JP7178188B2 - rudder system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rudder system, and relates to a technique that contributes to improving the propulsion efficiency of the rudder.

Conventionally, as described in, for example, US Pat. Some provide fins that generate a wake in the same direction as the propulsion propeller wake that causes it.

This reduces the generation of hub vortices in the core of the propulsion propeller wake flux. In other words, when the rudder is positioned at the rear center of the propulsion propeller, the rudder has the effect of suppressing hub vortices to some extent. However, in Patent Document 1, there is no rudder at the rear center of the propulsion propeller. Therefore, by installing propeller boss cap fins on the propeller boss cap, the generation of hub vortices at the center of the propulsion propeller wake flux is reduced, and the water flow that has passed through the propulsion propeller blades contributes to the improvement of propulsion efficiency. there is

In Patent Document 2, a rudder extending in the longitudinal direction of a vessel has rudder fins extending laterally from both sides, and has a rudder bulb at the mounting position of the rudder fins at the leading edge of the rudder. The rudder valve protrudes close to the propeller boss cap and protrudes forward toward the propeller boss cap in a generally hemispherical shape. Also, the protrusion is provided so as to fit within a range between the leading edge and the trailing edge of the ladder fin.

Patent No. 3751260 Patent No. 2837948

A hub vortex is generated by the speed difference between the speed of the water flow passing over the upper surface of the propeller blade and the speed of the water flow passing through the lower surface of the blade. . The swirling flow of the propeller wake is different on the port side and starboard side of the rudder blade. When the swirling flow rotates clockwise when viewed from the stern side to the bow side, the swirling flow flows downward from above on the starboard side and flows upward from below on the port side. Since the hub vortex flows into the port side of the rudder blade, the swirling flow of the propeller wake becomes a complicated flow on the port side of the rudder blade.

Therefore, by receiving the water flow that has passed through the propeller blades with the boss cap fins, it is possible to suppress the generation of hub vortices and contribute to the improvement of propulsion efficiency.

Further, the rudder valve suppresses the generation of hub vortices, and the rudder fins provided on the rudder valve receive the propeller wake flow, thereby contributing to the improvement of propulsion efficiency.

However, if the rudder valve is too large, it will become propulsion resistance, and if it is too small, the effect of suppressing the generation of hub vortices will be reduced. In addition, if the swirling water flow is disturbed, the lift generated in the rudder fins is reduced, which can result in propulsion resistance.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rudder system with improved propulsion efficiency.

In order to solve the above-described problems, the rudder system of the present invention includes a propulsion propeller that rotates clockwise when viewed from the stern side to the bow side, and a rudder arranged on the axis of the propulsion propeller, The propulsion propeller has a propeller boss cap, the propeller boss cap has boss cap fins that generate a wake swirling in the same direction as the swirling flow of the propulsion propeller wake, and the rudder is on the axis of the propulsion propeller. The rudder valve has a port fin and a starboard fin that protrude in the respective port and starboard directions on the starboard and starboard sides of the rudder plate, and the port and starboard fins are symmetrical about the axis of the propulsion propeller. and along the axial line of the propulsion propeller from the rudder valve , the width of the port fin in the broadside direction is shorter than that of the starboard fin, and the port fin has a length of 20% of the propeller diameter in the broadside direction. , the starboard fin has a length in the broadside direction of 30% of the propeller diameter, each length having a tolerance of -5% to +5% .

Further, in the rudder system of the present invention, the propeller boss cap has a circular flat surface perpendicular to the axial center line, and the rudder valve has a hemispherical front end surface facing the cap rear end surface. It is also possible to have a space forming a dead water area between the rear end face of the cap and the front end face of the valve.

Alternatively, in the rudder system of the present invention, the propeller boss cap has a hemispherical rear end face, and the rudder valve has a hemispherical front end face facing the rear end face of the cap. It is also possible to have a configuration having a space forming a dead water area between the surfaces.

