A compact and retractable mast wing sail device

Abstract

The present application belongs to the technical field of ship sail device, and particularly relates to a telescopic mast wing type sail device with compact structure and lifting function. The present application comprises a rotating mechanism, a lifting mechanism and a sail blade assembly. The rotating mechanism is driven by a servo motor to mesh with a rotating support gearwheel through a pinion, so as to realize precise rotation of the sail body and have double locking functions of motor braking and gear self-locking, thereby ensuring small angle deviation under 8-grade wind waves. The lifting mechanism adopts symmetrical driving of double hydraulic cylinders and a pulley block labor-saving system, so as to make the mast lifting stable and free from unbalanced load. The sail blade is made of lightweight composite material wing type and has an upper and lower nested layout, so as to improve wind energy capturing efficiency, reduce height after lowering the sail and save land area. The device is particularly suitable for 5000-ton medium and small ships, can reduce main engine fuel consumption in actual measurement, and has significant flexibility and economic and environmental protection benefits.

Description

Technical Field

[0001] This invention belongs to the technical field of marine sail devices, and particularly relates to a compact, retractable mast-type sail device. Background Technology

[0002] Under the global trend of "dual carbon" goals and the green development of ships, wind power, as a clean and renewable auxiliary power source for ships, has become a key technological direction for reducing main engine fuel consumption and carbon emissions. Traditional ship sail systems mostly use fixed mast structures, which, while capable of capturing wind energy, suffer from the following core technological limitations, making them unsuitable for the navigation needs of small and medium-sized ships (5,000-10,000 tons):

[0003] First, there is structural redundancy and poor spatial adaptability. To ensure wind catchment area, traditional fixed-mast wing sails are often designed as an integral long mast structure, with a sail height generally exceeding 35 meters when raised. Moreover, the height cannot be adjusted according to navigation scenarios (such as port height restrictions or bridge navigation), which restricts the deck layout of small and medium-sized ships. Most small and medium-sized ships have compact deck space (length ≤ 100 meters, beam ≤ 18 meters), and the footprint (usually ≥ 10 square meters) and height of the fixed-mast wing device are redundant, easily interfering with the ship's superstructure and loading and unloading equipment, with an installation adaptability rate of less than 40%.

[0004] Secondly, the lifting and lowering systems suffer from severe uneven load distribution and low operational stability. Most existing liftable sails employ a single hydraulic cylinder drive or a single-sided rope traction structure. During lifting and lowering, the sail is prone to radial uneven load distribution due to uneven force (the uneven load can reach 15%-20%), leading to accelerated wear of the mast rails, lifting and lowering jams, and even the risk of sail tilting. Under turbulent conditions with a roll of ±15° and a pitch of ±10°, the uneven load problem of traditional lifting systems is further amplified, resulting in a failure rate as high as 25% per year, making it difficult to meet the reliability requirements for continuous navigation.

[0005] Third, the slewing lock is unreliable and the wind energy utilization efficiency is low. Traditional sail slewing mechanisms mostly rely on a single electromagnetic brake or mechanical lock. In winds and waves of level 8 or above (wind speed ≥17.2m / s), the angular deviation caused by brake failure or gear transmission clearance often exceeds 1°, making it impossible for the sail to be accurately aligned with the wind direction, and the wind energy capture efficiency drops to below 25%. At the same time, the slewing bearing components are mostly open structures, and the salt spray corrosion and silt intrusion in the marine environment can easily lead to wear of the transmission components. The average service life is only 2-3 years, and the maintenance cost accounts for more than 30% of the total equipment cost.

[0006] Fourth, there is insufficient compatibility between materials and processes. Traditional sail masts are mostly made of ordinary carbon steel, which is prone to brittle fracture in low-temperature environments (below -20℃), and cannot meet the navigation requirements of high-latitude sea areas; the sail blades are mostly made of steel or single glass fiber. Steel sail blades are heavy (single blade weight ≥20 tons) and have high energy consumption, while single glass fiber sail blades have weak wind load resistance (maximum wind speed ≤25m / s), making it difficult to balance the dual requirements of lightweight and structural strength.

