Ship cylindrical rudder

Abstract

[Problem] To provide a ship cylindrical rudder for generating much larger steering force and turning moment than a conventional rudder. [Solution] An outer frame (2) of a D-shaped cross section having a circular arc frame (3) having a propeller shaft (7) and a chord plate (6) for connecting a pair of end edges (4, 5) of the circular arc frame (3), and a steering shaft (10) for rotatably mounting the chord plate (6) of the outer frame (2) to the ship bottom of the ship are provided in the ship cylindrical rudder. The cylindrical region formed by the outer frame (2) is completely separated from the propulsion region formed by the propeller of the ship along the propeller shaft (7), the outer frame (2) is rotated around the steering shaft (10), and the steering angle of the outer frame (2) with respect to the propeller shaft (7) is changed.

Description

Cylindrical rudder for ships

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

[0002] The following Patent Document 1 shows a Becker rudder in which the flap plate, rotatably connected to the rear part of the rudder 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 mounted on the rudder plate to support radial and thrust loads, thereby rotatably supporting the flap plate, and the lower hinge shaft is supported by a lower bearing also mounted on the rudder plate to support radial loads, thereby rotatably supporting the flap plate. The Becker rudder, which supports the upper and lower hinge shafts with 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 complex upper and lower bearings.

[0003] Patent Document 2 shows a Kort nozzle developed by Ludwig Kort, which has 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 provided at substantially diagonal positions 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 vortex at any angular position relative to the ship's longitudinal axis, forming all flow patterns uniformly, and preventing the occurrence of recirculation or vortex.

[0004] Patent Document 3 shows a marine rudder in which the longitudinal chord length of the rudder blade on the rudder lower end face of the rudder where the lower end vortex control plate is provided is defined as the lower end rudder length, and the range of 5% to 15% of the lower end rudder length aft of the front end of the rudder lower end face is defined as the lower end first region. This marine rudder has a structure in which the range of 5% to 50% of the lower end rudder length aft of the rearmost end of the rudder lower end face is defined as the lower end second region, the front end of the lower end vortex control plate is located within the lower end first region, and the rear end of the lower end vortex control plate is located within 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 fore-and-aft position over at least 80% of the longitudinal direction of the lower end vortex control plate. In addition, the upper water flow control plate, which is installed 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.

[0005] Patent No. 3769708 Patent No. 5184907 Patent No. 6643404

[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 greater steering force and turning moment than conventional rudders, improving maneuverability and providing various excellent operational effects, which will be described later.

[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 arranged along a propeller shaft (7), and a rudder stock (10) for rotatably attaching 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).

[0008] The cylindrical rudder (1) for a ship of the present invention, which has a D-shaped cross-section outer frame (2) mounted on the propeller shaft (7) at a distance from the propulsion area of ​​the propeller of the ship, has the following advantages: (1) The cylindrical rudder (1) of the present invention, which has a D-shaped cross-section, i.e., a cylindrical outer frame (2), has a larger effective area than the conventional flat rudder, and generates a high steering force. (2) The distance X from the center of gravity of the ship to the rudder center is large. R and high lift F N The ship turning moment N is expressed as the product of R (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 loss of propulsion energy of the ship is small.

[0009] The accompanying drawings show the following: A perspective view of the marine tubular rudder of the present invention A cross-sectional view of the marine tubular rudder shown in Figure 1 A side view of a steering device attached to the marine tubular rudder A perspective view showing the relationship between the marine tubular rudder and the propeller A plan view showing the outer frame and swing shaft rotatably attached to the bottom of the ship A plan view showing the outer frame rotated from Figure 5 at a rudder angle of 0 degrees to a rudder angle of 35 degrees A dynamic diagram of the turning movement of the hull during steering and various forces acting on the rudder A side view showing the dimensions of the marine tubular rudder of the present invention used in the numerical analysis test A side view showing the dimensions of comparative rudder I used in the numerical analysis test A side view showing the dimensions of comparative rudder II used in the numerical analysis test

[0010] An embodiment of the cylindrical rudder for ships of the present invention shown in the accompanying drawings will be described below. As shown in Figures 1 and 2, the cylindrical rudder for ships (1) of the present invention comprises an outer frame (2) of D-shaped cross section having an arc-shaped frame (3) and a chord plate (6) connecting a pair of end edges (4, 5) of the arc-shaped 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 (pivotally) around the vertical axis (8) from the bottom of the ship, at a certain distance rearward from the propeller, i.e., the screw propeller (30) shown in Figure 4, which is rotatably mounted on the rear bottom of the hull and navigates the ship. The screw propeller (30) is mounted adjacent to the cylindrical rudder (1).

