Device for removing entanglement on fishing boat propeller

Abstract

The invention discloses a device for removing entanglements on a fishing boat propeller, which belongs to the technical field of propeller manufacturing, comprises a shaft body and a propeller arranged at the end part of the shaft body, and is characterized by further comprising a cutting mechanism synchronously rotating with the shaft body, the cutting mechanism comprises a connecting rod circumferentially arranged around the shaft body, and the connecting rod is connected with a blade; one end of the connecting rod can axially move relative to the shaft body so as to adjust the position of the blade relative to the propeller, the connecting rod is composed of two rod bodies hinged to each other, a fixed sleeve and a sliding sleeve are arranged on the shaft body, the two tail ends of the connecting rod are hinged to the fixed sleeve and the sliding sleeve respectively, the sliding sleeve is located between the fixed sleeve and the propeller, and an elastic piece is connected between the sliding sleeve and the fixed sleeve. The cutting position of the blade can be automatically adjusted according to the rotating speed of the propeller, the adaptive cutting range is obtained, and a beneficial scheme is provided for entanglement removal and propeller power.

Description

Technical Field

[0001] This invention belongs to the field of shipbuilding technology, specifically relating to a device for removing debris entangled on the propeller of a fishing boat. Background Technology

[0002] Ships, submarines, and other vessels frequently encounter the problem of propellers becoming entangled with suspended debris during operation. This is primarily due to the exposed propeller shaft and high-speed rotating blades; once entangled by aquatic plants or discarded fishing nets, the entanglement deepens and tightens, increasing propeller drag and wasting energy. In severe cases, it can render the main engine inoperable, forcing a shutdown and causing loss of control, potentially leading to unpredictable consequences and posing significant safety hazards. As the conditions in the waters where operations are required become increasingly complex, entanglement of the propeller shaft significantly increases the resistance to propeller drive, further hindering the vessel's normal operation. Most existing anti-entanglement devices use a cutting blade to directly cut the entangled material on the circumference of the propeller shaft. The cutting effect is generally poor and the propeller shaft is easily damaged. At the same time, the entangled material can only be cut when the unmanned vessel is stationary. The unmanned vessel shaft needs to be treated for entanglement every once in a while, which is cumbersome and increases the workload.

[0003] Korean invention patent application number KR1020170172882 discloses a device for preventing propeller damage. The device includes a first shaft with blades attached and rotatably mounted on the hull; a sensor unit that detects the diameter of the first shaft to determine the presence of impurities on it; and a cutting unit located on the periphery of the first shaft and movable along its axial direction to remove impurities. This invention uses visual judgment combined with the cutting unit to remove entangled impurities during ship navigation, thus protecting the propeller. The applicant believes that this invention has the following areas for improvement: the sensor's visual detection has a lag, and blades wrapped around the shaft are difficult to detect, making it difficult to control the cutting unit to perform cutting actions in a timely manner; the first and second cutters remove impurities only when they intersect, resulting in a limited cutting range, and it cannot effectively handle entangled materials at non-intersecting locations. Summary of the Invention

[0004] The purpose of this application is to provide a device for removing entangled material from the propeller of a fishing boat, which has the advantages of real-time cleaning of entangled material, avoiding damage to the propeller, requiring no downtime operation, and providing comprehensive cleaning coverage.

[0005] The technical solution adopted by the present invention to achieve the above objectives is as follows: A device for removing debris entangled on a fishing boat propeller includes: a shaft with a propeller at one end; characterized in that it further includes a cutting mechanism that rotates synchronously with the shaft, the cutting mechanism including a connecting rod arranged circumferentially around the shaft, the connecting rod being connected to a blade, one end of the connecting rod being axially movable relative to the shaft to adjust the position of the blade relative to the propeller.

[0006] Preferably, the blade is always positioned on one side of the propeller connecting shaft, and the blade never comes into contact with the propeller.

[0007] Preferably, the connecting rod consists of two rods that are hinged to each other. A fixed sleeve and a sliding sleeve are provided on the shaft. The two ends of the connecting rod are respectively hinged to the fixed sleeve and the sliding sleeve. The sliding sleeve is located between the fixed sleeve and the propeller. An elastic element connects the sliding sleeve and the fixed sleeve.

