Marine lifting platform and marine lifting device

Abstract

The invention belongs to the field of marine lifters, and particularly relates to a marine lifting platform and a marine lifting device. In order to improve the bearing capacity, the marine lifting platform comprises a platform body and a connecting part used for being in transmission connection with a lifting mechanism, the left side and the right side of the platform body are each provided with a set of righting rollers, each set of righting rollers comprises at least two righting rollers which are arranged up and down, and the connecting part is located on the vertical plane where the rolling axes of all the righting rollers are located; the front side and the rear side of each centralizing roller are used for being in guiding fit with the guide rail in the vertical direction, at least the outer sides or at least the inner sides of the two centralizing rollers are provided with limiting rings, and the inner side faces or the outer side faces of the limiting rings are used for being in stopping fit with the guide rail in the horizontal direction. The invention further provides a marine lifting device comprising the marine lifting platform. Limiting and guiding of the table body are achieved through cooperation of the two sets of righting rollers on the left side and the right side and the guide rails, so that it is guaranteed that the table body can ascend and descend normally when the table body is in an unbalance loading state, and the bearing capacity is improved.

Description

Technical Field

[0001] This invention belongs to the field of marine elevators, and in particular relates to a marine lifting platform and a marine lifting device. Background Technology

[0002] In the original technology, elevators were generally installed on land (e.g., Chinese utility model patent CN206767553U, authorized on December 19, 2017) for vertical transport of supplies. For ships, it is also inevitable to transport supplies such as living necessities between two decks. Due to the swaying nature of ships and the significant passageway obstruction caused by elevators, scissor lifts with wheels are commonly used to transport supplies, and can be removed after transport. However, scissor lifts suffer from problems such as large size, low transmission efficiency, high maintenance costs, significant swaying during lifting, and environmental pollution caused by hydraulic oil leakage.

[0003] To address some of the aforementioned technical problems, those skilled in the art have modified the elevator to enable its application on ships. For example, Chinese invention patent application CN112357815A, published on February 12, 2021, discloses a marine elevator platform. This platform includes an eccentrically arranged platform to reduce the area occupied by the platform in the passageway, ensuring a sufficiently large passage area. Simultaneously, the platform is equipped with a first limiting roller to overcome the overturning moment caused by the platform's eccentric loading, preventing lateral swaying and ensuring stable transport of materials. The platform is also equipped with a second limiting roller to further limit the platform's movement, overcoming the overturning moment caused by the platform's own weight and the materials transported, thus improving the platform's stability and safety.

[0004] However, on the one hand, the aforementioned marine lifting platforms use hydraulic cylinders and pulley blocks for drive, which are prone to oil leakage and cause environmental pollution; on the other hand, the weight of the materials and the entire weight of the lifting platform contribute to the overturning moment. When the overturning moment that the lifting platform can withstand is certain, the rated load capacity of the lifting platform is relatively small, and the weight of materials that can be transported at one time is relatively small. Summary of the Invention

[0005] The present invention also aims to provide a marine lifting platform to solve the technical problem of the small rated load capacity of existing marine lifting platforms.

[0006] The purpose of this invention is to provide a marine lifting device to solve the same technical problems mentioned above.

[0007] To achieve the above objectives, the technical solution for the marine lifting platform provided by this invention is as follows: A marine lifting platform includes a platform for supporting objects and a connecting part for transmission connection with a lifting mechanism that drives the platform to lift. A set of straightening rollers is provided on both the left and right sides of the platform, and each set of straightening rollers includes at least two straightening rollers arranged vertically. The connecting part is located on the vertical plane containing the rolling axes of all the straightening rollers. The front and rear sides of each straightening roller are used for guiding and engaging with a guide rail in the vertical direction. At least the outer or inner side of each set of straightening rollers has a limiting ring. The inner or outer side of the limiting ring is used for stopping and engaging with the guide rail in the left and right direction to limit the left and right position of the platform. The vertical plane containing the rolling axes of the straightening rollers is at different distances from the front and rear ends of the platform to achieve eccentric loading of the platform.