[0011] In the present invention, a shell 2 and a rudder stock 10 are attached to a vessel behind a screw propeller 30 that constitutes a propeller for driving the vessel. The cylindrical region formed by the shell 2 is spaced along the propeller shaft 7 from the propulsion region formed by the propeller of the vessel. The shell 2 is rotated around the rudder stock 10 to change the rudder angle of the shell 2 relative to the propeller shaft 7. A rib 16 is fixed to the bottom wall 2c of the shell 2 and the bottom surface 6a of the chord plate 6 along the propeller shaft 7, and a shaft tube 17 is fixed vertically to the rear edge 16a of the rib 16, with a moving shaft 13 disposed within the shaft tube 17. The inner diameter of the shell 2 is preferably within a range of 0.8 to 1.5 times the diameter of the screw propeller 30. Furthermore, when a screw propeller (30) is used as a propeller for a ship, it is preferable that the cylindrical region formed by the outer frame (2) is spaced 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 fitted. A known mechanism can be used for the slidable fitting 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 when the rudder stock (10) rotates, the outer frame (2) rotates around the rudder stock (10), which in turn causes the moving shaft (13) to rotate around the rudder stock (10). When the moving shaft (13) rotates around the rudder stock (10), the connecting pipe (14) and the rudder blade (15) also rotate around the swing shaft (12). A shaft tube (17) having a cylindrical bracket (17a) is provided at the rear edge (16a) of the rib (16). The moving shaft (13) is arranged within the cylindrical bracket (17a), and the hinge (15a) of the rudder blade (15) is connected to the moving shaft (13) so that the rudder blade (15) can rotate (swing) around the moving shaft (13). The outer frame (2), the rib (16) and the moving 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 swing shaft (12), so that the rudder blade (15) rotates (revolves) around the rudder stock (10) and rotates (swings) around the moving shaft (13).

[0014] Figures 1, 4 and 5 show the cylindrical rudder (1) at a rudder angle of 0 degrees before the cylindrical rudder (1) is operated. When the rudder angle of the cylindrical rudder (1) is changed, the ship's steering device is driven by a manual steering device, an electric or hydraulic power steering device, an automatic steering device, etc. When the rudder stock (10) is rotated counterclockwise by the steering device, 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 axis (12), also rotate (revolve) around the rudder stock (10) and at the same time rotate (swing) around the moving axis (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 lengths of the connecting pipe 14 and the swing shaft 12, and the rudder blade 15 rotates around the rudder stock 10 and moves around the moving shaft 13 to a rudder angle corresponding to the rotation angle of the rudder stock 10 relative to the rib 16 [for example, the same angle as the rotation angle of the rudder stock 10]. In this way, the rudder plate 15, which swings around the moving shaft 13 and is held at that rudder angle, reinforces the steering force of the tubular rudder 1 and the ship's turning moment. When the swing 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), but the telescopic rod (25) slides within the connecting pipe (14) to absorb the changing distance between the swing 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 Figure 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 integrally with the rudder stock 10 around the rudder stock 10 from a rudder angle of 0 degrees to a rudder angle of ±35 degrees as shown in Figure 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 also 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 rudder stock (10), the rudder plate (15) rotates around the rudder stock (10) and also rotates (swings) around the moving shaft (13) at an angle corresponding to or the same as the rotation angle of the rudder stock (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 rudder plate (15) while maintaining its fitted state in the connecting pipe (14).

[0019] The rudder dynamics of a ship will be explained with reference to Figure 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 rudder force coefficient, and the lift is F N , U is the relative water flow velocity entering the rudder, and 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 represented by the practical formula (C). (C) N R =F N ・X R ・cos δ Therefore, when the steering angle is small, high lift F N is essentially a high steering force F R The larger 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 RThe area of ​​the cylindrical rudder (1) that is attached along the propeller shaft (7) at a distance from the propulsion area where the ship's propeller acts is larger than that of a conventional rudder, and the distance X from the center of gravity of the ship to the center of the rudder is large. R and high lift F N The ship turning moment N is expressed as the product of R The large turning radius allows the vessel to change course quickly and easily.

[0021] A numerical analysis test using computer simulation to confirm the operational effects of the cylindrical rudder for ships (1) according to the present invention was conducted in December 2022 at the Fluid Machinery Laboratory of Tokushima University. ANSYS 18.0 CFX analysis software was used for the numerical analysis test. The screw propeller diameter D was set to D = 1100 mm, the external fluid domain was a cylinder with a diameter of 6D, and the inlet surface of the screw propeller was located 4D away from the inlet where the fluid flows into the external fluid domain, and the outlet surface of the screw propeller was located 10D away from the outlet where the fluid flows out of the external fluid domain. 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 Figure 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 is shown in Figure 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]

[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, so if the rudder angle is δ, the rudder force N R is N R =F N / cos δ, and the lift force F N, that is, the 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 approximately 3.9 times that of Comparative Rudder II. R is the generated lift F N At a rudder angle of 35 degrees, the cylindrical rudder of the present invention generates a lift force F of -8324N. N On the other hand, the comparative rudder I generates -4127N and the 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 significantly superior lift force F compared to a normal flat rudder. N , that is, the steering force N R occurs.