[0008] Preferably, the connecting rod includes a long rod and a short rod. One end of the long rod is hinged to the fixed sleeve, the middle part of the long rod is hinged to one end of the short rod, the other end of the long rod is provided with a blade, and the other end of the short rod is hinged to the sliding sleeve. The multiple long rods are distributed in a divergent manner towards the propeller.

[0009] Preferably, the elastic element is a cylindrical spring, which is sleeved on the shaft.

[0010] Preferably, the rod is a frame structure consisting of two strip-shaped pieces spaced apart and connected, with clamping blocks symmetrically arranged between the two pieces of the long rod, and blades detachably provided between the clamping blocks via threaded parts.

[0011] Preferably, the sliding sleeve is provided with a guide plate, which is arranged around the outer circumference of the sliding sleeve and configured to contact the positively impacting water and carry the sliding sleeve close to the propeller.

[0012] Preferably, the guide plate has a guide portion that expands in the direction of the propeller. The guide portion is a conical surface and is made of elastic rubber material, which can contact and compress with the propeller to prevent the sliding sleeve from colliding with the propeller.

[0013] Preferably, the fixed sleeve is fixed to the shaft body, and the sliding sleeve is axially slidably connected to the shaft body.

[0014] Preferably, the axes of the two rods are always coplanar with the axis of the shaft.

[0015] Compared with the prior art, this invention has the following advantages: The cutting mechanism adjusts the blade position by axial movement of the connecting rod, realizing adaptive adjustment of the cutting range. At high speed, it narrows to reduce resistance, and at low speed, it expands the range to enhance cutting ability; the dynamic annular cutting trajectory of the blade covers the root of the propeller blade, eliminating blind spots and effectively removing entangled objects; the double connecting rod, sliding sleeve, and elastic element cooperate to buffer displacement and avoid rigid collisions, ensuring smooth blade switching and extending the life of the device; the guide plate converts water flow impact into driving force, realizing real-time adjustment of blade position with rotation speed and rapid response; the frame-type rod body reduces weight and load, the detachable blade facilitates replacement and maintenance, the connecting rod forms a protective enclosure in the narrowed state, and the spring blocks sand and gravel to protect the shaft; the coplanar design of the rod body ensures stable motion trajectory, avoids interference, improves cutting coordination and reliability, is suitable for high humidity and high salt environments, and has a reliable mechanical structure. Attached Figure Description

[0016] Figure 1 A side view of a device for removing debris entangled on a fishing boat propeller; Figure 2 A perspective view of a device for removing debris entangled on the propeller of a fishing boat; Figure 3 This is a schematic diagram showing the positions of the fixed sleeve and the sliding sleeve on the shaft. Figure 4 This is a schematic diagram of the guide vane and its guide section. Figure 5 This is a schematic diagram of the linkage attitude under high-speed propeller rotation. Figure 6 This is a schematic diagram of the linkage attitude when the propeller is rotating at low speed. Figure 7 This is a schematic diagram showing the positions of the sliding sleeve and the fixed sleeve in Embodiment 2 of the present invention.

[0017] Reference numerals: Shaft 1; Propeller 2; Long rod 31; Short rod 32; Fixed sleeve 41; Sliding sleeve 42; Elastic element 43; Blade 5; Guide plate 6; Guide section 61. Detailed Implementation

[0018] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings: Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0019] Example 1: See Figures 1-2A device for removing debris entangled on a fishing boat propeller includes: a shaft 1, with a propeller 2 at one end of the shaft 1; characterized in that it further includes a cutting mechanism 3 that rotates synchronously with the shaft 1; the cutting mechanism 3 includes a connecting rod arranged circumferentially around the shaft 1, with a blade 5 connected to the connecting rod; one end of the connecting rod is axially movable relative to the shaft 1 to adjust the position of the blade 5 relative to the propeller 2. The shaft 1 refers to the power transmission component that carries the propeller 2, with one end connected to a drive device inside the hull and the other end connected to the propeller 2.