[0007] Based on the aforementioned technical pain points, there is an urgent need to develop a new type of telescopic mast airfoil wind turbine that is compact in structure, has no lifting or off-center load, reliable rotation locking, and is suitable for small and medium-sized ships. By optimizing the transmission structure, material selection, and collaborative control logic, the shortcomings of traditional wind turbines in terms of spatial adaptability, operational stability, and environmental adaptability can be solved, thereby promoting the large-scale application of wind-powered propulsion technology for small and medium-sized ships. Summary of the Invention

[0008] To address the problems of complex structure, poor spatial adaptability, unreliable slewing lock, unstable operation, and poor environmental adaptability of existing ship sail devices, this invention proposes a compact, liftable telescopic mast-type sail device, including a slewing mechanism, a lifting mechanism, a sail assembly, and a mast assembly.

[0009] The slewing mechanism includes a base, a motor, a reducer, a pinion, and a slewing bearing gear. The base is fixed to the ship's deck. The motor drives the pinion through the reducer. The pinion meshes with the slewing bearing gear. The inner ring of the slewing bearing gear is rigidly connected to the lower mast. The slewing bearing gear drives the lower mast to rotate under the drive of the motor.

[0010] The lifting mechanism includes a pair of symmetrically arranged hydraulic cylinders, a movable pulley, a wire rope, and a fixed pulley. The lower end of the hydraulic cylinder is hinged to the base through a spherical bearing, and the upper end is connected to the movable pulley.

[0011] The mast assembly includes an upper mast and a lower mast. A steel wire rope passes over a movable pulley and a fixed pulley and is connected to the upper mast. The upper mast cooperates with the inner slide rail of the lower mast through a guide slider to achieve telescopic movement.

[0012] The sail assembly includes an upper sail and a lower sail. The upper sail is fixed to the top of the upper mast, and the lower sail is fixed to the outside of the lower mast. The upper sail and the lower sail are nested together, and when the sail is lowered, the upper sail is nested outside the lower sail.

[0013] According to the above-described compact, liftable telescopic mast airfoil device, the slewing mechanism further includes a brake, which is located at the motor output end and works in conjunction with the reducer input end for braking.

[0014] According to the above-described compact, liftable telescopic mast airfoil device, the hydraulic cylinders are symmetrically arranged on both sides of the lower mast. The lower end of the hydraulic cylinder is hinged to the base through a spherical bearing, with a swing angle of ±5°, and the upper end is rigidly connected to the movable pulley through a flange.

[0015] According to the above-described compact, liftable telescopic mast airfoil device, the movable pulley is connected to the piston rod of the hydraulic cylinder via a deep groove ball bearing, and the fixed pulley is fixedly mounted on the top of the lower mast by welding with a bracket, and reinforcing ribs are provided at the welded joint of the bracket.

[0016] According to the above-described compact and retractable mast-shaped sail device, the end of the wire rope is fixed with a wedge-shaped joint; the rope winding method forms a twice-efficiency structure.

[0017] According to the above-described compact, liftable telescopic mast-shaped sail device, both the upper mast and the lower mast are made of Q355ND low-temperature toughness steel, and their cross-sections are both chamfered squares.

[0018] According to the above-described compact and retractable mast airfoil device, both the upper and lower sail blades are made of glass fiber reinforced epoxy resin composite material, and the lower sail blade is fixed to the lower mast by high-strength bolts.

[0019] According to the above-described compact and retractable mast-shaped sail device, the radial gap between the upper and lower sail blades is 5-10 mm, and the circumferential misalignment is 180°.

[0020] According to the above-described compact, liftable telescopic mast airfoil device, the outer side of the upper mast is welded with an MC nylon guide slider, and the clearance between the guide slider and the inner side slide rail of the lower mast is 0.5-1mm.

[0021] According to the above-described compact and retractable mast airfoil sail device, the device further includes a sail blade follow-up adjustment component, which synchronously drives the lower sail blade to rotate around the hinge during the mast lifting and lowering process via a linkage mechanism.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. Overcoming height limitations and enhancing scenario adaptability. Through a multi-section telescopic mast and a lifting mechanism driven by hydraulic cylinders, pulleys, and steel cables, stepless adjustment of the sail height is achieved. In non-operating conditions, the sail can be retracted to a low height, completely solving the problem of traditional fixed masts being unsuitable for low-altitude scenarios such as port height restrictions and bridge navigation. No additional disassembly or rerouting costs are required, significantly improving the vessel's operational flexibility in complex navigation environments.

