Automatic butt-joint rigid mechanical arm device for LNG (liquefied natural gas) shore port transmission system

Abstract

The invention discloses an automatic docking rigid mechanical arm device for an LNG shore port transmission system. A middle arm rotating system is connected with a supporting system and used for controlling pitching rotation of a middle arm; the counterweight balance mechanism comprises a counterweight block roller, a small arm roller, a steel wire rope and a steel wire rope transmission mechanism, the counterweight block roller is connected with a counterweight block through a counterweight block inner shaft, and the counterweight balance mechanism is mounted on the middle arm and used for ensuring that the small arm of the LNG unloading arm keeps static balance when receiving LNG from an LNG transport ship; the tensioning mechanism is fixed to the middle arm and used for guaranteeing that the balancing weight and a small arm of the LNG discharging arm rotate synchronously. A big arm conveying pipeline is arranged in a big arm of the supporting system and connected with the continuous rotating sealing pipe connecting structure. In the unloading process, the safety and stability are achieved, the unloading device adapts to more complex transmission occasions, the operation cost of an LNG receiving station is reduced, and the overall economic benefits are improved.

Description

Technical Field

[0001] The invention belongs to the field of LNG transportation and reception, and in particular relates to an automatic docking rigid mechanical arm device for an LNG port transmission system. Background Art

[0002] As global energy demand grows, liquefied natural gas (LNG) has gained attention for its high efficiency and cleanliness. As an energy source, LNG has the advantages of being easy to store and transport, and its volume is only 1 / 600 of the same mass of natural gas, making LNG an important part of global energy trade. In addition, LNG produces fewer pollutants during combustion, which helps reduce greenhouse gas emissions, and is therefore regarded as an environmentally friendly energy source.

[0003] The application scale of LNG is constantly expanding, especially in the marine field, and the LNG port transmission system has become particularly important. The increase in marine LNG production and the frequent marine transportation have made the LNG port transmission system an important bridge connecting offshore natural gas resources with the land market. The effective operation of these systems is crucial to ensure the stability and reliability of energy supply.

[0004] The offshore LNG transmission system is a key component of the offshore natural gas supply chain and requires continuous research and development to ensure the safety of offshore operations. The offshore environment is complex and changeable, including extreme weather, waves, seawater corrosion and other factors, which have put forward higher technical requirements and safety challenges for the LNG transmission system. Therefore, the development of a more reliable and efficient LNG port transmission system is crucial to improving the safety and efficiency of offshore operations.

[0005] The LNG unloading arms used by coastal LNG receiving stations for a long time rely on imports, which are difficult to localize, have small calibers, and few options. This dependence not only increases costs, but may also affect energy security due to unstable supply. Therefore, the development of domestically produced LNG unloading arms is of great significance to ensuring national energy security, reducing costs, and improving market competitiveness.

[0006] Traditional automatic docking rigid robotic arm devices usually use a double counterweight system, which has a large overall weight and high energy consumption, which is not conducive to the safety and stability of the unloading process. In addition, the power and speed are unbalanced, which easily causes the LNG unloading arm to shake during operation. Summary of the invention

[0007] The object of the present invention is to provide an automatic docking rigid mechanical arm device for an LNG port transmission system to solve the problems raised in the above-mentioned background technology.

[0008] The purpose of the present invention is achieved through the following technical solutions:

[0009] An automatic docking rigid mechanical arm device for an LNG port transmission system comprises: a counterweight balancing mechanism, a tensioning mechanism, a continuously rotating sealed pipe connection structure, a middle arm rotation system, and a support system; the middle arm rotation system is connected to the support system and is used to control the pitch rotation of the middle arm; the counterweight balancing mechanism comprises a counterweight roller, a roller at a forearm, a wire rope, and a wire rope transmission mechanism; the counterweight roller is connected to the counterweight through an inner shaft of the counterweight; the counterweight balancing mechanism is installed on the middle arm and is used to ensure that the forearm of the LNG unloading arm maintains static balance when receiving LNG from an LNG transport ship; the tensioning mechanism is fixed on the middle arm and is used to ensure that the counterweight and the forearm of the LNG unloading arm rotate synchronously; a large arm transport pipeline is provided inside the large arm of the support system, and the large arm transport pipeline is connected to the continuously rotating sealed pipe connection structure.

