Cylindrical rudder for vessel

Abstract

To provide a cylindrical rudder for vessel generating significantly greater steering force and turning moment in comparison to a conventional rudder.SOLUTION: An outer frame (2) of D shape cross section having an arc frame (3) having a propeller shaft (7) and a string board (6) connecting a pair of end edges (4,5) of the arc frame (3) and a rudder shaft (10) attaching the string board (6) of the outer frame (2) to a bottom of a vessel rotatably are provided in a cylindrical rudder for vessel. A cylindrical range formed by the outer frame (2) is completely separated from a propulsion region formed by a propeller of the vessel along the propeller shaft (7), rotating the outer frame (2) around the rudder shaft (10), and a rudder angle of the outer frame (2) against the propeller shaft (7) is varied.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cylindrical rudder for a ship that generates high steering force and high turning moment and has excellent maneuverability. [Background technology]

[0002] The following Patent Document 1 shows a Becker rudder in which a flap plate rotatably connected to the rear part of the rudder plate by a hinge shaft is divided into an upper hinge shaft and a lower hinge shaft, and each hinge shaft is fixed to the front part of the flap plate. The Becker rudder has a structure in which the upper hinge shaft is supported by an upper bearing provided on the rudder plate to support radial and thrust loads, and the lower hinge shaft is supported by a lower bearing also provided on the rudder plate to support radial loads, and the flap plate is supported by a lower bearing provided on the rudder plate to support radial and thrust loads. The Becker rudder, which supports the upper and lower hinge shafts by upper and lower bearings to support the radial and thrust loads of the flap plate, has the advantage of not requiring separate support structures and upper and lower bearings with complex structures.

[0003] Patent document 2 shows the Kort nozzle developed by Ludwig Kort, which is equipped with a nozzle ring that forms a wall and surrounds the ship's propeller, and is configured to be rotatable about a vertical axis. At least two openings, which are provided substantially diagonally on the diameter of the cylindrical wall of the Kort nozzle, have inner and outer opening areas. The Kort nozzle has the advantage of avoiding or reducing the occurrence of recirculation or swirl at any angular position relative to the ship's longitudinal axis, forming a uniform flow pattern all around, and preventing the occurrence of recirculation or swirl.

[0004] Patent Document 3 shows a ship rudder in which the longitudinal chord length of the rudder lower end face of the rudder where the lower end vortex control plate is provided is the lower end rudder length, and the range of 5% to 15% of the lower end rudder length behind the front end of the rudder lower end face is the lower end first region. This ship rudder has a structure in which the range of 5% to 50% of the lower end rudder length in front of the rearmost end of the rudder lower end face is the lower end second region, the front end of the lower end vortex control plate is located in the lower end first region, and the rear end of the lower end vortex control plate is located in the lower end second region, and the width of the lower end vortex control plate is 5% to 30% of the rudder width of the rudder lower end face at the front and rear positions over at least 80% of the longitudinal direction of the lower end vortex control plate to form the lower end vortex control plate. In addition, the upper water flow control plate, which is located at the top end of the propeller tip rotation circle, straightens out the turbulent water flow with a tip vortex from the propeller tip and directs it onto the surface of the rudder, which has the advantage of increasing the steering force of the rudder and reducing the resistance of the rudder.The small resistance of the upper water flow control plate itself reduces the resistance of the entire rudder and increases the propulsive force. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3769708 [Patent Document 2] Patent No. 5184907 [Patent Document 3] Patent No. 6643404 Summary of the Invention [Problem to be solved by the invention]

[0006] The inventor has developed a revolutionary cylindrical rudder for ships that has never been proposed before. The new cylindrical rudder for ships generates significantly larger steering force and turning moment than conventional rudders, improving maneuverability and producing various excellent effects as described below. [Means for solving the problem]