[0008] Furthermore, the ratio of the distances L1 to L2 between the vertical plane containing the rolling axis of the straightening roller and the front and rear ends of the platform satisfies: 1:1 < L1:L2 < 4:1.

[0009] Furthermore, the connecting part is at the same height as the center of the same set of straightening rollers, and the connecting part is located on the outside of the two sets of straightening rollers.

[0010] Furthermore, each of the straightening rollers is provided with a limiting ring on both the left and right sides.

[0011] Furthermore, the connecting part includes connecting pins for passing through the chain holes in the chain of the lifting mechanism. At least two connecting pins are provided on the left and right sides of the platform, and on either the left or right side of the platform, the midpoint of all connecting pins is at the same height as the midpoint of all the straightening rollers in the same set of straightening rollers.

[0012] The beneficial effects of the marine lifting platform provided by this invention are as follows: the limiting ring cooperates with the guide rail to achieve left and right limiting; the front and rear sides of the two sets of rollers cooperate with the guide rail to achieve front and rear limiting and anti-tipping; and finally, the two sets of straightening rollers cooperate with the guide rail to achieve limiting and guiding of the platform body, ensuring that the platform body can be raised and lowered normally when it is under eccentric load. At the same time, there are parts of the platform body on both the front and rear sides of the vertical plane where the rolling axis of the straightening rollers is located, which can reduce the eccentric load and enable the marine lifting platform to carry heavier cargo.

[0013] Furthermore, by using multiple connecting pins inserted into the chain holes, the position of the lifting platform can be better limited, ensuring the fit tolerance between the straightening rollers and the guide rails, and ensuring the smooth lifting of the platform.

[0014] To achieve the above objectives, the technical solution of the marine lifting device provided by the present invention is as follows: A marine lifting device includes a lifting platform, a lifting mechanism for driving the lifting platform to move up and down, and a guiding mechanism for guiding the vertical movement of the lifting platform. The guiding mechanism includes vertically extending guide rails. The lifting platform includes a platform for supporting an object and a connecting part for transmission connection with the lifting mechanism that drives the platform to move up and down. A set of straightening rollers is provided on both the left and right sides of the platform. Each set of straightening rollers includes at least two straightening rollers arranged vertically. The connecting part is located on the vertical plane containing the rolling axes of all the straightening rollers. The front and rear sides of each straightening roller are used for guiding and engaging with the guide rails in the vertical direction. At least the outer or inner side of each set of straightening rollers has a limiting ring. The inner or outer side of the limiting ring is used for stopping the guide rails in the left and right direction to limit the left and right position of the platform. The vertical plane containing the rolling axes of the straightening rollers is at different distances from the front and rear ends of the platform to achieve eccentric loading of the platform.

[0015] Furthermore, in the forward and backward direction, let L1 be the distance from the vertical plane containing the rolling axis of the straightening roller to the end of the platform away from the side wall of the cabin, and L2 be the distance from the other end of the platform. Then, 1:1 < L1:L2 < 4:1.

[0016] Furthermore, the guide rail is an annular guide rail with a notch, the straightening roller is disposed at the notch and cooperates with the guide rail for guidance, the connecting part is at the same height as the center of the same set of straightening rollers, and the connecting part is located outside the two sets of straightening rollers and within the receiving cavity enclosed by the annular guide rail.

[0017] Furthermore, the lifting mechanism includes a sprocket and chain mechanism located within the receiving cavity. The sprocket and chain mechanism includes sprockets located at the upper and lower ends of the receiving cavity and chains that are connected to the sprockets for transmission. The connecting part includes connecting pins that pass through the chain holes to drive the lifting mechanism and the marine lifting platform. At least two connecting pins are provided on the left and right sides of the platform body, and on either the left or right side of the platform body, the midpoint of all connecting pins is at the same height as the midpoint of all the straightening rollers in the same set of straightening rollers.