[0010] Furthermore, the support system includes a base, on which a column is installed, the column is connected to the large and middle arm connecting structure through trunk A and trunk B, the large and middle arm connecting structure is rotatably connected to the middle arm, one end of the middle arm is rotatably connected to the forearm, the middle arm is connected to the middle arm transport pipeline through a middle arm pipeline fixing ring, and the forearm is connected to the forearm transport pipeline through a forearm pipeline fixing ring, and the support system is used to ensure the stability of the entire device during transportation.

[0011] Furthermore, the continuous rotating sealing pipe connection structure includes a forearm transport pipeline and a middle arm transport pipeline, and the forearm transport pipeline and the middle arm transport pipeline are connected through an intermediate transport pipeline and a rotating sealing structure. The rotating sealing structure includes a sealing gasket 1, a bearing retaining ring, a limiting nut, a sealing gasket 2, a bushing, a spring and a deep groove ball bearing 1 and a deep groove ball bearing 2. The forearm transport pipeline is continuously connected with a sealing gasket 1, a deep groove ball bearing 1, a spring, a deep groove ball bearing 2 and a sealing gasket 2, and then connected to the middle arm transport pipeline, and finally fixed with a limiting nut. The rotating sealing structure is used to ensure the sealing of the connection of the pipeline during rotation, and double sealing gaskets are used for sealing, which further enhances the sealing effect.

[0012] Furthermore, the counterweight balancing mechanism comprises a counterweight roller and a roller at the forearm, wherein the roller at the forearm is installed on the middle arm near the forearm end through end cover 1, and the counterweight roller is installed on the other end on the right side of the middle arm through end cover 2, and a steel wire rope is wound around the counterweight roller and the roller at the forearm, the inner shaft of the counterweight is coaxial with the counterweight roller (9), and the counterweight is installed on the inner shaft of the counterweight.

[0013] Furthermore, the middle arm rotation system includes a hydraulic cylinder support installed on a column, a hydraulic cylinder is installed on the hydraulic cylinder support, the hydraulic cylinder is connected to one end of a middle arm driving connecting rod, and the other end of the middle arm driving connecting rod moves in a groove of the middle arm, thereby driving the middle arm to rotate up and down.

[0014] Furthermore, the tensioning mechanism includes a motor and a wire rope lifting device, the motor is installed on a motor lifting support, and the lifting support is installed in the middle section of the middle arm near the forearm; the motor is connected to the screw, and the screw is connected to the wire rope lifting device.

[0015] Furthermore, the wire rope lifting device includes a base, and the base is connected to support frame one and support frame two through a group of support rods respectively, the support frame one is fixedly installed at the end of the screw away from the motor, and the support frame two is movably installed at the end of the screw close to the motor, the support frame one and the support frame two are respectively connected to the roller support through a group of support rods and a group of connecting rods, and the number of each group of support rods and connecting rods is four, and the support wheel is installed on the roller support through a support shaft, and the support wheel is close to the wire rope, and the motor rotates the support frame two when it works, driving the support frame two to move, thereby raising the roller support and lifting the wire rope, thereby achieving the tensioning purpose.

[0016] The present invention may also include: an operation method of the automatic docking rigid mechanical arm device for the LNG port transmission system as described above, the method comprising the following steps:

[0017] Phase 1: When the LNG carrier arrives at the port and stays at the designated position, the hydraulic cylinder drives the middle arm to drive the connecting rod to control the middle arm to start rotating. During this process, in order to ensure the overall balance of the unloading arm and reduce the load on the hydraulic cylinder, the tensioning mechanism works to ensure that the transmission energy of the wire rope transmission mechanism is transmitted to the rollers at the forearm and the counterweight rollers. The wire rope transmission mechanism starts to work, and the inner shaft of the counterweight at the tail end of the middle arm and the counterweight need to move at the same time until the LNG unloading arm reaches the designated working position, and then further fine-tune the position while maintaining the static balance of the entire system;

[0018] Phase 2: The forearm joint starts to connect with the LNG carrier until the LNG is received. During this process, the LNG carrier may shake slightly due to external factors such as waves. The connection device needs to be able to move with the LNG carrier. When the shaking degree or the displacement distance of the LNG carrier is too large, emergency separation can occur.

[0019] The third stage: when the liquefied natural gas transportation is completed, the arm joint begins to separate from the LNG carrier; then the hydraulic cylinder and wire rope transmission mechanism start to work to restore the LNG unloading arm to the standby position. This process is equivalent to the process in the first stage.

