A retractable ship propeller boss cap fin

Abstract

The application provides a scalable propeller hub cap fin for a ship, and belongs to the field of ship propulsion. The application solves the problem of poor energy-saving effect of a traditional cap fin in the whole voyage. The application comprises a propeller hub, a plurality of blades which are uniformly distributed on the propeller hub, a propeller hub cap which is arranged at the rear end of the propeller hub, a plurality of fin blades which are arranged one by one and correspond to each blade, all the fin blades are in sliding connection with the propeller hub, and a hydraulic adjusting device which is arranged in the propeller hub cap and is used for driving each fin blade to extend out of the propeller hub or retract. The application is mainly used for changing the running state of the propeller.

Description

Technical Field

[0001] This invention belongs to the field of ship propulsion, and in particular relates to a retractable marine propeller hub cap fin. Background Technology

[0002] Tests show that about 30% of the energy in a ship's propulsion system is wasted in the ship's wake. In order to save energy and reduce carbon emissions, it is recommended to install energy-saving devices to recover the energy in the ship's wake.

[0003] Currently, most devices used to recover energy from ship wakes are expensive to manufacture, complex in structure, have poor energy-saving effects, and are limited by ship type. Propeller hub caps, on the other hand, have a wide range of applications, are easy to install, and offer significant energy savings, thus they are widely used in ocean-going vessels.

[0004] During operation, marine propellers experience a low-pressure zone at the hub due to its presence, which reduces propeller efficiency and generates cavitation at the hub vortex.

[0005] However, traditional propeller hub fin optimization processes only consider the design conditions of transport vessels, without taking into account vessels operating under multiple conditions or propulsion system control strategies in extreme sea states. Traditional propeller hub fins can improve propulsion efficiency at low advance speeds by reducing hub vortices, but at high advance speeds, they generate negative thrust, affecting efficiency. Summary of the Invention

[0006] In view of this, the present invention aims to propose a retractable marine propeller hub cap fin to solve the problem of poor energy-saving effect of traditional cap fins throughout the entire voyage.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a retractable marine propeller hub cap fin, comprising:

[0008] A hub, on which multiple blades are evenly distributed around the circumference;

[0009] The propeller hub cap is located at the rear end of the propeller hub.

[0010] Fins, multiple of which are provided and correspond one-to-one with each of the propeller blades, and all the fins are slidably connected to the propeller hub; and

[0011] A hydraulic adjustment device, located inside the propeller hub cap, is used to drive each of the fins to extend or retract from the hub.

[0012] Furthermore, the ratio of the fin length to the propeller length is 0.18-0.33.

[0013] Furthermore, the difference between the mounting angle of the fin at the corresponding position and the root pitch angle of the propeller blade is -20 to 30°.

[0014] Furthermore, the ratio of the distance between the fin and the blade at the corresponding position to the propeller diameter is 0.2-0.5.

[0015] Furthermore, the hydraulic regulating device includes a cylinder, a first oil chamber, a second oil chamber, a piston, a piston rod, a first control valve, a pipeline, and a second control valve. The piston is slidably disposed inside the cylinder, dividing the cylinder into a first oil chamber and a second oil chamber. An oil inlet pipeline is disposed inside the cylinder, communicating with both the first and second oil chambers. One end of the piston rod is connected to the piston, and the other end slidably passes through the second oil chamber and the top wall of the cylinder, connecting to a fin at a corresponding position. The first and second oil chambers are connected through a pipeline, and a second control valve is disposed within the pipeline. A first control valve is disposed within the first oil chamber.

[0016] Furthermore, a sealing ring is provided at the sliding connection between the piston rod and the oil cylinder.

[0017] Furthermore, a sealing ring is provided at the sliding connection between the piston rod and the propeller hub cap.

[0018] Furthermore, the oil inlet pipeline is connected to an external oil pump.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The hub cap fin can reduce the hub vortex generated by the hub by setting the fin blades, thereby recovering the energy and reducing the impact of the low-pressure area behind the hub on the propulsion efficiency.

