Ship

Abstract

Disclosed is a ship comprising: a tail shaft providing a driving force generated by a power generating device of the ship; a pair of left and right wings, each having one end rotatably coupled to the tail shaft, an intermediate portion between the one end and the other end extending in a width direction symmetrically with respect to a longitudinal cross section of a hull passing through the tail shaft, and the other end having a propeller installed at one end of a propeller shaft receiving the driving force provided by the tail shaft; and a wing rotation amount adjustment unit for adjusting the height of the propeller with respect to the hull by adjusting the rotation amount by driving the pair of left and right wings. Since the propeller is divided into two parts, the diameter is reduced, and the vertical position of the propeller provided at the end of the wing can be lowered, so that the propeller can be completely submerged at a low draft without ballast water, and environmental pollution and economic loss due to seawater ballast can be eliminated or minimized.

Description

shipping

[0001] The present invention relates to a ship having a small amount of ballast water, and more specifically, to a ship capable of minimizing the amount of ballast water by satisfying various regulations regarding propeller submersion, turning radius, bow draft, and center ballast length (PBL) only with ballast water for trim adjustment and an unknown weight in a light load state, thereby reducing operating expenses during ocean voyages.

[0002] Ships sail by propulsion through the rotation of their propellers. However, if the propeller is exposed above the sea surface, propulsion efficiency is reduced, noise generation, and propeller damage can occur. Therefore, ships typically sail by filling their ballast tanks with seawater when there is no cargo, ensuring that the propeller is completely submerged below the sea surface. Legal regulations require that the propeller be fully submerged (100%) as the minimum draft in the "Common Structural Rules (CSR) for Bulk Carriers and Oil Tankers." Typical low-speed, large-diameter ships, such as bulk carriers and oil tankers, use propellers with low rotational speeds (RPM) and large diameters to improve propulsion efficiency. Full submersion requires a deep draft, requiring a large amount of ballast water, which increases newbuilding prices and operating expenses at light drafts.

[0003] To solve this problem, the following two non-patent documents and two patent documents were searched as prior art.

[0004] Two non-patent documents and patent document 1 propose a modified hull, but it is difficult to satisfy all the requirements for propeller submersion, turning radius, bow draft, and centerline balance length (PBL) by modifying the hull alone.

[0005] Patent Document 2 discloses a technology for varying the height of a propeller by tilting the rotation axis of the propeller relative to the power axis. However, since the propeller is tilted relative to the hull, a decrease in propulsion efficiency cannot be avoided, and there are also restrictions on adjusting the height of the propeller.

[0006] Therefore, a new structural vessel that can satisfy the regulations on propeller submersion, turning radius, bow draft, and centerline ballast length (PBL) with only ballast water for trim adjustment and unknown weight under light load has not been provided in the prior art, and the need for such a vessel still exists.

[0007] The present invention was created to solve the problems of the prior art as described above, and the purpose of the present invention is to provide a ship with a new structure that can satisfy various regulations regarding propeller submersion, turning radius, bow draft, and center ballast length (PBL) with only an unknown weight and ballast water for trim adjustment in a light load state.

[0008] The purpose of the present invention is to provide a ship that enables smooth navigation by changing the height of the propeller according to the draft state by changing the power transmission device without increasing the number of main engines constituting the propeller, thereby completely submerging the propeller while minimizing ballast water even at low draft.

[0009] The purpose of the present invention is to provide a ship that enables smooth navigation and berthing by minimizing the displacement below the ballast waterline and securing the required length of the central ballast section by changing and improving the central cross-sectional shape of the hull.

[0010] According to one embodiment of the present invention, a ship comprises: a tail shaft that provides driving force generated by a power generation device of the ship; a pair of left and right blades, each end of which is rotatably connected to the tail shaft, and a middle portion between each end and the other end extends in the width direction of the ship symmetrically with respect to a longitudinal cross-section of the ship passing through the tail shaft, and each other end is provided with a propeller installed at one end of a propeller shaft that receives the driving force provided by the tail shaft; and a blade rotation amount control unit that controls the height of the propeller relative to the hull by controlling the rotation amount by driving the pair of left and right blades.