[0018] Furthermore, each straightening roller is equipped with a limit ring on both the left and right sides.

[0019] The beneficial effects of the marine lifting device provided by this invention are as follows: the limiting ring cooperates with the guide rail to achieve left and right limiting; the front and rear sides of the two sets of rollers cooperate with the guide rail to achieve front and rear limiting and anti-tipping; and finally, the two sets of straightening rollers cooperate with the guide rail to achieve limiting and guiding of the platform, ensuring that the platform can be raised and lowered normally when it is under eccentric load. At the same time, there are parts of the platform on both the front and rear sides of the vertical plane where the rolling axis of the straightening rollers is located, which can reduce the eccentric load and enable the marine lifting platform to carry heavier cargo.

[0020] Furthermore, by using multiple connecting pins inserted into the chain holes, the position of the lifting platform can be better limited, ensuring the fit tolerance between the straightening rollers and the guide rails, and ensuring the smooth lifting of the platform. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a marine lifting device. Figure 2 This is a front view of the marine lifting device when the lifting platform is at its lowest position. Figure 3 This is a front view of the marine lifting device when the lifting platform is at its highest position. Figure 4 A side view of the marine lifting device when the lifting platform is at its highest position; Figure 5 This is a partial structural diagram of the lifting mechanism (the chain and the sprocket located at the upper end of the receiving cavity are omitted). Figure 6 This is a schematic diagram of the guiding mechanism; Figure 7 This is a structural schematic diagram of the lifting platform; Figure 8 This is a top view of the lifting platform; Figure 9 This is a schematic diagram of the structure when the lifting platform is used in conjunction with the circular guide rail. Figure 10 This is a schematic diagram of the structure when the straightening roller is engaged with the circular guide rail.

[0022] Explanation of reference numerals in the attached figures: 1. Base; 2. Lifting mechanism; 2-1. Motor; 2-2. Reducer; 2-3. Coupling; 2-4. Sprocket; 3. Lifting platform; 3-1. Straightening roller; 3-1-1. Limit ring; 3-1-2. Wheel body; 3-2. Connecting pin; 3-3. Platform body; 3-3-1. Roller; 3-4. Locking mechanism; 3-5. Block; 4. Baffle mechanism; 5. Operating platform; 6. Quick-release fence; 7. Guide rail; 7-1. Receiving cavity; 8. Support structure; 8-1. Diagonal brace; 8-2. Longitudinal brace; 8-3. Horizontal brace; 8-4. Adapter block; 9. Stop block; 10. First protective cover; 11. Second protective cover; 12. Connecting plate; 13. Support; 14. Offset axis; 15. Central axis; A. First mating area; B. Second mating area; C. Third mating area; D. Fourth mating area. Detailed Implementation

[0023] To address the problems in the background art, the core inventive concept of this invention is as follows: two sets of straightening rollers that cooperate with the guide rail for guidance and limiting are arranged on the left and right sides of the platform, and the transmission connection between the platform and the lifting mechanism is located on the vertical plane where the rolling axis of the straightening rollers is located. On the one hand, this can prevent the platform from moving back and forth and left and right; on the other hand, it can achieve off-center loading of the platform, improve the passage of the channel, and the parts of the platform on the front and rear sides of the vertical plane can support the goods, thereby improving the conveying capacity.

[0024] Furthermore, the fit between the connecting pin and the chain is used to limit the tolerance between the straightening roller and the guide rail, so as to ensure the smooth operation of the lifting platform.

[0025] In this invention, the extension direction of the rolling axis of the straightening roller is defined as the left-right direction. Depending on the observer's orientation, this left-right direction can be the actual front-back direction. The observer can rotate their orientation to make the left-right direction in this invention the same as the actual left-right direction.

[0026] The present invention will be further described in detail below with reference to the embodiments.

