JP7521149B2 - External thruster unit - Google Patents

Description

The present invention relates to an external thruster mounted on a vessel.

Traditionally, large ships have often been fitted with devices called "side thrusters," which are power units used to move the ship sideways. They are used when docking and undocking to save time and effort, as well as ensure safety. In recent years, the effectiveness of side thrusters has also been recognized on leisure ships, and an increasing number of ships are being equipped with them.

When a ship is docked or undocked, it is not easy to do so using only the ship's propulsion engine. Especially in crosswinds or strong winds, the bow of the ship may be pushed downwind, and there is a risk of it colliding with the quay or other ships anchored in the port.
For this reason, it is effective to equip the bow or stern with a mechanism that uses power called a side thruster, which applies thrust at right angles to the right or left of the normal propulsion direction.

Of these side thrusters, those installed at the bow are called bow thrusters, and those installed at the stern are called stern thrusters.
Since the stern usually has a rudder, it is not particularly difficult to move the stern from side to side, so in the case of small vessels, they often only have a bow thruster and do not have a stern thruster.

On the other hand, even small vessels, especially leisure boats such as motor cruisers and sailing cruisers, are often operated by a single person or a small number of people, making it difficult to maneuver the vessel when mooring it at the desired mooring location when entering port, and an increasing number of vessels are being fitted with side thrusters.

When a side thruster is attached to a newly built ship or a used ship hull 105 afterwards, a thruster called a tunnel thruster is usually attached, as shown in FIG.
This thruster has a structure in which a hole, i.e., a tunnel 103, is drilled in the water below the waterline 116 near the bow, perpendicular to the direction of the ship's travel, and a propeller 101a is placed near the center of this hole and rotated by an electric motor 102a placed outside the tunnel 103.

The rotation of the electric motor 102a is transmitted to the propeller 101a via a bevel gear, generating a water current, which generates a thrust force in a lateral direction relative to the direction of travel of the ship as a reaction to the current. In addition, the direction of the thrust force can be changed by switching between forward and reverse rotation.
By using this device, the bow of the vessel 105 can be moved laterally.

SIDE SHIFT Monohull Thruster, Canada (https://shop.sideshift.com/) KAWASAKI Side Thruster (https://www.khi.co.jp/mobility/marine/machinery/side.html)

The problem with installing a tunnel thruster is that, not only on new ships, but especially when retrofitting a used ship, it is necessary to open the tunnel 103 below the waterline 116 in the bow of the ship.

The work of drilling the tunnel 103 is not easy, even though the material of the hull 105 is metal or glass fiber reinforced plastic, and it is complicated and takes several days to install the propeller 101a, the electric motor 102a, and the thick pipe that will become the tunnel 103 inside. Therefore, high costs are incurred according to the work time.
Furthermore, in the case of retrofitting, there is a risk that poor construction may occur at the joint between the tunnel 103 where additional work was performed and the hull 105 due to lack of skill of the workers, etc.

In the unlikely event that a ship runs aground, the bow will be the first to run aground on rocks or other objects. In the case of a tunnel thruster, this could cause distortion at the joint between the tunnel 103 attached to the bow and the hull 105, causing the joint to break and become flooded, which could result in a serious accident.
Furthermore, since the propeller 101a is always underwater, marine organisms such as barnacles and oysters may attach to it and impede the rotation of the propeller 101a.

In addition, since a portion of the drive shaft for driving the propeller 101a extending from the electric motor 102a is always underwater, a mechanical seal or the like must be provided to prevent water from entering the hull 105, and leakage must be completely stopped so that water does not enter the vessel even if the vessel is left abandoned for a long period of time.
Furthermore, the tunnel 103 of the tunnel thruster creates resistance to the water flow when the ship is normally sailing, which causes the ship's sailing speed to decrease.

In view of the above problems, the present invention aims to provide a safe and inexpensive external thruster for moving a ship laterally.

In order to solve the above problems, the present invention provides a method for solving a problem by moving a thruster to a dry space above the waterline of the ship when the thruster is not in use, the method comprising: a hull mounting part having a hinge element, an arm , and a thruster attached to one end of the arm, the hull mounting part being fixed near the bow and/or stern of the ship, the other end of the arm being connected to the hinge element, the thruster being composed of an electric motor and a propeller rotated by the electric motor, the position of the thruster being changeable by rotation around the hinge element, when the thruster is in use, the thruster is moved to a position lower than the waterline of the ship and the propeller is rotated to obtain thrust in a direction different from the direction of travel of the ship, and when the thruster is not in use, the thruster is moved to a position higher than the waterline of the ship and maintained there.