[0011] Inside each of the left and right pairs of wings, a power transmission mechanism is installed that converts the rotational motion of the tail shaft into reciprocating motion and then converts it back into the rotational motion of the propeller shaft, so that the driving force provided by the tail shaft is transmitted to the propeller shaft.

[0012] The power transmission mechanism installed inside each of the left and right pairs of wings is composed of a driving crank formed on the tail shaft, a driven crank formed on the propeller shaft, and a connecting rod connecting the driving crank and the driven crank.

[0013] Alternatively, the power transmission mechanism installed inside each of the left and right pairs of wings is composed of a driving crank formed on the tail shaft, a driven crank formed on the propeller shaft, an intermediate crank shaft installed between the propeller shaft and the tail shaft, and a connecting rod connecting them.

[0014] Alternatively, the power transmission mechanism installed inside each of the left and right pairs of wings is configured with a driving bevel gear provided on the tail shaft, a driven bevel gear formed on the propeller shaft, and a connecting rod having a first bevel gear meshing with the driving bevel gear and a second bevel gear meshing with the driven bevel gear at both ends.

[0015] The above wing rotation amount control unit includes a lever having one end fixed to a female hinge formed at one end of the wing and rotatably receiving the tail shaft, and an intermediate portion between the one end and the other end extending toward the upper side of the hull, and a hydraulic cylinder installed at the other end of the lever to rotate the lever relative to the tail shaft.

[0016] The center hull balance section of the above ship has a cross-section in which the upper part of the ballast sailing waterline has a rectangular cross-section, and the lower part has an inverted isosceles trapezoidal cross-section with a width narrower than the width of the upper rectangle, and the upper and lower parts form a discontinuous section.

[0017] A plurality of foldable columns are installed on the discontinuous section of the central balanced section of the hull of the above ship.

[0018] The above vessel is composed of an upper rudder plate and a lower variable rudder plate that moves up and down by a driving device installed inside the rudder plate, and the variable rudder plate has a length-variable rudder that moves so that the height of the lower end of the variable rudder plate is linked to the height of the lower end of the propeller.

[0019] The above vessel is provided with a tail shaft having a pair of cranks with a 180-degree phase difference installed at the stern and transmitting power to left and right propellers; a pair of left and right wings that tilt the shaft with a hinge axis; a propeller shaft having a thruster block and a crank installed at the end of the wing; and a connecting rod that is installed laterally in the wing and connects the crank of the tail shaft and the crank of the propeller shaft to transmit power.

[0020] If the length of the above connecting rod is long and the buckling rigidity is insufficient, the connecting rod is divided into two or more and an intermediate crank shaft is installed at the connecting point. The tilting of the wing is achieved by the left-right movement of the hydraulic cylinder attached to the upper part of the lever that protrudes in the shape of the letter "L" from the hinge axis to the upper part of the hull and is fixed at an obtuse angle close to a right angle to the wing, and the tilting of the wing changes the height of the propeller shaft attached to the outer end.

[0021] In a light draft state, when the propeller is lowered by tilting the blades, a significant portion of the propeller blades will go below the ship's baseline, and the amount of propeller wake flowing into the rudder will decrease. In preparation for the case where the steering force is reduced and the minimum turning radius standard is not met, a variable-length rudder whose length can be extended is provided.

[0022] Additionally, the hull cross-section below the waterline adopts a multi-node lower protruding cross-section, providing a vessel that satisfies the centerline parallel length (PBL) regulations while having a small displacement.

[0023] For stable redocking, it is recommended to install retractable posts / legs (preferably 4) on the sides formed by the central balance section.