[0027] Embodiments of the marine lifting device provided by the present invention: like Figures 1-10 As shown, the marine lifting device includes a lifting platform 3, a lifting mechanism 2 for driving the lifting platform 3 to rise and fall, and a guide mechanism for guiding the vertical movement of the lifting platform 3. The guide mechanism includes vertically extending guide rails 7. The lifting platform 3 includes a platform 3-3 for supporting objects and a connecting part for transmission connection with the lifting mechanism 2 that drives the platform 3-3 to rise and fall. A set of straightening rollers 3-1 is provided on both the left and right sides of the platform 3-3. Each set of straightening rollers 3-1 includes at least two straightening rollers 3-1 arranged vertically. The connecting part is located on the vertical plane where the rolling axes of all the straightening rollers 3-1 are located. The front and rear sides of each straightening roller 3-1 are used for guiding and cooperating with the guide rails 7 in the vertical direction, and at least the outer or inner side of each set of straightening rollers 3-1 has a limiting ring 3-. 1-1, The inner or outer side of the limiting ring 3-1-1 is used to cooperate with the guide rail 7 in the left and right direction to limit the left and right position of the platform 3-3; the vertical plane where the rolling axis of the straightening roller 3-1 is located is at different distances from the front and rear ends of the platform 3-3 to achieve the off-center loading of the platform 3-3. Specifically, in the front and rear direction, the distance from the end of the platform 3-3 away from the side wall of the compartment where the rolling axis of the straightening roller 3-1 is located is defined as L1, and the distance from the other end of the platform 3-3 is defined as L2, then 1:1 < L1:L2 < 4:1. Figure 8 As shown, at this time, the off-center load axis 14 does not coincide with the central axis 15 of the platform 3-3, and the off-center load axis 14 is located on the vertical plane where the rolling axes of all the straightening rollers 3-1 are located.

[0028] exist Figures 1-10 In this configuration, each set of centering rollers 3-1 consists of two centering rollers 3-1, but can also have three, four, or more. Limiting rings 3-1-1 are provided on both the left and right sides of the centering rollers 3-1 to restrict the left and right positions of the platform 3-3. However, limiting rings 3-1-1 can also be provided only on the inner side of all centering rollers 3-1 (the side closest to the platform 3-3, i.e., the left side of the right-side centering roller 3-1 and the right side of the left-side centering roller 3-1), or only on the outer side of all centering rollers 3-1 (the side furthest from the platform 3-3, i.e., the right side of the right-side centering roller 3-1 and the left side of the left-side centering roller 3-1). The lifting mechanism 2 can be a winch lifting mechanism (the winch's wire rope is connected to the lifting platform, the connection point being the connecting part) or a sprocket and chain lifting mechanism, etc. The specific ratio of L1:L2 can be 2:1, 2.5:1 (i.e. 5:2) or 3:1, or 3:2 < L1:L2 < 2:1, and L1:L2 can be 8:5 or 9:5.

[0029] From an engineering practice perspective, firstly, determine the front-to-back length of the lifting platform 3, i.e., determine the sum of the lengths L1 and L2; then, keeping the sum of the lengths L1 and L2 constant, arrange the lifting platform 3 as close to the wall as possible in the front-to-back direction; finally, arrange the lifting mechanism 2 as close to the wall as possible in the front-to-back direction, with a larger ratio of L1 to L2, the closer the lifting mechanism 2 is to the wall. In actual engineering, the space occupied by the lifting mechanism 2 needs to be comprehensively considered to determine the ratio of L1 to L2.

[0030] In use, supplies such as daily necessities can be placed on the platform 3-3, and the lifting mechanism 2 drives the lifting platform 3 to move between the two decks to transfer supplies. When the lifting platform 3 is raised or lowered, the wheels 3-1-2 of the two sets of straightening rollers 3-1 can cooperate with the guide rail 7 to prevent the lifting platform 3 from tipping over. At the same time, the limiting rings 3-1-1 of the straightening rollers 3-1 can cooperate with the guide rail 7 to limit the left and right movement of the lifting platform 3, so that the lifting platform 3 can be raised and lowered vertically.