The present invention also provides a method for a watercraft comprising: a hull mounting part; an extendable slider; and a thruster attached to one end of the slider, the hull mounting part being fixed near the bow and/ or stern of the ship; the other end of the slider being connected to the hull mounting part; the thruster comprising an electric motor and a propeller rotated by the electric motor; the position of the thruster can be changed by extending and retracting the slider; when the thruster is used, the thruster is moved to a position lower than the waterline of the ship to rotate the propeller and obtain thrust in a direction different from the direction of travel of the ship; and when the thruster is not used, the thruster is moved to a position higher than the waterline of the ship and maintained there in a dry space.

In addition, the present invention provides a method for moving the hull in any direction by providing the external thruster device near the bow or stern of the ship, or at two locations near the bow and stern of the ship, and providing a mechanism for rotating the thruster horizontally. The thruster can be rotated with a joystick to point the thrust direction of the thruster in any direction, and the thrust of the thruster can be used to move the hull in any direction.

The present invention also provides a means for positioning the thruster at a position according to the draft depth of the ship, by providing an anti-roll fin that extends along the side of the ship's hull on one end of the slider that comes into contact with the side of the ship.

The thruster device of the present invention makes it possible to provide an inexpensive thruster for moving a ship laterally without drilling a large hole in the hull.

Diagram showing a conventional tunnel thruster FIG. 1 shows a folding thruster according to an embodiment of the present invention. FIG. 1 shows a groove trail type thruster according to an embodiment of the present invention. A diagram showing the straight arm system of the embodiment of the present invention. FIG. 1 shows a slider system according to an embodiment of the present invention. FIG. 1 is an explanatory diagram of a bevel gear and a propeller pitch when a motor is fixed according to an embodiment of the present invention. FIG. 1 is a diagram showing a combination of a folding system and a sliding system according to an embodiment of the present invention. A diagram showing propellers attached to both sides of the electric motor of the embodiment of the present invention. An explanatory diagram of the operation of both the bow thruster and the stern thruster in an embodiment of the present invention. An explanatory diagram of the rotation mechanism and thruster of the embodiment of the present invention. FIG. 1 is an explanatory diagram of a thruster operation system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The main feature of the external thruster device according to the present invention is that the thruster can be easily attached externally to a ship.
It should be noted that the overall shape and the shapes of each part of the external thruster device shown below are not limited to the embodiments described below, and can be modified as appropriate within the scope of the technical idea of the present invention, i.e., within the range of shapes and dimensions that can achieve the same functional effects.
In the following explanation, a bow thruster mounted on the bow is described, but the same can be applied to a stern thruster mounted on the stern.

Example 1
The present invention will be described with reference to FIGS. 2 to 4, 6 and 8. FIG.
Figure 2 shows a folding thruster: Figure 2(a) shows a manual folding thruster, Figure 2(b) shows a folding thruster using an electric motor, and Figure 2(c) shows the operation of the folding thruster.
3A and 3B are diagrams of a groove trail type thruster, in which Fig. 3A shows the groove trail type thruster when separated, Fig. 3B shows the groove trail type thruster when attached, Fig. 3C shows the relationship between the groove and the protrusion, Fig. 3D shows the shape of the rod-shaped protrusion, and Fig. 3E shows the shape of the plate-shaped protrusion.
Figure 4 is a diagram of a straight arm type thruster: Figure 4(a) is a top view of the straight arm type, Figure 4(b) is a diagram showing the operation of the straight arm type, Figure 4(c) is a diagram of the straight arm type with a manual lever attached, and Figure 4(d) is a diagram of the straight arm type with a cylinder added.
FIG. 6 is an explanatory diagram of the bevel gear and the propeller pitch when the electric motor is fixed.
Fig. 8 shows a diagram in which a propeller is attached to both sides of an electric motor. Fig. 8(a) shows a diagram in which a propeller is attached to both sides of an electric motor, and Fig. 8(b) shows a diagram in which a propeller is attached to each of two electric motors.

The external thruster device 1 is a device that is attached to the bow, stern, etc. of a ship and changes the thruster to a standby state or a usage state (standby state) depending on the necessity of the thruster. In this embodiment, a folding type thruster will be described.
A manual case will be described, and an electric case will be described as a modified example.
The external thruster device 1 mainly comprises a hull mounting part 106, an arm 107a, and a thruster 104 (FIG. 2).
(About hull mounting parts)
The hull mounting part 106 is a rod-shaped body that mounts the external thruster device 1 to the hull 105. The cross section is roughly U-shaped and consists of a central surface and two side surfaces that contact the central surface. The angle between the central surface and the side surfaces is an obtuse angle so that the side surfaces fit along the surface of the hull 105 to which they are attached.
A hull mounting hole 110 is drilled in the side of the hull mounting part 106. The hull mounting hole 110 is fixed with a bolt or the like into a small hole drilled above a waterline 116 at the bow or stern of the hull 105.
The waterline used here refers to the intersection of the water surface and the hull when the ship is floating on the water, and is a line that changes depending on the load.
One end of the hull mounting part 106 has a hinge element 117, and is connected to the arms 107a, etc. via the hinge element 117.