[0020] When shaft 1 drives propeller 2 to rotate, cutting mechanism 3 rotates synchronously. During rotation, one end of the connecting rod moves axially with shaft 1, changing the position of blade 5 relative to propeller 2 and the distance between blade 5 and shaft 1. This allows for automatic adjustment of the cutting range of blade 5 during ship movement. Without increasing the number of blades or expanding the blade size, the cutting coverage of blade 5 is expanded, facilitating more effective cutting of entangled materials on the shaft 1 and blades of propeller 2, thus improving the removal effect and efficiency. This solution achieves adaptive adjustment through a purely mechanical structure, starting operation the instant propeller 2 starts, with blade 5 position matching the speed change in real time. Traditional cutting blades are fixed on the outside to form static protection; this solution dynamically adjusts the cutting range of blade 5, avoiding increased fluid resistance in cutting mechanism 3 at high speeds and expanding the working area at low speeds. Cutting operations are performed synchronously with navigation, eliminating the need for maintenance shutdowns. The mechanical linkage structure offers superior reliability compared to electronic control systems, making it particularly suitable for high-humidity and high-salinity shipboard operating environments.

[0021] The blade 5 is always positioned on one side of the shaft 1 connecting the propeller 2, and the blade 5 never contacts the propeller 2. The blade 5 is arranged in the same area on the same side of the connection between the propeller 2 and the shaft 1. Specifically, the blade 5 can be installed at the end of the connecting rod and the connecting rod is distributed circumferentially around the shaft 1. This arrangement ensures that the blade 5 only acts on the winding material at the connection between the shaft 1 and the propeller 2 during rotation, avoiding interference with the blades of the propeller 2.

[0022] The connecting rod consists of two rods that are hinged to each other. A fixed sleeve 41 and a sliding sleeve 42 are provided on the shaft 1. The two ends of the connecting rod are hinged to the fixed sleeve 41 and the sliding sleeve 42 respectively. The sliding sleeve 42 is located between the fixed sleeve 41 and the propeller 2. An elastic element 43 is connected between the sliding sleeve 42 and the fixed sleeve 41.

[0023] The hinged rods refer to two rods that rotate relative to each other through a hinge point. This can be achieved by connecting the two rods with a pin. The hinge structure allows the rods to change angles as the shaft 1 rotates to accommodate the displacement of the sliding sleeve 42. The fixed sleeve 41 is a ring-shaped component fixedly connected to the shaft 1. It can be fixed to the shaft 1 by a key connection or welding, providing a stable hinge point for the connecting rod. The sliding sleeve 42 is a ring-shaped component that can slide along the axial direction of the shaft 1. It can be slidably connected to the shaft 1 by a groove. The displacement of the sliding sleeve 42 is linked to the fixed sleeve 41 via the elastic element 43 to adjust the connecting rod angle. The elastic element 43 provides elastic restoring force. Its two ends abut against the fixed sleeve 41 and the sliding sleeve 42 respectively, buffering the displacement of the sliding sleeve 42 and maintaining the correspondence between the position of the blade 5 and the rotational speed of the propeller 2.

[0024] See Figures 5-6 When the hull moves forward or backward, the shaft 1 drives the propeller 2 to rotate. At this time, the sliding sleeve 42 is impacted by the water flow in the forward or backward direction and moves away from or towards the fixed sleeve 41 along the axial direction. The elastic element 43 is stretched or compressed, and the angle of the two hinged rods changes accordingly, which in turn pushes the blade 5 closer to or away from the propeller 2. When the propeller 2 rotates at high speed, the sliding sleeve 42 moves closer to the propeller 2, the elastic element 43 is stretched, and the connecting rod drives the blade 5 to contract and move closer to the shaft 1. This reduces the projected area of ​​the blade 5 in the high-speed water flow, reduces water resistance and energy consumption, and avoids eddy current interference or structural fatigue caused by excessive extension of the blade 5, thus balancing the cutting function and navigation efficiency. When the propeller 2 rotates at low speed, the elastic element 43 returns to its original position, causing the sliding sleeve 42 to move closer to the fixed sleeve 41. The included angle formed by the two hinged rods decreases, and the blade 5 moves away from the shaft 1 with the connecting rod. At this time, the rotation radius of the blade 5 increases, that is, under the condition of limited rotation speed, the cutting line speed of the blade 5 is increased, enhancing the cutting ability of fishing nets, seaweed and other entangled objects, and avoiding the aggravation of entanglement due to insufficient power at low speed.