[0007] The cylindrical rudder (1) for a ship of the present invention comprises an outer frame (2) of D-shaped cross section having an arc frame (3) and a chord plate (6) connecting a pair of end edges (4, 5) of the arc frame (3) and disposed along a propeller shaft (7), and a rudder stock (10) for rotatably mounting the chord plate (6) of the outer frame (2) to the bottom of the hull. The cylindrical region formed by the outer frame (2) is separated along the propeller shaft (7) from the propulsion region formed by the propeller of the ship, and the rudder angle of the outer frame (2) relative to the propeller shaft (7) is changed by rotating the outer frame (2) around the rudder stock (10). Effect of the Invention

[0008] The cylindrical rudder (1) for a ship of the present invention, which has an outer frame (2) with a D-shaped cross section mounted on the propeller shaft (7) away from the propulsion area of ​​the propeller of the ship, has the following advantages. (1) The cylindrical rudder (1) of the present invention has a D-shaped cross section, i.e. a cylindrical outer frame (2), which has a larger effective area than the conventional flat rudder, and generates high steering force. (2) The longest distance X from the center of gravity of the ship to the center of the rudder R and high lift F N The ship turning moment N expressed as the product of R It also has a large turning radius, allowing the ship to change course quickly and easily. (3) The main water flow behind the propeller is always straightened by passing through the outer frame (2) of the cylindrical rudder (1), so the ship's propulsion energy loss is small. [Brief description of the drawings]

[0009] The accompanying drawings show: [Figure 1] FIG. 1 is a perspective view of a cylindrical rudder for a ship according to the present invention; [Diagram 2] Cross-sectional view of the ship's tubular rudder shown in Figure 1 [Diagram 3] Side view of a steering device attached to a cylindrical rudder for a ship [Figure 4] FIG. 1 is a perspective view showing the relationship between a marine tubular rudder and a propeller. [Diagram 5] FIG. 1 is a plan view showing an outer frame and a swing shaft rotatably attached to the bottom of a ship. [Figure 6] A plan view showing the outer frame rotated from Figure 5 at a steering angle of 0 degrees to a steering angle of 35 degrees. [Figure 7] Dynamics of the turning movement of the ship during steering and the various forces acting on the rudder [Figure 8] FIG. 1 is a side view showing the dimensions of the cylindrical rudder for ships of the present invention used in a numerical analysis test. [Figure 9] A side view showing the dimensions of the comparative rudder I used in the numerical analysis test. [Figure 10] Side view showing the dimensions of the comparative rudder II used in the numerical analysis test DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a cylindrical rudder for a ship according to the present invention will now be described with reference to the accompanying drawings. As shown in Figures 1 and 2, the cylindrical rudder (1) for a ship of the present invention comprises an outer frame (2) of D-shaped cross section having a chord plate (6) connecting a pair of end edges (4, 5) of the arc frame (3) and the arc frame (3) and arranged along a propeller shaft (screw propeller shaft) (7), and a rudder stock (10) for rotatably mounting the chord plate (6) of the outer frame (2) to the bottom of the ship on a horizontal plane along a vertical axis (8). The rudder stock (10) of the cylindrical rudder (1) is mounted rotatably (swingably) around the vertical axis (8) from the bottom of the ship, at a certain distance behind the propeller (i.e., the screw propeller (30) of Figure 4, which is rotatably mounted to the rear bottom of the ship and navigates the ship. The screw propeller (30) is mounted adjacent to the cylindrical rudder (1).

[0011] In the present invention, the outer frame (2) and the rudder stock (10) are attached to the ship behind the screw propeller (30) constituting the propeller that drives the ship. The cylindrical area formed by the outer frame (2) is separated along the propeller shaft (7) from the propulsion area formed by the propeller of the ship. The outer frame (2) is rotated around the rudder stock (10) to change the rudder angle of the outer frame (2) relative to the propeller shaft (7). A rib (16) is fixed to the bottom wall (2c) of the outer frame (2) and the bottom surface (6a) of the chord plate (6) along the propeller shaft (7), a shaft tube (17) is fixed vertically to the rear edge (16a) of the rib (16), and a movable shaft (13) is arranged inside the shaft tube (17). The inner diameter of the outer frame (2) is preferably within a range of 0.8 to 1.5 times the diameter of the screw propeller (30). In addition, when a screw propeller (30) is used as a ship's propeller, it is preferable that the cylindrical region formed by the outer frame (2) is separated from the propulsion region of the screw propeller (30) along the propeller shaft (7) by a distance of 0.1 to 7.0 times, particularly 0.2 to 3.0 times, the diameter of the screw propeller (30).