[0024] The vessel according to the present invention has a small displacement below the light draft line, a deep light draft, a plurality of propellers with small diameters, and a propeller installed at the tip by tilting the blades to lower the height, so that the propeller is completely submerged only with ballast water for trim adjustment, thereby eliminating or emptying the existing ballast tank area, and improving the flow of seawater flowing into the propeller, thereby improving propulsion efficiency and reducing the cost of light draft operation, making it environmentally friendly and economical.

[0025] Figure 1 is a photograph of a propeller at light draft of a typical cargo ship.

[0026] Figure 2 is a model photograph of the tail shaft mounting part of a typical cargo ship.

[0027] Figure 3 is a central cross-sectional view showing the ballast tank of a very large crude carrier (VLCC).

[0028] Figure 4 is a perspective view schematically showing a propulsion device of a ship according to one embodiment of the present invention.

[0029] FIG. 5 is a perspective view showing the state of coupling between the hull of a ship and the hull of a propulsion device according to one embodiment of the present invention.

[0030] FIG. 6 is a side view illustrating the stern profile of a ship according to one embodiment of the present invention, superimposed on an existing ship.

[0031] Figure 7 is a front view illustrating the behavior of a propulsion device of a ship according to one embodiment of the present invention.

[0032] Figure 8 is a perspective view showing a propulsion device of a ship according to one embodiment of the present invention.

[0033] Figure 9 is a drawing for explaining the operation of the crank mechanism, which is a power transmission mechanism inside the wing illustrated in Figure 8.

[0034] Fig. 10 is a drawing showing the configuration and connection structure of a propulsion device of a ship according to one embodiment of the present invention.

[0035] Figure 11 is a drawing for explaining another example of a wing internal power transmission mechanism.

[0036] The purpose, specific advantages, and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments thereof, taken in conjunction with the accompanying drawings. In this specification, when reference numerals are given to components in each drawing, it should be noted that, as far as possible, the same components are given the same numerals even if they are shown in different drawings or are symmetrically positioned on the left and right. In describing the present invention, a detailed description of a related known technology will be omitted if it is determined that it may unnecessarily obscure the gist of the present invention. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0037]

[0038] As shown in Fig. 1, which shows a photo of a propeller in a light draft of a typical cargo ship, and Fig. 2, which shows a model photo of a tail shaft mounting portion of a typical cargo ship, a conventional cargo ship has a structure in which a propeller (102) is directly connected to and rotates a tail shaft (201) that provides driving force generated by a power generation device (not shown). In this case, in a light draft state, more than half of the propeller (102) that generates thrust is exposed above the water surface (W1). To solve this problem, as shown in Fig. 3, which is a central cross-sectional view of a ballast tank of a very large crude carrier (VLCC), seawater (302) is injected into a ballast tank (301) to sink the hull, completely submerging the propeller (102) under the water surface, and the ship navigates. In order to fill the ballast tank (301) with seawater, a pump and piping facility (not shown) of an appropriate standard must be installed, and the price of a new ship increases due to the use of ballast coating to prevent corrosion of the internal steel plate and thick steel plate with extra thickness for corrosion allowance, and in a light draft state, the operating cost increases by filling the ballast water (in this specification, 'ballast water' and 'ballast water' are used interchangeably).

[0039]

[0040] As illustrated in FIGS. 4, 5, and 6, a vessel (401) according to one embodiment of the present invention has a pair of left and right wings (402) having a fat airfoil shape (602, preferably NACA0020~0030) attached to the position of a conventional propeller (102), and a method of fastening the wings (402) to the tail shaft (802, FIG. 8) will be described later. A propeller (403) having a reduced diameter is installed at the ends of the wings (402), and the stern profile has been changed and improved from a complex linear shape (203, 601) with a conventional sunken part to a simple linear shape (603) without a sunken part.