Alternatively, in the rudder system of the present invention, the propeller boss cap has a circular flat surface whose rear end surface of the cap is perpendicular to the axis, and the rudder valve has a front end surface of the valve that faces the rear end surface of the cap and is perpendicular to the axis. It is also possible to form a circular flat surface to form a circular flat surface and have a space forming a dead water area between the rear end surface of the cap and the front end surface of the valve.

Further, in the rudder system of the present invention, the maximum outer diameter of the portion of the rudder valve protruding forward from the rudder plate is 40 to 70% of the leading edge diameter of the boss cap fin.

Also, in the rudder system of the present invention, the rudder bulb can extend the maximum width of the area on the rudder blade to 100% of the leading edge diameter of the boss cap fin.

In the rudder system of the present invention, the port fin and the starboard fin may have the same length in the shipboard direction, which is 20-30% of the propeller diameter.

A ship according to the present invention is characterized by having any one of the rudder systems having the above configurations.

With the above configuration, the water flow passing through the propeller blades is less likely to deflect due to the speed difference between the speed of the water flow passing over the upper surface of the propeller blade and the speed of the water flow passing through the lower surface of the blade. That is, the water flow around the propeller blades receives the ground effect from the fin upper surfaces of the boss cap fins, thereby increasing the thrust of the propulsion propeller.

In addition, the existence of the rudder valve eliminates the region where the hub vortex is generated, thereby suppressing the generation of the hub vortex. As a result, the hub vortex that flows into the port side of the rudder plate is reduced, the factors that disturb the swirling flow of the propeller wake on the port side of the rudder plate are reduced, the lift generated by the port fins is increased, and the propulsion efficiency is improved.

Furthermore, by suppressing the hub vortex by the boss cap fins, it is possible to suppress the area occupied by the rudder valve behind the propeller boss cap, thereby reducing the propulsion resistance of the rudder valve.

In addition, the pressure increases in the dead water area between the rear end face of the cap and the front end face of the valve, and this pressure contributes as a force to push the propeller boss cap, contributing to improvement in propulsion efficiency.

1 is a plan view showing a rudder system according to an embodiment of the invention; FIG. Bottom view showing the same rudder system Right side view showing the same rudder system Left side view showing the same rudder system Front view showing the rudder of the same rudder system Rear view showing the rudder of the same rudder system Left front upper perspective view showing the rudder of the same rudder system Left front lower perspective view showing the rudder of the same rudder system Left rear upper perspective view showing the rudder of the same rudder system Left rear lower perspective view showing the rudder of the same rudder system

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a rudder system of the present invention will be described below with reference to the drawings. 1 to 10 show the marine rudder 10 as a high-lift rudder, but the present invention is also applicable to ordinary rudders. The marine rudder 10 is arranged coaxially behind the propulsion propeller 20, and the propulsion propeller 20 rotates clockwise when viewed from the stern side to the bow side. The marine rudder 10 has a top end plate 40 and a bottom end plate 50 projecting to the port and starboard sides at the top and bottom ends of the rudder blade 30, respectively.

The rudder blade 30 consists of a front edge portion 31, an intermediate portion 32, and a rear edge portion 33 in the contour of the horizontal cross section, and the front edge portion 31 projects forward in a semicircular shape. The intermediate portion 32 following the front edge portion 31 has a shape in which the width increases in a streamline shape toward the maximum width portion 32a and then gradually decreases toward the minimum width portion 32b. The maximum width portion 32 a corresponds to the maximum rudder thickness of the rudder plate 30 . The trailing edge portion 33, which is continuous with the minimum width portion 32b of the intermediate portion 32, gradually increases in width toward the maximum trailing edge width portion 33a having a predetermined width, and then the rear end 33b protrudes rearward in a semicircular shape. form. The top end plate 40 and the bottom end plate 50 are shaped such that front edges 41, 51 and rear edges 42, 52 protrude in an arc shape.

The propulsion propeller 20 has a propeller boss cap 21, and the propeller boss cap 21 has boss cap fins 22. The boss cap fins 22 generate a wake swirling in the same direction as the swirling flow of the propulsion propeller wake. It has a wing shape that allows it to fly.