[0025] This solution utilizes a mechanical linkage structure to automatically adjust the position of the blade 5 according to the rotational speed. This reduces resistance at high speeds and expands the cutting range at low speeds. The elastic element 43 buffers the displacement of the sliding sleeve 42, preventing rigid structural collisions. It adapts to different working conditions without the need for sensors. The cooperation between the elastic element 43 and the sliding sleeve 42 further ensures smooth switching of the blade 5 between its retracted and extended states, avoiding cutting blind spots. Simultaneously, the hinged rod structure enhances the adaptability of the connecting rod to different distributions of wound materials, improving cutting efficiency and device reliability. It adapts to different working conditions without the need for sensors, and the cooperation between the elastic element 43 and the sliding sleeve 42 further ensures smooth switching of the blade 5 between its retracted and extended states, avoiding cutting blind spots.

[0026] See Figure 3The connecting rod includes a long rod 31 and a short rod 32. One end of the long rod 31 is hinged to the fixed sleeve 41, and the middle part of the long rod 31 is hinged to one end of the short rod 32. The other end of the long rod 31 is provided with a blade 5, and the other end of the short rod 32 is hinged to the sliding sleeve 42. Multiple long rods 31 are distributed in a divergent manner towards the propeller 2.

[0027] The long rod 31 refers to a rod-shaped component with an extended length, which can be more than twice the length of the short rod 32, and is used to support the blade 5 to form an effective cutting radius. The short rod 32 is connected to the long rod 31 through a hinge point, and is used to convert the axial displacement of the sliding sleeve 42 into the radial displacement of the blade 5. The divergent distribution refers to the radial arrangement of multiple long rods 31 around the axis of the shaft 1, including but not limited to a uniformly spaced arrangement. For example, the included angle between adjacent long rods 31 can be 15° to 45°, which is used to expand the cutting area coverage.

[0028] When the propeller 2 rotates at high speed, the sliding sleeve 42 contacts the water body in the forward direction, generating axial displacement and moving away from the fixed sleeve 41. The short rod 32 pushes the long rod 31 to rotate around the hinge point of the fixed sleeve 41. Since the middle part of the long rod 31 is hinged to the short rod 32 to form a double linkage mechanism, each blade 5 generates radial displacement with the end of the long rod 31 and converges towards the shaft 1. The divergent distribution of multiple long rods 31 causes the blades 5 to form a cutting ring around the shaft 1 when they converge. When the propeller 2 rotates at high speed, the sliding sleeve 42 moves closer to the propeller 2, causing the blades 5 to converge near the shaft 1. At low speed, the sliding sleeve 42 moves away from the propeller 2, causing the blades 5 to extend to the blade area of ​​the propeller 2. Compared with the prior art, the existing cutting unit can only move along the axial direction to perform linear cutting, while the divergent distribution of the long rods 31 causes the blades 5 to form a dynamically changing annular cutting trajectory. In existing technologies, the fixed cutting area formed by intersecting cutters cannot cover the root area of ​​the propeller 2 blades. However, this solution uses the radial displacement of the blades 5 to remove entangled material at the connection between the propeller 2 blades and the shaft 1, achieving dynamic adjustment of the cutting range of the blades 5. It automatically switches between a convergence protection mode and an extended cutting mode at different propeller 2 speeds. Multiple blades 5 distributed in a divergent pattern form an overlapping cutting area, eliminating the cutting blind spots in existing technologies, effectively removing entangled material accumulated at the root of the propeller 2 blades, and preventing secondary entanglement of fishing net residue fibers at the connection between the shaft 1 and the blades.

