structure in a state of force balance. During maintenance, the pins or calipers of the locking mechanism 110 can be hydraulically released, and the detachable connection of the counterweight can be quickly disassembled for flexible adjustment, allowing the inner arm support 201 to rotate freely around the hinge point to the maintenance position.

[0069] Through the above technical solution, this application solves the problem of swaying caused by structural instability of the loading and unloading arm in a static state, while avoiding the safety hazards caused by complex disassembly operations during maintenance. The modular design of the counterweight allows the weight adjustment operation to be completed on the dock ground without the need for high-altitude operations, and the rigid constraint of the locking mechanism 110 effectively eliminates random swaying caused by wind.

[0070] In some of these embodiments, such as Figure 1 , Figure 2 and Figure 3 As shown, this application further proposes an outer arm assembly 300 including an outer arm tie rod 301, an outer arm support 302, a lower swing beam 303, and an outer arm drive cylinder 304. The front end of the outer arm tie rod 301 is hinged to the rear end of the outer arm support 302 through a bearing, and the rear end is hinged to the top end of the lower swing beam 303 through a bearing. The middle and rear ends of the outer arm support 302 and the bottom end of the lower swing beam 303 are respectively connected to the inner arm support 201 through corresponding seated bearings, forming a parallelogram four-bar linkage mechanism.

[0071] Among them, the outer arm tie rod 301 refers to the rigid transmission component that connects the outer arm support and the lower swing beam. Specifically, it can be implemented using a rod-shaped structure made of high-strength alloy steel, which is used to convert the thrust of the outer arm drive cylinder into the rotational motion of the outer arm support.

[0072] Among them, the mounted bearing refers to a rolling bearing assembly with a mounting base, specifically a conventionally known turntable load-bearing rotating base, used to bear the radial and axial loads generated during the movement of the four-bar linkage. The parallelogram four-bar linkage refers to a hinged structure with two sets of parallel sides, consisting of an outer arm support 302, an outer arm tie rod 301, a lower swing beam 303, and an inner arm support 201. This can be achieved by controlling the coaxiality tolerance of each hinge point to ensure that the outer arm assembly 300 maintains geometric symmetry during deployment. The outer arm tie rod 301 and the outer arm support 302 can specifically adopt a conventionally known triangular or rectangular cross-section steel frame structure, mainly composed of steel, and connected by welding or bolting to form a frame or truss structure.

[0073] Specifically, when the outer arm drive cylinder 304 pushes the lower swing beam 304 to rotate around its bottom hinge point, the outer arm tie rod 301 transmits the displacement of the top of the lower swing beam 303 to the rear end of the outer arm support 302, causing the outer arm support 302 to rotate around its hinge point with the inner arm support 201. Since the middle and rear ends of the outer arm support 302 and the bottom end of the lower swing beam 303 respectively form two sets of parallel hinge points with the inner arm support 201 through bearing seats, the four-bar linkage maintains the geometric characteristic that the two sets of opposite sides are equal in length and parallel during movement. This structure ensures a linear correspondence between the unfolding angle of the outer arm support 302 and the rotation angle of the lower swing beam 303, eliminating the risk of elastic deformation present in traditional wire rope drives.

[0074] Compared to existing technologies, traditional loading booms using wire ropes to drive the boom result in elastic deformation in the transmission system. This solution, however, directly converts the linear motion of the drive cylinder into the rotational motion of the boom using a rigid four-bar linkage, avoiding transmission errors caused by wire rope elongation. Existing technologies require regular maintenance and adjustment of the sheave system; this solution, employing a hinged structure with mounted bearings, significantly reduces maintenance frequency. Simultaneously, the parallelogram geometric constraints ensure the boom assembly maintains a stable posture during deployment.

[0075] Through the above technical solution, this application solves the risk of equipment runaway caused by the instability of the wire rope transmission structure. The rigid four-bar linkage enhances the load-bearing capacity of the outer boom assembly 300, enabling it to adapt to the installation requirements of large-diameter pipelines. The combination of the mounted bearing and the parallelogram effectively disperses the dynamic load during movement, reduces the wear rate at the hinge points, and eliminates the safety hazards caused by wire rope slack in traditional solutions.

[0076] In some of these embodiments, such as Figure 1 and Figure 3 As shown, this application further proposes that a second outer arm cylinder support 305 is provided at the lower middle end of the lower swing beam 303, and the two ends of the outer arm drive cylinder 304 are respectively hinged to the second outer arm cylinder support 305 and the first outer arm cylinder support 104 on the pivot box 102.

