JPH05116687A - Skeg for ship rudder - Google Patents

Abstract

PURPOSE:To provide the skeg of a marine rudder excellent in course keeping performance, course stability and turning performance by disposing a rudder shaft in the state of being inserted through the skeg, and providing the skeg with a current plate, projecting toward the board side, at the part near above the top part of a rudder plate. CONSTITUTION:A skeg 1 is provided protruding downward from a stern hull 2. A rudder shaft 3 interlocked with a steering gear in the hull is inserted through the skeg 1, and the rudder shaft 3 is rotatably supported at the skeg 1 through a bearing 4. The top part of a rudder plate 5 is supported at the rudder shaft 3, and a pintle 6 added to the rudder plate 5 is rotatably supported at the skeg 1 through a bearing 7. A current plate 8 projecting toward the board side is further disposed at the part, near above the top part of the rudder plate 5, of the skeg 1. In the case of disposing a top end plate 9 on the top face of the upper rudder plate 5a of the rudder plate 5, the top end plate 9 is formed in such a way as not to interfere with the skeg 1 due to the rotation of the rudder plate 5. The top end plate 9 and the current plate 8 are then partially overlapped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skeg of a ship rudder.

[0002]

2. Description of the Related Art Conventionally, particularly in a relatively large vessel equipped with a marine-type rudder, it is possible to improve fuel-holding ability and course stability during ocean navigation to reduce fuel consumption. At the same time, in the harbor and narrow waterways, there is an increasing demand for rudders that can improve the turning performance of the hull and easily avoid the risk of collision. A conventional mariner type rudder is, for example, as shown in FIG.
Is a rudder shaft 51 that supports the top of the rudder blade 50, and a stern hull 52.
It is rotatably supported by a bearing structure 53 protruding downward from the steering plate 50 to almost the center of the steering plate 50.
A pintle 54 is provided between 0 and the bearing structure 53. The horizontal section of the rudder blade 50 is a normal blade section,
That is, it has a convex streamline as a whole.

[0003]

However, the conventional Mariner type rudder has a horizontal cross-sectional profile that is a wing cross section, that is, a convex streamline as a whole. Therefore, it is difficult to generate a moment for turning the hull. However, the water pressure acting vertically on the rudder surface can only be utilized, and laminar flow separation is likely to occur at the trailing edge of the rudder while the vessel is traveling straight, that is, when the rudder is in the neutral position. In other words, when some external force acts on the hull while sailing in the ocean and the boat is about to deviate from the predetermined course, the ability to immediately return to the predetermined course by the rudder and make the ship go straight is low, and However, there is a problem that the straight-line performance of the hull is low due to the laminar flow separation, and the ability to turn the hull at a steep angle is low when a danger of collision occurs in a harbor or a narrow waterway.

It is an object of the present invention to solve the above problems and provide a skeg of a marine vessel rudder capable of obtaining high lift characteristics and having excellent needle retention, course stability and turning performance.

[0005]

In order to solve the above-mentioned problems, the ship rudder of the present invention has a skeg which has a streamlined or fish-shaped outer surface and which is provided so as to project from the stern hull. In addition to disposing the rudder shaft, a rectifying plate that projects in the port side direction is provided at a position close to the top of the rudder plate top of the skeg.

[0006]

With the above construction, when the rudder is in the neutral position while the vessel is traveling straight, the wake of the propeller flows along the left and right surfaces of the skeg and the rudder blade. Further, at the time of steering, an angle is given to the rudder blade to cause a difference in water pressure acting on both right and left sides of the rudder blade due to the wake of the propeller, thereby turning the hull.

The skeg surrounding the rudder shaft reduces resistance, and when the wake of the propeller flows along the surface of the skeg and the rudder blade, the water flow is directed to the outside of the rudder blade by the straightening plate provided in the skeg. To prevent it from escaping,
The hydraulic power behind the propeller can be effectively applied to the rudder blade, the propulsion efficiency can be increased, and the course stability can be improved. Further, it is possible to improve the steering efficiency by delaying the stall area of the rudder at the time of turning.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 4, the skeg 1 is provided so as to project downward from the stern hull 2, and a rudder shaft 3 that interlocks with a steering device (not shown) in the hull is provided through the skeg 1. There is. The rudder shaft 3 is rotatably supported by the skeg 1 via a bearing 4.

Then, the top is supported by the rudder shaft 3 and the rudder plate 5
And a pintle 6 provided in the middle of the rudder blade 5 in the vertical direction is rotatably supported by the skeg 1 via a bearing 7. Therefore, the rudder blade 5 is rotated around the axis of the rudder shaft 3 and the pintle 6 by the rotational drive of the rudder shaft 3.

Further, as shown in FIGS. 3 to 4, the rudder blade 5
In a horizontal cross section including the skeg 1 in the neutral state of the rudder and the upper rudder plate 5a of the rudder plate 5 located behind the skeg 1, the front edge of the skeg 1 has a semicircular shape and the skeg continuous to the front edge. In the middle part of 1 and the upper rudder blade 5a, the cross-sectional width gradually increases rearward in the bow-stern direction to reach the maximum width, and thereafter the cross-sectional width gradually decreases to the minimum width, and then the rudder blade 5 It has a shape in which the cross-sectional width gradually increases over a relatively short period extending in the bow-stern direction to the trailing edge.

A rectifying plate 8 that projects in the port side direction is arranged at a portion of the skeg 1 that is close to the top of the rudder plate, and the rectifying plate 8 is provided from the front end to the rear end of the skeg 1. When the top end plate 9 is provided on the top surface of the upper rudder plate 5 a of the rudder plate 5, the front end plate 9 is formed so that the front portion does not interfere with the skeg 1 due to the rotation of the rudder plate 5. There is. Further, the top end plate 9 and the current plate 8 are partially overlapped with each other, and are formed so as not to be lost even when a steering angle is given. It is also possible to provide a bottom end plate on the bottom of the rudder blade 5.