[0041]

[0042] The hull's center (balance) cross-section (501) is formed by combining a rectangular upper section (502) and a smaller inverted isosceles trapezoidal lower section (503) to form a section (504) to create a long center balance section (505) with a small displacement below the water surface (W1). The lower edge of the upper section (502) forms a right angle and acts as a bilge keel to increase the rolling period.

[0043]

[0044] A plurality of retractable posts (506), for example, four, are installed on the surface formed by the discontinuous step (504) of the central hull balance of the ship. The retractable posts (506) are used to maintain the left-right balance by being folded and unfolded when the hull is placed in a dry dock, and it is preferable that they have a rigidity greater than the breaking load of a half timber. The mutual connection relationship or mechanical drive for folding and unfolding the retractable posts will not be described in detail, and any technique known to those skilled in the art for folding and unfolding posts and varying their lengths can be applied. For example, the retractable posts may be configured such that two or more square or circular columns are joined lengthwise in order of larger cross-sectional areas to be adjusted in a telescopic manner, and the drive for varying the length may be performed by a hydraulic cylinder provided therein.

[0045]

[0046] It is preferable that the rudder of the vessel of the embodiment be provided with a variable length type. As illustrated in FIGS. 4 and 5, the variable length rudder is composed of an upper rudder plate (404) and a lower variable rudder plate (405) that moves up and down by a driving device (not shown) installed inside the rudder plate (404). Reference numeral 406 in FIG. 6 indicates the stroke length of the variable rudder plate (405). For smooth steering, it is preferable that the variable rudder plate (405) is moved so that the height of the lower end of the variable rudder plate (405) is linked to the height of the lower end of the propeller (403). This is to prevent the minimum turning radius standard from not being satisfied due to a decrease in the amount of propeller wake flowing into the rudder when the height of the lower end of the propeller (403) is lowered, which reduces the steering force. For example, if the inside of the upper rudder plate (404) is hollow and the variable rudder plate (405) is configured to be inserted therein, the variable rudder plate (404) can be driven by a hydraulic cylinder provided inside the upper rudder plate (404). It is considered obvious to those skilled in the art that the movement so that the height of the lower end of the variable rudder plate (405) has a height linked to the height of the lower end of the propeller (403) can be achieved by various mechanical and electronic controls, and thus a detailed description thereof will be omitted.

[0047]

[0048]

[0049] *Referring to FIGS. 7 to 10, the vessel of the embodiment comprises a tail shaft (801) that provides driving force generated by a power generation device (not shown) of the vessel; a pair of left and right blades (402), each end of which is rotatably connected to the tail shaft (801), and a middle portion between each end and the other end extends symmetrically in the width direction of the vessel with respect to a longitudinal section of the vessel passing through the tail shaft (801), and each other end is provided with a propeller (403) installed at one end of a propeller shaft (803) that receives the driving force provided by the tail shaft (801); and a blade rotation amount control unit (701, 702) that controls the height of the propeller (402) relative to the vessel's body by driving the left and right pair of blades (402) to control the rotation amount.

[0050]

[0051] Referring to FIGS. 7 and 8, the change in the height (height, up-and-down position) of the propeller by the rotation of the blade (402) will be described. First, the thrust generated by the conventional single propeller (102) is distributed to the two propellers (403) on the left and right, so that the diameter of the propeller becomes smaller and the draft at which the propeller is completely submerged is lowered from W2 to W3. In addition, the tilting (rotation) of the lever (701) fixed to the blade (402) (the tilting angle of the two levers (701) is indicated by the drawing reference numeral 703) lowers the position of the upper tip of the propeller from W3 to W1, and ultimately lowers the draft from W2 to W1. At this time, the lower tip goes below the hull reference line (704), but in the case of a light draft, it is sufficiently separated from the seabed compared to the full load draft, so that no contact with the seabed occurs. The tilting of the lever (701) is achieved by the operation of the hydraulic cylinder (702), and the positioning of the wing (402) is fixed by a stopper (not shown) attached to the lever (701). It is preferable that the lever (701) and the hydraulic cylinder (702) be installed in multiple units of two or more, as shown in Fig. 8, to distribute the load and maintain balance. The connection between the wing (402) and the hull (401) is achieved by the tail shaft (801) and the hinge pin (802), which will be described in more detail later.

