A pumpless seabed mining conveying system

Abstract

The present invention discloses a pumpless seabed mining conveying system, comprising a surface ship, an underwater storage bin and a conveying device for conveying minerals in the underwater storage bin to the surface ship, the conveying device comprising a cable and a driving assembly arranged on the surface ship, the two ends of the cable are connected to the driving assembly, the middle part of the cable is wound around the underwater storage bin, and two lifting sections driven up and down by the driving assembly are formed between the underwater storage bin and the driving assembly; each lifting section is equipped with a lifting bin that can be carried by the lifting section to move between the surface ship and the underwater storage bin, and the lifting bin is provided with an openable and closable feeding mechanism for docking with the underwater storage bin to receive the minerals and an openable and closable discharging mechanism for discharging the minerals. The present invention has the advantages of simple structure, low cost, good working reliability and continuity, simple deployment, recovery and maintenance, and low requirements on the carrying capacity and performance of the surface ship.

Description

Technical Field

[0001] The invention relates to the technical field of underwater mining equipment, and in particular to a pumpless seabed mining and conveying system. Background Art

[0002] At present, the deep-sea mining system commonly used by various countries is: using the mother ship on the sea surface as the support platform of the system, the ship arranges the conveying hard pipe until it is several hundred meters away from the seabed, and the end of the hard pipe is connected to the intermediate warehouse, which is connected to the ore collection vehicle through a hose; the ore collection vehicle operates on the seabed, transports the collected ore to the intermediate warehouse, and then transports it to the surface through a pipeline system up to several thousand meters. This solution can continuously transport ore through pipelines with high transportation efficiency, but due to the existence of several thousand meters of hard pipe pipelines, it puts forward high requirements on the performance and carrying capacity of the ship; at the same time, the pump is easy to damage the impeller, guide vane and flow-through parts in the process of conveying ore particles, making it difficult to achieve long-term operation, and the replacement process is also complicated and difficult; and the layout of the hard pipe is complicated and time-consuming, especially in severe sea conditions, the ship's pipeline system will have great uncertainty. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a pumpless seabed mining and transportation system with simple structure, low cost, good working reliability and continuity, simple deployment, recovery and maintenance, and low requirements on the carrying capacity and performance of surface ships.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A pumpless seabed mining and conveying system comprises a surface vessel, an underwater storage bin and a conveying device for conveying minerals in the underwater storage bin to the surface vessel, the conveying device comprising a cable and a driving assembly arranged on the surface vessel, both ends of the cable are connected to the driving assembly, the middle portion of the cable is wound around the underwater storage bin, and two lifting sections driven up and down by the driving assembly are formed between the underwater storage bin and the driving assembly; each lifting section is equipped with a lifting bin that can be moved between the surface vessel and the underwater storage bin by the lifting section, and the lifting bin is provided with an openable and closable feeding mechanism for docking with the underwater storage bin to receive minerals and an openable and closable discharging mechanism for discharging the minerals.

[0006] As a further improvement of the above technical solution:

[0007] The underwater storage bin includes a cabin body with a storage cavity, and each lifting bin on the cabin body is provided with a discharge port connected to the storage cavity, and each discharge port is provided with an opening and closing control component for opening and closing the discharge port. The openable and closable feeding mechanism is a feeding mechanism that is driven to open by the opening and closing control component when the opening and closing control component opens the discharge port, and is driven to close by an elastic component when the opening and closing control component closes the discharge port.

[0008] The lifting bin includes a shell having an inner cavity, the openable and closable feeding mechanism includes a feeding port arranged on the shell and connected to the inner cavity, and a feeding control door hingedly mounted on the shell and capable of swinging around a hinge axis to open and close the feeding port, the feeding control door is connected to an elastic component that forces the feeding control door to swing to a state of closing the feeding port when the feeding control door is not subjected to external force, the opening and closing control assembly includes a discharging control door hingedly mounted on the cabin body and capable of swinging around a hinge axis to open and close the discharging port, and an opening and closing driving component for driving the discharging control door to swing, the feeding port is connected to the discharging port when the lifting bin is docked with the underwater storage bin, and the discharging control door forces the feeding control door to overcome the action of the elastic component and swing to open the feeding port when the discharging control door swings to open the discharging port.

