A semi-submersible ship shaft and rudder system structure

Abstract

This application relates to the field of ship design technology, and in particular to a semi-submersible rudder system structure. It includes: a rudder arm connecting the rudder blade and the stern shaft; a connecting assembly including at least a hydraulic nut and a detachable plate connecting the stern shaft to the rudder arm; the detachable plate has a disassembly hole, the maximum width of which is not less than the diameter of the stern shaft, and the end of the stern shaft passes through the disassembly hole. This allows for convenient disassembly of the stern shaft without disassembling the rudder blade.

Description

Technical Field

[0001] This application relates to the field of ship design technology, and in particular to a shaft and rudder system structure for a semi-submersible ship. Background Technology

[0002] Semi-submersible vessels, as large marine engineering vessels for special purposes, are widely used for transporting ultra-heavy cargo such as offshore drilling platforms and large structural components. Their propulsion shafting is typically designed to be quite long, with the stern shaft passing through the stern tube for installation. The propeller and related accessories are mounted at the end of the stern shaft, and the rudder for steering is located directly behind the propeller. During vessel operation and maintenance, when the stern shaft needs to be removed for repair or replacement due to wear, corrosion, or other mechanical failures, the propeller and its accessories must first be removed, and then the rudder blades located directly behind the shafting must be removed to eliminate obstacles to axial extraction before the stern shaft can be pulled aft along the stern tube.

[0003] Large ships typically use a conical hydraulic connection between the rudder blade and the rudder stock. While this connection structure ensures reliable transmission of high torque, its assembly and disassembly process is complex and requires extremely high precision in hydraulic tooling and operation. Even more challenging is the fact that the rudder blades of large semi-submersible vessels often weigh tens of tons, and their installation location is in the narrow space at the bottom of the stern, often surrounded by the hull structure.

[0004] Under these conditions, large dock cranes, either due to height limitations or insufficient lifting capacity, cannot directly assist in the lifting of the rudder blade. In actual maintenance, only temporary welded eyeplates to the hull structure, combined with simple lifting tools such as hand-operated hoists, can be used for manual lifting, translation, and transfer. This method is not only extremely labor-intensive and risky, but also extremely inefficient. After the shafting repair is completed, the rudder blade must be reinstalled using the same tedious process. In practice, the difficulty and time spent on disassembling and assembling the rudder blade often exceed the time required for the stern shaft repair itself, significantly increasing ship maintenance costs, extending dock repair cycles, and severely impacting the ship's operational economy. Summary of the Invention

[0005] Therefore, it is necessary to provide a semi-submersible shaft and rudder system structure that allows for easy disassembly of the stern shaft without removing the rudder blades.

[0006] To solve the above-mentioned technical problems, this application provides the following technical solution: A semi-submersible vessel shaft and rudder system structure includes: The rudder arm connects the rudder blades and the stern shaft; The connecting assembly includes at least a hydraulic nut and a detachable plate for connecting the stern shaft to the rudder arm; The detachable plate has a disassembly hole, the maximum width of which is not less than the diameter of the stern shaft, and the end of the stern shaft passes through the disassembly hole.

[0007] Understandably, when stern shaft maintenance is required, the operator first releases the electrical limit of the rudder, allowing the rudder blade to continue rotating from its working angle until it reaches the enlarged mechanical limit. Because the detachable plate has a disassembly hole, and the maximum width of this hole has a preset relationship with the rudder blade deflection angle, when the rudder blade rotates to its maximum limit, the projected width of the disassembly hole along the stern shaft axis is greater than the stern shaft diameter. This provides sufficient clearance for the stern shaft to be pulled back without removing the rudder blade. This completely avoids the mechanical interference between the rudder pin and the stern shaft in traditional structures. Throughout the process, it is unnecessary to remove the rudder blade, which weighs tens of tons, or to use a large crane for high-risk, high-difficulty lifting operations. Only simple hydraulic release and manual plate disassembly are required, significantly reducing maintenance labor intensity, shortening the dock repair cycle, and allowing for convenient stern shaft disassembly without removing the rudder blade.

[0008] In one embodiment, the rudder arm is connected to the hydraulic nut via a rudder pin.

[0009] In one embodiment, the height of the end wall of the rudder pin near the stern shaft is higher than the height of the highest point of the stern shaft.

