JP2920206B2 - Internally driven flapping thruster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internally driven flapping propulsion device for the purpose of quietly and efficiently propelling a ship or underwater vehicle underwater.

[0002]

2. Description of the Related Art A rotary propeller (hereinafter referred to as a propeller) is the mainstream of a conventional propulsion device for an underwater vehicle. It has a simple operating principle, a simple structure, and can be easily mounted via a simple shaft system because the ordinary power source is a rotary machine, and has excellent propulsion efficiency. In order to improve propulsion efficiency, propellers are usually mounted at the stern end. This is because the propeller is operated in the flow that is slowed down by an additional object such as the hull or rudder, that is, in the wake of the hull. The intention is to increase economics. However, on the other hand, the non-uniform flow in the wake of the hull and the high-speed movement of the propeller blades due to the rotation generate large fluctuation forces on the propeller blades. The frequency of the fluctuating force is a frequency sufficient to vibrate the hull. The frequency is also sufficient to be sensed as a sound wave. For this reason, the conventional propeller is the largest cause of undesirable hull vibration and noise.

[0003] The rotation of the propeller also increases the velocity of water at the outer ends of the propeller blades, which often causes cavitation. Cavitation also fluctuates and fluctuates with uneven wake distribution, which also doubles hull vibrations and noise.

As described above, the conventional rotary propeller cannot be said to be an excellent propulsion device in terms of vibration and noise.

[0005]

Conventionally, ships such as submarines that sail underwater have a screw propeller at the stern end,
Although this is rotated and propelled, an oscillating force having a frequency corresponding to the rotation speed is generated because the propeller is operated by the rotational motion. In addition, since the operating position of the propeller is in an uneven wake affected by the hull and rudder, it corresponds to [number of blades x number of wake peaks] on the propeller and propeller shaft during one revolution of the propeller. This generates harmful vibrations and noises on the hull by generating more and more fluctuating force, which causes the hull to vibrate and generate sound. As a result, work using the underwater acoustic equipment becomes difficult.

In addition, the conventional propeller has a situation in which cavitation tends to occur on the propeller blade surface because the speed of water due to the rotational motion becomes extremely high. Cavitation is also a major cause of hull noise, but also results in propeller damage.

[0007] The present invention is an internal drive type that fundamentally reduces the propeller vibrating force and cavitation that cause harmful vibration and noise as described above, and also prevents damage to the propulsor itself due to cavitation. It is an object of the present invention to provide a fluttering type propulsion device.

[0008] Other objects and novel features of the present invention will be clarified in embodiments described later.

[0009]

In order to achieve the above object,
The following items were considered.

Reduction of Propeller Vibration Force The causes of the generation of the vibration force of the propeller are (1) rotational movement at a relatively high speed, and (2) non-uniform flow at the operating position.

In order to eliminate the factor (1), an effective solution is to adopt a propulsion method that does not depend on the rotational movement. One such propulsion method is a propulsion method using swinging wings that simulates a swimming method for underwater animals. It would be better to flap the wings on the side of the body, as in the method of propelling rays or penguins, or to move the wings in the tail, such as fish such as whales and horse mackerel. this house
For the factor (2), flapping rays or penguins that do not have a propulsion unit at the tail are effective.

Reduction of Cavitation Since the fluttering type propulsion device can easily have a large area along the side of the hull, a propulsion force can be obtained by a relatively gentle operation. For this reason, the water velocity on the wing surface is greatly reduced as compared with the conventional propeller, and the occurrence of cavitation is extremely small. From the viewpoint of preventing cavitation, it is also effective to provide pressure sensors at several points on the wing surface and monitor the signal to detect cavitation in advance and reduce the movement of the wing. As a solution, such control is also possible with such a slowly operating propulsion wing.

Ensuring Suitability as a Propulsion Device for a Ship or the Like In general, a propulsion device imitating an animal propulsion method induces the hull of the hull by its operation. In particular, when the propulsion method of whales or horse mackerel is imitated, the rocking wings are located away from the center of gravity of the ship, and the hull causes pitching whenever the propulsion wings rock, resulting in poor ride comfort, and It is considered not suitable as a vessel. On the other hand, since the fluttering type propulsion device is close to the center of gravity of the ship, such hull sway is small. Therefore, as a means for solving the above problems, a propulsion device using a mechanism that makes such a fluttering motion is effective.

In order to realize this mechanism, if a mechanism for driving the propulsion wing is provided outside, this mechanism disturbs the flow and generates new vibrations and fluctuating forces. It will not solve the problem. Therefore, the drive mechanism needs to be housed inside the fluttering propulsion wing.