[0009] The lifting bin includes a shell having an inner cavity, the openable and closable feeding mechanism includes a feeding port provided on the shell and connected to the inner cavity, and a feeding control door hingedly mounted on the shell and capable of swinging around a hinge axis to open and close the feeding port, and the openable and closable feeding mechanism also includes a feeding control component for controlling the swinging of the feeding control door.

[0010] The underwater storage bin comprises a cabin body with a storage cavity, and each lifting bin on the cabin body is provided with a discharge port connected with the storage cavity, and each discharge port is provided with an opening and closing control component for opening and closing the discharge port, and the opening and closing control component comprises a discharge control door hingedly mounted on the cabin body and capable of swinging around a hinge axis to open and close the discharge port, and an opening and closing driving member for driving the discharge control door to swing; the feed control door of the openable and closable feeding mechanism swings toward the inner cavity of the shell when opening the feed port, and the The unloading control door of the opening and closing control assembly swings toward the outside of the cabin when opening the unloading port; the feeding control assembly includes an elastic component and the unloading control door driven by the opening and closing drive component, the elastic component is connected to the feeding control door and forces the feeding control door to be in a closed feeding port state when the feeding control door is not subjected to external force, the feeding port is connected to the unloading port when the lifting bin is docked with the underwater storage bin, and when the unloading control door swings toward the outside of the cabin, it forces the feeding control door to overcome the action of the elastic component and swing to open the feeding port.

[0011] The storage cavity includes a main cavity and discharge cavities whose number is the same and one-to-one with the discharge ports. Each discharge cavity is located below the main cavity, each discharge port is communicated with the corresponding discharge cavity, and each discharge cavity is provided with an inclined guide surface for guiding the mineral in the main cavity to the discharge port.

[0012] The underwater storage bin also includes a feed pipe, one end of which serves as an ore inlet for connecting to a ore collection vehicle, and the other end of which serves as an ore outlet connected to the middle of the main cavity, and each unloading cavity is located around the main cavity.

[0013] The openable and closable discharge mechanism includes a discharge port disposed on the shell and connected to the inner cavity, and a discharge control door hingedly mounted on the shell and capable of swinging around a hinge axis to open and close the discharge port, and the discharge control door is connected to a swinging drive member for driving the discharge control door to swing.

[0014] The upper end and the lower end of the shell are both conical, the feed port is arranged at the upper end of the shell, and the discharge port is arranged at the lower end of the shell.

[0015] The shell is provided with a plurality of guide fins extending up and down, and the plurality of guide fins are arranged at intervals around the four sides of the shell.

[0016] The underwater material storage bin is provided with a positioning opening corresponding to each lifting bin for the lifting bin to be inserted and positioned when the lifting bin moves downward and docks with the underwater material storage bin.

[0017] The driving component is a winch, both ends of the cable are connected to the drum of the winch, and when the winch drives any one lifting section to move upward, it simultaneously drives another lifting section to move downward.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] The pumpless seabed mining and transportation system of the present invention uses a cable driven by a driving component to drive two lifting bins to move up and down, so that the lifting bin moves between the surface ship and the underwater storage bin. When the lifting bin moves to the underwater storage bin and docks with the underwater storage bin, the minerals in the underwater storage bin can be received by controlling the openable and closable feeding mechanism. When the lifting bin is loaded with minerals and moves to the surface ship, the minerals can be unloaded onto the surface ship by controlling the openable and closable discharging mechanism, thereby realizing the transportation of minerals in the underwater storage bin to the surface ship. The main structure of its transportation and transportation of minerals is only a cable, a driving component and a lifting bin. Compared with the prior art, it has the advantages of simple structure, low cost, good working reliability and continuity, and simple deployment, recovery and maintenance. It can greatly reduce the carrying capacity and performance requirements of surface ships. At the same time, it has high transportation safety and strong risk resistance, which can solve the problem of long-distance material transportation of deep-sea minerals in harsh environments, and will not cause environmental disturbances caused by the transportation of bottom seawater to the sea surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the main structure of a pumpless seabed mining and transportation system.

[0021] Figure 2 It is a partially enlarged structural schematic diagram of the conveying device when a lifting bin is connected to an underwater storage bin.