[0020] The beneficial effects of the present invention are:

[0021] The counterweight balancing mechanism of the present invention adopts a single counterweight block for balancing. Not only is it simpler in design, it does not have the complex structure and multiple counterweight points of the double counterweight system. This simplicity not only reduces the complexity and manufacturing cost of the system, but also improves the reliability and maintainability of the system. At the same time, the overall mass can be reduced while ensuring performance. This helps to reduce the energy consumption of the LNG unloading arm and improve the operating efficiency of the equipment. In addition, the lighter mass also helps to reduce the load on the LNG connecting pipe on the ship, further ensuring the safety and stability of the unloading process. The single counterweight balancing mechanism is designed to ensure that the equipment can maintain balance in any position. This balance not only helps to reduce the vibration and shaking of the equipment during movement, but also reduces the requirements for the drive system, thereby reducing energy consumption and extending the service life of the equipment. The manufacturing cost and maintenance cost of the single counterweight balancing mechanism are also relatively low. This helps to reduce the operating cost of the LNG receiving station and improve the overall economic benefits.

[0022] The present invention adopts steel wire rope for high-strength transmission. It has high tensile strength and fatigue strength and can withstand high loads and impact loads. Therefore, it is suitable for high-strength transmission occasions. Secondly, the steel wire rope has a long life: compared with torque transmission components, the steel wire rope is not easy to be damaged and has a long service life. The steel wire rope has excellent flexibility. Compared with traditional belt transmission methods, the steel wire rope is more flexible and has a wide transmission angle range, which can adapt to more complex transmission occasions. Finally, the cost of the steel wire rope is low, and the cost of its installation, maintenance and replacement is less, and the required cycle is much shorter.

[0023] The driving mode of the present invention adopts hydraulic cylinder drive. The hydraulic cylinder transmission can stably output power under low speed and high torque, meeting the frequent load-bearing requirements of the LNG unloading arm. The power and speed provided by the hydraulic cylinder are very balanced, with the characteristics of stable output, reducing the adverse factors such as shaking and vibration of the LNG unloading arm during operation. In addition, the reaction speed of the hydraulic cylinder is faster than that of the arm motor, and it can be quickly avoided in an emergency.

[0024] Compared with the traditional structure, the optimized version of the continuous rotating sealing tube connection structure of the present invention newly adds a sealing gasket, adopts double sealing gaskets for sealing, and further enhances the sealing effect; secondly, the output end transport tube and the input end and the limit nut adopt over-fitting, which reduces the friction loss between the parts; in addition, two deep groove ball bearings are newly added between the input end input tube and the output end transport tube, which further reduces the friction resistance between the parts and ensures the smoothness of the rotation.

[0025] The present invention draws on the structure of a jack in the design of the tensioning mechanism: a tensioning mechanism is designed using a screw nut structure, and the purpose of saving energy is achieved through the self-locking effect of the screw nut (support frame). The drive motor only works when the wire rope needs to be tensioned, which saves resources while achieving the purpose and completes the work well. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Attached Figure 1 It is a schematic diagram of the structure of the present invention.

[0027] Attached Figure 2 It is the front view of the present invention.

[0028] Attached Figure 3 It is a left view of the present invention.

[0029] Attached Figure 4 It is a partial cross-sectional view of the forearm of the present invention.

[0030] Attached Figure 5 It is a structural schematic diagram of the tensioning mechanism of the present invention.

[0031] Attached Figure 6 It is a calculation model diagram of the single counterweight balancing system of the LNG unloading arm of the present invention.

[0032] In the attached figure: 1. End cover 1; 2. Roller at forearm; 3. Tensioning mechanism; 4. Wire rope; 5. Middle arm; 6. Middle arm transport pipe; 7. Connection between large and middle arm; 8. End cover 2; 9. Counterweight roller; 10. Counterweight; 11. Counterweight inner shaft; 12. Big arm driving connecting rod; 13. Middle wall transport pipe fixing ring; 14. Trunk B; 15. Trunk A; 16. Hydraulic cylinder; 17. Hydraulic cylinder support; 18. Column; 19. Base; 20. 1. Deep groove ball bearing 1; 21. Washer; 22. Limit nut; 23. Intermediate transport pipe; 24. Forearm; 25. Bearing retaining ring; 26. Sealing gasket; 27. Spring; 28. Bushing; 29. ​​Forearm transport pipe; 30. Deep groove ball bearing 2; 31. Bearing retaining ring; 32. Sealing retaining ring 2; 33. Elastic retaining ring for shaft; 34. Support; 35. Wire rope transmission mechanism; 36. Forearm transport pipe fixing ring; 37. Forearm joint;