[0012] A steering device (11) for swinging a rudder (flap) (15) is attached to the rear surface (2a) of the outer frame (2). A swing shaft (12) to which the steering device (11) is connected is immovably, rotatably and vertically attached to a fixed position on the bottom of the ship. The steering device (11) includes a telescopic rod (25) having one end fixed radially and horizontally to the swing shaft (12), and a connecting pipe (14) disposed radially and horizontally on the swing shaft (12) and having an internal cavity into which the other end of the telescopic rod (25) is slidably engaged. A known mechanism can be used for the slidable engagement structure between the telescopic rod (25) and the connecting pipe (14).

[0013] The upper end of the rudder plate (15) is fixed to the bottom of the connecting pipe (14), so that the outer frame (2) rotates around the rudder stock (10) when the rudder stock (10) rotates, and the movable shaft (13) also rotates around the rudder stock (10). When the movable shaft (13) rotates around the rudder stock (10), the connecting pipe (14) and the rudder plate (15) also rotate around the swing shaft (12). A shaft tube (17) having a cylindrical bracket (17a) is provided on the rear edge (16a) of the rib (16). The movable shaft (13) is arranged inside the cylindrical bracket (17a), and the hinge (15a) of the rudder plate (15) is connected to the movable shaft (13) so that the rudder plate (15) can rotate (swing) around the movable shaft (13). The outer frame (2), the rib (16) and the movable shaft (13) rotate together with the rotation of the rudder stock (10), and at the same time, the connecting pipe (14), the rudder blade (15) and the telescopic rod (25) rotate together with the oscillating shaft (12), so that the rudder blade (15) rotates (revolves) around the rudder stock (10) and rotates (oscillates) around the movable shaft (13).

[0014] Figures 1, 4 and 5 show the cylindrical rudder (1) with a rudder angle of 0 degrees before the cylindrical rudder (1) is operated. When changing the rudder angle of the cylindrical rudder (1), the ship's steering device is driven by a manual steering device, an electric or hydraulic power steering device, an automatic steering device, or the like. When the steering device rotates the rudder stock (10) counterclockwise, the outer frame (2) of the cylindrical rudder (1) is rotated counterclockwise, for example, from the rudder angle of 0 degrees in Figure 5 to a rudder angle of 35 degrees in Figure 6. Since the rib (16) and the connecting pipe (14) rotate around the rudder stock (10) together with the rotation of the outer frame (2), the connecting pipe (14) and the rudder blade (15), which rotate around the swing shaft (12), also rotate (revolve) around the rudder stock (10) and at the same time rotate (swing) around the moving shaft (13).

[0015] As shown in Figures 5 and 6, when the rudder stock (10) is rotated, the moving shaft (13) rotates around the rudder stock (10), so that the distance between the swing shaft (12) and the connecting pipe (14) changes. Therefore, the telescopic rod (25) slides in the connecting pipe (14), changing the relative length between the connecting pipe (14) and the swing shaft (12), and the rudder blade (15) rotates around the rudder stock (10) and moves to a rudder angle corresponding to the rotation angle of the rudder stock (10) [for example, the same angle as the rotation angle of the rudder stock (10)] around the moving shaft (13). In this way, the plank rudder (15), which swings around the moving shaft (13) and is held at that rudder angle, reinforces the rudder force of the tubular rudder (1) and the ship's turning moment. When the oscillating shaft (12) rotates, the connecting pipe (14) and the rudder blade (15) rotate around the rudder stock (10) and swing around the moving shaft (13), while the telescopic rod (25) slides within the connecting pipe (14) to absorb the changing gap between the oscillating shaft (12) and the moving shaft (13).