[0010] In one embodiment, the detachable plate is rotated such that the maximum projected width of the detachment hole along the stern shaft axis is not less than the diameter of the stern shaft.

[0011] In one embodiment, the mechanical limiting angle of the rudder blade is greater than the electrical limiting angle, which is greater than the operating angle.

[0012] In one embodiment, the maximum mechanically limited rotation angle of the rudder blade is ±68°.

[0013] In one embodiment, the electrical limiting angle is ±46°.

[0014] In one embodiment, the working angle is ±45°.

[0015] In one embodiment, the axial direction of the disassembly hole is coaxial with the axial direction of the stern shaft.

[0016] Compared to existing technologies, this semi-submersible rudder system structure allows operators to first release the electrical limit of the rudder gear when stern shaft maintenance is required, enabling the rudder blade to continue rotating from its working angle until it reaches the enlarged mechanical limit. Because the detachable plate has a disassembly hole with a preset relationship between the maximum width of this hole and the rudder blade deflection angle, when the rudder blade rotates to its maximum limit, the projected width of the disassembly hole along the stern shaft axis is greater than the stern shaft diameter. This provides sufficient clearance for the stern shaft to be pulled back without removing the rudder blade. This completely avoids the mechanical interference between the rudder pin and the stern shaft in traditional structures. The entire process does not require removing the rudder blade, which weighs tens of tons, or using large cranes for high-risk, high-difficulty lifting operations. Only simple hydraulic release and manual plate disassembly are needed, significantly reducing maintenance labor intensity, shortening dock repair cycles, and allowing for convenient stern shaft disassembly without removing the rudder blade. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure of a semi-submersible ship shaft and rudder system provided in this application.

[0019] Figure 2 This is a schematic diagram showing the rudder blade rotating to its maximum angle in a semi-submersible rudder system structure provided in this application.

[0020] The component labels are as follows: 1. Servo motor; 2. Rudder stock; 3. Rudder arm; 4. Rudder blade; 5. Connecting assembly; 51. Removable plate; 511. Removal hole; 52. Hydraulic nut; 53. Rudder pin; 6. Stern shaft. Detailed Implementation

[0021] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0022] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is considered to be "connected to" another component, it can be directly connected to the other component or there may be an intermediate component present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application's specification are for illustrative purposes only and do not represent the only possible implementation.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact through an intermediate medium. Furthermore, "above," "over," and "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0026] Semi-submersible vessels, as large marine engineering vessels for special purposes, are widely used for transporting ultra-heavy cargo such as offshore drilling platforms and large structural components. Their propulsion shafting is typically designed to be quite long, with the stern shaft passing through the stern tube for installation. The propeller and related accessories are mounted at the end of the stern shaft, and the rudder for steering is located directly behind the propeller. During vessel operation and maintenance, when the stern shaft needs to be removed for repair or replacement due to wear, corrosion, or other mechanical failures, the propeller and its accessories must first be removed, and then the rudder blades located directly behind the shafting must be removed to eliminate obstacles to axial extraction before the stern shaft can be pulled aft along the stern tube.

[0027] Large ships typically use a conical hydraulic connection between the rudder blade and the rudder stock. While this connection structure ensures reliable transmission of high torque, its assembly and disassembly process is complex and requires extremely high precision in hydraulic tooling and operation. Even more challenging is the fact that the rudder blades of large semi-submersible vessels often weigh tens of tons, and their installation location is in the narrow space at the bottom of the stern, often surrounded by the hull structure.

[0028] Under these conditions, large dock cranes, either due to height limitations or insufficient lifting capacity, cannot directly assist in the lifting of the rudder blade. In actual maintenance, only temporary welded eyeplates to the hull structure, combined with simple lifting tools such as hand-operated hoists, can be used for manual lifting, translation, and transfer. This method is not only extremely labor-intensive and risky, but also extremely inefficient. After the shafting repair is completed, the rudder blade must be reinstalled using the same tedious process. In practice, the difficulty and time spent on disassembling and assembling the rudder blade often exceed the time required for the stern shaft repair itself, significantly increasing ship maintenance costs, extending dock repair cycles, and severely impacting the ship's operational economy.

[0029] Therefore, it is necessary to provide a semi-submersible shaft and rudder system structure that allows for easy disassembly of the stern shaft without removing the rudder blades.