[0033] 301, motor; 302, motor fixing seat; 303: connecting rod one; 304: connecting rod two; 305: support rod one; 306: connecting rod three; 307: support rod two; 308: connecting rod four; 309: connecting rod five; 310: connecting rod six; 311: base; 312: support rod three; 313: connecting rod seven; 314: support rod four; 315: lead screw; 316 connecting rod eight; 317: support frame one; 318: support rod five; 319: support rod six; 320: support base; 321: support wheel; 322 support shaft; 323: support rod seven; 324: support rod eight; 325: support frame two. DETAILED DESCRIPTION

[0034] It should be noted that, in the absence of conflict, the examples and features in the examples of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with examples.

[0035] In order to make the purpose, technical solution and advantages of the examples of the present invention clearer, the technical solution in the examples of the present invention will be clearly and completely described below in conjunction with the drawings in the examples of the present invention. Obviously, the described examples are only part of the examples of the present invention, not all of the examples. The following description of at least one exemplary example is actually only illustrative and is by no means a limitation on the present invention and its application or use. Based on the examples in the present invention, all other examples obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0036] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the term "comprising" or "including" is used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0037] Unless otherwise specifically stated, the relative arrangement of the parts and steps, the numerical expressions and the numerical values ​​set forth in these examples do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary examples may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0038] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0039] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0040] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0041] Embodiment 1:

[0042] According to an embodiment of the present invention, there is provided an automatic docking rigid mechanical arm device for an LNG port transmission system, as shown in the attached Figure 1 As shown, it includes: a counterweight balancing mechanism, a tensioning mechanism 3, a continuously rotating sealed pipe connecting structure, a middle arm rotation system, and a supporting system; the middle arm rotation system is connected to the supporting system to control the pitch rotation of the middle arm 5; the counterweight balancing mechanism includes a counterweight roller 9, a roller 2 at the forearm, a wire rope 4, and a wire rope transmission mechanism 23; the counterweight roller 9 is connected to the counterweight 10 through the counterweight inner shaft 11; the counterweight balancing mechanism is installed on the middle arm 5 to ensure that the forearm of the LNG unloading arm maintains static balance when receiving LNG from the LNG transport ship; the tensioning mechanism 3 is fixed on the middle arm to ensure that the counterweight 10 rotates synchronously with the forearm of the LNG unloading arm; the upper arm of the supporting system has an upper arm transportation pipeline inside, and the upper arm transportation pipeline is connected to the continuously rotating sealed pipe connecting structure.

[0043] The support system described in this embodiment is as shown in the attached Figure 1 As shown, it includes: a base 19, a column is installed on the base, and the base 19 is kept in a vertical state. The column 18 is installed on the base 19, and the column 18 is connected to the large and medium arm connection structure 7 through the trunk A14 and the trunk B15. The large and medium arm connection structure 7 is rotatably connected to the middle arm 5, and one end of the middle arm 5 is rotatably connected to the small arm 24. The middle arm 5 is connected to the middle arm transportation pipeline 6 through the middle arm pipeline fixing ring 13, and the small arm 24 is connected to the small arm transportation pipeline 29 through the small arm pipeline fixing ring. The support system is used to ensure the stability of the entire device during transportation. The entire support system is fixed on a flat ground with high rigidity to ensure the stability of the entire system.

[0044] The counterweight balancing mechanism described in this embodiment is as shown in the attached Figure 1-3 As shown, it includes: a counterweight roller 9 and a roller 2 at the forearm, the roller 2 at the forearm is installed on the middle arm near the forearm end through an end cover 1, and the counterweight roller is installed on the other end on the right side of the middle arm through an end cover 2 3, and a steel wire rope is wound around the counterweight roller 9 and the roller 2 at the forearm, the inner shaft of the counterweight is coaxial with the counterweight roller 9, and the counterweight is installed on the inner shaft of the counterweight.

[0045] The middle arm rotation system described in this embodiment is as shown in the attached Figure 1-3 As shown, it includes: a hydraulic cylinder support 17 installed on a column 18, a hydraulic cylinder 16 is installed on the hydraulic cylinder support 17, the hydraulic cylinder 16 is connected to one end of the middle arm driving connecting rod 12, and the other end of the middle arm driving connecting rod 12 moves in the groove of the middle arm 5, thereby driving the middle arm 5 to rotate up and down.