[0016] When the power steering device is driven in the reverse direction, the rudder stock (10) rotates in the reverse direction, so that the outer frame (2), the rib (16) and the barrel (17) rotate around the rudder stock (10) together with the rudder stock (10) from the rudder angle of 0 degrees shown in FIG. 5 to the opposite rudder angle of -35 degrees.

[0017] In this way, when the power steering device of the steering plate device (11) is driven to rotate the rudder stock (10), the outer frame (2), the rib (16) and the barrel (17) rotate around the rudder stock (10) integrally with the rudder stock (10) from a rudder angle of 0 degrees to a rudder angle of ±35 degrees as shown in Fig. 5, so that the moving shaft (13) or the rudder blade (15) in the barrel (17) rotates, i.e., revolves around the rudder stock (10) and at the same time rotates, i.e., swings, within the barrel (17). At this time, the moving shaft (13) or the rudder blade (15) rotates, i.e., swings, within the barrel (17) and rotates, i.e., revolves around the rudder stock (10) in a direction away from the swing shaft (12), so that the connecting pipe (14) moves away from or approaches the swing shaft (12).

[0018] By the rotation of the moving shaft (13) around the rudderstock (10), the plank rudder (15) rotates around the rudderstock (10) and also rotates (swings) around the moving shaft (13) at an angle corresponding to or the same as the rotation angle of the rudderstock (10). At this time, the connecting pipe (14) moves away from or close to the swinging shaft (12), so that the telescopic rod (25) in the connecting pipe (14) maintains its connected state with the swinging shaft (12), the moving shaft (13) and the plank rudder (15) while maintaining its engagement state in the connecting pipe (14).

[0019] The rudder dynamics of a ship is explained in Fig. 7. The lift force F acting on the rudder N and drag force F T The vector sum of and is the rudder force (direct rudder pressure) F R Then, when the steering angle is small, the high lift F N High steering force F R Approximately equal to A R is the rudder area, ρ is the density of water, C FR is the steering coefficient, and F is the lift coefficient. N , U is the relative water flow velocity into the rudder, F is the rudder force R , rudder direct pressure F RY , and the rudder angle is δ, the lift force F N and steering force F R is represented by formulas (A) and (B). (A) F N =F RY =N R cos δ (B) F R =(1 / 2) ρ A R ·U 2 C FR

[0020] Also, the distance from the center of gravity of the hull to the center of gravity of the rudder is X R Then, when the rudder angle is small, the turning moment of the hull is N R is expressed by the practical formula (C). (C) N R =F N X R cos δ Therefore, when the steering angle is small, the high lift F N is effectively a high steering force F R It means the longest distance X from the center of gravity of the hull to the center of gravity of the rudder.R and high lift F N The high turning moment N when the ship is turning is expressed as the product of R The area of ​​the cylindrical rudder (1) that is mounted at a distance along the propeller shaft (7) from the propulsion area where the ship's propeller acts is a large distance X from the ship's center of gravity to the rudder center when the distance is larger than that of a conventional rudder. R and high lift F N The ship turning moment N expressed as the product of R It also has a large turning radius, allowing the ship to change course quickly and easily.

[0021] A numerical analysis test using computer simulation to confirm the action and effect of the cylindrical rudder for ships (1) according to the present invention was conducted at the Fluid Machinery Laboratory of Tokushima University in December 2022. ANSYS 18.0 CFX analysis software was used for the numerical analysis test. The diameter D of the screw propeller was D = 1100 mm, the external fluid region was a cylinder with a diameter of 6D, the inlet surface of the screw propeller was located 4D from the inlet where the fluid flows into the external fluid region, and the outlet surface of the screw propeller was located 10D away from the outlet where the fluid flows out of the external fluid region. X-direction area A = 981754 mm 2 The shape of the cylindrical rudder (1) for ships of the present invention used in the numerical analysis test is shown in FIG. 10. The area A1 in the X direction is A1=747864 mm 2 The shape of the comparative rudder I having the above is shown in Figure 9, and the area A2 in the X direction is A2 = 253800 mm 2 The shape of the comparative rudder II having the above structure is shown in Fig. 10.

