Ship

Abstract

A ship is disclosed comprising a tail shaft that provides driving force generated by a power generation device of the ship, a pair of left and right wings each having one end rotatably coupled to the tail shaft, with the intermediate portion between each end and the other end extending in the beam direction symmetrically with respect to the longitudinal cross-section of the hull passing through the tail shaft, and each other end having a propeller installed at one end of a propeller shaft that receives the driving force provided by the tail shaft, and a wing rotation amount control unit that controls the height of the propeller relative to the hull by driving the pair of left and right wings and controlling the rotation amount. Since the propeller is divided into two parts, the diameter is reduced and the vertical position of the propeller provided at the wing tip can be lowered, allowing the propeller to be completely submerged at a low draft without ballast water, thereby eliminating or minimizing environmental pollution and economic losses caused by seawater ballast.

Description

Technology Field

[0001] The present invention relates to a ship having a small amount of ballast water, and more specifically, to a ship that can minimize the amount of ballast water by satisfying all regulations regarding propeller submersion, turning radius, bow draft, and centerline ballast water (PBL) with only unknown weight and ballast water for trim adjustment under light load conditions, thereby reducing operating costs during ocean voyages. Background Technology

[0002] Ships navigate by generating thrust through the rotation of propellers; however, when propellers are exposed above the water surface, propulsion efficiency decreases, and noise generation and propeller damage may occur. Consequently, when unloaded, conventional vessels fill their ballast tanks with seawater to ensure the propellers are completely submerged below the water surface for navigation. Legally, the Common Structural Rules for Bulk Carriers and Tankers (CSR) adopt 100% propeller submersion as the minimum draft requirement. Ships such as bulk carriers and tankers, which are typical low-speed, large-sized vessels, utilize propellers with low RPMs and large diameters to improve propulsion efficiency. Achieving full submersion requires a deep draft, necessitating a large amount of ballast water, which leads to increased newbuilding costs and higher operating expenses at light drafts.

[0003] Two non-patent documents and two patent documents as follows were found as prior art to solve this problem.

[0004] Two non-patent documents and patent document 1 propose a modified hull shape, but it is difficult to satisfy all the requirements for propeller submersion, turning radius, bow draft, and center balance length (PBL) solely through the modification of the hull shape.

[0005] Patent Document 2 discloses a technology that varies the height of a propeller by tilting the rotation axis of the propeller relative to the power shaft, but since the propeller is tilted relative to the hull, a decrease in propulsion efficiency cannot be avoided and there are limitations on adjusting the height of the propeller.

[0006] Therefore, a new type of vessel structure capable of satisfying regulations regarding propeller submersion, turning radius, bow draft, and centerline balance length (PBL) using only unknown weight and trim adjustment ballast water under light load conditions has not been provided in the prior art, and the need for such a vessel remains. Prior art literature

[0007] Korean Patent Publication No.; 1020100049150(2010.05.12.) Korean Patent Registration No.; 1021689440000(2020.10.16.)

[0008] The Effect of Rise Angle of V-Hull Non Ballast Ship on Seakeeping PerformanceHESHAM ELKADY, Prof. HAN DUANFENG and Prof. GAO LIANGGAO :(Harbin Engineering University, College of Shipbuilding Engineering, China, 150001)Ballast-free concept designs (Posidonia 2016:(DNV-GL MARITIME) The problem to be solved

[0009] The present invention was created to solve the problems of the prior art as described above, and aims to provide a ship of a new structure that can satisfy all regulations regarding propeller submersion, turning radius, bow draft, center balance section length (PBL), etc., using only unknown weight and ballast water for trim adjustment under light load conditions.

[0010] The present invention aims to provide a vessel capable of smooth navigation by changing the height of the propeller to match the draft condition by modifying the power transmission device without increasing the number of main engines constituting the propeller, thereby minimizing ballast water even at low drafts and achieving complete submersion of the propeller.