A rudder valve 60 is provided on the front edge portion 31 of the rudder plate 30 on the axis of the propulsion propeller 20 . The rudder valve 60 faces the propeller boss cap 21 of the propulsion propeller 20 and protrudes forward from the leading edge of the rudder plate 30 toward the propeller boss cap 21 .

In the present embodiment, the rudder valve 60 has a maximum outer diameter of 40 to 70% of the leading edge diameter of the boss cap fin 22 at the portion protruding forward from the rudder plate 30, and the portion above the rudder plate 30 The maximum width is expandable up to 100% of the boss cap fin 22 leading edge diameter.

In the present embodiment, the propeller boss cap 21 has a flat circular surface having a rear end surface 23 perpendicular to the axis, and the rudder valve 60 has a front end surface 61 facing the rear end surface of the cap having a hemispherical shape. None, there is a space forming a dead water area between the cap rear end face 23 and the valve front end face 61 .

The rudder valve 60 has port fins 62 and starboard fins 63, so-called fin valves, which are present along the axial line of the propulsion propeller from the side surface of the rudder valve 60 to the control surface of the rudder plate 30 and project on both sides. is doing. The port fin 62 and the starboard fin 63 are located at the same level as the axial center of the propulsion propeller 20 in the vertical direction of the rudder plate 30 and are symmetrical with respect to the axial center line of the propulsion propeller. The port fin 62 and the starboard fin 63 have the same length in the broadside direction of 20-30% of the propeller diameter.

In the above configuration, the water flow passing through the propeller blades is strongly changed in the direction of rotation due to the speed difference between the speed of the water flow passing over the upper surface of the propeller blades of the propulsion propeller 20 and the speed of the water flow passing through the lower surface of the blades. This causes hub vortices to occur.

However, in the present embodiment, propeller boss cap 21 has boss cap fins 22, so that the direction of water flow is reduced. That is, the water flow around the propeller blades receives a ground effect from the fin upper surfaces of the boss cap fins 22, thereby increasing the thrust. Further, the existence of the rudder valve 60 eliminates the region where the hub vortex is generated, thereby suppressing the generation of the hub vortex.

Therefore, the hub vortex that would have flowed into the port side of the rudder plate 30 in the absence of the boss cap fin 22 and the rudder valve 60 is reduced. As a result, factors that disturb the swirling flow of the propeller wake on the port side of the rudder plate 30 are reduced, the lift generated by the port fins 62 is increased, and the propulsion efficiency is improved.

Furthermore, since the hub vortex is suppressed by the boss cap fins 22, the area occupied by the rudder valve 60 behind the propeller boss cap 21 can be suppressed, and the rudder valve 60 can reduce propulsion resistance.

In addition, since the cap rear end face 23 forms a circular flat surface perpendicular to the axis and the valve front end face 61 forms a hemispherical surface, it occurs in the dead water area between the cap rear end face 23 and the valve front end face 61. The applied pressure presses the flat surface of the cap rear end surface 23 and contributes to the thrust. On the other hand, since the valve front end surface 61 forms a hemispherical surface, the pressure received from the dead water area can be released, and the propulsion resistance can be reduced.

As another embodiment of the present invention, the cap rear end surface 23 of the propeller boss cap 21 is formed into a hemispherical surface, and the valve front end surface 61 of the rudder valve 60 facing the cap rear end surface 23 is formed into a hemispherical surface. is also possible.

In this case, the basic effects of the present invention described above can be achieved without change. Although the contribution of the pressure of the dead water region acting on the cap rear end face 23 is reduced, the hemispherical shape of the valve front end face 61 allows the pressure received from the dead water region to be released, thereby reducing propulsion resistance.

Furthermore, as another embodiment of the present invention, the cap rear end surface 23 of the propeller boss cap 21 is formed into a circular flat surface orthogonal to the axial center line, and the valve front end surface of the rudder valve 60 facing the cap rear end surface 23 is formed. It is also possible to form 61 on a circular flat surface perpendicular to the axis.

In this case, the basic effects of the present invention described above can be achieved without change. Although the influence of the pressure in the dead water region acting on the front end face of the valve increases, the pressure received from the dead water region contributes to the thrust because the cap rear end face 23 forms a flat surface.