[0046] The continuous rotating sealing pipe connection structure described in this embodiment is as shown in the attached Figure 4 As shown, it includes: a small arm transport pipeline 29, a middle arm transport pipeline 6, the small arm transport pipeline 29, the middle arm transport pipeline 6 are connected through the middle transport pipeline 23, and a rotary sealing structure, the rotary sealing structure includes a sealing gasket 21, a bearing retaining ring 31, a limiting nut 22, a sealing gasket 232, a sleeve 28, a spring 27 and a deep groove ball bearing 20, a deep groove ball bearing 230, the small arm transport pipeline 29 is respectively connected with a sealing gasket 21, a deep groove ball bearing 20, a spring 27, a deep groove ball bearing 230, and a sealing gasket 232, and then connected to the middle arm transport pipeline 23, and finally fixed with a limiting nut 22, the rotary sealing structure is used to ensure the sealing of the connection of the pipeline during the rotation process. The double sealing gasket is used for sealing, which further enhances the sealing effect. The output end transport tube is overfitted with the input end and the limit nut to reduce the friction loss between the parts; in addition, two deep groove ball bearings are used between the input end input tube and the output end transport tube to further reduce the friction resistance of the parts and ensure the smoothness of the rotation.

[0047] The tensioning mechanism 3 in this embodiment includes a motor 301 and a wire rope lifting device. The motor 301 is installed on a motor lifting support 302, and the lifting support 302 is installed in the middle section of the middle arm near the forearm; the motor 301 is connected to the screw 315, and the screw 315 is connected to the wire rope lifting device.

[0048] The wire rope lifting device includes a base 311, and the base 311 is connected to a support frame 1 317 and a support frame 2 325 through a group of support rods, respectively. The support frame 1 317 is fixedly installed at the end of the screw 315 away from the motor, and the support frame 2 325 is movably installed at the end of the screw 315 close to the motor. The support frame 1 317 and the support frame 2 325 are respectively connected to the roller support 320 through a group of support rods, and the number of support rods in each group is four. The support wheel 321 is installed on the roller support 320 through a support shaft 322, and the support wheel 321 is close to the wire rope. When the motor works, the support frame 2 325 is rotated, and the support frame 2 325 is driven to move, thereby raising the roller support 320 and lifting the wire rope, thereby achieving the tensioning purpose.

[0049] The counterweight block 10 in this embodiment is connected to the tail end of the middle arm through the inner shaft of the counterweight block 11, and the small arm 24 is connected to the front of the middle arm 5. The roller 2 at the small arm where the two are connected and the roller 9 of the counterweight block control the wire rope 4 to rotate synchronously through the wire rope transmission mechanism 23. Assuming that the length of the wire rope 4 does not change, theoretically, the counterweight beam and the small arm will not rotate relative to each other. In actual design, the tension of the wire rope is increased by the tensioning mechanism, thereby increasing the friction between the wire rope and the rotating shaft to ensure that the counterweight and the small arm will not rotate relative to each other.

[0050] The calculation model of the single counterweight balance system of the LNG unloading arm is established as shown in the attached figure. Figure 6 As shown, the counterweight is connected to the tail of the middle arm through a slewing support, the outer arm is connected to the front of the middle arm through a slewing support, the counterweight and the outer arm realize synchronous parallel rotation through a wire rope transmission, and the tensioning mechanism does not affect the overall calculation. It is not marked in the figure to ensure that there is no relative sliding between the two. In theory, the angle between the counterweight and the middle arm and the angle θ between the outer arm and the middle arm always remain the same.

[0051] M1=m3gL3'sinγ#(1)

[0052] M2=m4gL4'sinγ+m5gL4sinγ#(2)

[0053] M3=m1gL1'sinθ+m4g L1sinθ+L4'sinγ+m5g(L4sinγ+L1sinθ)#(3)

[0054] M4=m2gL2'sinθ+m3g L3'sinγ+L2sinθ#(4)

[0055] According to the previous analysis of the LNG unloading arm balance conditions, we can get: M1 = M2, M3 = M4, and by deduction we can get:

[0056] m3L3'=m4L4'+m5L4#(5)

[0057] m1L1'+m4L1+m5L1 sinθ+m4L4'+m5L4=m2L2'+m3L2 sinγsinθ+m3L3'sinγ# (6)

[0058] Substituting formula 1 into formula 2, we can further obtain: m1L1'+m4L1+m5L1=m2L2'+m3L2#(7)