[0030] Please see Figures 1 to 2 This application provides a semi-submersible vessel rudder system structure including a rudder motor 1 for controlling the steering of the rudder blade 4. The rudder motor 1, as the power source of the entire rudder system, is typically hydraulic or electric, possessing high torque output capability to meet the maneuvering response requirements of large semi-submersible vessels under different speeds and operating conditions. A rudder stock 2 is coaxially mounted on the drive end of the rudder motor 1, arranged vertically or approximately vertically, with its top end fixedly connected to the drive end of the rudder motor 1. This fixed connection can be achieved through keyed connections, flange connections, or tapered interference fits, ensuring that the torque output by the rudder motor 1 is efficiently and reliably transmitted to the rudder stock 2, driving the rudder stock 2 to perform precise rotational motion around its own axis.

[0031] At the lower middle part of the rudder stock 2, in the transition section between the rudder servo 1 and the rudder blade 4, a rudder arm 3 is also provided. The rudder arm 3 is typically a box-shaped or cast steel component with high structural strength. One end is rigidly connected to the rudder stock 2, and the other end extends to the mounting position of the rudder blade 4. Specifically, the rudder arm 3 is used to drive the rudder blade 4 to rotate via the rudder stock 2. The rudder arm 3 and the rudder blade 4 can be fixed together by bolts, pins, or welding, forming a unified moving unit. When the rudder servo 1 drives the rudder stock 2 to rotate, the rotation of the rudder stock 2 directly causes the rudder arm 3 to swing around the axis of the rudder stock 2. The rudder arm 3 then transmits torque to the rudder blade 4, causing the rudder blade 4 to produce a corresponding deflection angle relative to the longitudinal center plane of the hull.

[0032] Through the aforementioned transmission path—rudder 1, rudder stick 2, rudder arm 3, and finally rudder blade 4—this application enables continuous and stable changes in the angle of rudder blade 4. The change in the angle of rudder blade 4 directly alters the hydrodynamic distribution of the water flow acting on its surface, generating a lateral force component. This lateral force forms a steering torque around the ship's center of gravity, thereby precisely changing the ship's course. By using the rudder arm 3 as an intermediate force transmission component, this application allows rudder blade 4 to be positioned offset from directly behind the rudder stick 2, or provides sufficient axial removal space between rudder blade 4 and stern shaft 6. This means that when maintenance or replacement of stern shaft 6 is required, rudder blade 4 does not need to be completely removed; simply moving rudder blade 4 laterally provides an unobstructed path for stern shaft 6 to be pulled aft along the stern tube. This significantly simplifies the stern shaft 6 maintenance process, reduces reliance on large lifting equipment, and lowers maintenance costs and timelines.

[0033] Preferably, the servo motor 1, servo stick 2, servo arm 3, and servo blade 4 can adopt a modular design, with standardized connection interfaces between components, facilitating disassembly and replacement. Furthermore, bearings or bushings can be installed at the connection between the servo stick 2 and the servo arm 3 to reduce friction and improve transmission efficiency.

[0034] In some embodiments, the rudder arm 3 is connected to the stern shaft 6 via a connecting assembly 5. Specifically, the connecting assembly 5 includes a detachable plate 51 sleeved on the outside of the stern shaft 6. This detachable plate 51 is typically a semi-annular or split structure, composed of two or more separable arc-shaped plate segments, allowing it to be directly wrapped around and installed on the outer cylindrical surface of the stern shaft 6 from the radial direction without disassembling other components at both ends of the stern shaft 6. One or more hydraulic nuts 52 are provided on the side of the detachable plate 51 near the rudder arm 3. The hydraulic nut 52 is a fastener that uses high-pressure hydraulic oil to push a piston to generate axial thrust, enabling precise control of preload and facilitating operation in confined spaces. The hydraulic nut 52 is connected to the rudder arm 3 via a rudder pin 53. The rudder pin 53 is a high-strength cylindrical or conical metal pin. One end is fixed in the pin hole of the rudder arm 3, and the other end passes through the center hole of the hydraulic nut 52 or its mating lug. The piston of the hydraulic nut 52 rests against the corresponding bearing surface of the detachable plate 51. When high-pressure oil is injected into the hydraulic nut 52, its piston extends, pushing the detachable plate 51 to produce axial displacement relative to the rudder pin 53, thereby tightening the connection between the detachable plate 51 and the rudder arm 3, so that the detachable plate 51 tightly clamps the stern shaft 6, thus achieving a rigid connection between the stern shaft 6 and the rudder arm 3.