[0077] The second outer arm cylinder support 305 is a rigid connecting piece fixedly installed at the lower end of the lower swing beam. It can be implemented using a welded or bolted metal base, providing a stable hinge point for the outer arm drive cylinder 304. The hinged connection at both ends of the outer arm drive cylinder 304 means that the piston rod end and cylinder body end are rotatably connected to their respective cylinder supports via pins. This can be achieved using a hinged structure with self-lubricating bearings, allowing the outer arm drive cylinder 304 to adapt to the movement trajectory of the four-bar linkage during extension and retraction.

[0078] Specifically, the cylinder body of the outer arm drive cylinder 304 is hinged to the first outer arm cylinder support 104 on the pivot box 102, while the piston rod end is hinged to the second outer arm cylinder support 305 at the lower end of the lower swing beam 303. When the cylinder extends or retracts, the driving force acts directly on the lower swing beam 303, causing the outer arm tie rod 301 and the outer arm support 302 to move synchronously in a parallelogram four-bar linkage. Since the second outer arm cylinder support 305 is located at the lower end of the lower swing beam 303, the thrust direction of the cylinder forms a perpendicular component with the motion plane of the four-bar linkage, thereby improving the driving force transmission efficiency.

[0079] In addition, such as Figures 1 to 3 , Figures 6 to 9As shown, this application further proposes a liquid phase pipeline 400, a gas phase pipeline 500, and a three-dimensional connector 600. The lower end of the liquid phase pipeline 400 passes through the hollow cavity of the column body 101, and the upper end is flexibly installed on the inner arm support 201 and the outer arm support 302 in sequence. The lower end of the gas phase pipeline 500 is flexibly installed on the outer wall of the column body 101, and the upper end is flexibly installed on the inner arm support 201 and the outer arm support 302 in sequence. The three-dimensional connector 600 is flexibly installed at the front end of the outer arm support 302 and is connected to the liquid phase pipeline 400 and the gas phase pipeline 500 respectively, and it is detachably connected to the LNG ship.

[0080] The liquid phase pipeline 400 refers to the pipeline used to transport liquefied natural gas. Specifically, it can be installed on the inner arm support 201 and outer arm support 302 using a segmented flexible support method. The hollow cavity of the column body 101 serves as the axial load-bearing channel, allowing the pipeline system to bear only the medium pressure and its own weight. The gas phase pipeline 500 refers to the pipeline used to maintain the pressure balance of the LNG vessel. Specifically, it can be independently arranged on the outside of the column body 101 and flexibly connected to achieve synchronous movement with the inner and outer arms, forming a pressure balance system independent of the support structure. The three-dimensional joint 600 refers to the interface device connecting the pipeline and the vessel. Specifically, it can adopt a multi-directional hinged structure to achieve dynamic sealing and adapt to the relative displacement between the vessel and the loading / unloading arm through a flexible installation method.

[0081] Specifically, the lower end of the liquid phase pipeline 400 passes through the hollow cavity of the column body 101. Its axial load is directly transmitted to the ground through the column body 101, while the lateral load is distributed through the flexible mounting points of the inner arm 201 and the outer arm support 302, preventing the rotary joint from bearing excessive bending moment. The gas phase pipeline 500 is independently arranged on the outside of the column body 101 and moves synchronously with the inner and outer arms through flexible connections. It maintains the stability of the pipeline direction when the four-bar linkage is in operation, ensuring the continuous operation of the pressure balance system. The three-dimensional joint 600 compensates for the relative displacement between the ship and the loading arm through a multi-directional hinge structure. Its flexible installation method allows the joint to be adjusted slightly in three-dimensional space, ensuring both sealing reliability and facilitating quick assembly and disassembly.

[0082] Through the above technical solutions, this application achieves reliable sealing of large-diameter pipelines under complex motion conditions, reduces the risk of rotary joint leakage, and ensures efficient transmission of liquefied natural gas; the independent arrangement of the gas phase pipeline 400 maintains the pressure balance of LNG ships and avoids pressure fluctuations in the gas phase space during loading and unloading; the flexible connection structure of the three-dimensional joint 600 adapts to the dynamic displacement of ships, improves the reliability of interface sealing, and meets the loading and unloading needs of large terminals with a capacity of 300,000 tons or more.

[0083] Combination Figures 1 to 9As shown, this utility model, through the synergistic effect of a four-bar linkage and dual-drive hydraulic cylinders, adopts a rigid connection to replace the traditional wire rope transmission, effectively solving the technical problems of frequent maintenance and significant safety hazards of traditional equipment. It has the advantages of high structural strength, safe operation, and convenient maintenance, and can meet the design requirements of large-diameter / large-tonnage wharves.

[0084] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0085] Secondly, the accompanying drawings of the embodiments disclosed in this utility model only involve the structures involved in the embodiments disclosed in this utility model. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this utility model can be combined with each other.