(About the arm)
The arm 107a is a part that holds the thruster 104. Overall, it has the same appearance as the hull mounting part 106 and is a rod-shaped body. The cross section is roughly U-shaped and consists of a central surface and two side surfaces that contact the central surface. The angle between the central surface and the side surfaces is an obtuse angle so that the side surfaces follow the surface of the hull 105 to which they are attached.
The thruster 104 is attached to a central surface of one end of the arm 107a. The other end of the arm 107a is connected to the hull mounting part 106 via a hinge element 117.
Thus, the thruster 104 and arm 107a can change position by rotating about the hinge element.
The axial direction of the propeller 101a of the thruster 104 is the width direction of the arm 107a, and when the arm 107a is grounded on the hull 105, is approximately perpendicular to the traveling direction of the ship.
One end of a lifting rope 108 is fixed to the middle part of the longitudinal direction of the central surface of the arm 107a. The lifting rope 108 is used to keep the thruster 104 in a dry space above the waterline 116.
The arm 107a has a protrusion extending in the width direction at the end of the side surface facing the hull mounting part 106, and one end of an arm fixing rope 109 is fixed to the tip of the protrusion. The arm fixing rope 109 is used to press the thruster 104 against the hull when the thruster 104 is in use.

(About thrusters)
The thruster 104 is a propulsion unit for moving the vessel in a direction other than the forward direction. The thruster 104 is composed of an electric motor 102a and a propeller 101a.
The electric motor 102a is an electric motor for rotating the propeller 101a. It is usually driven by a 12V or 24V DC power source using a lead-acid battery or the like. Although a hole is required to pass the electric wires for driving the motor, drilling holes for wiring is not necessary when wiring on the deck. Even if a hole is drilled in the hull 105, the electric wire introduction hole is a small hole, so the strength of the hull 105 is not reduced. If simple water-stopping measures are taken, water will hardly flow in through the hole.
The propeller 101a generates propulsive force in water by rotating, and can be selected from commercially available general underwater propellers and screws depending on the required propulsive force.

Also shown are modified examples of the electric motor and propeller.
As shown in FIG. 8A, propellers 101c and 101d can be attached to two ends of the rotating shaft of an electric motor 102c of a thruster 104.
In the case of a single propeller, the motor creates resistance depending on the direction of the water flow, and usually there is a difference in thrust between the left and right sides of the propeller. In contrast, by attaching propellers to both ends of the motor 102c, the motor does not create resistance and the water flow can be created efficiently.

Also, as shown in FIG. 8(b), the electric motors 102d and 102e may be integrated with metal fittings or the like. As in the case of FIG. 8(a), a water flow can be efficiently created, and the force of each electric motor can be applied to each propeller, improving the propulsive force.

Also, as shown in FIG. 6, a gear box 413 may be used.
The rotation output of the electric motor 408 is transmitted to a slide shaft 409, and then to an input side bevel gear 411. For the sake of explanation, the rotation direction is assumed to be clockwise 414 when viewed from above.

By rotating the input bevel gear 411 provided in the gearbox, the output bevel gears 412a, 412b are rotated, and at the same time the directly connected propellers 415a, 415b are rotated in the rotational directions 416a, 416b as shown in the figure, and water currents 417a, 417b are generated in the directions shown in the figure. As a reaction, thrust can be generated in the opposite direction to the water current.

(Operation of manual folding thruster device)
The operation of the manually folding type external thruster device will be described with reference to FIG.
The procedure for placing the thrusters 104 in a standby position for use will now be described.
The lifting rope 108 and the arm fixing rope 109 are used to move and fix the thruster 104.
By loosening the lifting rope 108, the arm 107a moves in a rotation direction 114 from the arm position 113 in the dry upper storage state, with the hinge element 117 as the center of rotation, together with the thruster 104, into the water at a position lower than the waterline.

After the arm has moved sufficiently, the arm fixing rope 109 is pulled up. Then, the arm 107a moves in a direction to be pressed against the hull, centering on the hinge element 117. Similarly, the thruster 104 installed on the arm 107a also approaches the hull.
Since the arm fixing rope 109 is connected to a protrusion at the end of the arm 107a facing the hinge element, the force of the arm fixing rope 109 can be converted more efficiently into a rotational force around the hinge element as an axis than when it is directly connected to the arm 107a.