Further, as another embodiment of the present invention, the width of the port fin 62 in the port side direction is shorter than the starboard fin 63, the port fin 62 has a length of 20% of the propeller diameter in the side direction, and the starboard fin 63 is It is also possible to have a length of 30% of the propeller diameter in the broadside direction, each length having a tolerance of -5% to +5%. When the propulsion propeller 20 rotates counterclockwise, the lengths of the port fin 62 and the starboard fin 63 are reversed.

The swirling flow of the propeller wake becomes a complicated flow on the port side of the rudder plate 30 due to hub vortices and the like. has a length of 20% of the propeller diameter in the broadside direction, and the starboard fin 63 has a length of 30% of the propeller diameter in the broadside direction. Reduced resistance and improved propulsion efficiency.

Furthermore, on the starboard side where the propeller wake stream flows without disturbance, the width of the starboard fins 63 in the shipboard direction is made longer than the port fins 64, thereby increasing the lift generated in the starboard fins 63 and improving the propulsion efficiency. improves.

10 Marine rudder 20 Propulsion propeller 21 Propeller boss cap 22 Boss cap fin 23 Cap rear end surface 30 Rudder plate 31 Leading edge 32 Intermediate portion 33 Trailing edge 32b Minimum width portion 40 Top end plate 41, 51 Leading edge 42, 52 Rear end Rim 50 Bottom end plate 60 Rudder valve 61 Valve front end face 62 Port fin 63 Starboard fin

Claims (8)

Equipped with a propulsion propeller that rotates clockwise when viewed from the stern side to the bow side, and a rudder arranged on the axis of the propulsion propeller,
The propulsion propeller has a propeller boss cap, the propeller boss cap has boss cap fins for generating a swirling wake in the same direction as the swirling flow of the propulsion propeller wake,
The rudder has a rudder valve on the axis of the propulsion propeller, and the rudder valve has a port fin and a starboard fin that protrude in the respective shipboard directions on the port and starboard sides of the rudder plate,
the port and starboard fins are symmetrical about the axis of the propulsion propeller and along the axis of the propulsion propeller from the rudder valve;
the width of the port fin in the broadside direction is shorter than the starboard fin, the port fin having a length in the broadside direction of 20% of the propeller diameter and the starboard fin having a length in the broadside direction of 30% of the propeller diameter, respectively A rudder system characterized in that the length of has a tolerance of -5% to +5% . The propeller boss cap has a circular flat surface where the rear end surface of the cap is perpendicular to the axis,
The rudder valve has a hemispherical surface on the front end face of the valve facing the rear end face of the cap,
2. A rudder system according to claim 1, characterized in that there is a space forming a dead water zone between the rear end face of the cap and the front end face of the valve. The rear end face of the propeller boss cap has a hemispherical surface,
The rudder valve has a hemispherical surface on the front end face of the valve facing the rear end face of the cap,
2. A rudder system according to claim 1, characterized in that there is a space forming a dead water zone between the rear end face of the cap and the front end face of the valve. The propeller boss cap has a circular flat surface where the rear end surface of the cap is perpendicular to the axis,
The rudder valve has a circular flat surface that is perpendicular to the axial center line on the front end surface of the valve that faces the rear end surface of the cap,
2. A rudder system according to claim 1, characterized in that there is a space forming a dead water zone between the rear end face of the cap and the front end face of the valve. 5. The rudder according to any one of claims 1 to 4, wherein the rudder valve has a maximum outer diameter of a portion protruding forward from the rudder plate that is 40 to 70% of the leading edge diameter of the boss cap fin. system. A rudder system according to claim 5, characterized in that the rudder bulb is expandable to a maximum width of 100% of the leading edge diameter of the boss cap fin in the area on the rudder blade. Rudder system according to any one of the preceding claims, characterized in that the port and starboard fins have the same length in the broadside direction of 20-30% of the propeller diameter. A marine vessel comprising a rudder system according to any one of claims 1 to 7 .

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