[0052]

[0053] Inside each of the left and right pairs of wings (402), a power transmission mechanism is installed that converts the rotational motion of the tail shaft (801) into reciprocating motion and then converts it back into the rotational motion of the propeller shaft (803), so that the driving force provided by the tail shaft (801) is transmitted to the propeller shaft (803) to rotate the propeller (403).

[0054]

[0055] Fig. 9 illustrates a power transmission mechanism in which the driving force (rotational torque; Qt) of the tail shaft (801) is transmitted to the propeller shaft (803) to generate thrust. The driving cranks (904, 905) formed on the tail shaft (801) and the driven crank (903) formed on the propeller shaft (803) are connected by a connecting rod (804), and the rotational force (Qt) of the tail shaft (803) is divided in half and transmitted to the left and right propeller shafts (803), causing the propeller (403) to rotate (Qp) to generate thrust. The generated thrust is transmitted to the wing (402) by the thrust block (901), thereby moving the hull (401) whose forward and backward position is fixed with respect to the wing (402) forward or backward.

[0056]

[0057] To describe the load transmission mechanical elements mentioned above in more detail, the drive cranks (904, 905) formed on the tail shaft (801) are designed to have a phase difference of 180 degrees within a range that does not exceed the diameter of the tail shaft (801) (preferably, an arm length of 2 / 3 of the tail shaft radius) in order to remove the shaft toward the engine room, thereby canceling out the unbalanced force. The propeller shaft (803) installed on the outer end of the wing (402) has a thrust block (901) for transmitting thrust and a driven crank (903) having the same arm length as the tail shaft and a balance weight (902). The connecting rod (804) connecting the driving crank (904, 905) of the tail shaft and the driven crank (903) of the propeller shaft has excellent rigidity against the tensile force (+F) of iron, so it is effective to design it as a rod with a small cross-sectional area, but since the buckling rigidity against the compressive force (-F) is weak, it is preferable to divide the connecting rod into two or more and separately install an intermediate crank shaft (805) between the connecting rods.

[0058]

[0059] Fig. 10 illustrates in detail the mechanism by which the wing (402) and the hull (401) are coupled and the power transmission mechanism. The tail shaft (801) and the hinge pin (802) are positioned at an angle (1000) based on the tail shaft axis XX, and the tail shaft (801) is provided with a driving crank (904, 905) having an arm length of 2 / 3 of the radius of the tail shaft that transmits rotational power to the left and right propeller shafts (803). In addition, the tail shaft (801) and the hinge pin (802) are inserted into a gudgeon of hinge (1001, 1004) fixed to the hull and share the gudgeon of hinge (1004). The tail shaft (801) is removed toward the engine room area (not shown) in the forward direction, and the hinge pin (802) is removed toward the stern direction. In addition, female hinges (1002, 1003) are installed on the left and right wings (402), and a lever (701) for driving the wings (402) is installed as described above, except for the female hinge at the rear side where the wing (402) is thin. The inside of the wing (402) is not shown, but is a watertight area, and the crank drive section is protected by an oil film or a water film and other seals (not shown) and maintains air pressure corresponding to the external water pressure to maintain watertightness.

