JPH06156378A - Ducted screw for vessel - Google Patents

Abstract

PURPOSE:To propel marine vessel more efficiently by restraining a lowering of the efficiency due to the resistance of a housing forming the duct of a ducted screw. CONSTITUTION:Let a part of water flow 40 generated by the rotation of a screw main body 30 flow in the circular hollow section 24 of the housing 22 of a duct 20, and it is led to the advancing direction along the outer periphery of the housing 22 out of the circular hollow section 24 of the housing 22 at the vicinity of the front section of the duct 20, so that side flow 42 along the circumferential surface of the duct 20 from the head to the rear is thereby produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved ducted screw for a ship, which is used to propel a ship using a gasoline engine, a solar engine or the like as a drive source.

[0002]

2. Description of the Related Art A ducted screw comprises a screw body arranged in a housing forming a duct, and the screw body is connected to a power source through a screw transmission mechanism. When the screw body is driven by a power source and rotates, the water flowing from the front end of the duct is discharged from the rear of the duct, so cavitation is unlikely to occur and the water flow is throttled in a jet shape, so high propulsive force can be obtained. This is advantageous because it can.

[0003]

However, in the ducted screw, the water flow is generally resisted at the front end of the duct's housing, and a vortex is apt to occur at the outer periphery of the duct, resulting in a decrease in the propulsion efficiency of the ship. There is a drawback that it is difficult to propel a ship with higher efficiency.

SUMMARY OF THE INVENTION An object of the present invention is to provide a ducted screw for a ship, which can suppress a decrease in efficiency due to resistance of a duct housing and can propel a ship more efficiently.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention relates to a ducted screw for a ship, which comprises a screw body arranged in a housing forming a duct, in which a water flow generated by rotation of the screw body is generated. Side flow generating means for generating a side flow from the front to the rear of the housing is drawn out in the traveling direction along the outer periphery of the housing from the hollow of the housing near the front of the duct in the vicinity of the front of the duct. An object of the present invention is to provide a ducted screw for ships, which is characterized by being provided.

[0006]

As described above, when a side flow is generated from the front to the rear on the peripheral surface of the housing forming the duct, the vortex flow generated on the peripheral surface of the housing is eliminated to eliminate the low-speed region of the boundary layer, and thus high propulsion is achieved. You can get the power.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Referring to the drawings, an embodiment of the present invention will be described in detail. FIG. 1 shows a ship 12 using a ducted screw 10 for a ship according to the present invention. It consists of a hull 14 equipped with such a power source.

In the illustrated embodiment, a ducted screw 10 for a boat is provided with a column 1 that is suspended from a hull 14 of a boat 12.
6 is attached, but it is also applicable to an outboard motor that is attached to the rear end of the hull 14 and is used to propel the ship 10.

As shown in FIG. 2, the ducted screw 10 of the present invention includes a housing 22 forming a duct 20.
It consists of a screw body 30 arranged inside. In the illustrated embodiment, the housing 22 is fixed to the stanchions 16 depending from the hull 14. As illustrated, the housing 22 has an annular hollow portion 24, a front end 22A of which is formed in a divergent shape and a rear end 22B of which is formed in a tubular shape. The screw body 30 is driven via a screw transmission mechanism that is transmitted from a power source mounted on the hull 14, and a part 32 of this transmission mechanism is schematically shown in FIG. 2 and its details are omitted. Has been done.

The ducted screw 10 for ships of the present invention
Is the water flow 4 generated by the rotation of the screw body 30.
A part of 0 is an annular hollow portion 2 of the housing 22 of the duct 20.
4 that flows into the inside of the duct 20 and is guided near the front of the duct 20 from the annular hollow portion 24 of the housing 22 along the outer circumference of the housing 22 in the traveling direction to generate a side flow 42 along the front surface of the duct 20 from the front to the rear The flow generating means 26 is provided.

In the illustrated embodiment, the side flow generating means 26 is
An inlet 34 formed in the inner periphery near the rear end of the housing 22 for introducing a part of the water flow 40 generated by the rotation of the screw body 24 into the annular hollow portion 24 of the housing 22.
And an outlet port 36 formed on the outer periphery of the housing 22 near the front end thereof, for flowing out the water flow that has flowed into the annular hollow portion 24 to form a side flow 42.

In this way, when the side flow 42 is generated from the front to the rear on the peripheral surface of the housing 22, the side flow 42 eliminates the vortex generated on the peripheral surface of the housing 22 and the low speed region of the boundary layer. Can be eliminated. Therefore, the ducted screw 10 can apply a high propulsive force to the ship 10 while avoiding the performance deterioration due to the resistance of the housing 22.

In the above embodiment, the housing 22 forming the duct 20 is widened toward the front end 22A, but it may be cylindrical over the entire length. In addition, the inflow port 34 is provided in FIG.
As shown in (A) and (B), the rear end of the inflow port 34 may be curved upward or downward.

[0014]

As described above, according to the present invention, there is a merit that the ship can be propelled more efficiently by suppressing the decrease in efficiency due to the resistance of the duct housing.

[Brief description of drawings]

FIG. 1 is a schematic side view of a ship equipped with a ducted screw for ships according to the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the ducted screw for ships according to the present invention.

FIG. 3 is a side view of the inflow port 2 of the side flow generating means used in the present invention.
It is sectional drawing which shows two different forms.

[Explanation of symbols]

 10 Ducted Screws for Ships 12 Ships 14 Hulls 16 Struts 20 Ducts 22 Housings 22A Front Ends 22B Rear Ends 24 Annular Hollow Parts 26 Side Flow Generating Means 30 Screw Main Body 32 Screw Transmission Mechanism Part 34 Inlet 36 Outlet 40 Water Flow 42 Sidestream

Claims (1)

[Claims] 1. A ducted screw for a ship, comprising a screw main body arranged in a housing forming a duct, wherein a water flow generated by rotation of the screw main body flows into a hollow portion of the housing, and the water flow generated near the front of the housing. The ducted marine vessel is provided with a side flow generating means that is drawn out from a hollow portion of the housing along an outer periphery of the housing in a traveling direction to generate a side flow from a front side to a rear side on a peripheral surface of the housing. screw.