By providing sufficient tension to the arm fixing rope 109, the position of the arm becomes the arm position 115 in the standby state as shown in Fig. 2(c) . The thruster 104 and the arm are biased to the hull 105 by the tension of the arm fixing rope 109. Therefore, the thruster 104 and the arm are stably fixed, and the direction of the water current caused by the thruster 104 can be stabilized.
In addition, the sides of the arm 107a are shaped to conform to the surface of the hull 105, so that the two side surfaces sandwich the bow and stern of the hull 105.
The reaction force caused by the water current tends to shift the arm 107a and thruster 104 laterally relative to the hull 105, but since the two side surfaces are structured to sandwich the hull, this shifting can be prevented.
In this state, the propeller can be rotated to obtain thrust in a direction different from the ship's traveling direction, making it easier for the ship to leave and dock.

The procedure for moving the thrusters 104 to the upper stowed position will now be described.
The arm fixing rope 109 is loosened, and the force of the arm 107 a and the thruster 104 against the hull 105 is removed.
Then, by pulling on the lifting rope 108, the arm 107a rotates about the hinge element 117, lifting the arm 107a and thruster 104 out of the water.
By continuing to pull the lifting rope 108, the arm moves to and is held at an upper stowed state arm position 113, which is a dry space above the waterline. In this state, the arm 107a can be stably fixed in the upper stowed state by fixing the lifting rope 108 to a deck or the like on the hull 105.

In this way, by using the above-mentioned structure, it can be easily added to existing ships, and the thruster can be easily switched between use and standby, contributing to user convenience.

(Electrified arm rotation)
An example of automating the rotational movement of the arm using an arm drive motor 111 will be described with reference to FIG.
An arm drive motor 111 and an arm drive gear 112 are disposed between the arm 107 b and the hull mounting part 106 .
The arm drive gear 112 reduces the number of rotations of the rotational motion generated by the arm drive motor 111 and increases the rotational torque.
By using the arm drive motor 111 and the arm drive gear 112, it is possible to rotate the arm without using the arm fixing rope 109 or the pull-up rope 108. The arm drive motor 111 is driven by supplying an external power source via wiring.
With this configuration, the arm 107b and thruster 104 can be easily rotated and moved, and fixed in the upper storage state and standby state, thereby reducing the workload when moving the arm.

In addition, other arm drive methods described below can also be easily automated using electric motors, linear cylinders, etc.

(Folding method using a horseshoe groove)
The folding method using the horseshoe groove will be described with reference to FIG.
In FIG. 3A, a horseshoe-shaped groove plate 202 having a horseshoe-shaped groove is attached to the lower part of the hull mounting part 106.
In FIG. 3B, a protrusion of an arm 107 c is attached to one side, and two protrusions 203 are inserted into the arm 107 c so that the protrusions slide in a horseshoe-shaped groove 205 .
FIG. 3C shows the thruster 104 moving from an arm position 210 in the upper stored state, through an arm position 211 in the intermediate state, to an arm position 212 in the standby state.
At this time, the positions of the protrusions are as follows: protrusion position 206 in the upper storage state, protrusion position 207 in the intermediate state, and protrusion position 208 in the standby state.

Because the groove is horseshoe shaped, when the attached rope 201 is pulled up, a force pressing the arm 107 c against the hull 105 is applied.
The horseshoe shape allows the arm to rotate through an angle of more than 180 degrees.
However, the gist of the present invention does not necessarily have to be a horseshoe-shaped groove, and a U-shaped groove may also be used.
As for the shape of the protrusion, besides the rod-like protrusion 213 as shown in Fig. 3(d), a plate-like protrusion 214 as shown in Fig. 3(e) is also conceivable. By using the plate-like protrusion 214, it is possible to achieve smoother rotation.

(Straight arm type)
The straight arm system with simplified functions will be described with reference to FIG.
Fig. 4(a) is a top view of the hull 105, and the thruster 104 is attached to the intersection of the starboard side arm 301a and the port side arm 301b. The arms 301a and 301b rotate as indicated by the arrow 305 in Fig. 4(b) around the fulcrums 302a and 302b of the respective arms. Here, only the port side is shown.

In addition, in FIG. 4(b), by loosening the rope 303 that was being pulled up in the pulling direction 304a, the arm at the arm position 311 in the upper storage state moves underwater by its own weight to the arm position 312 in the standby state.

At this time, the rope 303 can be pulled from the deck above the hull 105 in the lifting direction 304b to press the thruster 104 against the hull 105.

Depending on the location and direction of pulling up the rope 303, it can have the function of both pulling up the thruster 104 into a dry space above the waterline 116 and pressing it against the hull 105.
The rope 303 is fixed to the hull 105 while remaining in the pulled-up state.

In Fig. 4(c), the arm to which the thruster 104 is attached can be moved from arm position 313 in the upper stored state to arm position 314 in the standby state by rotating about fulcrum 302b. This is done by gripping lever 307 with one hand and pushing it toward the bow.
The arms may be fixed using an arm fixing rope 318 or the like, or a ratchet mechanism or the like may be added to the fulcrums 302a and 302b.