[0022] Figure 3 It is a partial enlarged structural schematic diagram of the conveying device when both lifting bins are not connected to the underwater storage bin.

[0023] Figure 4 The figure is a schematic diagram of the structure of the lifting bin.

[0024] Figure 5 It is a partial enlarged structural diagram of the docking of the lifting bin and the underwater storage bin.

[0025] Figure 6 for Figure 5 Enlarged structural diagram at A in the middle.

[0026] Legend:

[0027] 1. Surface vessel; 2. Underwater storage silo; 21. Cabin; 22. Storage cavity; 23. Discharge port; 24. Discharge control door; 25. Opening and closing drive member; 26. Feed pipe; 27. Positioning port; 3. Cable; 31. Lifting operation section; 4. Drive assembly; 5. Lifting bin; 51. Openable and closable feed mechanism; 511. Feed port; 512. Feed control door; 513. Elastic component; 52. Openable and closable discharge mechanism; 521. Discharge port; 522. Discharge control door; 53. Shell; 54. Guide fin. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] like Figures 1 to 4 As shown, the pumpless seabed mining and conveying system of this embodiment includes a surface ship 1, an underwater storage bin 2 and a conveying device for conveying minerals in the underwater storage bin 2 to the surface ship 1, the conveying device includes a cable 3 and a driving assembly 4 arranged on the surface ship 1, both ends of the cable 3 are connected to the driving assembly 4, the middle part of the cable 3 is wound around the underwater storage bin 2, and two lifting sections 31 driven by the driving assembly 4 to move up and down are formed between the underwater storage bin 2 and the driving assembly 4, each lifting section 31 is equipped with a lifting bin 5 that can be moved between the surface ship 1 and the underwater storage bin 2 by the lifting section 31, and the lifting bin 5 is provided with an openable and closable feeding mechanism 51 for docking with the underwater storage bin 2 to receive minerals and an openable and closable discharging mechanism 52 for discharging the minerals.

[0030] The pumpless seabed mining and transportation system uses a cable 3 driven by a driving component 4 to drive two lifting bins 5 to move up and down, so that the lifting bin 5 moves between the surface ship 1 and the underwater storage bin 2. When the lifting bin 5 moves to the underwater storage bin 2 and docks with the underwater storage bin 2, the minerals in the underwater storage bin 2 can be received by controlling the openable and closable feeding mechanism 51. When the lifting bin 5 is loaded with minerals and moves to the surface ship 1, the minerals can be unloaded onto the surface ship 1 by controlling the openable and closable discharging mechanism 52, thereby realizing the transportation of the minerals in the underwater storage bin 2 to the surface ship 1. The main structure of the transportation and transportation of minerals is only the cable 3, the driving component 4 and the lifting bin 5. Compared with the prior art, it has the advantages of simple structure, low cost, good working reliability and continuity, and simple deployment, recovery and maintenance. It can greatly reduce the carrying capacity and performance requirements of the surface ship 1. At the same time, it has high transportation safety and strong risk resistance, which can solve the problem of long-distance material transportation of deep-sea minerals in harsh environments, and will not cause the problem of environmental disturbance caused by the transportation of bottom seawater to the sea surface.

[0031] In this embodiment, the underwater storage bin 2 includes a cabin 21 with a storage cavity 22, and a discharge port 23 connected to the storage cavity 22 is provided on the cabin 21 corresponding to each lifting bin 5, and each discharge port 23 is provided with an opening and closing control component for opening and closing the discharge port 23, and the openable and closable feeding mechanism 51 is a feeding mechanism that is driven to open by the opening and closing control component when the opening and closing control component opens the discharge port 23, and is driven to close by the elastic component when the opening and closing control component closes the discharge port 23. The openable and closable feeding mechanism 51 does not need to be provided with a separate power drive, which can save costs, improve the simplicity and compactness of the structure, and reduce the difficulty of control. In addition, the openable and closable feeding mechanism 51 is opened synchronously during the opening of the discharge port 23, and the minerals in the underwater storage bin 2 can enter the lifting bin 5 in a timely, reliable, and leak-free manner.