[0029] When the long rod 31 and short rod 32 are in the contracted state, they can form a protective wrap around the outside of the shaft 1 as the shaft 1 rotates. Compared with setting a sleeve or disc-shaped blade 5 on the shaft 1, the above solution reduces the weight of the cutting body and helps to reduce the load on the propeller 2 shaft.

[0030] The elastic element 43 is a cylindrical spring, which is sleeved on the shaft 1. The elastic deformation capability of the cylindrical spring in the axial direction can provide elastic force for axial expansion and contraction. Sleeving on the shaft 1 means that the inner diameter of the spring is adapted to the outer diameter of the shaft 1. Specifically, this can be achieved by mounting the spring around the surface of the shaft 1, so that the direction of the spring's expansion and contraction is parallel to the axis of the shaft 1, avoiding the occupation of extra space and ensuring that the direction of elastic force transmission is consistent with the direction of movement of the sliding sleeve 42.

[0031] When the propeller 2 rotates at different speeds, the sliding sleeve 42 is impacted by the water flow, causing axial displacement. The cylindrical spring fitted onto the shaft 1 generates a reverse force through compression or extension, thereby adjusting the relative position of the blade 5 and the propeller 2. For example, when the propeller 2 rotates at high speed, the sliding sleeve 42 is impacted by the water flow and approaches the propeller 2, the spring is stretched and stores elastic potential energy; when the propeller 2 rotates at low speed, the spring releases its potential energy, pulling the sliding sleeve 42 back to its original position, causing the blade 5 to move away from the shaft 1. The coaxial arrangement of the spring and the shaft 1 ensures that the elastic force transmission path coincides with the movement path of the sliding sleeve 42, avoiding lateral force components that could cause structural displacement.

[0032] The cylindrical spring ensures that the blade 5 responds quickly to position changes at different speeds, while avoiding fatigue fracture of the elastic element due to eccentric force, thus extending the service life of the device. The spring sleeved on the shaft 1 rotates with the shaft 1 and can also provide local protection for the shaft 1. Especially when the propeller 2 rotates at low speed, the spring is in a contracted state, and its own clearance is small, which can effectively block the impact of fluid carrying sand and gravel passing through at high speed on the shaft 1.

[0033] The rod body is a frame structure consisting of two spaced and connected strip-shaped plates. A clamping block is symmetrically positioned between the two plates of the long rod 31, and a blade 5 is detachably mounted between the clamping blocks via threaded fittings. The frame structure refers to a three-dimensional support structure formed by two parallel strip-shaped plates connected by transverse connectors, which can be achieved through welding or bolting. The threaded fittings are threaded fasteners, specifically stainless steel bolts and nuts, which, when tightened, create pressure to fix the clamping blocks and blade 5.

[0034] The clamping blocks are symmetrically arranged inside the blade body, forming a clamping space with a width matching the thickness of the blade 5. After the blade 5 is inserted into the gap between the clamping blocks, it is secured by bolts that pass through the clamping blocks and the blade 5, with the cutting edge of the blade 5 facing the rotation direction of the propeller 2. When the blade 5 needs to be replaced, simply loosen the bolts to remove the worn blade 5 from the gap between the clamping blocks, replace it with a new blade 5, and then retighten. The above technical solution enables quick replacement of the blade 5 and avoids structural damage caused by repeated disassembly and assembly of the rod. The frame structure reduces its own weight while maintaining the stability of the rod during cutting operations, and the symmetrical arrangement of the clamping blocks effectively prevents the blade 5 from deflecting or shifting during high-speed rotation. The rod, which is composed of blades to form a frame structure, further reduces weight compared to a solid rod, thereby reducing the rotational load on the propeller 2. At the same time, the blades can cut and break up some fragile impurities at low speeds, reducing the cutting blind zone.