[0011] The present invention aims to provide a vessel capable of smooth navigation and berthing by changing and improving the shape of the midline cross-section of the hull to minimize the displacement below the ballast waterline and secure the necessary midline balance length. means of solving the problem

[0012] A ship according to one embodiment of the present invention comprises: a tail shaft that provides driving force generated by a power generation device of the ship; a pair of left and right wings, each having one end rotatably coupled to the tail shaft, with the intermediate portion between each end and the other end extending in the beam direction symmetrically with respect to the longitudinal cross-section of the hull passing through the tail shaft, and each other end having a propeller installed at one end of a propeller shaft that receives the driving force provided by the tail shaft; and a wing rotation amount adjustment unit that controls the height of the propeller relative to the hull by driving the pair of left and right wings to adjust the rotation amount.

[0013] A power transmission mechanism is installed inside each of the above-mentioned pair of left and right 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.

[0014] The power transmission mechanism installed inside each of the pair of left and right wings consists 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.

[0015] Alternatively, the power transmission mechanism installed inside each of the pair of left and right wings comprises 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.

[0016] Alternatively, the power transmission mechanism installed inside each of the pair of left and right wings comprises 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.

[0017] The wing rotation amount adjustment unit comprises a lever, one end of which is fixed to an arm hinge formed at one end of the wing to rotatably accommodate the tail shaft, and the intermediate portion between the one end and the other end extending upward toward the hull, and a hydraulic cylinder installed at the other end of the lever to rotate the lever relative to the tail shaft.

[0018] The center of the hull of the above-mentioned vessel has a cross-section in which the upper part of the ballast waterline is a rectangular section, and the lower part is a cross-section of an inverse isosceles trapezoid with a width narrower than the width of the upper rectangle, so that the upper and lower parts form discontinuous sections.

[0019] A plurality of foldable columns are installed on the discontinuous step surface of the central balance section of the hull of the above-mentioned vessel.

[0020] 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 is equipped with a length-variable rudder that moves such that the height of the lower end of the variable rudder plate is linked to the height of the lower end of the propeller.

[0021] The above vessel is positioned at the stern and comprises: a tail shaft having a pair of cranks with a 180-degree phase difference that transmit power to left and right propellers; a pair of left and right wings that tilt using the shaft as a hinge axis; a propeller shaft equipped with a thruster block and a crank installed at the end of the wings; and a connecting rod installed transversely within the wings to connect the crank of the tail shaft and the crank of the propeller shaft to transmit power.

[0022] If the buckling rigidity is insufficient due to the long length of the above connecting rod, the connecting rod is divided into two or more parts, and an intermediate crankshaft is installed at the connection point. The tilting of the wing is achieved by the left and right movement of a hydraulic cylinder attached to the upper part of a lever that protrudes in an "L" shape from the hinge axis to the upper part of the hull and is fixed at an obtuse angle close to a right angle with respect to the wing, and the height of the propeller shaft attached to the outer end is changed by the tilting of the wing.

[0023] In preparation for a situation where the propeller goes down due to the tilting of the blades in light draft conditions, a significant amount of the propeller blades go down below the ship's baseline, and the amount of propeller wake flowing into the rudder is reduced, resulting in a decrease in steering force and thus failing to satisfy the minimum turning radius standard, a length-variable rudder is provided that can be extended.

[0024] In addition, the hull section below the light draft adopts a multi-joint lower protruding section, providing a vessel that satisfies the PBL (Partial Parallel Line) regulations while having a small displacement.

[0025] For stable redocking, it is recommended to install retractable posts / legs (preferably four) on the surfaces formed by the steps on the left and right sides of the central leveling section. Effects of the invention

[0026] The vessel according to the present invention is environmentally friendly and economical, as it has a small displacement below the light draft, a deep light draft, and a plurality of propellers with small diameters, and by tilting the blades to lower the height of the propellers installed at the ends so that the propellers are completely submerged with only trim-adjusting ballast water, it is possible to eliminate or empty the existing ballast tank area, and the flow of seawater into the propellers is improved, thereby enhancing propulsion efficiency and reducing light draft operating costs. Brief explanation of the drawing