[0032] In this embodiment, Figure 4 and Figure 5As shown, the lifting bin 5 includes a shell 53 with an inner cavity, the openable and closable feeding mechanism 51 includes a feeding port 511 arranged on the shell 53 and connected to the inner cavity, and a feeding control door 512 hingedly mounted on the shell 53 and capable of swinging around a hinge axis to open and close the feeding port 511, the feeding control door 512 is connected to an elastic component 513 for forcing the feeding control door 512 to swing to a state of closing the feeding port 511 when the feeding control door 512 is not subjected to external force, the opening and closing control assembly includes a discharge control door 24 hingedly mounted on the cabin 21 and capable of swinging around a hinge axis to open and close the discharge port 23, and an opening and closing driving member 25 for driving the discharge control door 24 to swing, the feeding port 511 is connected to the discharge port 23 when the lifting bin 5 is docked with the underwater storage bin 2, and when the discharge control door 24 swings toward the outside of the cabin 21, it forces the feeding control door 512 to overcome the action of the elastic component 513 and swing to open the feeding port 511 (see Figure 5 and Figure 6 That is, when the opening and closing driving member 25 drives the discharge control door 24 to swing open the discharge port 23, the discharge control door 24 swinging outward directly pushes the feed control door 512 to overcome the action of the elastic component 513 to swing to synchronously open the feed port 511, thereby realizing synchronous opening of the feed port 511 during the process of opening the discharge port 23 to discharge, and when the opening and closing driving member 25 drives the discharge control door 24 to swing close the discharge port 23, the elastic component 513 forces the feed control door 512 to swing to a state of closing the feed port 511. The above-mentioned openable and closable feeding mechanism 51 and the opening and closing control assembly have a simple structure, low cost, stable and reliable operation, and are easy to manufacture and maintain.

[0033] Preferably, the feed control door 512 of the openable and closable feeding mechanism 51 swings toward the inner cavity of the shell 53 when opening the feed port 511, and the unloading control door 24 of the opening and closing control assembly swings toward the outside of the cabin 21 when opening the unloading port 23. When the unloading control door 24 swings toward the outside of the cabin 21 to open the unloading port 23, it directly drives the feed control door 512 of the lifting bin 5 located outside the cabin 21 to swing toward the inner cavity of the shell 53 to open the feed port 511. While achieving synchronous control of the unloading control door 24 and the feed control door 512 using only the opening and closing drive component 25, the compactness of the overall structure is ensured.

[0034] Preferably, the elastic component 513 adopts a torsion spring. In other embodiments, the elastic component 513 may also adopt other elastic components that can force the feed control door 512 to be in a closed feed port 511 state when the feed control door 512 is not affected by external force, such as a telescopic spring. Preferably, the opening and closing drive 25 adopts a telescopic oil cylinder, and may also adopt other existing drive components such as a hydraulic motor, a telescopic air cylinder, and an electric push rod that can drive the unloading control door 24 to swing.

[0035] In this embodiment, the storage cavity 22 includes a main cavity and discharge cavities that are the same in number and correspond to the discharge ports 23. Each discharge cavity is located below the main cavity, each discharge port 23 is connected to the corresponding discharge cavity, and each discharge cavity is provided with an inclined material guide surface for guiding the minerals in the main cavity to the discharge port 23. This structure facilitates the minerals in the storage cavity 22 to enter the lifting bin 5.

[0036] In this embodiment, the underwater storage bin 2 further includes a feed pipe 26, one end of which is used as an inlet for connecting to a ore collecting vehicle, and the other end of which is used as an outlet for connecting to the middle of the main cavity, and each unloading cavity is located around the main cavity. The minerals collected by the ore collecting vehicle are transported to the middle of the main cavity through the feed pipe 26, and after entering the middle of the main cavity, the minerals move around and enter each unloading cavity, which is convenient for unloading the minerals.

[0037] In this embodiment, the openable and closable discharging mechanism 52 includes a discharging port 521 provided on the housing 53 and communicating with the inner cavity, and a discharging control door 522 hingedly mounted on the housing 53 and capable of swinging around a hinge axis to open and close the discharging port 521. The discharging control door 522 is connected to a swinging driving member (not shown in the figure) for driving the discharging control door 522 to swing. Preferably, the swinging driving member adopts a telescopic oil cylinder, and other existing driving members such as a hydraulic motor, a telescopic air cylinder, and an electric push rod that can drive the discharging control door 522 to swing can also be adopted. The swinging driving member drives the discharging control door 522 to swing, and the discharging port 521 can be opened and closed. The openable and closable discharging mechanism 52 has a simple structure, low cost, and stable and reliable operation.