FIG. 4(d) shows an automated system using a linear cylinder.
The thruster 104, which is attached to the arm at arm position 315 in the upper storage state by the cylinder 317, is normally held in a dry space above the waterline 116, and when in use, by retracting the cylinder 317, it rotates as in rotation 310, and the arm becomes a position similar to arm position 316 in the standby state, and the thruster 104 moves into the water.

By adopting this structure, the thruster 104 is supported at two points, the left and right, so the arm is less likely to warp due to the thrust of the thruster 104, and lateral displacement of the thruster 104 can be prevented.

In addition, with this straight arm method, the device can be attached to the hull 105 by drilling only one hole each on the left and right sides of the fulcrum 302a and 302b, reducing the amount of modification required to the hull 105.

The folding thruster, groove trail thruster, and straight arm thruster using the arm drive motor 111 described above are variations of the folding external thruster device.

The straight arm type with a manual lever attached as shown in Figure 4(c) and the cylinder type as shown in Figure 4(d) are both variations of the folding type external thruster device.

Example 2
Another embodiment will be described with reference to Fig. 5. The same parts as in the first embodiment will be omitted.
(Slide type thruster)
Fig. 5 is a diagram showing the slider system, Fig. 5(a) is a diagram showing the slider, Fig. 5(b) is a diagram showing the slider system, Fig. 5(c) is a diagram showing the slider system when stored, Fig. 5(d) is a diagram showing the slider system when extended, Fig. 5(e) is a diagram showing the slider system with the motor fixed, and Fig. 5(f) is a diagram showing the slide shaft.

In the first embodiment, an external thruster device that can be easily retrofitted and can be moved to a standby state and a waiting state has been described.
However, depending on the vessel, when the waterline changes due to cargo, number of people, etc., the optimum position of the thruster may change in response to the change in the waterline. Therefore, there was a demand for technology to change the thruster position.

In this embodiment, a slide type thruster will be described, and as a modified example, a fixed motor slide type thruster will be described.
The external thruster device 1 of this embodiment is a device that is attached to the bow, stern, etc. of a ship, and can switch the thruster to a standby state or an in-use state depending on the need for the thruster, and can arbitrarily set the position of the thruster when in use.

The external thruster device 1 mainly comprises a hull attachment part 406, a slider 407, and a thruster 104 (FIGS. 5(c) and 5(d)).
The thruster 104 is the same as that in the first embodiment.
(Hull mounting parts)
The hull mounting part 106 is a part for mounting the external thruster device 1 to the hull 105, similarly to the first embodiment.
The hull attachment part 106 is fixed to the first stage of the slider 407. In other words, it can be said that the hull attachment part 106 is fixed to the other end of the slider 407.

(Slider)
The slider 407 is of a three-stage type and can move an object linearly. A slider retracted state 401 shows the slider in a retracted state, and a slider extended state 402 shows the slider in an extended state.
To ensure that each stage of the slider moves smoothly, various measures are taken, such as using lubricant oil to improve the sliding properties of each slider and using steel balls called slide steel balls.

The slider 407 itself may be a general commercial product, or a finished product may be purchased and used as a part of the present invention. These sliders are designed with a stopper to prevent them from coming apart if they are pulled out beyond the specified distance.

The thruster 104 is attached to the end plate which is the third stage when the slider 407 is extended. Also, one end of the lifting rope 403 is connected to the third stage.
A lateral vibration prevention fin 308 is attached to the end plate of the third stage at the position where the thruster 104 is attached. The lateral vibration prevention fin 308 prevents the thruster 104 and the like from shifting laterally relative to the hull 105 when the thruster 104 is in use.
The anti-side sway fin 308 is located on the side of one end of the slider that comes into contact with the side of the ship, and is composed of two plates extending toward the hull 105, with the two plates being formed with surfaces that conform to the hull they come into contact with.
In other words, the hull 105 is sandwiched between the anti-side shake fins 308 .

The operation of the external thruster device 1 will now be described.
The operation up to fixing the thruster 104 in the standby state will be described with reference to FIG.
The slider 407 is initially fixed in an upper stored state by a lifting rope 403 (FIG. 5(c)).
By loosening the pull-up rope 403, the slider 407 gradually slides from the slider storage position 404 into the water due to the weight of the thruster 104.
The slider 407 extends and moves together with the thruster 104 into the water below the waterline, reaching the slider extended state 405 (FIG. 5D).

When the thruster 104 is used, a reaction from the water current generates a large lateral force on the thruster 104 and the slider 407. This force may cause the thruster 104 and the slider 407 to shift positions relative to the bow and stern, preventing the thruster from achieving its intended performance.
Furthermore, there is a possibility that the slider may bend or be damaged. Therefore, the lateral vibration prevention fin 308 holds the hull 105 to prevent bending and lateral displacement of the thruster and slider.
If the slider itself is strong, this structure is not necessary.