[0021] 2. The hub cap fin can generate positive thrust through the fin blades in the low-speed range, thereby increasing the propeller thrust;

[0022] 3. The hub cap fin can reduce the extension length of the fin blades when traveling at high speeds, preventing insufficient thrust when thrust needs to be guaranteed in extreme environments. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0024] Figure 1 This is a schematic diagram of the structure of a retractable marine propeller hub cap fin according to the present invention.

[0025] Figure 2 This is a state diagram of the fin retraction process described in this invention;

[0026] Figure 3 This is a schematic diagram of the hydraulic regulating device described in this invention.

[0027] 1. Blade; 2. Fin; 3. Hydraulic adjustment device; 3-1. Cylinder; 3-2. First oil chamber; 3-3. Second oil chamber; 3-4. Piston; 3-5. Piston rod; 3-6. First control valve; 3-7. Pipeline; 3-8. Second control valve; 3-9. Sealing ring; 4. Propeller hub cap; 5. Hub. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other, and the described embodiments are only some embodiments of the present invention, not all embodiments.

[0029] Referring to the accompanying drawings, this embodiment describes a retractable marine propeller hub cap fin, comprising:

[0030] A hub 5, on which multiple blades 1 are evenly distributed around the circumference;

[0031] Propeller hub cap 4 is located at the rear end of propeller hub 5;

[0032] Multiple fins 2 are provided and are arranged one-to-one with each of the blades 1. All the fins 2 are slidably connected to the hub 5. The arrangement of the fins 2 can reduce the impact of the low-pressure area formed by the hub 5 on the propeller efficiency, reduce the generation of cavitation at the hub vortex, help the propeller to operate within a better efficiency range, and improve the power recovery efficiency.

[0033] A hydraulic adjustment device 3, located within the propeller hub cap 4, drives each fin 2 to extend or retract from the hub 5. The hydraulic adjustment device 3 controls the extension or retraction of the fins 2, allowing for timely adjustments based on the vessel's navigation conditions to ensure optimal operation. For example, at low speeds, the fins 2 reduce the impact of low-pressure areas in the hub on propeller efficiency and decrease the likelihood of cavitation at the hub vortex. At high speeds, excessive extension of the fins 2 can generate reverse thrust; in extreme sea states, to maintain thrust, the fins 2 need to be retracted or partially retracted.

[0034] In this embodiment, the ratio of the length of the fin 2 to the length of the propeller blade 1 is 0.18-0.33. Within this ratio range, the fin 2 can meet different operating requirements at different length ratios, allowing the ship to operate under optimal conditions.

[0035] In this embodiment, the difference between the installation angle of the fin 2 at the corresponding position and the root pitch angle of the propeller blade 1 is -20 to 30°. Within this ratio range, the fin 2 can meet different operating requirements at different length ratios, allowing the ship to operate under optimal conditions.

[0036] In this embodiment, the ratio of the distance between the fin 2 and the propeller blade 1 at the corresponding positions to the propeller diameter is 0.2-0.5. Within this ratio range, the fin 2 can meet different operating requirements at different length ratios, allowing the ship to operate under optimal conditions.

[0037] During the commissioning phase, based on the influence of the extension length of fin 2 on propeller efficiency, the mapping relationship between various lengths and propeller characteristics was obtained through CFD simulation and DOE test design, and then programmed into the control module of hydraulic adjustment device 3.

[0038] In this embodiment, the hydraulic regulating device 3 includes a cylinder 3-1, a first oil chamber 3-2, a second oil chamber 3-3, a piston 3-4, a piston rod 3-5, a first control valve 3-6, a pipeline 3-7, and a second control valve 3-8. The piston 3-4 is slidably disposed inside the cylinder 3-1, dividing the cylinder 3-1 into a first oil chamber 3-2 and a second oil chamber 3-3. An oil inlet pipeline is disposed inside the cylinder 3-1, communicating with both the first and second oil chambers 3-2 and 3-3. One end of the piston rod 3-5 is connected to the piston 3-4, and the other end slidably passes through the second oil chamber 3-3 and the top wall of the cylinder 3-1, connecting to the corresponding fin 2. The first and second oil chambers 3-2 are connected through the pipeline 3-7, the second control valve 3-8 is disposed inside the pipeline 3-7, and the first control valve 3-6 is disposed inside the first oil chamber 3-2. Oil is supplied through the inlet pipe. When the first control valve 3-6 is open, the second control valve 3-8 is closed. At this time, the oil pressure drives the piston 3-4 to move, which in turn moves the piston rod 3-5, causing the corresponding fin 2 to extend from the propeller hub cap 4, thus increasing the extension length of the fin 2. When the first control valve 3-6 is closed and the second control valve 3-8 is open, oil enters the second oil chamber 3-3. The oil pressure drives the piston 3-4 to reset, and the fin 2 retracts, which is suitable for high-speed driving conditions.