The operation of the above configuration will be described below. When the rudder is in the neutral position while the ship is going straight, the propeller 10
In the wake of the propeller generated by the rotation of the propeller, the upper semicircular portion of the propeller wake flows along both the left and right surfaces from the skeg 1 to the upper rudder blade 5a, and the lower semicircular portion of the propeller wake flows to the left and right of the lower rudder blade 5b. Flow along both surfaces.

At this time, when some sort of external force acts on the hull while the ship is traveling straight, or when the hull is about to come off the predetermined course due to the course stability inherent to the hull, the hull is removed by an automatic pilot device or the like. A small angle is given to the rudder in the direction to be corrected.

In this case, in the conventional rudder, the water pressure acting on both the left and right sides of the rudder plate is different due to the wake of the propeller,
This is only the moment that turns the hull.
On the other hand, in the rudder of the present embodiment, the propeller wake is diverted along the surface of the rudder plate formed continuously over the skeg 1 and the rudder plate 5, and the reaction force due to this is also applied to the rudder plate 5. Therefore, a large hull turning moment is generated, and the effect of quickly restoring the hull to a predetermined course is exhibited. Also, when the ship is straight ahead, that is, in the neutral position of the rudder, the wake of the propeller flows along the concave surface of the rudder plate, so laminar flow separation is less likely to occur, and therefore, the effect of straightening the ship is exhibited and the hull moves in a zigzag manner. However, the fuel consumption is reduced because the resistance is reduced and the traveling distance is shortened by proceeding in a straight line.

When a ship is in danger of collision while navigating in a harbor or a narrow waterway, the rudder is turned at a large angle. A large hull turning moment cannot be obtained because it depends only on the difference in water pressure that acts, or because there is a limit to the angle of the rudder that can use the water pressure difference and a large rudder angle has no effect. The turning circle of the hull cannot be reduced.

On the other hand, when the skeg of this embodiment is used, in addition to the action due to the above-mentioned water pressure difference, the water flow formed on the surface of the rudder plate is prevented from escaping upward, and the reaction force is more effective. And the reaction force acts, the limit of the rudder angle can be made larger than that of the conventional rudder.
Due to this combined effect, the skeg of the present embodiment can generate a large hull turning moment and extremely reduce the diameter of the turning circle of the hull, and can easily avoid the risk of collision.

The skeg 1 which surrounds the rudder axle 3
While reducing the resistance of the water flow flowing along the upper stern hull of the rudder blade 5, and when the wake of the propeller flows along the surface of the skeg 1 and the rudder blade 5, the straightening plate 8 and the top end plate 9 The propeller wake flowing along the ridge is prevented from escaping to the outside of the rudder blade 5, and the hydraulic power of the propeller wake is effectively applied to the rudder blade 5, so that a larger hull turning moment can be generated. Since laminar flow separation is less likely to occur, the course stability of the ship can be improved. Further, it is possible to improve the steering efficiency by delaying the stall area of the rudder at the time of turning.

5 to 6 show a suspension rudder according to another embodiment of the present invention. Members having the same functions as those of the previous embodiment are designated by the same reference numerals and the description thereof will be omitted. 5 to 6, the rudder shaft 3 is surrounded by a skeg 21 projecting downward from the stern hull 2, and a rudder plate 22 is supported at the lower end of the rudder shaft 3. A rectifying plate 23 is provided on the lower end surface of the skeg 21 so as to project in the port side direction.

According to this structure, when the wake of the propeller flows along the surfaces of the skeg 21 and the rudder blade 22, the skeg 21 surrounding the rudder axle 3 reduces the resistance and the straightening vane 23 forms the rudder blade. Since the propeller wake flowing along the surface is prevented from escaping to the outside of the rudder blade 22 and the hydraulic power of the propeller wake is effectively applied to the rudder blade 22, a larger hull turning moment can be generated. it can.
Although the above-described embodiment is a case of a suspended rudder, the above-described configuration can be applied to a rudder of the type in which the bottom of the rudder plate 22 is supported by the shoe piece of the hull via a support shaft. is there.

[0020]

As described above, according to the present invention, the skeg surrounding the rudder shaft reduces the resistance with respect to the propeller wake, and the rectifying plate provided in the skeg rectifies the propeller wake to the rudder plate. It is possible to prevent the water from escaping to the outside of the vehicle, effectively apply the hydraulic power of the wake of the propeller to the rudder blade, improve the propulsion efficiency, and improve the course stability. Further, it is possible to improve the steering efficiency by delaying the stall area of the rudder at the time of turning.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a ship rudder showing an embodiment of the present invention.

FIG. 2 is an overall side view of the same embodiment.

FIG. 3 is a sectional view of the rudder in FIG. 2 taken along the line nn.

4 is a cross-sectional view taken along the line nn of the rudder when the rudder angle in FIG. 2 is large.

FIG. 5 is an overall perspective view of a suspension rudder according to another embodiment of the present invention.

FIG. 6 is an overall side view of the suspension rudder according to the embodiment.

FIG. 7 is an overall side view of a conventional marine vessel rudder.

[Explanation of symbols]

 1 Skeg 3 Rudder shaft 5 Rudder plate 8 Straightening plate 9 Top end plate

Claims (1)

[Claims] 1. In a skeg provided with a streamlined or fish-shaped outer surface and protruding from the stern hull, the rudder shaft is disposed through the skeg, and the skeg is located near the top of the rudder plate. A ship rudder skeg characterized in that a rectifying plate extending in the port side direction is provided on the side.