[0027] Figure 1 is a photograph of a propeller of a typical cargo ship at a light draft. Figure 2 is a model photograph of the tail shaft mounting section of a typical cargo ship. Figure 3 is a central cross-sectional view illustrating the ballast tank of a very large crude carrier (VLCC). FIG. 4 is a schematic perspective view of a propulsion device for a ship according to one embodiment of the present invention. FIG. 5 is a perspective view illustrating the combined state of the hull of a ship and the propulsion device with the hull according to one embodiment of the present invention. FIG. 6 is a side view showing the stern profile of a ship according to one embodiment of the present invention superimposed with an existing ship. FIG. 7 is a front view illustrating the behavior of a ship's propulsion device according to one embodiment of the present invention. FIG. 8 is a perspective view showing a propulsion device of a ship according to one embodiment of the present invention. Figure 9 is a diagram illustrating the operation of a crank mechanism, which is a power transmission mechanism inside the wing shown in Figure 8. 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. Figure 11 is a drawing illustrating another example of a power transmission mechanism inside a wing. Specific details for implementing the invention

[0028] The objects, specific advantages, and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments in conjunction with the accompanying drawings. It should be noted that in assigning reference numerals to the components of each drawing in this specification, the same components are assigned the same number whenever possible, even if they are shown in different drawings or differ symmetrically on the left and right. In describing the present invention, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the invention. A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] As shown in Fig. 1, which shows a photograph of a propeller at a light draft of a conventional cargo ship, and Fig. 2, which shows a model photograph of a tail shaft mounting part of a conventional cargo ship, the conventional cargo ship has a structure in which a propeller (102) is directly connected to a tail shaft (201) that provides driving force generated by a power generation device (not shown) and rotates. 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, seawater (302) is injected into the ballast tank (301) to sink the hull, as shown in Fig. 3, which is a central cross-sectional view illustrating a ballast tank of a large oil tanker (VLCC), so that the propeller (102) is completely submerged below the water surface and the ship sails. In order to fill the ballast tank (301) with seawater, a pump and piping equipment of appropriate specifications (not shown) must be installed, and the cost of the new ship increases due to the ballast coating to prevent corrosion of the inner steel plate and the use of thick steel plates with extra thickness for corrosion prevention, and the operating cost increases due to the filling of ballast water (in this specification, 'ballast water' and 'ballast water' are used interchangeably) in light draft conditions.

[0032] As illustrated in FIGS. 4, 5, and 6, a ship (401) according to one embodiment of the present invention has a pair of left and right wings (402) having a sagging airfoil (602, preferably NACA0020~0030) attached at the location of the existing propeller (102), and the method of connecting the wings (402) and the tail shaft (802, FIG. 8) will be described later. A propeller (403) with a reduced diameter is installed at the ends of the wings (402), and the stern profile is changed and improved from a complex hull shape (203, 601) with a conventional depression to a simple hull shape (603) without a depression.

[0034] The cross-section (501) of the center of the hull (balancing section) is formed by combining a rectangular upper section (502) and an inverted isosceles trapezoidal lower section (503) that is narrower than the rectangular upper section (502) to form a step (504), thereby creating a long central balancing section (505) with a small amount of displacement below the water surface (W1). The lower corner of the upper section (502) forms a right angle and acts as a bilge keel to increase the rolling period.

[0036] A plurality of retractable posts (506), for example, four, are installed on the surface formed by the discontinuous section (504) of the central balance section of the ship's hull. The retractable posts (506) are intended to be used to maintain left-right balance by being unfolded (unfolded) when the hull is placed in a dry dock, and it is desirable for them to have a rigidity greater than the breaking load of a half-barrel. The interlocking relationship or mechanical drive for folding and unfolding the retractable posts is not described in detail, and any technique known to a person skilled in the art for varying the length while folding and unfolding the posts may be applied. For example, the retractable posts may be configured such that two or more prismatic or cylindrical posts are joined in the longitudinal direction from a large cross-sectional area to a small cross-sectional area so that the length is adjusted in a telescopic manner, and the drive for varying the length may be performed by a hydraulic cylinder provided inside.

[0038] It is preferable that the rudder of the vessel of the embodiment be of a variable length type. As shown in FIGS. 4 and 5, the variable length rudder consists 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) be operated so that the height of the lower end of the variable rudder plate (405) moves to a height that corresponds 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 steering force caused by a reduction in the amount of propeller wake flowing into the rudder when the height of the lower end of the propeller (403) is lowered. For example, the upper rudder plate (404) is configured to be hollow so that the variable rudder plate (405) can be inserted into it, and the driving of the variable rudder plate (404) can be achieved by a hydraulic cylinder provided inside the upper rudder plate (404). It is considered obvious to a person skilled in the art that the lower height of the variable rudder plate (405) can be moved to a height that corresponds to the lower height of the propeller (403), so a detailed explanation thereof is omitted.