[0025]

[0026] Lift in the X direction is F N [N], and the density of water is ρ [kg / m 3 ], the representative speed (propeller tip peripheral speed) is U [m / s], and the representative 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 representative speed (propeller tip peripheral speed) is U [m / s], then the lift coefficient C L and the drag coefficient C D are calculated by the formula (D) and formula (E), respectively. 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 L and the drag coefficient C D The change in the lift coefficient C of the cylindrical rudder (1) of the present invention is shown. L is 6.63 x 10 at a steering angle of 20 degrees as shown in Table 2. -3 , 1.12 x 10 at 35 degree steering angle -2 On the other hand, the steering angle of the comparative rudder I is 20 degrees, and the steering angle is 6.58 x 10 -3 , 7.29 x 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 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] 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 x 10 at a steering angle of 35 degrees -３ In contrast, the steering angle of comparative rudder I is 20 degrees, which is 3.36 x 10 -３ , 5.55 x 10 at a steering angle of 35 degrees -３ Therefore, the cylindrical rudder (1) of the present invention has a large drag coefficient C when the steering angle is 35 degrees. D The steering force is large, and 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-described embodiment can be modified in various ways. For example, although the example in which the moving shaft 13 is attached to the rear surface 2a of the outer frame 2 has been shown, the moving shaft 13 of the steering device 11 can also be attached to the front surface 2b of the outer frame 2. Although the example in which a screw propeller is used as the propeller has been shown, a waterjet propeller, a Voith-Schneider propeller, or a pod propeller may be used instead of the screw propeller. While Figures 1 and 3 show the shaft tube 17 formed from a single cylindrical member, the shaft tube 17 may be formed from multiple cylindrical members arranged coaxially instead of a single cylindrical member. Furthermore, if multiple screw propellers or other types of propellers are installed on a single ship and multiple barrel rudders 1 are installed behind the propellers, the steering force and turning moment of the barrel rudders 1 can be further strengthened. In the above embodiment, an example is shown in which the telescopic rod (25) is fixed to the swing shaft (12), and the connecting pipe (14) that connects the telescopic rod (25) telescopically is fixed to the rudder (15). However, conversely, the connecting pipe (14) may be fixed to the swing shaft (12), and the telescopic rod (25) that connects to the connecting pipe (14) telescopically may be fixed to the rudder (15).

[0030] In addition to the effects (1) to (3) described in paragraph 0008, the embodiment of the present invention also produces the following effects. (4) The cylindrical rudder (1) has a rudder blade area of ​​approximately 4.14 times the rudder blade area of ​​the rudder body plus 3.14 times the diameter of the outer frame (2), and therefore receives approximately four times the thrust compared to a conventional single-plate rudder, improving the 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, allowing the water flow to flow more smoothly inside the outer frame (2). (6) The swing shaft (12) rotates with the rotation of the rudder stock (10), and the plate rudder (15) swings around the moving axis (13), thereby reinforcing the steering force of the cylindrical rudder (1) and the ship's turning moment. (7) The lift force F acting on both sides of the rudder due to the influence of the turning flow of the propeller is reduced. N Normal flat rudder has a product life of about 10 years and needs to be replaced because the direction of the rudder changes and vibration occurs in the rudder. However, the cylindrical rudder (1) for ships of the present invention does not vibrate even when affected by the turning flow of the propeller, and has a product life of more than 10 years. (8) Even on ships where the propeller shaft is installed on the same axis as the rudder, the propeller shaft can be efficiently attached and detached without the need for detaching and attaching the cylindrical rudder (1). (9) With a single-plate rudder, the water flow behind the propeller has the disadvantage of splashing up at the rear of the hull and causing energy loss. However, with the present invention, the water flow can be made to flow inside the cylindrical rudder (1), making it possible to utilize the propulsion force generated by the propeller without waste. (10) Whether the cylindrical 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 both sides, so the ship has good straight-line stability. However, a single-plate rudder has different turning characteristics on the left and right. (11) The hull has the characteristic of turning in the direction of the rudder even when moving backward. (12) The front tip of the outer frame (2) of the tubular rudder (1) made of steel can be chamfered or rounded to reduce water resistance.

[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.