[0031] Two sets of straightening rollers 3-1 are installed on the left and right sides of the platform 3-3, which cooperate with the guide rail 7 for guidance and limiting. The transmission connection between the platform 3-3 and the lifting mechanism 2 is located on the vertical plane where the rolling axis of the straightening rollers 3-1 is located. On the one hand, this can prevent the platform 3-3 from moving back and forth and left and right. On the other hand, it can realize the off-center loading of the platform 3-3, improve the passage of the channel, and the parts of the platform 3-3 on the front and rear sides of the vertical plane can support the goods with a small off-center load, thus improving the conveying capacity.

[0032] like Figure 10As shown, in the left-right direction, the limiting ring 3-1-1 of the straightening roller 3-1 and the guide rail 7 have a first mating area A and a second mating area B. In the front-back direction, the wheel body 3-1-2 of the straightening roller 3-1 and the guide rail 7 have a third mating area C and a fourth mating area D. During the design process, it is necessary to properly handle the four mating areas. If the mating areas are too tight, the lifting platform 3 will experience sluggish operation and excessive noise, resulting in uneven operation of the entire device. If the mating areas are too loose, the lifting platform 3 will tilt forward and experience significant swaying in all directions, resulting in unstable operation of the entire device.

[0033] During the design process, the fit tolerance of the contact surface between the straightening roller 3-1 and the guide rail 7 must be strictly controlled. This can be achieved through rigorous simulation analysis and finite element analysis. During the production process, the process flow must be strictly controlled so that the fit of each contact surface between the straightening roller 3-1 and the guide rail 7 can be strictly controlled.

[0034] In addition, measures such as connecting the lifting platform 3 with multiple joints at the sprocket and chain mechanism are taken to control the fit tolerances in each fit area.

[0035] In a preferred embodiment, such as Figure 10 As shown, the guide rail 7 is an annular guide rail with a notch (specifically a C-shaped guide rail). The straightening roller 3-1 is located at the notch and guides and cooperates with the guide rail 7. The connecting part is at the same height as the center of the same set of straightening rollers 3-1, and the connecting part is located outside the two sets of straightening rollers 3-1 and inside the receiving cavity 7-1 surrounded by the annular guide rail. The structure is simple and can provide protection for the connecting part located inside the receiving cavity 7-1.

[0036] like Figure 6 As shown, the guide structure also includes a support structure 8 and a support 13 for supporting the guide rail 7. The support structure 8 includes a diagonal brace 8-1, a horizontal brace 8-3, and a longitudinal brace 8-2. The diagonal brace 8-1 and the longitudinal brace 8-2 can be connected to the cabin wall through a transition block 8-4. The transition block 8-4 can be welded and fixed to the cabin. The diagonal brace 8-1 and the longitudinal brace 8-2 are bolted to the transition block 8-4. The two ends of the horizontal brace 8-3 are bolted to the two annular guide rails respectively. The support 13 is fixed on the cabin deck and is fixedly connected to the bottom of the annular guide rail through a connecting plate 12.

[0037] In a preferred embodiment, such as Figures 7-10As shown, the lifting mechanism 2 includes a sprocket and chain mechanism located within the receiving cavity 7-1. The sprocket and chain mechanism includes sprockets 2-4 located at the upper and lower ends of the receiving cavity 7-1 and a chain that is drivenly connected to the sprockets 2-4. The connecting part includes a connecting pin 3-2 passing through the chain hole to drively connect the lifting mechanism 2 and the marine lifting platform 3. At least two connecting pins 3-2 are respectively provided on the left and right sides of the platform 3-3. Figure 7 Specifically, there are two (in the middle), and on either the left or right side of the platform 3-3, the midpoint of all connecting pins 3-2 is at the same height as the midpoint of all straightening rollers 3-1 in the same group of straightening rollers 3-1, so as to better position the relative position of the straightening rollers 3-1 and the annular guide rail, thereby making the fit tolerance of each mating area more accurate.

