JPH075037Y2 - Reaction fins for ships - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement in a propulsion device for a ship.

[Prior Art] FIGS. 5 to 7 are examples of a conventional propulsion device for a ship, FIG. 5 is a side view of the stern portion thereof, and FIG. 6 is a sectional view taken along line VI-VI of FIG. Figure 7 shows the wake distribution map.

Conventionally, a propeller is installed eccentrically within the radius of the propeller on the side where the propeller blade descends from the center of the hull, and the vertical vortex existing in the stern is effectively flown into the propeller to improve the propeller efficiency. Invented. FIGS. 4 and 5 show the case where the propeller is rotated to the right (when thrust is generated in the right direction, forward thrust is generated).

The stern frame 2 is provided at the rear end of the hull 1, and the bossing 3 is fixed to the stern frame 2 and the hull 1,
A propeller shaft 4 is rotatably provided through the inside thereof, a front end thereof is connected to a main engine (not shown), and a rear end thereof is connected to a propeller 5. At this time, the propeller 5 is eccentrically installed from the center CL of the hull on the side where the propeller blades descend when the propeller rotates forward.

The rudder horn 6 is stern-turned and fixed to the upper end of 2, and the rudder 7 is attached to the rudder horn 6.

The hull 1 having the above-mentioned configuration is propeller 5 driven by a main engine (not shown).
When turning and moving forward, there is an inward longitudinal vortex symmetrically with respect to the center CL of the hull at the stern. When the propeller 5 is installed in the center of the hull, the longitudinal vortices flowing into the propeller are canceled during one revolution because the flow components in the propeller rotation direction are opposite to each other on the port side and starboard side. However, if the propeller 5 is installed eccentrically, the average during one rotation has a component of the flow in the direction opposite to the propeller rotation direction. The remaining rotary flow is reduced and the propeller efficiency is improved.

[Problems to be solved by the invention]

However, in the conventional ship propulsion device, as shown in FIG. 7, it shows the direction of the flow into the propeller when targeting a large tanker hull form. The direction of the arrow indicates the direction of flow in the ship width / depth direction, and the length of the arrow indicates its speed. According to it, there is almost no flow component in the direction opposite to the propeller rotation direction in the range of 90 ° to 225 °. Therefore, in the range of 90 ° to 225 °, there is no action to reduce the rotational flow of the propeller wake, and there is no action to improve the propeller efficiency, so the effect of improving propeller efficiency is not very high.

The present invention is intended to solve the above-mentioned drawbacks, and the reaction fin of a ship in which the propeller efficiency is improved and the required horsepower is significantly reduced by uniformly reducing the rotational flow of the propeller wake in the entire range. The purpose is to provide.

[Means for solving problems]

Therefore, the reaction fin of the ship of the present invention is a uniaxial ship in which the propeller is installed eccentrically within the radius of the propeller from the center of the hull on the side where the propeller blade descends when the propeller is rotating forward, In front of the propeller, the fins radially projecting from the fin boss surrounding the bossing are centered on the downward slope on the side where the propeller blade descends, and from the vicinity of the side where the propeller blade descends, to the downward slope on the rising side. A plurality of fins are installed between the two, and the fins are provided with a twist so that the flow of water can be changed in the direction opposite to the forward rotation direction of the propeller.

[Action]

With the above configuration, the flow in the direction opposite to the propeller rotation direction flowing into the propeller is centered on the lower slope on the side where the propeller blade descends and between the vicinity of the side where the propeller blade descends and the vicinity of the lower slope where the propeller blade descends. Increases as in the other parts, and the rotating flow behind the propeller decreases uniformly.

〔Example〕

1 to 4 show an embodiment of a reaction fin for a ship according to the present invention. FIG. 1 is a side view of a stern of the reaction fin, and FIG.
Figures and 3 are sectional views taken along the lines II-II and III-III in FIGS. 1 and 2, and FIG. 4 is a performance diagram.

The figure shows the case where the propeller rotates clockwise.

In the figure, those having the same numbers as the conventional ones are equivalent components, and therefore the description thereof is omitted.

The fin boss 8 is fixed so as to surround the bossing 3, and fins 9a to 9d are installed so as to radially project from the fin boss 8.
However, the fins 9a to 9d are about 90 along the propeller rotation direction.
It is mounted at positions of 135 °, 180 °, and 225 °, and is provided with a twist so that the water flow is bent in the direction opposite to the direction of rotation of the propeller, that is, counterclockwise.

When the hull 1 having the above-mentioned configuration is traveling forward with the propeller 5 being rotated by the main engine (not shown in the figure), the action of the fins 9a to 9d causes the water flow to bend in the direction opposite to the rotation direction of the propeller 5. As a result, the rotational flow of the propeller wake is reduced and the propeller efficiency is improved as compared with the conventional one.

Fig. 4 shows the required horsepower as a result of testing in a water tank using a model ship for a large tanker hull form. According to it, the conventional one is normal (when the propeller is in the center of the hull)
A reduction of about 3% in horsepower was shown to be 5% lower than that of the present invention, and an effect of reduction in horsepower of about 8% was shown compared to the usual case.

[Effect of device]

As described above in detail, the reaction fin of the present invention has an effect that the required horsepower is significantly reduced by improving the propeller efficiency as compared with the conventional one.

[Brief description of drawings]

1 to 4 show an embodiment of a reaction fin of a ship according to the present invention. FIG. 1 is a side view of the stern of the ship, and FIG.
Figures and 3 are sectional views taken along the lines II-II and III-III in FIGS. 1 and 2, and FIG. 4 is a performance diagram. 5 to 6 show examples of conventional propulsion devices for ships. FIG. 5 is a side view of the stern part thereof, FIG. 6 is a sectional view taken along line VI-VI of FIG. 5 and FIG. A flow distribution map is shown. In the figure 1 ... Hull, 3 ... Bossing, 5 ... Propeller, 8 ... Fin boss, 9
a-9b ... Fins

Claims (1)

[Scope of utility model registration request] 1. A uniaxial vessel in which a propeller is installed eccentrically within the radius of the propeller from the center of the hull on the side where the propeller blade descends when the propeller is rotating forward,
In front of the propeller, the fins radially projecting from the fin boss surrounding the bossing are centered on the downward slope on the side where the propeller blade descends, and from the vicinity of the side where the propeller blade descends, to the descending descending side on the ascending side. A reaction fin for a ship, wherein a plurality of fins are provided in the vicinity of the slope, and the fins are provided with a twist so as to change the flow of water in a direction opposite to the forward rotation direction of the propeller.