[0039] In this embodiment, a sealing ring 3-9 is provided at the sliding connection between the piston rod 3-5 and the oil cylinder 3-1 to prevent oil leakage.

[0040] In this embodiment, a sealing ring 3-9 is provided at the sliding connection between the piston rod 3-5 and the propeller hub cap 4. This prevents water from affecting the interior of the hydraulic regulating device 3.

[0041] In this embodiment, an external oil pump is connected to the oil inlet pipeline. The oil pump drives the hydraulic regulating device 3.

[0042] In operation, the extension or retraction of fin 2 is determined based on the operating conditions. Oil is then pumped into the inlet line. When the first control valve 3-6 is open, the second control valve 3-8 is closed. At this time, the oil pressure drives the piston 3-4, which in turn moves the piston rod 3-5, causing the corresponding fin 2 to extend from the propeller hub cap 4, thus increasing its extension length. When the first control valve 3-6 is closed and the second control valve 3-8 is open, oil enters the second oil chamber 3-3. The oil pressure then drives the piston 3-4 to reset, retracting the fin 2. This is suitable for high-speed driving conditions.

[0043] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A retractable marine propeller hub cap fin, characterized in that, include: A hub (5) is provided with multiple blades (1) evenly distributed around its circumference. The propeller hub cap (4) is located at the rear end of the propeller hub (5); Fins (2) are provided in multiples, each corresponding to one of the blades (1), and all fins (2) are slidably connected to the hub (5); and A hydraulic adjustment device (3) is provided inside the propeller hub cap (4) for driving each of the fins (2) to extend or retract from the hub (5); The ratio of the length of the fin (2) to the length of the propeller (1) is 0.18-0.33; The difference between the mounting angle of the fin (2) located at the corresponding position and the root pitch angle of the blade (1) is -20-30°; The ratio of the distance between the fin (2) and the blade (1) located at the corresponding positions to the propeller diameter is 0.2-0.5; The hydraulic regulating device (3) includes a cylinder (3-1), a first oil chamber (3-2), a second oil chamber (3-3), a piston (3-4), a piston rod (3-5), a first control valve (3-6), a pipeline (3-7), and a second control valve (3-8). A piston (3-4) is slidably disposed within the cylinder (3-1), dividing the cylinder (3-1) into a first oil chamber (3-2) and a second oil chamber (3-3). The cylinder (3-1) is connected to the first oil chamber (3-2) and the second oil chamber (3-3). The first oil chamber (3-2) and the second oil chamber (3-3) are connected by an oil inlet pipe. One end of the piston rod (3-5) is connected to the piston (3-4), and the other end can slide through the second oil chamber (3-3) and the top wall of the oil cylinder (3-1) and connect to the fin (2) at the corresponding position. The first oil chamber (3-2) and the second oil chamber (3-3) are connected by a pipe (3-7). A second control valve (3-8) is provided in the pipe (3-7), and a first control valve (3-6) is provided in the first oil chamber (3-2).

2. The retractable marine propeller hub cap fin according to claim 1, characterized in that: A sealing ring (3-9) is provided at the sliding connection between the piston rod (3-5) and the oil cylinder (3-1).

3. The retractable marine propeller hub cap fin according to claim 2, characterized in that: A sealing ring (3-9) is provided at the sliding connection between the piston rod (3-5) and the propeller hub cap (4).

4. The retractable marine propeller hub cap fin according to claim 1, characterized in that: The oil inlet pipeline is connected to an external oil pump.

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