[0040] Referring to FIGS. 7 to 10, the ship of the embodiment comprises: a tail shaft (801) that provides driving force generated by a power generation device (not shown) of the ship; a pair of left and right wings (402), each having one end rotatably coupled to the tail shaft (801), and the middle portion between each end and the other end extending in the beam direction symmetrically with respect to the longitudinal cross-section of the hull passing through the tail shaft (801), and each other end having 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 wing rotation amount adjustment unit (701, 702) that adjusts the height of the propeller (402) relative to the hull by driving the pair of left and right wings (402) to adjust the amount of rotation.

[0042] Referring to FIGS. 7 and 8, the change in the height (height, upper / lower position) of the propeller due to the rotation of the wing (402) is explained as follows: First, the thrust generated by the conventional single propeller (102) is distributed to the two left and right propellers (403), causing the diameter of the propeller to decrease and the draft at which the propeller is completely submerged to decrease from W2 to W3. Additionally, the upper tip position of the propeller decreases from W3 to W1 due to the tilting (rotation) of the lever (701) attached to the wing (402) (the tilting angle of the two levers (701) is indicated by the reference numeral 703), and finally, the draft decreases from W2 to W1. At this time, the lower tip goes down below the hull reference line (704), but in the case of light draft, it is sufficiently separated from the seabed compared to full load draft, so contact with the seabed does not occur. Tilting of the lever (701) is achieved by operating the hydraulic cylinder (702), and fixing the position of the wing (402) is achieved by a stopper (not shown) attached to the lever (701). For load distribution and maintaining balance, it is preferable to have two or more sets of the lever (701) and hydraulic cylinder (702), as shown in FIG. 8. The connection between the wing (402) and the hull (401) is made by a tail shaft (801) and a hinge pin (802), which will be explained in more detail later.

[0044] A power transmission mechanism is installed inside each of the left and right pairs of wings (402) to convert the rotational motion of the tail shaft (801) into reciprocating motion and then convert 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).

[0046] 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 crank (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 (1 / 2) and transmitted to the left and right propeller shafts (803), causing rotation (Qp) of the propeller (403) to occur and generate thrust. The generated thrust is transmitted to the wing (402) via the thrust block (901), causing the hull (401), which has a fixed front-rear position relative to the wing (402), to move forward or backward.

[0048] To explain the load transfer mechanical elements mentioned above in more detail, the drive crank (904, 905) formed on the tail shaft (801) is designed to have a 180-degree phase difference within a range that does not exceed the diameter of the tail shaft (801) in order to remove the shaft toward the engine room (preferably 2 / 3 arm length of the tail shaft radius) to counteract the unbalanced force. The propeller shaft (803) installed on the outer end of the wing (402) is equipped with a thrust block (901) for thrust transfer and a driven crank (903) having an arm length equal to that of the tail shaft and a counterweight (902). The connecting rod (804) connecting the driving crank (904, 905) of the tail shaft and the driven crank (903) of the propeller shaft is designed to be a rod with a small cross-sectional area, as it has excellent rigidity against the tensile force (+F) of iron, but is weak in buckling rigidity against the compressive force (-F). Therefore, it is desirable to divide the connecting rod into two or more and install an intermediate crank shaft (805) separately between the connecting rods.

[0050] FIG. 10 illustrates in detail the mechanism for joining the wing (402) and the hull (401) and the power transmission mechanism. The tail shaft (801) and the hinge pin (802) are positioned intermittently (1000) with respect to the tail shaft axis XX, and the tail shaft (801) is equipped with a drive crank (904, 905) with an arm length of 2 / 3 of the tail shaft radius to transmit rotational force to the left and right propeller shafts (803). Additionally, these tail shafts (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 bow 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 rear female hinge where the wing (402) has a thin thickness. The interior of the wing (402) is a watertight area, although not shown, and the crank drive unit is protected by an oil film or a water film and other sealing (not shown) and maintains watertightness by maintaining air pressure corresponding to external water pressure.