[0032] (1) - Marine cylindrical rudder, (2) - Outer frame, (2a) - Trailing edge, (2b) - Leading edge, (2c) - Bottom, (3) - Arc frame, (4, 5) - Edge, (6) - Chord board, (6a) - Bottom, (7) - Propeller shaft, (8) - Vertical shaft, (10) - Rudder stock, (11) - Steering gear, (12) - Oscillating shaft, (13) - Moving shaft, (14) - Connecting pipe, (15) - Flat rudder (flap), (16) - Rib, (16a) - Trailing edge, (17) - Shaft tube, (18) - Reinforcing plate, (19) - Lower shaft, (25) - Telescopic rod, (30) - Propeller (screw propeller),

Claims

1. A cylindrical rudder for a ship (1), comprising: 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 arranged 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 a ship, wherein a cylindrical region formed by the outer frame (2) is spaced along the propeller shaft (7) from a propulsion region formed by a 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).

2. The cylindrical rudder (1) 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. A cylindrical rudder (1) for a ship as claimed in claim 2, in which the propeller for propelling the ship is a screw propeller, and the outer frame (2) of the cylindrical rudder (1) and the rudder stock (10) are attached to the ship behind the screw propeller.

4. A cylindrical rudder (1) for a ship as claimed in claim 1, wherein a rib (16) is fixed to the bottom wall (2c) of the outer frame (2) and 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 within the shaft tube (17).

5. A marine cylindrical rudder (1) as claimed in claim 1, comprising an operating plate device (11) attached to the rear surface (2a) or the front surface (2b) of the outer frame (2), the operating plate device (11) comprising a swing shaft (12) attached rotatably and spaced apart from the rudder stock (10) of the outer frame (2) and parallel to the rudder stock (10), a moving shaft (13) attached to the rear surface (2a) or the front surface (2b) of the outer frame (2), and a plank rudder (15) rotatably attached to the moving shaft (13).

6. A cylindrical rudder (1) for a ship as claimed in claim 1, wherein a rib (16) is fixed to the bottom wall (2c) of the outer frame (2) and the chord plate (6) along the propeller shaft (7), and the moving shaft (13) is attached to the rear surface (2a) of the outer frame (2) in parallel with the rib (16).

7. The cylindrical rudder for a ship (1) according to claim 5, wherein the oscillating shaft (12) is connected to a connecting pipe (14) to which the plank rudder (15) is fixed and to a telescopic rod (25) connected to the connecting pipe (14) so ​​as to be freely extendable and retractable; and by the rotation of the oscillating shaft (12), the connecting rod (14) and the telescopic rod (25) change their angles relative to the propeller shaft (7), and the plank rudder (15) oscillates around the moving axis (13) to change its angle relative to the propeller shaft (7).

8. The cylindrical rudder (1) for a vessel as claimed in claim 7, wherein the upper end of the plank rudder (15) is fixed to the connecting pipe (14), the rib (16) of the outer frame (2) has a cylindrical bracket (16a), and the rudder plank (15) rotates around the moving shaft (13) disposed within the cylindrical bracket (16a).

9. The cylindrical rudder (1) for a ship as claimed in claim 8, wherein the outer frame (2), the rib (16) and the moving shaft (13) rotate together with the rotation of the rudder stock (10), and at the same time, the rudder blade (15) swings around the moving shaft (13).

10. When the rudder stock (10) is rotated around the vertical axis (8), the outer frame (2) and the movable shaft (13) rotate together with the rudder stock (10) at the same angle, and the revolution and rotation of the movable shaft (13) around the rudder stock (10) causes the telescopic rod (25) to telescope relative to the connecting pipe (14), so that the plank rudder (15) is inclined at an angle corresponding to the rotation angle of the rudder stock (10).

11. A cylindrical rudder (1) for a ship as claimed in claim 1, wherein the cylindrical region formed by the outer frame (2) is spaced along the propeller shaft (7) from the propulsion region formed by the ship's propeller, and the outer frame (2) is rotated around the rudder shaft (10) to change the rudder angle of the outer frame (2) relative to the propeller shaft (7).

12. A cylindrical rudder (1) for ships as set forth in claim 1, wherein the inner diameter of the outer frame (2) is formed within the range of 0.8 to 1.5 times the diameter of the screw propeller (30) constituting the propulsion device.

13. A cylindrical rudder (1) for a ship as described in claim 9, wherein when a screw propeller (30) is used for the ship's propulsion, 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 the diameter of the screw propeller (30).

14. The cylindrical rudder (1) for a ship as claimed in claim 11, wherein the cylindrical region formed by the outer frame (2) is spaced from the propulsion region of the screw propeller (30) along the propeller shaft (7) by a distance between 0.2 and 3.0 times the diameter of the screw propeller (30).

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