[0059] In the above formula: m1: total mass of the front end of the middle arm and the transmission wheel and other parts; m2: total mass of the rear end of the middle arm and the transmission wheel and other parts; m3: total mass of the counterweight block; m4: total mass of the forearm and other parts; m5: total mass of the connecting device; M1: torque of the counterweight balancing system relative to the rotation center of the rear end of the middle arm; M2: torque of the outer arm relative to the rotation center of the front end of the middle arm; M3: torque of the entire front of the column rotation center relative to the column rotation center; M4: torque of the entire rear of the column rotation center relative to the column rotation center; L1: length of the front end of the middle arm; L1': distance from the center of gravity of the front end of the middle arm to the rotation center; L2: total length of the rear end of the middle arm; L2': distance from the center of gravity of the rear end of the middle arm to the rotation center; L3': distance from the center of gravity of the counterweight block to the rear end point of the middle arm of the unloading arm; L4: length of the forearm; L4': distance from the center of gravity of the forearm and other parts connected to the outer arm to the front end point of the middle arm of the unloading arm;

[0060] Analysis shows that when equation 5 is satisfied, the torque of the counterweight block and the arm of the unloading arm are equal, and the two are balanced at this time; when equations 5 and 6 are satisfied, the overall system balance of the LNG unloading arm can be achieved. At this time, the system balance is independent of the motion position and rotation angle, that is, when the system is balanced at any position, it can be balanced at all motion positions.

[0061] Embodiment 2:

[0062] According to the automatic docking rigid mechanical arm device of the LNG port transmission system described in Example 1 of the present invention, the installation method of the support system in this embodiment is as follows: first, find a horizontal rigid ground to avoid the device from tipping over and failing due to tilting or land collapse. Install the base 19 on the ground by cement pouring or other methods, then install the column 18 on the base 19 by screws, first install the trunk A14 and the trunk B15 on the column 18 by screws, then connect the trunk A14 and the trunk B15 together by screws, install the large and small arm connection 7 on the trunk A14 and the trunk B15, fix the middle arm 5 at the large and small arm connection, and further fix it with the end cover 8. Install the internal drive hydraulic cylinder support 17, the middle wall transport pipe fixing ring 13, and the small arm transport pipe fixing ring 36.

[0063] The installation method of the continuous rotating sealing pipe connection structure in this embodiment is as follows: first, the middle arm transport pipe 24 is installed, and fixed with the middle wall transport pipe fixing ring 13, the intermediate connecting transport pipe 23 is installed on the notch of the middle arm transport pipe 24, and then the sealing gasket 26, the bearing retaining ring 25, the deep groove ball bearing 20, the spring 27, the deep groove ball bearing 30, the bearing retaining ring 31, and the sealing gasket 32 ​​are installed in sequence, and finally fixed with the limit nut 22, and the small arm transport pipe 29 is installed on the intermediate connecting transport pipe 23, and fixed with the small arm transport pipe fixing ring 36.

[0064] The installation method of the tensioning mechanism in this embodiment is as follows: first, the motor fixing seat 302 and the base 311 are installed and fixed with screws, the support rods 305 and 307 are installed and fixed with connecting rods 308, and the support rods 312 and 314 are connected and fixed with connecting rods 310. The support rods 312, 314 and the support frame 317 are connected and fixed with connecting rods 313, the support rods 305, 307 and the support frame 323 are connected and fixed with connecting rods 304, the lead screw 315 passes through the support frame 317 and the support frame 323, and the lead screw 315 is connected to the motor 301, and the motor 301 is fixed to the motor fixing seat 302. Then, the support rods 319 and 318 are connected to the support frame 317 and fixed with connecting rods 316. The support rods 324 and 323 are fixed to the support frame 325 and fixed with connecting rods 303. Then, support rod 319 and support rod 318 are connected to roller support 320 and fixed with connecting rod 309, support rod 323 and support rod 324 are connected to 320 and fixed with connecting rod 306, and then support wheel 321 is installed on roller support 320 through support shaft 322.

[0065] The installation method of the counterweight balancing mechanism in this embodiment is as follows: the sleeve 28 is installed on the middle arm 5, the roller 2 at the forearm is installed on the sleeve 28, the counterweight roller 9 is installed on the middle arm 5, the counterweight inner shaft 11 is installed between the counterweight roller 9 and the middle arm 5, and the counterweight 10 is installed on the counterweight inner shaft 11. The support 34 is installed on the middle arm 5, the wire rope transmission mechanism 35 is installed on the support 34, the wire rope 4 is installed on the wire rope transmission mechanism 35, and the wire rope 4 is wound around the roller 2 at the forearm, the counterweight roller 9 and the tensioning structure 3.