In FIG. 5(d), the lifting rope 403 is fixed to the hull 105 at the position where the thruster 104 has lowered to prevent it from getting entangled in the propeller 101b. In addition, a mechanism such as a linear ratchet may be required to fix the arm so that it does not rise above the water surface while the slider is in operation.

(Description of optional position settings)
Although the use of the slider 407 in the fully extended state has been described, a method of fixing the thruster at an arbitrary position will now be described.
In contrast, general thrusters are often installed in tunnels or other holes in the hull of the ship, and their installation position is fixed. Also, the draft changes depending on factors such as the amount of cargo.

When a ship is moved sideways by a thruster, the thrust of the thruster is concentrated at a single point on the side of the ship where the thruster is located. The water resistance, which acts against the thrust of the thruster, is thought to consist of the resistance of the water in shallow and deep areas from the thruster position.
If there is a difference between these two resistance forces, the ship will be pushed by either the upper part, which is shallow, or the lower part, which is deep, causing the ship to sway or tilt.
It is believed that the difference in resistance changes depending on the position of the waterline.

Therefore, in order to improve the stability of a ship when using thrusters, it is considered effective to place the thrusters in positions where the resistance of the shallow and deep water against the thrust of the thrusters can be obtained, depending on the position of the waterline.

The following description will be given of an example in which the installation positions of the thrusters are changed.
As described above, since the relationship between the draft and the optimum installation position of the thruster is important, the relationship between the position of the waterline and the optimum installation position of the thruster is measured, calculated, and converted into data in advance.
When using the thruster, the position of the waterline is confirmed and the optimal installation position of the thruster is determined based on prior data.
The lifting rope 403 is loosened and the slider 407 is extended.
When the thruster 104 reaches the optimum installation position, a lifting rope 403 is stretched and fixed to a deck or the like, and the position of the thruster 104 is fixed to the optimum installation position.
By propelling the thrusters 104 in this position, the swaying and tilting of the ship caused by the use of the thrusters can be minimized.
In addition, since the thruster 104 portion has anti-lateral vibration fins 308, lateral deviation due to the thrust of the thruster can be prevented regardless of the position at which it is fixed.

In this way, by setting the position of the thrusters according to the draft depth (position of the waterline), the rocking of the ship when using the thrusters can be reduced, and by using anti-rollover fins, the thrusters can be installed in any position and used stably.

(Slider type with fixed motor)
The slider system for fixing the motor will be described with reference to Fig. 5(e) and (f). Fig. 5(e) is a diagram showing the slider system for fixing the motor, and Fig. 5(f) is a diagram showing the slide shaft.
In FIG. 5( e ), an electric motor 408 is attached to the first stage of the slider 407 or to the hull 105 and fixed to the fixing part 406 .

The rotating shaft of the electric motor 408 is connected to a slide shaft 409, which in Figure 5 (e) is connected to a gear box 413 attached to the second stage slider. This slide shaft 409 expands and contracts, moving into the water. Note that Figure 5 (e) shows the state immediately before entering the water.

FIG. 5(f) is a diagram showing the operation of the slide shaft.
The outer shaft can transmit rotation to the inner shaft, and the inner shaft is free to move in the axial or shaft sliding direction 410 .

This structure allows the electric motor 408, an electrical component, to always be placed in a dry space above the waterline, reducing corrosion of electrical components caused by seawater and extending the life of the equipment.

(Combines folding and sliding methods)
A combination of the folding and sliding methods will be described with reference to FIG.
In this figure, the slider 423 first slides in a sliding direction 430 and then folds down from a hinge element 422 attached to the tip of the slider 423 .
A thruster 104 is attached to the tip of the arm 421. The arm 421 rotates 420 about a hinge element 422 and moves in the water.

(Explanation of the operation of thrusters on ships)
The operation of the thruster in the ship will be described with reference to FIG.
FIG. 9 is a diagram showing the installation of both the bow thruster and the stern thruster.
Figure 9(a) shows a bow thruster 501 attached to the bow of the hull 105 and a stern thruster 502 attached to the stern, and Figures 9(b), 9(c), and 9(d) show the operating states of each thruster when operated, as viewed from above the hull 506. Figure 9(b) shows the state when only the bow thruster is operated, Figure 9(c) shows the state when the bow thruster and stern thruster are operating with water flow in the same direction, and Figure 9(d) shows the state when the bow thruster and stern thruster are operating with water flow in opposite directions.

The above explanation has mainly focused on thrusters mounted on the bow, but they can also be mounted on the stern.

9B shows the state where only the bow thruster 501 is operated. The bow thruster 501 attached to the bow can rotate only the bow without moving the stern much. The water current flows in the direction of the water current 503a.
As a reaction, rotation direction 504a indicates the direction of rotational movement of the hull 105 at that time.