[0035] See Figure 4 The sliding sleeve 42 is equipped with a guide plate 6, which surrounds the outer circumference of the sliding sleeve 42 and is configured to contact the positively impacting water and carry the sliding sleeve 42 closer to the propeller 2. The guide vane 6 refers to a plate-like structure arranged around the outer circumference of the sliding sleeve 42. The guide vane 6 generates thrust through contact with the water flow, driving the sliding sleeve 42 to move axially. The forward impact water body refers to the water flow generated in the direction of propulsion by the rotation of the propeller 2 during ship navigation, while the reverse impact water body refers to the water flow in the opposite direction to the propulsion generated by the rotation of the propeller 2 during ship navigation. This design converts the water flow impact force into the driving force for the axial movement of the sliding sleeve 42, eliminating the need for an additional power source.

[0036] When the ship is sailing, the guide plate 6 comes into contact with the water flow in the direction of propulsion of the propeller 2. The impact force of the water flow acts on the surface of the guide plate 6, pushing the sliding sleeve 42 to slide along the shaft 1 towards the propeller 2. The movement of the sliding sleeve 42 drives the linkage mechanism to adjust the relative position of the blade 5 and the propeller 2. When the ship accelerates, the impact force of the water flow increases, and the guide plate 6 pushes the sliding sleeve 42 closer to the propeller 2, causing the blade 5 to retract to reduce resistance. When the ship decelerates or stops, the impact force of the water flow weakens, the elastic element 43 pushes the sliding sleeve 42 to reset, and the blade 5 unfolds to expand the cutting range. That is, through the direct action of the guide plate 6 and the impact force of the water flow, the position of the blade 5 is automatically adjusted according to the sailing state, avoiding sensor signal processing delay and simplifying the mechanical control structure. This invention solves the problem of response lag caused by the reliance on external detection devices for cutting unit adjustment in existing technologies. By using the guide plate 6 to directly convert the kinetic energy of water into the driving force of the sliding sleeve 42, the blade 5 can adapt to the changes in the speed of the propeller 2 in real time, reducing resistance during high-speed navigation and expanding the cutting range during low-speed or stationary navigation, thereby improving the efficiency of removing entangled materials and the reliability of the device.

[0037] The guide plate 6 has a guide portion 61 that expands in the direction of the propeller 2. The guide portion 61 is a conical surface and is made of elastic rubber material, which can contact and squeeze the propeller 2 to prevent the sliding sleeve 42 from colliding with the propeller 2.

[0038] When the propeller 2 rotates at high speed, the guide section 61 is impacted by the water flow, generating axial thrust, which drives the sliding sleeve 42 to move towards the propeller 2. At this time, the conical surface of the guide section 61 converts the water flow impact force into axial displacement, causing the blade 5 to converge closer to the shaft 1. When the sliding sleeve 42 moves to its limit position, the elastic rubber material of the guide section 61 contacts the surface of the propeller 2, absorbing the impact energy through its own compression deformation, thus preventing a rigid collision between the sliding sleeve 42 and the propeller 2. During this process, the conical surface of the guide section 61 continuously guides the water flow to form axial thrust, and the elastic rubber material undergoes compression deformation upon contact with the propeller 2, creating a flexible contact interface between the sliding sleeve 42 and the propeller 2. This solves the technical problem of damage caused by rigid collision between the movable cutting blade 5 and the propeller 2 in the prior art.

[0039] The fixed sleeve 41 is fixed to the shaft 1, and the sliding sleeve 42 is axially slidably connected to the shaft 1.

[0040] The axes of the two rods are always coplanar with the axis of shaft 1. The axis of a rod refers to its centerline along its length, which can be achieved using symmetrically distributed hinge points or guide structures. For example, by symmetrically arranging the hinge points of the long rod 31 and the short rod 32 within the same radial plane of shaft 1, the rods maintain coplanarity during movement. Coplanarity means that the axis of the rod and the axis of shaft 1 are in the same plane. This can be achieved through the axially symmetrical distribution of the fixed sleeve 41 and the sliding sleeve 42. For example, the hinge points of the fixed sleeve 41 and the sliding sleeve 42 can be evenly distributed circumferentially along shaft 1, ensuring that the trajectory of the rods always lies in the same plane. Specifically, during the rotation of shaft 1, the long rod 31 and the short rod 32 are linked by the hinge relationship between the fixed sleeve 41 and the sliding sleeve 42. Since the axis of the rod is coplanar with the axis of shaft 1, the rod will not deflect or twist when moving axially, thus ensuring the trajectory stability of the blade 5 during the rotational cutting process. For example, when the sliding sleeve 42 is impacted by water flow and approaches the propeller 2, the hinge point of the long rod 31 and the short rod 32 moves along the same plane, and the blade 5 adjusts its position synchronously with the rod, forming a contracted or extended state, while avoiding the limitation of the cutting range or structural interference caused by the deviation of the rod's movement trajectory.