[0024] 2. Reduce structural complexity and decrease failure risk. The redundant drive components and locking devices used in folding sail systems to balance the overturning torque are eliminated. Instead, an integrated structure of "gear reduction rotary mechanism + telescopic mast lifting mechanism" is adopted. The rotary drive simplifies the power transmission path through gear meshing, and the lifting mechanism shortens the hydraulic cylinder stroke based on the labor-saving principle of pulley systems. The number of moving parts is reduced by more than 30%, reducing potential failure points caused by complex structures from the source and improving the reliability of the device.

[0025] 3. Optimized stress distribution and extended device lifespan. The rotary drive mechanism adopts a closed transmission structure with a small gear driving a large gear. The speed reduction characteristic of the gear reduces the power requirement of the motor. Combined with the high load-bearing capacity of the spline connection, it can adapt to the power impact of frequent start-stop. The lifting mechanism adopts a hydraulic cylinder connection method of "one end hinged and one end floating", which greatly alleviates the impact of the off-center load on the hydraulic system. The wear rate of the seals and cylinder body is reduced by more than 50%. The symmetrical layout of the overall structure balances the load stress, reduces the stress deformation of the base, and extends the service life of the core components to more than 1.5 times that of traditional devices.

[0026] 4. Improved energy efficiency and economy, reducing overall costs. The high-precision power distribution characteristics of gear transmission reduce motor energy consumption by 15%-20%; pulley block drive shortens the hydraulic cylinder stroke to half that of traditional designs, reducing hydraulic system power consumption; non-metallic fiber composite material sail and lightweight mast design reduce lifting load, further reducing drive energy consumption. At the same time, the modular and compact layout reduces material usage, and the centralized arrangement of key components reduces manufacturing costs by 20%. Later maintenance eliminates the need to disassemble redundant structures, reducing maintenance workload and costs by more than 40%, significantly improving the economic efficiency throughout the equipment's life cycle.

[0027] 5. Enhance sail attitude coordination and improve wind energy utilization efficiency. The upper and lower sails are linked to the mast's raising and lowering via a sail-following adjustment component. The linkage mechanism synchronously drives the lower sail to rotate around the hinge during mast raising and lowering, ensuring the sail maintains optimal airfoil attitude at all times. The combination of streamlined guide vanes and a non-metallic fiber composite sail optimizes airflow characteristics, increasing wind energy capture efficiency by 10%-15% compared to traditional rigid airfoil sails, thus enhancing wind-assisted energy-saving effects.

[0028] 6. Excellent ship type versatility and environmental adaptability. The symmetrical layout and modular design allow the device to be adapted to various ship types, including oil tankers, bulk carriers, and chemical tankers, without requiring significant structural adjustments for different ship types. The application of sealed bearing housings, wear-resistant coatings, and anti-corrosion materials effectively prevents the intrusion of seawater, dust, and corrosive media, meeting the long-term working requirements of harsh marine environments and providing reliable support for the large-scale industrial application of wind-assisted propulsion technology.

[0029] 7. Energy conservation, environmental protection, and improved economic efficiency. From economic, environmental, and carbon credit perspectives, installing small airfoil sails offers the following benefits: Economic benefits: On average, each small airfoil sail installed on small and medium-sized vessels can save approximately 0.7 tons of fuel per day. Short investment payback period: The equipment investment cost can be recovered within 3 years through carbon credit benefits and fuel savings. 2. Wind energy is a zero-emission energy source. Adding a sail system not only helps vessels meet the IMO's GFI standards but also contributes to the global shipping industry's goal of achieving net-zero emissions by 2050. 3. Regarding carbon credit benefits: The new IMO regulations introduce a "reward-penalty" dual-track system, requiring non-compliant vessels to purchase carbon credits to offset excess emissions. Installing sails not only avoids the need to purchase remedial fuel recyclers (RUs) but also allows for additional benefits through the sale of fuel recyclers (SUs). Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a compact, liftable telescopic mast airfoil sail device of the present invention in the sail-raised state.

[0031] Figure 2 This is a schematic diagram of the structure of a compact, liftable telescopic mast airfoil windmill device of the present invention in the state of sail lowering.

[0032] Figure 3 This is a sectional view of the slewing mechanism of a compact, liftable telescopic mast-shaped sail device according to the present invention.

[0033] Figure 4 This is a top view and a cross-sectional view of the slewing mechanism of a compact, liftable telescopic mast-shaped sail device according to the present invention.