[0060]

[0061] Referring to FIG. 11 for explaining another example of a power transmission mechanism inside a wing, the power transmission mechanism inside a wing may be a mechanism using a bevel gear rather than the mechanism using a crank illustrated in FIG. 8. That is, it may be composed of a driving bevel gear (1101) provided on a tail shaft (801), a driven bevel gear (1102) formed on a propeller shaft (803), and a connecting rod (1105) having a first bevel gear (1103) meshing with the driving bevel gear (1101) and a second bevel gear (1104) meshing with the driven bevel gear (1102) at both ends. In cases where the length of the connecting rod (1105) is long and there is a concern that torsional vibration may occur during rotation, one or more bearings (1106) that prevent torsional vibration without impeding the rotation of the connecting rod (1105) are installed in the longitudinal direction of the connecting rod (1105) to reinforce it.

[0062]

[0063] Although the present invention has been described in detail through specific examples, this is intended to specifically explain the present invention, and the present invention is not limited thereto, and it will be apparent that modifications and improvements can be made by those skilled in the art within the technical spirit of the present invention.

[0064] All simple modifications or changes of the present invention fall within the scope of the present invention, and the specific protection scope of the present invention will be made clear by the appended claims.

[0065] The present invention is effective when applied to low-speed, large-scale vessels such as very large crude carriers (VLCCs) and bulk carriers, which have a large difference between the load waterline and the light waterline and require a double-hull structure.

Claims

1. Tail shaft providing driving force generated by the ship's power generation device; A pair of left and right wings, each end of which is rotatably connected to the tail shaft, the middle portion between each end and the other end extending in the width direction symmetrically with respect to the longitudinal section of the hull passing through the tail shaft, and each end having a propeller installed on one end of a propeller shaft that receives driving force provided by the tail shaft; and, A vessel including a wing rotation amount control unit that controls the height of the propeller relative to the hull by controlling the rotation amount by driving the pair of left and right wings.

2. In paragraph 1, A ship characterized in that a power transmission mechanism is installed inside each of the left and right pairs of wings to convert the rotational motion of the tail shaft into reciprocating motion and then convert it back into the rotational motion of the propeller shaft, so that the driving force provided by the tail shaft is transmitted to the propeller shaft.

3. In paragraph 2, A ship characterized in that the power transmission mechanism installed inside each of the left and right pairs of wings is composed of a driving crank formed on the tail shaft, a driven crank formed on the propeller shaft, and a connecting rod connecting the driving crank and the driven crank.

4. In paragraph 2, A ship characterized in that the power transmission mechanism installed inside each of the left and right pairs of wings is composed of a driving crank formed on the tail shaft, a driven crank formed on the propeller shaft, an intermediate crank shaft installed between the propeller shaft and the tail shaft, and a connecting rod connecting them.

5. In paragraph 2, A ship characterized in that the power transmission mechanism installed inside each of the left and right pairs of wings is composed of a driving bevel gear provided on the tail shaft, a driven bevel gear formed on the propeller shaft, and a connecting rod having a first bevel gear meshing with the driving bevel gear and a second bevel gear meshing with the driven bevel gear at both ends.

6. In paragraph 1, The above wing rotation amount control unit is, A ship characterized by comprising: a lever, one end of which is fixed to a female hinge formed at one end of the wing and rotatably receiving the tail shaft, the middle portion between the one end and the other end extending toward the upper side of the hull; and a hydraulic cylinder installed at the other end of the lever and rotating the lever relative to the tail shaft.

7. In paragraph 1, The hull of the above ship is characterized by having a central cross-section in which the upper part of the ballast waterline is rectangular and the lower part is a combination of inverted isosceles trapezoids having a width narrower than the width of the upper rectangle, and the upper and lower parts form discontinuous sections.

8. In paragraph 7, A ship characterized in that a plurality of foldable columns are installed on a discontinuous section formed by combining an upper rectangular section and a lower inverted isosceles trapezoid in the center hull balance section of the ship.

9. In paragraph 1, A ship comprising an upper rudder plate and a lower variable rudder plate that moves up and down by a driving device installed inside the rudder plate, wherein the variable rudder plate has a variable length rudder that moves so that the height of the lower end of the variable rudder plate is linked to the height of the lower end of the propeller.

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