[0038] The following section will cover topics not mentioned above.

[0039] like Figures 1-5 As shown, the marine lifting device also includes a base 1, and the lifting mechanism 2 further includes a drive mechanism for driving the sprocket and chain mechanism. The drive mechanism includes a motor 2-1, a reducer 2-2, a coupling 2-3, and a drive shaft connected in sequence. The sprocket 2-4 is driven onto the drive shaft so that the motor 2-1 drives the sprocket 2-4 to rotate. To ensure chain tension, a tensioning device commonly used in the art for tensioning chains can also be provided.

[0040] To prevent injury from the moving parts in the lifting mechanism 2, the marine lifting device also includes a first protective cover 10 and a second protective cover 11. The first protective cover 10 covers the guide rail 7, and the second protective cover 11 covers the base 1 to protect the moving parts and prevent injury.

[0041] In the above embodiment, the upper surface of the platform 3-3 is flat. When using it, the object needs to be lifted away. To facilitate the transportation of the object, as follows: Figures 1-10 As shown, in daily use, supplies such as daily necessities can be packed into boxes, which are then placed on rollers 3-3-1 of platform 3-3. A baffle mechanism 4 limits the position of the boxes, and a locking mechanism 3-4 locks their position to prevent accidental movement during lifting. The baffle of the baffle mechanism 4 can move up and down via a linkage mechanism and motor drive. When the baffle descends, the boxes can be moved horizontally by the rollers 3-3-1 for easy handling, and when the baffle rises, it prevents the boxes from moving. The locking mechanism 3-4 can be a spring-loaded locking pin, with corresponding locking holes on the boxes.

[0042] To ensure safety, a quick-release railing 6 is installed at the operating platform 5 on the upper deck to prevent personnel from falling into the pit corresponding to the lifting platform 3. The quick-release railing 6 includes the railing body and a quick-release mechanism connecting the railing body to the deck. When not transporting materials, the railing body can be lowered using the quick-release mechanism to reduce the space occupied by the railing body on the deck height. When transporting materials, the railing body is then erected. It should be noted that when not transporting materials, the lifting platform 3 can be in its highest position, or a warning tape can be installed at the pit corresponding to the lifting platform 3 to prevent accidental falls.

[0043] like Figure 7 As shown, the lifting platform 3 includes a platform body 3-3 and roller frames installed on the left and right sides of the platform body 3-3. The rollers and connecting pins 3-2 are both installed on the roller frames. The roller frames are fixedly connected to the platform body 3-3, and reinforcing ribs can be set between the roller frames and the platform body 3-3 to improve the structural strength and ensure the fit clearance at each mating area.

[0044] like Figures 1-3 As shown, the lifting platform 3 includes a collision block 3-5, and a stop block 9 is fixedly connected to the side wall of the compartment to limit the highest limit position of the lifting platform 3. When the lifting platform 3 rises to the highest position, the collision block 3-5 collides with the stop block 9 to limit the highest limit position of the lifting platform 3.

[0045] In this invention, when those skilled in the art know that adjacent components are connected by a fixed connection or other connection method, they can know which method to use to achieve this, and will not be elaborated here.

[0046] It should be noted that the marine lifting device in this invention operates in an open marine environment, so it needs to be able to resist the corrosion of marine climate (such as rain, seawater, mold and salt spray). Specifically, the main body is made of 316 stainless steel, the surface of the structural parts is treated with anti-corrosion, and a protective cover is added to improve the corrosion resistance. All electrical components are made of products suitable for marine environments.

[0047] In addition to protective designs, the electrical control system also emphasizes electromagnetic compatibility (EMC) design. For example, special shielding materials are added to the control box, and filters are installed inside the box to ensure its EMC performance. These measures enable the control box to withstand harsh environments such as rain, seawater, mold, and salt spray, while also providing strong electromagnetic shielding.