[0038] In this embodiment, Figure 4 As shown, the upper and lower ends of the shell 53 are both tapered, which is beneficial to reducing the water resistance when the lifting bin 5 moves up and down. The feed port 511 is set at the upper end of the shell 53, and the discharge port 521 is set at the lower end of the shell 53, which is beneficial to the entry and discharge of minerals into the lifting bin 5.

[0039] In this embodiment, Figure 4 As shown, the shell 53 is provided with a plurality of guide fins 54 extending up and down. The plurality of guide fins 54 are arranged at intervals around the shell 53, which is beneficial to the direction control of the lifting bin 5 during the up and down movement and improves the stability.

[0040] In this embodiment, preferably, the upper and lower ends of the housing 53 are respectively provided with connecting rings to facilitate connection with the cable 3. The housing 53 is preferably a rectangular parallelepiped structure.

[0041] In this embodiment, Figure 5As shown, the underwater storage bin 2 is provided with a positioning port 27 corresponding to each lifting bin 5 for the lifting bin 5 to be inserted for positioning when the lifting bin 5 moves downward and docks with the underwater storage bin 2. When the lifting bin 5 moves downward, it can be inserted into the positioning port 27 and positioned, and the lifting bin 5 is positioned in a state of docking with the underwater storage bin 2, ensuring stable, reliable and smooth reception of minerals. At the same time, the positioning port 27 is used for positioning, and the lifting bin 5 is allowed to move upward, so as to realize positioning and releasing positioning in cooperation with the lifting bin 5 in the form of up and down movement, without any control mechanism, and its structure is simple, cost-effective and easy to control.

[0042] In this embodiment, the driving component 4 is a winch, and both ends of the cable 3 are connected to the drum of the winch, and when the winch drives any one lifting section 31 to move upward, it synchronously drives the other lifting section 31 to move downward. That is, the two ends of the cable 3 are respectively wound on the drum of the winch from the positive and negative directions. When the drum rotates in any direction, the lifting section 31 on one side moves upward, and the lifting section 31 on the other side moves downward. The running directions of the two lifting sections 31 are always opposite, so that when one lifting bin 5 moves upward, the other lifting bin 5 moves downward. This type of driving component 4 has a simple structure, which can greatly reduce the power required for material lifting, improve the force of the winch, and improve the lifting efficiency of the winch.

[0043] In this embodiment, fixed pulleys are provided on both the surface ship 1 and the underwater storage bin 2, and the cables 3 are wound around the fixed pulleys on the surface ship 1 and the underwater storage bin 2 to improve the stability and smoothness of the operation. In addition, the fixed pulleys on the surface ship 1 and the underwater storage bin 2 make the two lifting operation sections 31 spaced apart by a preset distance to ensure that the movements of the two lifting bins 5 do not interfere with each other. During the transportation process, the cables 3 are always kept in a tensioned state, and by controlling the distance between the two cables 3, it is ensured that the cables 3 do not get entangled.

[0044] The pumpless seabed mining and transportation system of this embodiment can lift the underwater storage bin 2 off the seabed by lifting the winch after completing the mineral collection in an area, and use the movement of the surface ship 1 to switch the mining area, and control the ore collection vehicle to move to the next mining area synchronously. In case of severe sea conditions, the cable 3 can be separated from the surface ship 1 and arranged on the sea surface with the buoy, and the surface ship 1 can leave the strong wind and wave area to avoid the wind and waves, and reconnect the cable after the sea conditions improve to continue the collection and transportation operation.