[0066] The wire rope transmission mechanism 35 may be driven to move the wire rope by a hydraulic cylinder placed parallel to the wire rope, but is certainly not limited to this structure.

[0067] Please refer to Figure 1-2 The installation method of the middle arm rotation system in this embodiment is as follows: the hydraulic cylinder support 17 is installed on the column 18, the hydraulic cylinder 16 is installed on the hydraulic cylinder support 17, the hydraulic cylinder 16 and the middle arm driving connecting rod 12 are connected together by bolts, and the middle arm driving connecting rod 12 is installed in the groove of the middle arm 5.

[0068] Embodiment 3:

[0069] According to the automatic docking rigid mechanical arm device of the LNG port transmission system described in Example 1, its operation method is as follows:

[0070] Phase 1: When the LNG carrier arrives at the port and stays at the designated position, the hydraulic cylinder 16 drives the middle arm driving connecting rod 12 to control the middle arm 5 to start rotating. During this process, in order to ensure the overall balance of the discharge arm and reduce the load on the hydraulic cylinder 16, the tensioning mechanism 3 works to ensure that the transmission energy of the wire rope transmission mechanism 35 is transmitted to the roller 2 and the counterweight roller 9 at the forearm. The hydraulic cylinder 35 starts working, and the counterweight inner shaft 11 and the counterweight 10 at the tail end of the middle arm 5 need to move at the same time until the LNG discharge arm reaches the designated working position, and then further fine-tune the position while maintaining the static balance of the entire system;

[0071] The second stage: the arm joint 37 starts to connect with the LNG carrier until the LNG is received. During this process, the LNG carrier may be slightly shaken by external factors such as waves. The connection device needs to be able to move with the LNG carrier. When the shaking degree or the displacement distance of the LNG carrier is too large, emergency separation can occur.

[0072] The third stage: when the liquefied natural gas transportation is completed, the arm joint 37 begins to separate from the LNG carrier; then the hydraulic cylinder 16 and the wire rope transmission mechanism 35 start to work, so that the LNG unloading arm returns to the standby position. This process is equivalent to the process of the first stage.

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An automatic docking rigid mechanical arm device for LNG port transmission system, characterized in that: include: A counterweight balancing mechanism, a tensioning mechanism (3), a continuously rotating sealed pipe connection structure, a middle arm rotation system, and a support system; the middle arm rotation system is connected to the support system and is used to control the pitch rotation of the middle arm (5); the counterweight balancing mechanism comprises a counterweight roller (9), a roller (2) at a forearm, a steel wire rope (4), and a steel wire rope transmission mechanism (35); the counterweight roller (9) is connected to the counterweight (10) via a counterweight inner shaft (11); the counterweight balancing mechanism is installed on the middle arm (5) and is used to ensure that the forearm of the LNG unloading arm maintains static balance when receiving LNG from an LNG transport ship; the tensioning mechanism (3) is fixed on the middle arm and is used to ensure that the counterweight (10) rotates synchronously with the forearm of the LNG unloading arm; a large arm transport pipeline is provided inside the large arm of the support system, and the large arm transport pipeline is connected to the continuously rotating sealed pipe connection structure.

2. The automatic docking rigid mechanical arm device for LNG port transmission system according to claim 1 is characterized in that: The support system comprises a base (19), on which a column (18) is mounted, the column (18) being connected to a large-middle arm connection structure (7) via a trunk A (14) and a trunk B (15), the large-middle arm connection structure (7) being rotatably connected to the middle arm (5), one end of the middle arm (5) being rotatably connected to a small arm (24), the middle arm (5) being connected to a middle arm transport pipeline (6) via a middle arm pipeline fixing ring (13), and the small arm (24) being connected to a small arm transport pipeline (29) via a small arm pipeline fixing ring, and the support system is used to ensure the stability of the entire device during transportation.

3. The automatic docking rigid mechanical arm device for LNG port transmission system according to claim 1 is characterized in that: The continuous rotating sealing pipe connection structure comprises a small arm transport pipeline (29) and a middle arm transport pipeline (6). The small arm transport pipeline (29) and the middle arm transport pipeline (6) are connected through an intermediate transport pipeline (23) and a rotating sealing structure. The rotating sealing structure comprises a sealing gasket 1 (21), a bearing retaining ring (31), a limiting nut (22), a sealing gasket 2 (32), a shaft sleeve (28), a spring (27) and a deep groove ball bearing 1 (20), a deep groove ball bearing 2 (30). The small arm transport pipeline (29) is respectively and continuously connected with a sealing gasket 1 (21), a deep groove ball bearing 1 (20), a spring (27), a deep groove ball bearing 2 (30), and a sealing gasket 2 (32). The small arm transport pipeline (29) is then connected to the middle arm transport pipeline (23) and finally fixed with a limiting nut (22). The rotating sealing structure is used to ensure the sealing of the connection of the pipeline during rotation. Double sealing gaskets are used for sealing, thereby further enhancing the sealing effect.

