JP2577391Y2 - Off-center propeller single-axis ship - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved arrangement of a rudder in an off-center propeller single-axis ship.

[0002]

2. Description of the Related Art The stern of a conventional off-center propeller single-axle ship is shown in FIGS.

[0003] The stern frame 2 is provided at the rear end of the hull 1, and the lower portion of the frame 2 is connected to the bottom 3.
The boshing 4 is fixed to the stern frame 2 and the hull 1 in parallel with the hull center line CL. Propeller shaft 5
The front end of the propeller shaft 5 is connected to a main engine installed on the ship (not shown), and the rear end of the propeller shaft 5 is connected to the propeller 6.

At this time, as shown in FIGS. 5 and 6, the propeller 6 is deviated from the hull centerline CL toward the side where the propeller blades descend during forward rotation (rotation when thrust is generated forward). As installed, the boshing 4 and the propeller shaft 5 are configured off-center.
In the case of the present example, since the propeller is a clockwise propeller (when the thrust comes forward when turning clockwise as viewed from the rear to the front), the propeller 6 is deviated to the starboard side from the hull center line CL. , A propeller shaft 5 and a boshing 4 are respectively mounted.

On the other hand, the rudder horn 7 is fixed to the upper part of the stern frame 2, and the rudder 8 is attached to the rudder horn 7. At this time, the rudder horn 7 and the rudder 8 are installed on the hull center line CL, similarly to a normal propeller boat (when the propeller 6 is installed on the hull center line CL).

[0006] When the hull 1 having the above-described structure is running forward with the propeller 6 turned by the main engine installed on the ship (not shown), a vortex is sucked into the propeller 6. The vortex is generally called a bilge vortex, and is symmetric with respect to the hull center line CL as shown in FIG. In the case of this example, the propeller 6 is deflected to the starboard side and is clockwise, so that the direction of the flow of the vortex is mostly in the direction opposite to the rotation direction of the propeller 6. for that reason,
The rotational flow generated behind the propeller 6 in the same direction as the rotational direction of the propeller itself is reduced as compared with a normal propeller boat. As a result, a normal propeller ship (the propeller
Propeller propulsion efficiency is improved.

[0007] In FIG. 7, reference symbol D indicates a rotation locus of the blade tip of the propeller 6.

[0008]

In the case of the above-mentioned off-center propeller single-axis ship, since the propeller 6 is provided offset from the hull center line CL, the thrust T of the propeller 6 is used as shown in FIG. hull 1 generates a turning moment M _P on the side opposite to the side where the propeller 6 is provided.

From the rudder 8, since the flow along the port side surface of the rudder 8 is slower than the starboard side, a lateral force f is generated on the side where the propeller 6 is provided. Generates _R0 . Due to the above two moments, the hull 1 does not go straight but tries to turn to the port side.

On the other hand, in order to make the hull 1 go straight, FIG.
As shown in the figure, the rudder 8 is steered to the opposite side by the rudder angle δ and the lateral force F
Is generated, the operation is necessary to offset the moment M _P in turning moment M _R1 by the lateral force. At this time, since the resistance increases due to the steering angle δ, that is, the steering, an increase in the propeller propulsion efficiency due to the off-center installation is reduced.

[0011]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above problems, and has a main feature that a rudder is provided closer to a wing lowering side of a hull than a propeller shaft center.

Namely, off-center propeller 1 Jikusen of the present invention is, off the propeller is equipped with a propeller shaft to bias from the hull center line outboard side of the propeller blade is lowered when forward generating a thrust to rotate Center propeller 1
On the axle ship , the propellers should be
The above professionals should be further away from the hull centerline than the axis.
The rudder is located behind the prop .

[0013]

According to the off-center propeller uniaxial ship of the present invention, the turning moment generated by the propeller is canceled by the turning moment generated by the flow velocity difference between the two sides of the rudder at zero rudder angle. The function of moving the hull straight ahead without taking any action is performed.

[0014]

1 and 2 show an embodiment of the present invention. In the figure, the same reference numerals as those in the conventional art denote the same components, and the description thereof will be omitted, but the propeller shaft of the stern propeller 6 will be omitted.
5, the outboard side of the propeller blade is lowered when the propeller 6 generates a forward thrust to rotate clockwise, is equipped to bias from the hull center line CL.

A rudder horn 9 is fixed to the hull 1 behind the propeller 6, and a rudder 10 is attached to the rudder horn 9. At that time, the rudder horn 9 and the rudder 10
Is the hull center line CL more than the propeller center axis SCL.
And it is configured so as to be located outward in the away from. That is, as shown in FIG. 2, when the propeller 6 rotates and generates thrust forward, the rudder 10 has a position near the tip of the propeller blade close to the propeller center axis ACL.
Immediately after the area descending by the side, it is equipped offset from the hull center line CL. In this way, the rudder 10 is
5 on the same side as the hull centerline CL than the propeller shaft 5
From the rear of the propeller 6
You.

When the hull 1 having the above configuration is traveling forward with the propeller 6 turned by the main engine (not shown), the flow around the rudder 10 has a distribution on the hull center line CL side and a distribution on the outside is slow. As shown in FIG. 3, a lateral force f 'inward from the rudder 10 is generated. Therefore, as shown in FIG.
Since turning moment M _R2 thrust by the turning moment M _P in the opposite direction to the direction of the propeller 6 is generated, turning moment M _P hull 1 are canceled is as straight.

[0017] Although propulsion by the propeller provided by shifting from the hull center efficiency fraction is 3% to 5% (percentage of the total propulsion energy), the conventional off-center propenyl
With a single-axle ship, the propulsion efficiency reduction due to the increase in drag caused by the rudder is 1% to 2%, so the propulsion efficiency improvement by the conventional off-center propeller is 2% to 3%. On the other hand, the off-center propeller single-axle ship of the present invention eliminates the decrease of 1% to 2% due to the rudder, so that the propulsion efficiency can be improved by that much.

[0018]

[Effects of the Invention] As described above in detail, according to the off-center propeller single-shaft ship of the present invention, the steering operation is not required as compared with the conventional off-center propeller single-shaft ship, and resistance is increased by the steering. This has the effect of preventing a reduction in propulsion efficiency due to the occurrence of turbulence.

[Brief description of the drawings]

FIG. 1 is a side view of a stern of an off-center propeller single-axle ship according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is an explanatory view of the operation of the off-center propeller single-axis ship of the present invention.

FIG. 4 is a stern side view of a conventional off-center propeller single-axis ship.

FIG. 5 is a sectional view taken along the line BB of FIG. 4;

FIG. 6 is a cross-sectional view taken along the line CC of FIG. 5;

FIG. 7 is an explanatory diagram showing a mutual relationship between a rotation direction of an off-center propeller and a stern vortex.

FIG.

FIG. 9 is an explanatory view of the operation of the conventional off-center propeller single-axis ship.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hull 2 Stern frame 3 Ship bottom 4 Bossing 5 Propeller shaft 6 Propeller 7 Rudder horn 8 Rudder 9 Rudder horn 10 Rudder

Claims (1)

(57) [Scope of request for utility model registration] 1. A off-center propeller uniaxial ship propeller vanes is equipped with a propeller shaft to bias from the hull center line outboard side descending when the propeller generates a thrust to forward rotate, and the propeller shaft On the same side, same professional
Above the hull centerline further than the propeller axis
An off-center propeller single-axle ship, characterized in that a rudder is arranged behind the propeller .