[0034] In the diagram: 1-Double hydraulic cylinder, 2-Moving pulley, 3-Wire rope, 4-Fixed pulley, 5-Upper sail, 6-Lower sail, 8-Base, 9-Upper mast, 10-Lower mast, 11-Motor, 12-Reducer, 13-Pin gear, 14-Slewing bearing gear, 100-Lifting mechanism, 200-Slewing mechanism. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0036] like Figures 1 to 4As shown: This embodiment of a compact, liftable telescopic mast airfoil sail device includes: a slewing mechanism 200, a lifting mechanism 100, an upper sail blade 5, a lower sail blade 6, an upper mast 9, and a lower mast 10. After assembly, the overall height is 29 meters with the sail raised and 17 meters with the sail lowered. The slewing diameter is 8 meters. Compared with existing fixed mast airfoil sails, it has significant advantages such as flexible operation, no lifting or eccentric load, and suitability for small and medium-sized ships.

[0037] In the slewing mechanism 200, the base 8 is integrally welded from EH36 high-strength steel. Eight sets of M30 high-strength bolts are passed through the pre-set bolt holes in the base 8 to securely fix the motor 11, reducer 12, and brake located at the output end of the motor 11 to the top surface of the base 8. The bottom of the base 8 is then welded to the ship's deck. The weld seam is inspected by 100% UT flaw detection, and Level II is acceptable. In actual sea trials, even when the ship is in a rolling ±15° and pitch ±10° turbulent condition, the power components remain without displacement or loosening, providing a stable bearing foundation for the slewing transmission.

[0038] Motor 11 is a servo motor with an electromagnetic brake, with a rated power of 5.5kW, a rated speed of 1500r / min, and a brake response time of ≤0.2s. The output shaft of motor 11 is connected to the input end of reducer 12 by an "L-key". The keyway fit tolerance is kept at H7 / h6, and the measured transmission clearance is ≤0.02mm, completely eliminating the angle adjustment error. Reducer 12 is a hardened cylindrical gear reducer with a reduction ratio of 1:120. Its input end is connected to the shaft of motor 11 by a flat key, and its output end is connected to pinion 13 by an involute spline. The parameters of the involute spline are: module 3, number of teeth 20, fit accuracy grade 7, and power transmission efficiency of over 96%. The pinion 13 is made of 20CrMnTi, with a carburized and quenched surface, achieving a tooth surface hardness of HRC58-62 and a tooth surface precision of grade 6. It has an interference fit with the spline at the output end of the reducer 12, with an interference amount of 0.015-0.03mm, ensuring lossless power transmission. The slewing bearing large gear 14 is a four-point contact ball slewing bearing structure, with a meshing center distance of 1200mm and a backlash of 0.15-0.25mm with the pinion 13. The outer ring is fixed to the base 8 by bolts, and the inner ring is rigidly connected to the lower mast 10 by 16 sets of M24 bolts, forming a closed transmission structure of "pinion driving large gear". This structure has shown no significant corrosion after 6 months of continuous use in a marine salt spray environment, with a mud and sand wear amount of ≤0.01mm and a stable transmission efficiency of ≥92%. The brake is an electromagnetic brake type with a coil voltage of DC24V and a braking torque of ≥200N・m. It is linked to the input end of the reducer 12 and, together with the 1.5° helix angle self-locking effect of the large gear 14 and small gear 13 of the slewing bearing, forms a "double locking structure". In the test of level 8 wind waves with wind speeds of 17.2-20.7m / s, the sail angle deviation was ≤0.3°, which is far better than the deviation of more than 1° of the traditional device, and the locking reliability is significantly improved.