FIG. 9(c) shows a case where a bow thruster 501 and a stern thruster 502 are attached to the bow and stern, respectively, and then operated in the same direction.
As shown in FIG. 9C, if water currents 503b and 503c are generated in the port direction, the movement direction of the hull 105 becomes direction 505.
In this way, the ship 105 can move away from the shore in a parallel manner. After it has left the shore sufficiently, as shown in the figure, the rudder is turned to the starboard side and the ship moves forward, preventing the stern from hitting the shore.

Figure 9 (d) shows bow thruster 501 and stern thruster 502 operated in the opposite direction. When each thruster is operated, the water flow direction becomes water flow 503d and water flow 503e, and the hull 105 can be rotated on the spot in rotation direction 504b. When the ship is stopped in a narrow bay, it can change direction.

Example 3
Another embodiment will be described with reference to Figures 10 and 11. The same parts as in the first embodiment will be omitted.
(Thruster Operation System)
FIG. 10 is an explanatory diagram of the rotation mechanism and the thruster.
11 is an explanatory diagram of the thruster operation system, in which (a) is an explanatory diagram of the joystick, (b) is a schematic diagram of the thruster operation system, and (c) is an explanatory diagram of the thruster operation.

In Example 1, an external thruster device that can be easily retrofitted and can be moved to a standby state and a waiting state is described. However, it is difficult to completely control movement with a single thruster, and even when two thrusters at the bow and stern are used, it is often not easy to control them in a coordinated manner.
Therefore, there was a demand for a system that could be easily controlled using a joystick or the like.

In this embodiment, we will explain an external thruster device that can arbitrarily change the horizontal angle of the thruster 104.

As shown in FIG. 10 , a rotation mechanism 602 is provided on the upper part of a thruster 605a. Normally, the thruster is fixed perpendicular to the direction of travel of the ship, but this rotation mechanism 602 can rotate the horizontal angle of the thruster 605a as shown by rotation 604.
This allows the hull to rotate or move in any direction.

For convenience of explanation, a method for obtaining thrust in eight directions by the thruster 605a will be described. The fixed shaft 601 is fixed to the hull and serves to transmit the thrust generated by the thruster 605a to the hull.
It has the function of inserting the thruster 605a into the water when in use by a folding or sliding insertion method.

Here we explain how to operate the bow thruster attached to the bow with an 8-way joystick.

Further improvements can be made by equipping the stern with thrusters, but explanation of this will be omitted as it would deviate from the gist of this invention.

The rotation mechanism 602 includes an electric motor, gears for increasing torque, and an angle detection mechanism for detecting the angle of the rotation shaft 603.

FIG. 11(a) is an explanatory diagram of a joystick for operating this thruster 605a.
It can be tilted in eight directions; in this diagram, the joystick is tilted diagonally forward to the right.

Figure 11(c) shows thruster 605c facing diagonally forward to the right. After the direction is set by supplying power to thruster 605c, supplying power to the thruster generates a water flow in the direction of water flow direction 631, and as a reaction, the bow obtains thrust in the direction indicated by thrust direction 632 diagonally forward to the right.

FIG. 11(b) shows a block diagram of this system.
An angle encoding signal 627 from an angle detection mechanism in the rotation mechanism 624 is input to the control unit 623, and the control unit 623 can know the current horizontal angle of the thruster 605b.

Typically, angle detection mechanisms use optical encoders that utilize light, magnetic encoders that utilize Hall elements, or mechanical contact types that use copper foil strip lines formed on a printed circuit board.
The power supply 622 supplies power 626 for the rotation mechanism to a control unit 623 and a rotation mechanism 624, and power 628 for the thruster is supplied from the control unit 623 to the thruster 605b.

In addition to the above method, if a stepping motor or the like is used as the electric motor in the rotation mechanism 602, one-way control without feedback can also be used.

The thruster 605a rotates 135 degrees from the forward direction 611 to the right rearward diagonal direction 614, and the remaining angles are reversed by switching the polarity of the current to the thruster 605a, and the direction of the thrust can be switched in 45 degree increments in all directions.

Forward direction 611 generates a forward thrust, right diagonal forward direction 612 generates a right diagonal forward thrust, right lateral direction 613 generates a right lateral thrust, right diagonal backward direction 614 generates a right diagonal backward thrust, and backward direction 615 generates a backward thrust.

It is also possible to rotate the thruster in all directions without switching the current. In this case, if the power is supplied using a slip ring or similar, there is no need to consider problems caused by rotating wires.

Unlike conventional methods that only provide lateral thrust with this method of rotating the thruster horizontally, thrust can also be obtained in the forward and backward directions by tilting the joystick 621a in Figure 11(a) in the forward direction 611 and reverse direction 615, so the ship can be moved forward and backward without using the main propulsion engine equipped on the ship.

In addition, when docking or undocking at slow speeds, there is no need to use a high-output main propulsion engine, making it easier to maneuver the ship within the bay.
In addition, if a stern thruster is also installed at the stern, control of the ship will be safer.