4. The automatic docking rigid mechanical arm device for LNG port transmission system according to claim 1 is characterized in that: The counterweight balancing mechanism comprises a counterweight roller (9) and a roller (2) at the forearm. The roller (2) at the forearm is installed on the middle arm near the end of the forearm through an end cover 1 (1). The counterweight roller is installed on the other end on the right side of the middle arm through an end cover 2 (3). Steel wire ropes are wound around the counterweight roller (9) and the roller (2) at the forearm. The inner shaft of the counterweight is coaxial with the counterweight roller (9), and the counterweight is installed on the inner shaft of the counterweight.

5. The automatic docking rigid mechanical arm device for LNG port transmission system according to claim 1 is characterized in that: The middle arm rotation system comprises a hydraulic cylinder support (17) mounted on a column (18), a hydraulic cylinder (16) being mounted on the hydraulic cylinder support (17), the hydraulic cylinder (16) being connected to one end of a middle arm driving connecting rod (12), the other end of the middle arm driving connecting rod (12) moving in a groove of the middle arm (5), thereby driving the middle arm (5) to rotate up and down.

6. The automatic docking rigid mechanical arm device for LNG port transmission system according to claim 1 is characterized in that: The tensioning mechanism (3) comprises a motor (301) and a wire rope lifting device, wherein the motor (301) is mounted on a motor lifting support (302), and the lifting support (302) is mounted on the middle section of the middle arm near the forearm; the motor (301) is connected to a lead screw (315), and the lead screw (315) is connected to the wire rope lifting device.

7. The automatic docking rigid mechanical arm device for LNG port transmission system according to claim 6 is characterized in that: The wire rope lifting device comprises a base (311), wherein the base (311) is connected to a support frame 1 (317) and a support frame 2 (325) respectively through a group of support rods, wherein the support frame 1 (317) is fixedly mounted on an end of the lead screw (315) away from the motor, and the support frame 2 (325) is movably mounted on an end of the lead screw (315) close to the motor, wherein the support frame 1 (317) and the support frame 2 (325) are respectively connected to a roller support (320) through a group of support rods and a group of connecting rods, wherein each group of support rods and connecting rods has four members, and a support wheel (321) is mounted on the roller support (320) through a support shaft (322), wherein the support wheel (321) is in close contact with the wire rope, and when the motor is working, the support frame 2 (325) is rotated to drive the support frame 2 (325) to move, thereby raising the roller support (320) and lifting the wire rope, thereby achieving the purpose of tensioning.

8. An operating method of the automatic docking rigid mechanical arm device for LNG port transmission system as described in claims 1-7, characterized in that: The method comprises the following steps: Phase 1: When the LNG carrier arrives at the port and stays at the designated position, the hydraulic cylinder (16) drives the middle arm driving connecting rod (12) to control the middle arm (5) to start rotating. During this process, in order to ensure the overall balance of the discharge arm and reduce the load on the hydraulic cylinder (16), the tensioning mechanism (3) works to ensure that the transmission energy of the wire rope transmission mechanism (35) is transmitted to the roller (2) and the counterweight roller (9) at the forearm. The wire rope transmission mechanism (35) starts to work, and the counterweight inner shaft (11) and the counterweight (10) at the tail end of the middle arm (5) need to move simultaneously until the LNG discharge arm reaches the designated working position, and then further fine-tune the position while maintaining the static balance of the entire system; The second stage: the arm joint (37) starts to connect with the LNG carrier until the LNG is received. During this process, the LNG carrier may be slightly shaken by external factors such as sea waves. The connection device needs to be able to move with the LNG carrier. When the shaking degree or the displacement distance of the LNG carrier is too large, emergency separation can be performed. The third stage: when the liquefied natural gas transportation is completed, the arm joint (37) begins to separate from the LNG carrier; then the hydraulic cylinder (16) and the wire rope transmission mechanism (35) start to work, so that the LNG unloading arm returns to the standby position. This process is equivalent to the process of the first stage.

Images