[0022] The results of the numerical analysis test are shown in Table 1 below. The mechanical unit is N (Newton), and the force in the X-axis direction is the lift force F N , the force in the Z-axis (screw propeller axis) direction is the drag force F T Represents.

[0023] [Table 1]

[0024] As a result of the experiment, at a steering angle of 20 degrees, the cylindrical rudder of the present invention has a lift force F of -4925N. N On the other hand, comparative rudder I generates -3723N and comparative rudder II generates -1264N. If the rudder angle is δ, the rudder force is N R is N R =F N / cos δ, and the lift force F N , that is, rudder direct pressure F RY The lift force F of the cylindrical rudder of the present invention is proportional to N It was found that the generated rudder force N was more than 1.3 times that of Comparative Rudder I and about 3.9 times that of Comparative Rudder II. R is the generated lift force F N At a rudder angle of 35 degrees, the cylindrical rudder of the present invention has a lift force F of -8324N. N In contrast, comparative rudder I generates -4127N and comparative rudder II generates -1400N, so the lift F of the cylindrical rudder of the present invention at a rudder angle of 35 degrees is N is twice that of Comparative Rudder I and about six times that of Comparative Rudder II. Therefore, the cylindrical rudder of the present invention has a remarkably superior lift force F compared to a normal flat rudder. N , that is, the steering force N R occurs.

[0025] [Table 2]

[0026] Lift in the X direction is F N [N], and the density of water is ρ [kg / m 3 ], characteristic speed (propeller tip peripheral speed) is U [m / s], and characteristic area is S [m 2 ], and the resistance in the Z-axis direction is F T [N], and the representative area is A [m 2 ], and the characteristic speed (propeller tip speed) is U [m / s], then the lift coefficient C L and the drag coefficient C D are calculated by the formulas (D) and (E), respectively. (D) C L =F N / (1 / 2 ρ U 2 S) (E) C D =F T / (1 / 2 ρ U 2 A)

[0027] Table 2 shows the lift coefficient C against the change in rudder angle. L and the drag coefficient C D The change in lift coefficient C of the cylindrical rudder (1) of the present invention is shown. L is 6.63×10 at a steering angle of 20 degrees as shown in Table 2. -3 , 1.12×10 at 35 degree steering angle -2 6.58×10 -3 , 7.29×10 at 35 degree steering angle -3 Therefore, the cylindrical rudder (1) of the present invention has a large lift coefficient at a steering angle of 20 degrees or more, and in particular, the lift coefficient C of the cylindrical rudder at a steering angle of 35 degrees is L is 1.5 times that of Comparative Rudder I, so ships equipped with a cylindrical rudder can travel on the water at high speeds.

[0028] The drag coefficient C of the cylindrical rudder (1) of the present invention D is 2.81 x 10 at a steering angle of 20 degrees -3 , 8.30×10 at 35 degree steering angle -3 In contrast, the steering angle of the comparative rudder I is 20 degrees, which is 3.36 x 10 -3 , 5.55×10 at 35 degree steering angle -3 Therefore, the cylindrical rudder (1) of the present invention has a large drag coefficient C at a steering angle of 35 degrees. D The steering force is large, so the ship can turn with a small turning radius and a large resistance to the movement of the ship at the turning position. For work boats, towing boats, push boats, and tugboats, the drag coefficient C D That is, a large braking force is advantageous.