[0045] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and changes obtained without departing from the technical concept of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A pumpless seabed mining and transportation system, comprising a surface vessel (1), an underwater storage bin (2), and a transportation device for transporting minerals in the underwater storage bin (2) to the surface vessel (1), characterized in that: The conveying device comprises a cable (3) and a driving assembly (4) arranged on a surface ship (1), the two ends of the cable (3) are connected to the driving assembly (4), the middle part of the cable (3) is wound around the underwater storage bin (2), and two lifting sections (31) driven by the driving assembly (4) to move up and down are formed between the underwater storage bin (2) and the driving assembly (4), each lifting section (31) is equipped with a lifting bin (5) that can be moved between the surface ship (1) and the underwater storage bin (2) by the lifting section (31), and the lifting bin (5) is provided with an openable and closable feeding mechanism (51) for docking with the underwater storage bin (2) to receive minerals and an openable and closable discharging mechanism (52) for discharging the minerals; The underwater storage bin (2) comprises a cabin (21) having a storage cavity (22); each lifting bin (5) on the cabin (21) is provided with a discharge port (23) in communication with the storage cavity (22); each discharge port (23) is provided with an opening and closing control component for opening and closing the discharge port (23); the openable and closable feeding mechanism (51) is a feeding mechanism which is driven to open by the opening and closing control component when the opening and closing control component opens the discharge port (23), and is driven to close by an elastic component when the opening and closing control component closes the discharge port (23); The lifting bin (5) comprises a shell (53) having an inner cavity, the openable and closable feeding mechanism (51) comprises a feeding port (511) provided on the shell (53) and connected to the inner cavity, and a feeding control door (512) hingedly mounted on the shell (53) and capable of swinging about a hinge axis to open and close the feeding port (511), the feeding control door (512) being connected to an elastic component (513) for forcing the feeding control door (512) to swing to a state of closing the feeding port (511) when the feeding control door (512) is not subjected to an external force, and the opening and closing control door (512) is The assembly comprises a discharge control door (24) hingedly mounted on the cabin (21) and capable of swinging about a hinge axis to open and close the discharge port (23), and an opening and closing driving member (25) for driving the discharge control door (24) to swing; when the lifting bin (5) is docked with the underwater storage bin (2), the feed port (511) is connected to the discharge port (23), and when the discharge control door (24) swings to open the discharge port (23), the feed control door (512) is forced to swing against the action of the elastic member (513) to open the feed port (511); The storage cavity (22) comprises a main cavity and discharge cavities that are the same in number and correspond one to one with the discharge ports (23), each discharge cavity is located below the main cavity, each discharge port (23) is communicated with the corresponding discharge cavity, and each discharge cavity is provided with an inclined material guide surface for guiding the mineral in the main cavity to the discharge port (23); The underwater material storage bin (2) is provided with a positioning opening (27) corresponding to each lifting bin (5) for the lifting bin (5) to be inserted and positioned when the lifting bin (5) moves downward to dock with the underwater material storage bin (2).

2. The pumpless seabed mining and transportation system according to claim 1, characterized in that: The underwater storage bin (2) further comprises a feed pipe (26), one end of the feed pipe (26) serving as an ore inlet for connection with a ore collection vehicle, and the other end of the feed pipe (26) serving as an ore outlet for connection with the middle of the main cavity, and each unloading cavity is located around the main cavity.

3. The pumpless seabed mining and transportation system according to claim 1, characterized in that: The openable and closable discharge mechanism (52) comprises a discharge port (521) provided on the housing (53) and communicating with the inner cavity, and a discharge control door (522) hingedly mounted on the housing (53) and capable of swinging about a hinge axis to open and close the discharge port (521); the discharge control door (522) is connected to a swing driving member for driving the discharge control door (522) to swing.

4. The pumpless seabed mining and transportation system according to claim 3 is characterized in that: The upper end and the lower end of the shell (53) are both conical, the feed port (511) is arranged at the upper end of the shell (53), and the discharge port (521) is arranged at the lower end of the shell (53).

5. The pumpless seabed mining and transportation system according to claim 1, characterized in that: The shell (53) is provided with a plurality of guide fins (54) extending up and down, and the plurality of guide fins (54) are arranged at intervals around the four sides of the shell (53).

6. The pumpless seabed mining and conveying system according to any one of claims 1 to 5, characterized in that: The driving component (4) is a winch, both ends of the rope (3) are connected to the drum of the winch, and when the winch drives any one lifting section (31) to move upward, it simultaneously drives another lifting section (31) to move downward.

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