[0035] The significant advantage of using the aforementioned connecting component 5 is that, under normal navigation conditions, the hydraulic nut 52 ensures reliable force transmission between the detachable plate 51 and the rudder arm 3 through preload, allowing the radial load and part of the axial thrust of the stern shaft 6 to be transmitted to the rudder arm 3 via the detachable plate 51 and rudder pin 53, and then to the hull structure, thus enhancing the support rigidity of the shafting. When the stern shaft 6 needs to be removed for maintenance, the operator only needs to release the hydraulic pressure of the hydraulic nut 52 and loosen the locking device of the nut to disconnect the connection between the detachable plate 51 and the rudder pin 53. Subsequently, the semi-annular plate segments of the detachable plate 51 are disassembled one by one and removed from the stern shaft 6. Due to the split design of the detachable plate 51, it can be removed without sliding along the axial direction of the stern shaft 6. Therefore, even if there are still rudder blades 4 or other structural components behind the stern shaft 6, disassembly can be completed as long as sufficient lateral space is provided. Compared to traditional techniques that require the complete removal of the rudder blade 4, which weighs tens of tons, this embodiment only requires the disassembly of a few separate plates and hydraulic nuts 52, significantly reducing labor intensity and hoisting requirements. Furthermore, the hydraulic nuts 52 can be equipped with pressure monitoring sensors to facilitate real-time monitoring of preload changes and improve connection reliability. Preferably, the rudder pin 53 and the rudder arm 3 employ a tapered interference fit and are installed using a hydraulic tensioner to ensure positioning accuracy and shear resistance. The contact surface between the removable plate 51 and the stern shaft 6 can be fitted with a wear-resistant bushing or coating to prevent fretting wear.

[0036] In a specific embodiment, following a conventional shaft and rudder system layout, the bottom of the rudder arm 3 only needs to be slightly higher than the upper edge of the stern shaft 6. This design assumes that the rudder blade 4 needs to be completely removed when repairing the stern shaft 6. Once the rudder blade 4 is removed, there are no obstacles behind the stern shaft 6, and only a small gap needs to be maintained between the bottom of the rudder arm 3 and the upper edge of the stern shaft 6 to facilitate the shaft removal operation. Therefore, the height requirement for the rudder arm 3 is relatively low, and the length of the rudder pin 53 is correspondingly shorter. However, in this application, in order to achieve the direct rearward removal of the stern shaft 6 without removing the rudder blade 4, the relative heights between the rudder arm 3, the rudder pin 53, and the stern shaft 6 must be re-coordinated.

[0037] Specifically, this application requires that the lower end face of the rudder pin 53 be higher than the stern shaft 6. More precisely, the height of the rudder arm 3 needs to be designed to be increased accordingly based on the length of the rudder pin 53, so that the height of the end wall of the rudder pin 53 near the stern shaft 6 is higher than the height of the highest point of the stern shaft 6. During the axial rearward withdrawal of the stern shaft 6, the rear end of the stern shaft 6 needs to pass through the removal hole 511 on the rudder blade 4 and the space below the rudder arm 3. If the lower end face of the rudder pin 53 is lower than the highest point of the stern shaft 6, the rudder pin 53 will create mechanical interference, blocking the withdrawal path of the stern shaft 6. By raising the lower end face of the rudder pin 53 above the highest point of the stern shaft 6, the stern shaft 6 can pass completely under the rudder pin 53 during rearward movement without removing the rudder pin 53 or the rudder blade 4.

[0038] To achieve this height relationship, the overall height of the rudder arm 3 needs to be increased accordingly, meaning the rudder arm 3 needs to extend downwards further. This is to ensure a reliable connection between the rudder pin 53 and the rudder arm 3 while raising the lower end face of the rudder pin 53 to a sufficiently high position. Simultaneously, due to the increased length of the rudder pin 53, its bending strength also needs to be checked and compensated accordingly, for example, by increasing the diameter of the rudder pin 53 or using a high-strength alloy material.