[0039] In the lifting mechanism 100, two hydraulic cylinders 1 are symmetrically arranged on both sides of the lower mast 10, forming a symmetrical drive structure. Combined with the "one end hinged, one end rigid" installation method, the lower end of the hydraulic cylinder is hinged to the base 8 through a spherical bearing, with a swing angle of ±5°. The actual measurement shows that it can absorb ±10% of radial off-center load, completely solving the problem of large off-center load in traditional lifting systems. The cylinder body of the dual hydraulic cylinder 1 is made of 45# steel with heat treatment, hardness HB220-250, cylinder diameter 160mm, piston rod diameter 90mm, stroke 800mm, working pressure 16MPa, and single cylinder output force ≥125kN, meeting the lifting requirements of a 25-ton sail. Both the movable pulley 2 and the fixed pulley 4 are made of cast steel, ZG35CrMo, with a diameter of 200mm and a groove bottom radius of 8.2mm. The surface is chrome-plated with a thickness of 0.05mm, which improves wear resistance by 3 times and extends service life to more than 5 years. The movable pulley 2 is connected to the hydraulic cylinder piston rod through a deep groove ball bearing, and the rotation resistance is ≤5N. The fixed pulley 4 is fixed to the top of the lower mast 10 through a 2205 duplex stainless steel bracket. The bracket has a 16mm thick triangular reinforcing rib at the welded joint. It can withstand a radial force of 50kN without deformation. The steel wire rope 3 has a 6×37+FC structure, a diameter of 16mm, a nominal tensile strength of 1770MPa, a breaking strength of ≥200kN, and a wedge-shaped joint at the end for fixing with an efficiency coefficient of ≥0.9. It forms a double-efficiency system by using a specific rope winding method. The measured lifting speed of the upper mast 9 is stable at 0.1m / s, and the acceleration is ≤0.05m / s². There is no jamming or deflection throughout the entire process, and the lifting stability far exceeds that of traditional single-cylinder drive devices. The lower mast 10 is made of Q355ND low-temperature toughness steel with a chamfered square cross-section, an circumscribed circle diameter of 800mm, a wall thickness of 20mm, a torsional section modulus ≥8000cm³, and no risk of brittle fracture at -30℃. Its overall straightness is ≤1mm / m, providing precise guidance for lifting. The upper mast 9 is made of the same material as the lower mast 10, with a cross-section circumscribed circle diameter of 720mm and a wall thickness of 18mm. It has MC nylon guide sliders welded to the outside, with a clearance of 0.5-1mm between the guide slider and the inner slide rail of the lower mast 10. The slide rail surface is coated with a MoS2 solid lubricant coating with a thickness of 0.03mm, and the measured friction coefficient is ≤0.08. With the addition of extreme pressure lithium-based grease every 30 days using an automatic grease nipple, the lifting resistance is reduced by 40%, and the energy consumption of a single lifting cycle is reduced by 25% compared to traditional devices.

[0040] In the sail assembly, the upper sail 5 is made of glass fiber reinforced epoxy resin composite material with a fiber volume content of 65%, integrally vacuum-cast, with a total weight of ≤15 tons, a 40% weight reduction compared to traditional steel sails, significantly reducing the mast load. Its airfoil has a relative thickness of 13%, a span of 8 meters, a chord length of 1.7 meters, a surface area of ​​145 m², a leading edge radius of 30 mm, a trailing edge thickness of 3 mm, and a surface roughness Ra≤0.8 μm. Wind tunnel testing shows a wind energy capture efficiency ≥35%, a 12% improvement over ordinary airfoil sails. The upper sail 5 is fixed to the top of the upper mast 9 at its root by 16 sets of M20×80 grade 12.9 high-strength bolts with a pre-tightening torque of 350 N·m, showing no loosening or deformation during strong wind testing. The lower sail 6 has the same structure and material as the upper sail 5, with a span of 9 meters, a chord length of 1.6 meters, and a surface area of ​​146 m². 2 The device utilizes a 12mm thick triangular stainless steel bracket coated with an epoxy zinc-rich primer and a polyurethane topcoat, resulting in a total thickness of 120μm. It is fixed to the outer side of the lower mast 10, providing excellent corrosion resistance. The upper sail 5 and lower sail 6 employ a nested arrangement, with a radial gap of 5-10mm and a circumferential misalignment of 180° when the sails are lowered. Measured wind resistance is 30% lower than that of a non-nested structure, and the overall footprint of the device is ≤6.4m². 2 It measures 8m x 0.8m and is suitable for the deck layout of a 5,000-ton medium-sized oil tanker with a length of 95m and a beam of 15m. The installation space is reduced by 40% compared to traditional fixed-mast sails.

[0041] After assembly, the device can be used in actual navigation applications on 5,000-ton oil tankers. The slewing mechanism 200 can achieve an angle adjustment of 0°-360° with an adjustment accuracy of ±0.5° and a response time of ≤2 seconds, which can quickly adapt to changes in wind direction. The lifting mechanism 100 takes 8 seconds each for raising and lowering the sail, which is 50% shorter than traditional devices. The height can be adjusted at any time during navigation, adapting to port height restrictions of ≤18 meters and navigation scenarios in bridge areas. The slewing and lifting actions work together without interference. Simulating the navigation of a ship on the US-Europe route, the device operates for 280 days a year. In wind conditions of 5-6, the wind-assisted propulsion can reduce the main engine fuel consumption by 15%-20%, saving more than 300,000 yuan in fuel costs per year, with significant economic and environmental benefits.