Therefore, in order to achieve the above object, an internally driven fluttering type propulsion device according to the present invention comprises an underwater vehicle, such as a submersible, or a watercraft having a sufficient draft, on both sides of the hull.
A configuration that promotes Promoting wings provided, prior to the hull
Move the drive arms of the
Provided in the span direction of the propulsion wing, and
The front and rear drive arms are wrapped in elastic wings and connected to the elastic wings.
And filling the elastic wings with liquid,
Connect the skeletal units with joints that can rotate freely and
Linear actuator that expands and contracts between adjacent skeleton units
In a drive unit having formed by bonding bending function and multiple coupling constitutes the driving arm, is characterized in that flapping of the elastic blade portion in the driving arm.

The skeletal units of the front and rear drive arms are mutually connected.
The elastic wings are joined by elastic ribs.
May be joined to the skeleton unit .

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an internally driven fluttering propulsion device according to the present invention will be described below with reference to the drawings.

First, the principle of thrust generation of the internally driven flapping type propulsion unit will be described with reference to FIG. As shown in FIG. 4A, the fluttering type propulsion device includes propulsion wings 1 attached to both sides of a hull 2 of an underwater vehicle such as a submersible or a watercraft having a sufficient draft. Along with moving the wing cross section up and down at each part (arbitrary horizontal position y in the span direction in the figure) of the propulsion wing (increase / decrease vertical position z with respect to the wing reference height)
The elevation angle と し た based on the hull advancing direction of the wing section is changed every moment. As a result, as shown in the drawing of the propulsion force at the position y in FIG. 4B, the cross section of each part of the wing receives the combined flow of the speed of the hull and the movement of the wing at the inflow angle α, and the lift of the wing Of fluid works. In particular, when the wing rises, the elevation angle is set so that the combined flow comes from the upper side, and when the wing descends, the elevation angle is set so that the combined flow comes from the lower side. The fluid force has a forward component, which is the driving force. Since the movement of the wings is given periodically in a sinusoidal manner, the propulsion force also increases and decreases periodically. By setting the value (approximately π / 2 radians), the propulsive force can always be generated in the forward direction. Therefore, the fluttering type propulsion device as a whole can generate a propulsive force in the forward direction, and can propel the hull.

FIG. 1 shows the overall configuration of an internally driven flapping type propulsion device, FIG. 2 shows a cross section of a driving arm, and FIG. 3 shows a driving unit which is a structural unit of the driving arm.

As shown in these figures, the internally driven flapping type propulsion device has a plurality of drive arms 3 provided therein,
A pair of propulsion wings 1 having elastic wings 4 enclosing them are provided on both sides of the hull 2. Each drive arm 3 has a propulsion wing 1
And is connected to the structural member of the hull 2 at the base of the propulsion wing 1. As shown in FIG. 2, the cross-sectional structure of the drive arm 3 is an aggregate of a large number of skeleton units 5 and linear actuators 6 that expand and contract by power. The skeletal units 5 are connected to each other by freely rotatable joints 7 and are also connected to each other by linear actuators 6 arranged in two layers. FIG. 3 shows a drive unit using the skeleton unit 5 and the actuator 6. That is, the drive arm 3 is configured as a connected assembly of such drive units. The dimensions of the skeleton unit 5 and the linear actuator 6 vary depending on the thickness of the driving arm 3 and its position in the span direction.

In FIG. 3, when a large number of actuators 6 expand and contract, respectively, the driving arms are curved due to the difference in the amount of expansion and contraction of the actuators 6 arranged in pairs vertically. For this reason, the propulsion wing can perform free wave motion that curves up and down.

Each drive arm 3 is connected to the front and rear drive arms by elastic wings 4. Therefore, when several front and rear drive arms swing in a wave-like manner with slightly different phases, the propulsion wing 1 is bent up and down, and at the same time, the wing cross section of each part is raised and lowered due to the difference in the vertical position of the front and rear drive arms. An angle is formed, and the elevation angle also changes sinusoidally. Taking this movement into account, when the individual linear actuators are precisely and periodically moved to a predetermined movement, the propulsion wing can achieve a predetermined vertical movement and wing twist movement.
As a result, a propulsive force is generated according to the principle described with reference to FIG. 4, and the hull 2 is advanced. The actuator is operated by electric, electromagnetic or hydraulic pressure, and its driving energy is supplied from the hull in electric or hydraulic form by a power tube disposed inside the wing. In addition, the movement of each linear actuator is controlled by an electric signal or an optical signal from a control center of the hull by electric wires or optical fibers.

As shown in FIGS. 2 and 3, the surface of the elastic wing portion 4 is covered with a tough and smooth surface film 8 rich in elasticity to form a smooth wing surface, and the inner surface thereof is a skeleton unit. 5 is joined. As shown in FIG. 1, the skeletal units 5 of the front and rear drive arms 3 are connected to each other by a large number of elastic rib members 9, and have a role of transmitting the thrust obtained at each portion to the entire wing and the hull. The space 10 inside the surface film 8 is filled with a liquid such as oil, and the pressure is adjusted to a value substantially equal to the water pressure applied to the outer surface of the blade. By doing so, the propulsion wing can be prevented from being crushed by water pressure in the deep sea, and the wing shape is always kept in a healthy state.