This configuration allows for precise control of the thrusters and allows them to take over for the main propulsion engine at very slow speeds, improving the control accuracy of the ship.

It is understood that the external thruster device according to the present invention has great industrial applicability as a thruster device that can be easily installed on existing ships.

1 External thruster device 101a Propeller 101b Propeller 101c Propeller 101d Propeller 102a Motor 102b Motor 102c Motor 102d Motor 102e Motor 103 Tunnel 104 Thruster 105 Hull 106 Hull mounting part 107a Arm 107b Arm 107c Arm 108 Lifting rope 109 Arm fixing rope 110 Hull mounting hole 111 Arm drive motor 112 Arm drive gear 113 Arm position in upper storage state 114 Rotation direction 115 Arm position in standby state 116 Waterline 117 Hinge element 201 Rope 202 Horseshoe-shaped groove plate 203 Protrusion 205 Horseshoe-shaped groove 206 Protrusion position in upper storage state 207 Protrusion position in intermediate state 208 Protrusion position 210 in standby state Arm position 211 in upper storage state Arm position 212 in intermediate state Arm position 213 in standby state Rod-shaped protrusion 214 Plate-shaped protrusion 301a Arm 301b Arm 302a Pivot 302b Pivot 303 Rope 304a Lifting direction 304b Lifting direction 305 Rotation 307 Lever 308 Anti-lateral sway fin 310 Rotation 311 Arm position 312 in upper storage state Arm position 313 in standby state Arm position 314 in upper storage state Arm position 315 in standby state Arm position 316 in upper storage state Arm position 317 in standby state Cylinder 318 Arm fixing rope 401 When slider is stored 402 When slider is extended 403 Lifting rope 404 When slider is stored 405 When slider is extended 406 Hull mounting fixing part 407 Slider 408 Electric motor 409 Slide shaft 410 Shaft slide direction 411 Input side bevel gear 412a Output side bevel gear 412b Output side bevel gear 413 Gearbox 414 Rotation direction 415a Propeller 415b Propeller 416a Rotation direction 416b Rotation direction 417a Water flow 417b Water flow 420 Rotation 421 Arm 422 Hinge element 423 Slider 430 Slide direction 501 Bow thruster 502 Stern thruster 503a Water flow direction 503b Water flow direction 503c Water flow direction 503d Water flow direction 503e Water flow direction 504a Rotation direction 504b Rotation direction 505 Movement direction 601 Fixed shaft 602 Rotation mechanism 603 Rotation shaft 604 Rotation 605a Thruster 605b Thruster 605c Thruster 611 Forward direction 612 Right diagonal forward direction 613 Right lateral direction 614 Right diagonal backward direction 615 Backward direction 621a Joystick 621b Joystick 622 Power supply 623 Control unit 624 Rotation mechanism 626 Power for rotation mechanism 627 Angle encoding signal 628 Power for thruster 631 Water flow direction 632 Thrust direction

Claims (3)

a hull attachment part having a hinge element, an arm, and a thruster attached to one end of the arm;
The hull mounting is fixed to the bow and/ or the stern of the vessel;
The other end of the arm connects to the hinge element;
The thruster includes an electric motor and a propeller rotated by the electric motor,
the thruster is capable of changing position by rotation about the hinge element;
The thruster is provided with a mechanism for rotating it horizontally,
When using the thruster,
The thruster is moved to a position lower than the waterline of the vessel, the thruster is rotated with a joystick to orient the thrust direction of the thruster in any direction, the propeller is rotated, thrust in a direction different from the traveling direction of the vessel is obtained, and the hull can be moved in any direction,
When the thruster is not in use, the thruster is moved to and maintained in a dry space above the waterline of the ship. The device comprises a hull attachment part, a retractable slider, and a thruster attached to one end of the slider;
The hull mounting is fixed to the bow and/ or the stern of the vessel;
The other end of the slider connects to the hull mounting part;
The thruster includes an electric motor and a propeller rotated by the electric motor,
The thruster is capable of changing its position by extending and contracting the slider;
The thruster is provided with a mechanism for rotating it horizontally,
When using the thruster,
The thruster is moved to a position lower than the waterline of the ship, and the thruster is rotated with a joystick to orient the thrust direction of the thruster in any direction, the propeller is rotated, and thrust in a direction different from the traveling direction of the ship is obtained, thereby moving the hull in any direction.
An external thruster device characterized in that, when the thruster is not in use, the thruster is moved and held in a dry space above the waterline of the ship. On the side of one end of the slider that comes into contact with the side of the ship, a lateral sway prevention fin extends along the side of the hull,
3. The external thruster device according to claim 2, wherein, when the thruster is used, the position of the thruster can be set arbitrarily at a position lower than the waterline of the ship.