[0048] An embodiment of the marine lifting platform provided by the present invention: The marine lifting platform is the lifting platform 3 in the embodiment of the marine lifting device of the present invention, and will not be described in detail here.

[0049] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features, or organically combine different embodiments to create the embodiments shown in the accompanying drawings. Of course, those skilled in the art can also create other embodiments not shown in the accompanying drawings. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A marine lifting platform, comprising a platform for supporting objects and a connecting part for transmission connection with a lifting mechanism that drives the platform to lift, characterized in that, The platform has a set of straightening rollers on both the left and right sides. Each set of straightening rollers includes at least two straightening rollers arranged vertically. The connecting part is located on the vertical plane where the rolling axes of all the straightening rollers are located. The front and rear sides of each straightening roller are used to guide and cooperate with the guide rail in the vertical direction. At least the outer or inner side of each set of straightening rollers has a limiting ring. The inner or outer side of the limiting ring is used to stop and cooperate with the guide rail in the horizontal direction to limit the left and right position of the platform. The vertical plane where the rolling axes of the straightening rollers are located is at a different distance from the front and rear ends of the platform to achieve the eccentric loading of the platform.

2. The marine lifting platform as described in claim 1, characterized in that, The ratio of the distances L1 to L2 between the vertical plane containing the rolling axis of the straightening roller and the front and rear ends of the platform satisfies: 1:1 < L1:L2 < 4:

1.

3. The marine lifting platform as described in claim 1, characterized in that, The connecting part is at the same height as the center of the same set of straightening rollers, and the connecting part is located on the outside of the two sets of straightening rollers.

4. The marine lifting platform as described in claim 1, characterized in that, Each straightening roller is equipped with a limiting ring on both its left and right sides.

5. The marine lifting platform as described in any one of claims 1 to 4, characterized in that, The connecting part includes connecting pins for passing through the chain holes in the chain of the lifting mechanism. At least two connecting pins are provided on the left and right sides of the platform, and on either the left or right side of the platform, the midpoint of all connecting pins is at the same height as the midpoint of all the straightening rollers in the same set of straightening rollers.

6. A marine lifting device, comprising a lifting platform, a lifting mechanism for driving the lifting platform to move up and down, and a guiding mechanism for guiding the vertical movement of the lifting platform, characterized in that, The guiding mechanism includes vertically extending guide rails, and the lifting platform is the marine lifting platform as described in claim 1.

7. The marine lifting device as described in claim 6, characterized in that, In the forward and backward direction, let L1 be the distance from the vertical plane containing the rolling axis of the straightening roller to the end of the platform away from the side wall of the cabin, and L2 be the distance from the other end of the platform. Then 1:1 < L1:L2 < 4:

1.

8. The marine lifting device as described in claim 6, characterized in that, The guide rail is a ring-shaped guide rail with a notch. The straightening roller is located at the notch and cooperates with the guide rail for guidance. The connecting part is at the same height as the center of the same set of straightening rollers, and the connecting part is located outside the two sets of straightening rollers and within the receiving cavity enclosed by the ring-shaped guide rail.

9. The marine lifting device as described in claim 8, characterized in that, The lifting mechanism includes a sprocket and chain mechanism located within the receiving cavity. The sprocket and chain mechanism includes sprockets located at the upper and lower ends of the receiving cavity and chains that are connected to the sprockets for transmission. The connecting part includes connecting pins that pass through the chain holes to drive the lifting mechanism and the marine lifting platform. At least two connecting pins are provided on the left and right sides of the platform body, and on either the left or right side of the platform body, the midpoint of all connecting pins is at the same height as the midpoint of all the straightening rollers in the same set of straightening rollers.

10. The marine lifting device as described in any one of claims 6 to 9, characterized in that, Each straightening roller is equipped with a limit ring on both the left and right sides.

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