[0039] Furthermore, the detachable plate 51 is also provided with a disassembly hole 511 for the stern shaft 6 to pass through. This disassembly hole 511 is not a simple through hole, but a functional opening with a specific shape and size. Specifically, the disassembly hole 511 completely penetrates the detachable plate 51 along the axial direction of the stern shaft 6, that is, from the side of the detachable plate 51 near the front end of the stern shaft 6 to the side near the rudder arm 3, forming an axially continuous channel through which the stern shaft 6 passes. Under normal operating conditions, the wall of the disassembly hole 511 does not directly contact the outer surface of the stern shaft 6, and a certain radial clearance is reserved between the two to avoid rotational interference and frictional wear. When the rudder blade 4 rotates, since the detachable plate 51 is fixedly connected to the rudder arm 3 through the hydraulic nut 52 and the rudder pin 53, and the rudder arm 3 rotates synchronously with the rudder stick 2 and the rudder blade 4, the detachable plate 51 will also rotate with the rudder blade 4, and there is no relative movement between the detachable plate 51 and the rudder blade 4. Consequently, the disassembly hole 511 located on the detachable plate 51 naturally rotates with the detachable plate 51, that is, the spatial orientation of the disassembly hole 511 changes with the turning angle of the rudder blade 4.

[0040] In a specific embodiment, the width of the disassembly hole 511 at its maximum width is greater than the diameter of the stern shaft 6. Considering that the stern shaft 6 is a cylindrical long rod with a circular cross-section and a diameter of D, if the stern shaft 6 is to be axially pulled out of the disassembly hole 511, the clear dimension of the disassembly hole 511 in the axial vertical plane of the stern shaft 6 must be greater than D. However, since the disassembly hole 511 is a solid hole opened in the detachable plate 51, and the radial dimension of the detachable plate 51 is limited by the installation space of the stern structure, simply making the entire disassembly hole 511 circular with a diameter greater than D would result in an excessively large outer edge dimension of the detachable plate 51, or excessively weaken its structure, affecting its load-bearing strength. To resolve this contradiction, this embodiment uses a non-circular irregularly shaped disassembly hole 511, such as an oblong, elliptical, or notched shape, so that its width in a specific direction is greater than D, while its width in other directions can be less than or equal to D.

[0041] To ensure the smooth removal of the stern shaft 6 while minimizing the actual opening size and avoiding impact on the structural strength of the rudder blade 4, this application further specifies that when the rudder blade 4 drives the detachable plate 51 to rotate, at the maximum mechanical angle (i.e., when the rudder blade 4 reaches its limit position of full left or full right rudder), the width of the detachment hole 511 projected along the axial direction of the stern shaft 6 is greater than the diameter of the stern shaft 6. In other words, at the zero rudder angle position during normal navigation (the rudder blade 4 is parallel to the mid-longitudinal section of the hull), the width of the detachment hole 511 in the projection direction may not be greater than the diameter of the stern shaft 6; however, when the rudder blade 4 deflects to the maximum angle, due to the synchronous deflection of the detachable plate 51, the spatial orientation of the detachment hole 511 changes, causing the axis of the stern shaft 6 to be precisely aligned with the long axis direction of the detachment hole 511. At this point, the effective width of the detachment hole 511 in this projection direction becomes its maximum width, thus exceeding the diameter of the stern shaft 6. Operators only need to rotate the rudder blade 4 to its maximum angle before maintenance to obtain sufficient space for shaft removal, without having to completely remove the rudder blade 4. This design fully utilizes the original steering function of the rudder blade 4, organically combining disassembly and assembly operations with steering actions, greatly simplifying the maintenance process of the stern shaft 6. Preferably, the maximum width direction of the disassembly hole 511 forms a preset angle with the zero rudder angle direction of the rudder blade 4. This angle is optimized according to the maximum steering angle range of the rudder blade 4 to ensure maximum alignment at the extreme steering angle. In addition, the inner wall of the disassembly hole 511 can be provided with a wear-resistant bushing or a guide slope to protect the surface of the stern shaft 6 from scratches during insertion. This structure achieves unobstructed removal of the stern shaft 6 without significantly weakening the strength of the rudder blade 4 and the removable plate 51.