[0024]

5 to 7 show an embodiment in which an internally driven flapping propulsion device according to the present invention is applied to a submarine.
5 is a side view of the embodiment, FIG. 6 is a plan view, and FIG. 7 is a front view. In this example, the movement of the center of the wing and the movement of the elevation angle are controlled and driven as in the following equation.

Vertical movement; z = (1/2) z _omax {1-cos (2πy / s)} sinωt Elevation angle movement; ψ = tan ⁻¹ {(v / U) cosωt} + α (radian) Inflow angle Change; α = (1/2) α _omax {1-cos (2πy / s)} sin (ωt−θ) (radian)

Here, y and z are the position coordinates shown in FIG. 4, t is time, U is the ship speed, ω is the angular frequency of the vertical motion of the propulsion wing, and v is the vertical speed of the wing section. That is, it is a time differential value of z. Also, s is a value twice as long as the span of one of the propulsion units, z _omax is a single amplitude of vertical movement of the tip of the propulsion wing, α _omax
Is the half amplitude of the inflow angle at the blade tip, and θ is the phase delay of α with respect to z.

As a specific example, the shape of the propulsion wing is made elliptical, the dimensions of each part are set as the numerical values (unit m) in FIGS. 5 to 7, and the numerical values of the control of the propulsion wing are as follows. When set, about 5m / s for the hull as shown
It is expected that it will be possible to sail at speeds around the ship.

Z _omax = 2.25 m, α _omax = 0.157
1 (radian), θ = π / 2 (radian), ω = 0.6
(Radian / second)

The frequency of the swing of the wings is very slow, about 0.1 Hz, and it is expected that no force in the frequency range that causes vibrations in the hull will be generated in the propulsion unit, and cavitation will occur. It is considered to be extremely unlikely to occur.

Although the embodiments of the present invention have been described above, it is obvious to those skilled in the art that the present invention is not limited to the embodiments and various modifications and changes can be made within the scope of the claims. There will be.

[0031]

As described above, a ship using the internally driven flapping type propulsion device according to the present invention has the following advantages as compared with a conventional ship driven by a propeller.

(1) The fluctuating force generated by the propulsion device has a very low frequency, and the vibration of the hull by the propulsion device is extremely small.

(2) The propulsion wing moves very slowly,
Very little cavitation.

(3) Due to the above (1) and (2), underwater noise caused by the propulsion unit is extremely reduced, and various operations using the underwater acoustic equipment can be easily performed.

(4) Since there is a propulsion device on the ship side, there are no moving objects at the stern, and towing of the towable equipment can be performed safely and easily at the stern.

(5) By providing a drive arm, in which a plurality of drive units each of which is a combination of a linear actuator and a skeletal unit are connected, in the elastic wing portion, the elastic wing portion can be bent and fluttered by internal driving.

In the case of a submarine, if the propulsion unit is fixed with its wings spread horizontally, the ship becomes an underwater glider,
When the hull is lowered by reducing the buoyancy of the hull, it is possible to sail long distances without power according to the principle of a glider.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an embodiment of an internally driven flapping type propulsion device according to the present invention.

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

FIG. 3 is a cross-sectional view of the drive unit according to the embodiment.

FIG. 4 is an explanatory view showing the operation principle of the internally driven fluttering type propulsion device according to the present invention.

FIG. 5 is a side view of an embodiment when the present invention is applied to a submersible.

FIG. 6 is a plan view of the same.

FIG. 7 is a front view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Propulsion wing 2 Hull 3 Drive arm 4 Elastic wing part 5 Skeletal unit 6 Linear actuator 7 Joint 8 Surface film 10 Internal space

Claims (2)

(57) [Claims] 1. A flapping type propulsion device for propelling an underwater vehicle such as a submersible or a watercraft having a sufficient draft with propulsion wings provided on both sides of a hull , wherein the fluttering propulsion unit is connected to the hull in a front-rear direction. Multiple articles so that the position is different
Drive arm in the span direction of the propulsion wing, and
Several drive arms are wrapped in elastic wings and the front and rear drive arms are
To connect with the elastic wings and
Filling liquid and rotating the skeleton units freely
Lines connected by nodes and stretched between adjacent skeleton units
A drive unit having formed by bonding bending function by an actuator with a plurality ligated constitute the driving arm, inner driven flapping propulsion unit, characterized in that flapping of the elastic blade portion in the driving arm. 2. The skeletal units of the front and rear drive arms are mutually elastic.
The elastic wings are joined by highly elastic ribs.
The internally driven flapping propulsion device according to claim 1, wherein a surface is joined to the skeleton unit .