[0042] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art who makes equivalent substitutions or modifications based on the technical solution and inventive concept of the present invention within the scope of the technology disclosed in the present invention is covered within the scope of protection of the present invention. For example: changing the hydraulic cylinder 1 to an electric cylinder; changing the motor series reducer to a geared motor or a hydraulic motor; integrating the reducer 12 and the pinion 13 into one unit, i.e., a set of high-ratio reducers or several reducers in series, such as a gearbox reducer in series with a planetary reducer.

Claims

1. A compact, retractable mast-shaped sail device, characterized in that, Includes a slewing mechanism (200), a lifting mechanism (100), a sail assembly, and a mast assembly; The slewing mechanism (200) includes a base (8), a motor (11), a reducer (12), a pinion (13), and a slewing bearing gear (14). The base (8) is fixed to the ship's deck. The motor (11) drives the pinion (13) through the reducer (12). The pinion (13) meshes with the slewing bearing gear (14). The inner ring of the slewing bearing gear (14) is rigidly connected to the lower mast (10). The slewing bearing gear (14) drives the lower mast (10) to rotate under the drive of the motor (11). The lifting mechanism (100) includes a pair of hydraulic cylinders (1) arranged symmetrically, a movable pulley (2), a wire rope (3) and a fixed pulley (4). The lower end of the hydraulic cylinder (1) is hinged to the base (8) through a joint bearing, and the upper end is connected to the movable pulley (2). The mast assembly includes an upper mast (9) and a lower mast (10). A steel wire rope (3) passes around a movable pulley (2) and a fixed pulley (4) and is connected to the upper mast (9). The upper mast (9) cooperates with the inner slide rail of the lower mast (10) through a guide slider to realize telescopic movement. The sail assembly includes an upper sail (5) and a lower sail (6). The upper sail (5) is fixed to the top of the upper mast (9), and the lower sail (6) is fixed to the outside of the lower mast (10). The upper sail (5) and the lower sail (6) are nested vertically. When the sail is lowered, the upper sail (5) is nested outside the lower sail (6). The slewing mechanism (200) also includes a brake, which is located at the output end of the motor (11) and works in conjunction with the input end of the reducer (12) for braking. The hydraulic cylinder (1) Symmetrically arranged on both sides of the lower mast (10), the lower end of the hydraulic cylinder (1) is hinged to the base (8) through a joint bearing, with a swing angle of ±5°, and the upper end is rigidly connected to the movable pulley (2) through a flange; the movable pulley (2) is connected to the piston rod of the hydraulic cylinder (1) through a deep groove ball bearing, and the fixed pulley (4) is fixedly installed on the top of the lower mast (10) by welding through a bracket, and a reinforcing rib is provided at the weld of the bracket; the end of the wire rope (3) is fixed with a wedge joint; the rope winding method forms a 2 times labor-saving structure.

2. The compact, retractable mast-shaped sail device according to claim 1, characterized in that, Both the upper mast (9) and the lower mast (10) are made of Q355ND low-temperature toughness steel, and their cross-sections are both chamfered squares.

3. The compact, retractable mast-shaped sail device according to claim 2, characterized in that, Both the upper sail (5) and the lower sail (6) are made of glass fiber reinforced epoxy resin composite material, and the lower sail (6) is fixed to the lower mast (10) by high-strength bolts.

4. The compact, retractable mast-shaped sail device according to claim 3, characterized in that, The radial gap between the upper sail (5) and the lower sail (6) is 5-10 mm, and the circumferential misalignment is 180°.

5. A compact, retractable mast-shaped sail device according to claim 4, characterized in that, The outer side of the upper mast (9) is welded with an MC nylon guide slider, which has a clearance of 0.5-1mm with the inner slide rail of the lower mast (10).

6. A compact, retractable mast-shaped sail device according to claim 5, characterized in that, The device also includes a sail follow-up adjustment component, which drives the lower sail (6) to rotate around the hinge synchronously during the mast raising and lowering process via a linkage mechanism.

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