[0052] Referring to FIG. 11 to explain another example of a power transmission mechanism within a wing, the power transmission mechanism within the wing may be a mechanism using bevel gears rather than a mechanism using a crank as 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) that meshes with the driving bevel gear (1101) and a second bevel gear (1104) that meshes with the driven bevel gear (1102) at both ends. If there is a risk of torsional vibration occurring during rotation due to the long length of the connecting rod (1105), one or more bearings (1106) are installed along the length of the connecting rod (1105) to prevent torsional vibration without hindering the rotation of the connecting rod (1105) and to reinforce it.

[0054] Although the present invention has been described in detail through specific embodiments, this is for the purpose of specifically explaining the invention and is not limited thereto. It is evident that modifications or improvements can be made by those skilled in the art within the technical scope of the present invention.

[0055] All simple variations or modifications of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be clarified by the appended claims. Industrial applicability

[0057] The present invention is effective when applied to ships such as very large crude carriers (VLCCs) and bulk carriers, which are low-speed, large vessels with a large difference between their full load and light load lines and require a double hull structure.

[0058] No content Explanation of the symbols

[0059] 101: Ship 102: Propeller 201: Tail Shaft 202: Propeller Boss 203: Profile with depressions 301: Ballast tank 302: Seawater 401: Ship 402: Wing 403: Propeller 404: Rudder board 405: Adjustable rudder board 406: Stroke length 501: Midline (balance) section 502: Upper section 503: Inverted isosceles trapezoidal lower section 504: Step 505: Central balancing section 506: Folding column 601: Complex linear 602: Airfoil (wing cross-section) 603: Simple linear shape 701: Lever 702: Cylinder 703: Tilting Angle 704: Base Line 801: Tail shaft 802: Hinge pin 803: Propeller shaft 804: Connecting rod 805: Crankshaft 901: Thrust block 902: Counterweight 903: Crank (arm) 904: Crank 905: Crank 1000: Disconnection (Separation) 1001: Arm hinge (Hull attachment) 1002: Female hinge (right wing attached) 1003: Female hinge (left wing attached) 1004: Common arm hinge (hull attachment) 1101: Drive bevel gear 1102: Driven bevel gear 1103: First bevel gear 1104: Second bevel gear 1105: Connecting rod 1106: Connecting rod bearing

Claims

Claim 1 A ship comprising: a tail shaft providing driving force generated by a power generation device of the ship; a pair of left and right wings, each having one end rotatably coupled to the tail shaft, with the intermediate portion between each end and the other end extending in the beam direction symmetrically with respect to the longitudinal section of the hull passing through the tail shaft, and each end having a propeller installed at one end of a propeller shaft that receives the driving force provided by the tail shaft; and a wing rotation amount adjustment unit that adjusts the height of the propeller relative to the hull by driving the pair of left and right wings to adjust the amount of rotation; wherein the wing rotation amount adjustment unit comprises a lever, having one end fixed to an arm hinge formed at one end of the wing and rotatably receiving the tail shaft, with the intermediate portion between the one end and the other end extending upward toward the hull, and a hydraulic cylinder installed at the other end of the lever to rotate the lever relative to the tail shaft. Claim 2 A ship according to claim 1, 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. Claim 3 A ship according to paragraph 2, wherein the power transmission mechanism installed inside each of the left and right pairs of wings comprises 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. Claim 4 A ship according to paragraph 2, wherein the power transmission mechanism installed inside each of the left and right pairs of wings comprises 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. Claim 5 A ship according to paragraph 2, wherein the power transmission mechanism installed inside each of the left and right pairs of wings is characterized by being composed of a driving bevel gear provided in the tail shaft, a driven bevel gear formed in 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. Claim 6 delete Claim 7 A vessel according to claim 1, characterized in that the hull of the vessel has a central cross section in which the upper part of the ballast waterline is rectangular, and the lower part is formed by combining an inverted isosceles trapezoid with a width narrower than the width of the upper rectangle, so that the upper and lower parts form discontinuous sections. Claim 8 A vessel according to claim 7, characterized in that a plurality of foldable columns are installed in a discontinuous section formed by combining an upper rectangular cross-section and a lower inverted isosceles trapezoid of the central balance section of the vessel's hull. Claim 9 A vessel according to claim 1, characterized by having a length-variable rudder comprising an upper rudder plate and a lower variable rudder plate that moves up and down by means of a driving device installed inside the rudder plate, wherein the variable rudder plate moves such 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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