[0029] The above embodiment can be modified in various ways. For example, the moving shaft (13) is attached to the rear surface (2a) of the outer frame (2) in the example shown, but the moving shaft (13) of the steering device (11) can be attached to the front surface (2b) of the outer frame (2). The example shown uses a screw propeller as a propeller, but a water jet propeller, a Voith Schneider propeller, or a pod propeller may be used instead of the screw propeller. Although the shaft tube (17) formed of a single cylindrical material is shown in Figures 1 and 3, the shaft tube (17) may be formed of multiple cylindrical materials arranged on the same axis instead of a single cylindrical material. In addition, if multiple screw propellers or other types of propellers are installed on one ship and multiple tubular rudders (1) are provided behind the propellers, the steering force and turning moment of the tubular rudders (1) are further strengthened. In the above embodiment, an example is shown in which the telescopic rod (25) is fixed to the pivot shaft (12), and the connecting pipe (14) that connects the telescopic rod (25) telescopically is fixed to the plank rudder (15). However, conversely, the connecting pipe (14) may be fixed to the pivot shaft (12), and the telescopic rod (25) that connects to the connecting pipe (14) telescopically may be fixed to the plank rudder (15).

[0030] In the embodiment of the present invention, in addition to the effects (1) to (3) described in paragraph 0008, the following effects are further obtained. (4) The cylindrical rudder (1), which has a rudder blade area of ​​about 4.14 times the rudder blade area of ​​the rudder body plus 3.14 times the diameter of the outer frame (2), receives about four times the thrust compared to a conventional single-plate rudder, thereby improving turning force during steering. (5) The length of the front part of the rudder is shorter than that of a normal flat rudder, minimizing the resistance of the water flow passing through the annular frame, so that the water flows more smoothly inside the outer frame (2). (6) The oscillating shaft (12) rotates with the rotation of the rudder stock (10), and the plate rudder (15) oscillates around the moving shaft (13) thereby reinforcing the steering force of the cylindrical rudder (1) and the ship's turning moment. (7) Lift force F acting on both sides of the rudder due to the influence of the swirling flow of the propeller NIn contrast, the cylindrical rudder for ships (1) of the present invention does not vibrate even when subjected to the rotating flow of the propeller, and has a product life of more than 10 years. (8) Even in a ship in which the propeller shaft is installed on the same axis as the rudder, the propeller shaft can be efficiently attached and detached without the need to attach and detach the tubular rudder (1). (9) With a single-plate rudder, the water flow behind the propeller bounces up at the rear of the hull, causing energy loss. However, with the present invention, the water flows inside the tubular rudder (1), making it possible to utilize the thrust generated by the propeller without waste. (10) Whether the tubular rudder (1) is turned to the right or left, quick rudder response is obtained, and the ship can turn with the same turning circle on either side, so the ship has good straight-line stability. On the other hand, a single-plate rudder has different turning characteristics on the left and right. (11) The vessel has the characteristic of turning in the direction the rudder is turned even when reversing. (12) The forward tip of the outer frame (2) of the tubular rudder (1) made of steel can be chamfered or radiused to reduce water flow resistance. [Industrial Applicability]

[0031] The cylindrical rudder for a ship of the present invention can be attached to a wide range of ships, from small ships to large power-driven ships, and can generate a large lift force to steer the ship. [Explanation of symbols]

[0032] (1) cylindrical rudder for ships, (2) outer frame, (2a) trailing edge, (2b) leading edge, (2c) bottom, (3) arc frame, (4,5) end edge, (6) chord plate, (6a) bottom, (7) propeller shaft, (8) vertical shaft, (10) rudder stock, (11) steering gear, (12) swing shaft, (13) moving shaft, (14) connecting pipe, (15) flap, (16) rib, (16a) trailing edge, (17) shaft tube, (18) reinforcing plate, (19) lower shaft, (25) telescopic rod, (30) propeller (screw propeller),

Claims

1. An outer frame having a D-shaped cross section, the outer frame having a circular arc frame and a chord plate connecting a pair of end edges of the circular arc frame and disposed along the propeller shaft; and a rudder stock for rotatably mounting the chord plate of the outer frame to the bottom of the ship, The cylindrical region defined by the outer frame is spaced apart along the propeller axis from a propulsion region defined by a propeller of the vessel; A cylindrical rudder for a ship, characterized in that the rudder angle of the outer frame relative to the propeller shaft is changed by rotating the outer frame around the rudder shaft.