[0042] In some embodiments, the normal operating angle range of the semi-submersible rudder blade 4 is typically set to ±45°, which meets the maneuverability requirements of the vessel under different speeds and sea states. To prevent over-rotation of the rudder blade 4 under extreme conditions, which could lead to overload of the hydraulic system or damage to the mechanical structure of the steering gear 1, an electrical limit switch is installed in the electrical system. Its trigger angle is ±46°; that is, when the rudder blade 4 rotates to this angle, the electrical control system cuts off the power source to the steering gear 1, stopping further rudder rotation. Furthermore, the steering gear 1 also has a mechanical limit device (such as a stop block) with an initial setting angle of ±47°. As a final safety protection, even if the electrical limit fails, the mechanical limit can forcibly prevent the rudder blade 4 from exceeding this angle.

[0043] However, in order for the stern shaft 6 to pass smoothly axially through the disassembly hole 511 on the rudder blade 4, the rudder blade 4 needs to rotate to a larger angle so that the maximum width direction of the disassembly hole 511 is aligned with the axis of the stern shaft 6. Based on this, this application, while maintaining the original working angle (±45°) and electrical limit angle (±46°) of the steering gear 1, only increases the mechanical limit angle of the steering gear 1 to ±68°. In normal navigation mode, the electrical system still cuts off power at ±46°, and the actual rotation range of the rudder blade 4 is limited to within ±45°, without affecting the ship's normal maneuverability and safety protection logic. When maintenance of the stern shaft 6 is required, the operator can temporarily release the electrical limit or enter "maintenance mode." At this time, the steering gear 1 can continue to drive the rudder blade 4 to rotate until the expanded mechanical limit of ±68° is reached. Since the mechanical limit only serves as a final physical stop and is manually controlled during maintenance, it will not cause overload damage. This tiered limiting strategy ensures safety during daily use while providing the necessary large rotation angle for the extraction of the stern shaft 6. It avoids the cumbersome operation of removing the rudder blade 4, which weighs tens of tons, as required by traditional methods, significantly reducing maintenance difficulty and time. During ship maintenance, only the removable plate 51 of the inspection hole at the hydraulic nut 52 of the rudder pin 53 needs to be removed. Then, the rudder blade 4 can be rotated to its maximum angle, allowing the stern shaft 6 to be extracted rearward from the hole in the rudder blade 4, achieving stern shaft 6 removal without disassembling the rudder blade 4.

[0044] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0045] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the patent protection scope of this application should be determined by the appended claims.

Claims

1. A semi-submersible vessel shaft and rudder system structure, characterized in that, include: The rudder arm (3) is attached to connect the rudder blade (4) and the stern shaft (6); The connecting assembly (5) includes at least a hydraulic nut (52) and a detachable plate (51) for connecting the stern shaft (6) to the rudder arm (3). The detachable plate (51) has a disassembly hole (511) with a maximum width not less than the diameter of the stern shaft (6) and the end of the stern shaft (6) passes through the disassembly hole (511).

2. The semi-submersible vessel shaft and rudder system structure according to claim 1, characterized in that, The rudder arm (3) is connected to the hydraulic nut (52) via a rudder pin (53).

3. The semi-submersible ship shaft and rudder system structure according to claim 2, characterized in that, The height of the end wall of the rudder pin (53) near the stern shaft (6) is higher than the height of the highest point of the stern shaft (6).

4. The semi-submersible ship shaft and rudder system structure according to claim 1, characterized in that, The detachable plate (51) is rotated so that the maximum projected width of the detachment hole (511) along the axial direction of the stern shaft (6) is not less than the diameter of the stern shaft (6).

5. The semi-submersible ship shaft and rudder system structure according to claim 1, characterized in that, The mechanical limiting angle of the rudder (4) is greater than the electrical limiting angle, which is greater than the working angle.

6. The semi-submersible ship shaft and rudder system structure according to claim 5, characterized in that, The maximum mechanical limit rotation angle of the rudder blade (4) is ±68°.

7. The semi-submersible ship shaft and rudder system structure according to claim 5, characterized in that, The electrical limiting angle is ±46°.

8. The semi-submersible ship shaft and rudder system structure according to claim 5, characterized in that, The working angle is ±45°.

9. The semi-submersible ship shaft and rudder system structure according to claim 1, characterized in that, The axial direction of the disassembly hole (511) is coaxial with the axial direction of the stern shaft (6).

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