[0041] Compared with existing technologies, the existing cutting devices lack planar constraints on the movement trajectory of the rod, which easily leads to collisions between the cutting unit and the propeller 2 or shaft 1, and the cutting range is limited by the asymmetrical movement trajectory. This solution, through coplanar design, ensures that the rod movement is always within the same plane, which not only expands the cutting range but also avoids structural interference caused by rod deflection, improving the coordination and reliability of the cutting action.

[0042] Example 2: See Figure 7 As a preferred embodiment, based on Embodiment 1 of the present invention, the positional relationship between the fixed sleeve 41 and the sliding sleeve 42, and the connection relationship between the fixed sleeve 41, the sliding sleeve 42 and the connecting rod can also be as follows: the fixed sleeve 41 is located between the sliding sleeve 42 and the propeller 2, one end of the long rod 31 is hinged to the sliding sleeve 42, the middle part of the long rod 31 is hinged to one end of the short rod 32, the other end of the long rod 31 is provided with a blade 5, the other end of the short rod 32 is hinged to the fixed sleeve 41, and multiple long rods 31 are distributed in a divergent manner towards the propeller 2 with the sliding sleeve 42 as the center.

[0043] When the hull moves forward or backward, shaft 1 drives propeller 2 to rotate. At this time, because sliding sleeve 42 is located on the side of fixed sleeve 41 away from propeller 2, when sliding sleeve 42 is impacted by the water flow in either direction, it moves axially closer to or further away from fixed sleeve 41, causing elastic element 43 to be compressed or stretched. The two hinged rods then change angle, pushing blade 5 away from or closer to propeller 2. Specifically, when propeller 2 rotates at high speed, sliding sleeve 42 approaches propeller 2, elastic element 43 is compressed, the angle between the two hinged rods decreases, and blade 5 moves away from shaft 1 along with the connecting rod. At this time, the rotation radius of blade 5 increases. Combined with the high-speed rotation of propeller 2 carrying cutting mechanism 3, the high-speed rotating blade 5 can cut tough fibers with greater kinetic energy, effectively removing high-strength, large-area entangled materials (such as fishing nets and long aquatic plants). Furthermore, the expanded cutting range can cover the outer periphery of propeller 2, intercepting floating objects near the blades in advance and reducing the probability of entangled materials entering the blade gaps. Although the extended blade 5 increases water resistance, the ship itself needs to overcome significant water flow resistance during high-speed navigation, making the additional resistance from blade 5 relatively small. Simultaneously, active cutting reduces the risk of propeller 2 "stall" caused by entanglement, indirectly ensuring stable propulsion system output power. If a large amount of entanglement suddenly occurs at high speed, such as a large area of ​​seaweed being instantly engulfed, the cutting resistance of blade 5 will react on the linkage system, forcing the sliding sleeve 42 away from the fixed sleeve 41. Blade 5 will automatically retract closer to the shaft 1 to reduce load, preventing motor overload or drive shaft breakage, thus providing mechanical transmission protection.