2. 2. The cylindrical rudder for a vessel according to claim 1, wherein the propeller is selected from a screw propeller, a water jet propeller, a Voith Schneider propeller, and a pod propeller.

3. The propulsion device that propels the ship is a screw propeller.

3. A marine cylindrical rudder according to claim 2, wherein an outer frame of the cylindrical rudder and a rudder stock are attached to the ship rearward of the screw propeller.

4. 2. A cylindrical rudder for a ship as claimed in claim 1, wherein a rib is fixed to the bottom wall of the outer frame and to the chord plate along the propeller shaft, a shaft cylinder is fixed vertically to the rear edge of the rib, and a moving shaft is arranged within the shaft cylinder.

5. Equipped with a steering device attached to the rear or front of the outer frame, The steering plate device comprises a swing shaft spaced apart from the rudder stock of the outer frame and rotatably attached parallel to the rudder stock, a moving shaft attached to the rear or front surface of the outer frame, and a plank rudder rotatably attached to the moving shaft.

6. A rib is fixed to the bottom wall of the outer frame and the chord board along the propeller shaft, 2. A cylindrical rudder for a vessel according to claim 1, wherein the moving shaft is attached to the rear surface of the outer frame in parallel with the ribs.

7. The swing shaft is connected to a connecting pipe to which the rudder is fixed and a telescopic rod connected to the connecting pipe so as to be telescopically movable.

6. A cylindrical rudder for a ship according to claim 5, wherein the angle of the connecting rod and the telescopic rod relative to the propeller shaft is changed by the rotation of the oscillating shaft, and the plate rudder is oscillated around the moving shaft to change the angle of the plate rudder relative to the propeller shaft.

8. The upper end of the rudder is fixed to the connecting pipe. The rib of the outer frame has a cylindrical bracket, 8. A marine tubular rudder according to claim 7, wherein the rudder blade rotates about a movement axis disposed within the cylindrical bracket.

9. 9. A cylindrical rudder for a vessel according to claim 8, wherein the outer frame, the ribs and the moving shaft rotate together with the rotation of the rudder stock, and the rudder blade swings about the moving shaft.

10. 2. The cylindrical rudder for a vessel according to claim 1, wherein when the rudder stock is rotated around the vertical axis, the outer frame and the movable shaft rotate at the same angle together with the rudder stock, and the revolution and rotation of the movable shaft around the rudder stock causes the telescopic rod to extend and retract relative to the connecting pipe, so that the plate rudder is inclined at an angle corresponding to the rotation angle of the rudder stock.

11. The cylindrical region defined by the outer frame is spaced apart along the propeller axis from a propulsion region defined by a propeller of the vessel; 2. A cylindrical rudder for a vessel according to claim 1, wherein the rudder frame is rotated around the rudder shaft to change the rudder angle of the rudder frame relative to the propeller shaft.

12. 2. A cylindrical rudder for a vessel according to claim 1, wherein the inner diameter of the outer frame is formed within a range of 0.8 to 1.5 times the diameter of the screw propeller constituting the propulsion device.

13. 10. The cylindrical rudder for a vessel according to claim 9, wherein when a screw propeller is used as a propeller for the vessel, the cylindrical region formed by the outer frame is separated from the propulsion region of the screw propeller along the propeller shaft by a distance of 0.1 to 7.0 times the diameter of the screw propeller.

14. 12. The cylindrical rudder for a vessel according to claim 11, wherein the cylindrical region formed by the outer frame is spaced from the propulsion region of the screw propeller along the propeller shaft by a distance of 0.2 to 3.0 times the diameter of the screw propeller.

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