[0086] Finally, the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A novel four-link loading and unloading boom for liquid chemical terminals, characterized in that, Includes a support column (100), an inner arm assembly (200), and an outer arm assembly (300), wherein: The support column (100) includes a column body (101) and a pivot box (102) disposed on the top of the column body (101). The side wall of the pivot box (102) is hinged to the middle and rear end of the inner arm assembly (200) through a seated bearing (109). The front and rear ends of the inner arm support (201) on the inner arm assembly (200) are respectively hinged to the outer arm support (302) and the lower swing beam (303) on the outer arm assembly (300), and the front end is hinged to the pivot box (102) via the inner arm drive cylinder (202); and The front and rear ends of the upper arm tie rod (301) of the upper arm assembly (300) are respectively hinged to the upper arm support (302) and the lower swing beam (303), and form a four-bar linkage with the inner arm support (201) on the inner side. The lower swing beam (303) is hinged to the pivot box (102) through the upper arm drive cylinder (304).

2. The novel four-link loading and unloading arm according to claim 1, characterized in that, The column body (101) is a hollow columnar structure with a liquid phase pipe (400) passing through its inner cavity. The bottom is fixed to the ground by a mounting base plate. The lower side wall is provided with a locking mechanism (110) that cooperates with the lower end of the inner arm support (201). The side wall is equipped with a vertically arranged first hand ladder (111).

3. The novel four-link loading and unloading arm according to claim 1, characterized in that, A first turntable base (105) is installed at the bottom of the shaft box (102), and a second turntable base (106) is installed at the bottom of the first turntable base (105), wherein: The first turntable base (105) and the second turntable base (106) are arranged symmetrically from left to right, and are respectively hinged to the first horizontal drive cylinder (107) and the second horizontal drive cylinder (108) installed on the top of the column body (101).

4. The novel four-link loading and unloading arm according to claim 1, characterized in that, The pivot box (102) is provided with a first inner arm cylinder support (103) and a first outer arm cylinder support (104) arranged vertically and staggered, wherein: The first inner arm cylinder support (103) is hinged to the cylinder body of the inner arm drive cylinder (202), and the first outer arm cylinder support (104) is hinged to the cylinder body of the outer arm drive cylinder (304), respectively for mounting the inner arm drive cylinder (202) and the outer arm drive cylinder (304).

5. The novel four-bar linkage loading and unloading arm according to claim 1, characterized in that, The inner arm assembly (200) includes an inner arm support (201) and an inner arm drive cylinder (202), wherein: The inner arm support (201) is provided with a second inner arm cylinder support (203) at its middle front end. The two ends of the inner arm drive cylinder (202) are respectively hinged to the second inner arm cylinder support (203) and the first inner arm cylinder support (103) on the shaft box (102).

6. The novel four-bar linkage loading and unloading arm according to claim 5, characterized in that, A second ladder (204) is provided on the outer wall of the inner arm support (201) along its length direction, and a maintenance platform (205) is provided at the top of the second ladder (204).

7. The novel four-bar linkage loading and unloading arm according to claim 5, characterized in that, The rear end of the inner arm support (201) is detachably provided with a counterweight block, and its rear end is detachably connected to the locking mechanism (110) on the lower side wall of the column body (101).

8. The novel four-link loading and unloading arm according to claim 1, characterized in that, The boom assembly (300) includes a boom tie rod (301), a boom support (302), a lower swing beam (303), and a boom drive cylinder (304), wherein: The front end of the outer arm tie rod (301) is hinged to the rear end of the outer arm support (302) via a bearing, and its rear end is hinged to the top end of the lower swing beam (303) via a bearing. The middle and rear ends of the outer arm support (302) and the bottom end of the lower swing beam (303) are respectively connected to the inner arm support (201) through corresponding bearing seats to form a parallelogram four-bar linkage.

9. The novel four-bar linkage loading and unloading arm according to claim 8, characterized in that, The lower end of the lower swing beam (303) is provided with a second outer arm cylinder support (305), and the two ends of the outer arm drive cylinder (304) are respectively hinged to the second outer arm cylinder support (305) and the first outer arm cylinder support (104) on the shaft box (102).

10. The novel four-bar linkage loading and unloading arm according to claim 1, characterized in that, It also includes liquid phase piping (400), gas phase piping (500), and three-dimensional connectors (600), wherein: The lower end of the liquid phase pipeline (400) passes through the hollow cavity of the column body (101), and the upper end is flexibly installed on the inner arm support (201) and the outer arm support (302) in sequence, for pumping liquefied natural gas in LNG ships. The lower end of the gas phase pipe (500) is flexibly installed on the outer wall of the column body (101), and its upper end is flexibly installed on the inner arm support (201) and the outer arm support (302) in sequence to maintain the LNG pressure balance inside the LNG ship. The three-dimensional connector (600) is flexibly installed at the front end of the outer arm support (302) and is connected to the liquid phase pipeline (400) and the gas phase pipeline (500) respectively, and is detachably connected to the LNG ship.

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