[0044] When propeller 2 rotates at low speed, the sliding sleeve 42 experiences less impact from the positive water flow, causing it to move away from propeller 2. Simultaneously, the elastic element 43 is reset, increasing the angle between the two hinged rods. The blade 5 then converges with the connecting rod, moving closer to shaft 1. This reduced rotation radius decreases the probability of blade 5 contacting underwater debris. If local entanglement occurs (e.g., with a small amount of rope), the cutting range of blade 5 in its converged state is concentrated near shaft 1. With a constant shaft 1 rotation speed, the entanglement point can be quickly cut off using a "small radius, high frequency" cut, preventing the entanglement area from expanding due to blade 5 extending outwards. At low speeds, blade 5 converges closer to shaft 1, reducing the underwater projected area and mitigating hydrodynamic interference during low-speed maneuvers, such as turbulent flow during reversing or turning, thus improving control precision. Furthermore, the proximity of blade 5 to shaft 1 reduces the probability of collision with underwater obstacles, making it particularly suitable for navigation in shallow or complex waters. When propeller 2 maneuvers at low speed, the vibration amplitude of the propeller 2 shaft system is relatively large. After the blade 5 retracts, the safe distance between it and the underwater part of the hull increases, reducing the risk of collision and protecting the integrity of the blade 5 and the hull structure. The lower part of the hull refers to common hull components such as the rudder blade and the shaft 1 support.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A device for removing debris entangled on a fishing boat propeller, comprising: A shaft (1) having a propeller (2) at its end, characterized in that: it further includes a cutting mechanism that rotates synchronously with the shaft (1), the cutting mechanism including a connecting rod (3) arranged circumferentially around the shaft (1), the connecting rod (3) being connected to a blade (5), one end of the connecting rod (3) being axially movable relative to the shaft (1) to adjust the position of the blade (5) relative to the propeller (2).

2. The device for removing debris entangled on a fishing boat propeller according to claim 1, characterized in that: The blade (5) is always positioned on the side of the propeller (2) connected to the shaft (1), and the blade (5) never contacts the propeller (2).

3. The device for removing debris entangled on a fishing boat propeller according to claim 1, characterized in that: The connecting rod (3) consists of two rods that are hinged to each other. The shaft (1) is provided with a fixed sleeve (41) and a sliding sleeve (42). The two ends of the connecting rod (3) are respectively hinged to the fixed sleeve (41) and the sliding sleeve (42). The sliding sleeve (42) is located between the fixed sleeve (41) and the propeller (2). An elastic element (43) is connected between the sliding sleeve (42) and the fixed sleeve (41).

4. The device for removing debris entangled on a fishing boat propeller according to claim 3, characterized in that: The fixed sleeve (41) is fixed to the shaft (1), and the sliding sleeve (42) is axially slidably connected to the shaft (1).

5. The device for removing debris entangled on a fishing boat propeller according to claim 3, characterized in that: The axes of the two rods are always coplanar with the axis of the shaft (1).

6. The device for removing debris entangled on a fishing boat propeller according to claim 3, characterized in that: The elastic element (43) is a cylindrical spring, which is sleeved on the shaft (1).

7. The device for removing debris entangled on a fishing boat propeller according to claim 3, characterized in that: The connecting rod (3) includes a long rod (31) and a short rod (32). One end of the long rod (31) is hinged to the fixed sleeve (41), and the middle part of the long rod (31) is hinged to one end of the short rod (32). The other end of the long rod (31) is provided with the blade (5), and the other end of the short rod (32) is hinged to the sliding sleeve (42). The multiple long rods (31) are distributed in a divergent manner towards the propeller (2).

8. The device for removing debris entangled on a fishing boat propeller according to claim 3, characterized in that: The sliding sleeve (42) is provided with a guide plate (6), which is arranged around the outer peripheral surface of the sliding sleeve (42) and configured to contact the positive impact water and carry the sliding sleeve (42) close to the propeller (2).

9. The device for removing debris entangled on a fishing boat propeller according to claim 7, characterized in that: The rod is a frame structure consisting of two strip-shaped pieces spaced apart and connected. Clamping blocks are symmetrically arranged between the two pieces of the long rod (31), and the blade (5) is detachably arranged between the clamping blocks via threaded parts.

10. The device for removing debris entangled on a fishing boat propeller according to claim 8, characterized in that: The guide plate (6) has a guide portion (61) that expands in the direction of the propeller (2). The guide portion (61) is a conical surface and is made of elastic rubber material. It can contact and squeeze the propeller (2) to prevent the sliding sleeve (42) from colliding with the propeller (2).

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