Vessel

Abstract

To provide a vessel capable of improving maneuvering.SOLUTION: This vessel comprises: a hull; a propeller that is provided behind the center of the hull in a bow-stern direction and that generates a water flow toward a rear side in the bow-stern direction; a rudder provided behind the propeller in the hull in the bow-stern direction; and a jet propulsion unit that is provided in the bottom of the hull and that generates a jet water flow. The jet propulsion unit includes a suction port for sucking water, and a discharge port for discharging the water sucked through the suction port as a jet water flow. The jet water flow can be discharged in an optional horizontal direction through the discharge port. The jet propulsion unit is provided above the propeller in a vessel height direction, and installed at a position in the same bow-stern direction as that of the propeller or behind the propeller in the bow-stern direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This disclosure relates to ships.

Background Art

[0002] Patent Document 1 discloses a ship including a propeller and a rudder disposed behind the propeller. Such a ship applies the water flow generated by the propeller to the rudder to generate a propulsive force in the ship width direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a ship as disclosed in Patent Document 1, the water flow of the propeller weakens during low-speed travel, and the rudder effectiveness deteriorates. That is, the deterioration of the ship handling performance during low-speed travel has been a problem.

[0005] This disclosure has been made to solve the above problems, and an object thereof is to provide a ship capable of improving ship handling performance.

Means for Solving the Problems

[0006] In order to solve the above problems, a ship according to the present disclosure includes a hull, a propeller provided on the rear side of the center of the hull in the fore-and-aft direction and generating a water flow toward the rear side in the fore-and-aft direction, a rudder provided on the rear side of the propeller in the fore-and-aft direction of the hull, and a jet propulsion unit provided on the bottom of the hull and generating a jet water flow, wherein the jet propulsion unit has a suction port for sucking water and a discharge port for discharging the water sucked from the suction port as the jet water flow, the jet water flow can be discharged from the discharge port in an arbitrary horizontal direction, the jet propulsion unit is provided above the propeller in the ship height direction and at the same position in the fore-and-aft direction as the propeller or on the rear side of the propeller in the fore-and-aft direction.

Effect of the Invention

[0007] According to the ship of the present disclosure, the maneuverability can be improved.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

MODE FOR CARRYING OUT THE INVENTION

[0009] <First Embodiment> (Configuration of Ship) Hereinafter, the ship 1 which concerns on the 1st Embodiment of this indication is demonstrated with reference to FIGS. 1 - 4. As shown in FIG. 1, the ship 1 includes a hull 2, a propeller 20, a rudder 30, a jet propulsion unit 40, and a drive source 7. The ship 1 of this embodiment is a single - screw single - shaft ship equipped with one propeller 20 and one rudder 30.

[0010] (Hull) The hull 2 is a box - shaped structure that generates buoyancy and floats on the water surface WL. The hull 2 has a bow 3, a stern 4, a side 5, a bottom 10, and an upper deck 6. A pair of sides 5 are provided facing each other on the left and right so as to connect the bow 3 and the stern 4. The bottom 10 connects the bow 3 and the stern 4 and also connects the lower ends of the pair of sides 5. The upper deck 6 connects the bow 3 and the stern 4 and also connects the upper ends of the pair of sides 5. Hereinafter, it is assumed that the entire bottom 10 is located below the water surface WL.

[0011] Hereinafter, the direction in which the bow 3 and the stern 4 are aligned in the horizontal direction is referred to as the longitudinal direction D1, and the direction in which a pair of side hulls 5 oppose each other in the horizontal direction is referred to as the width direction D2 for explanation. The longitudinal direction D1 and the width direction D2 are orthogonal to each other. The vertical direction orthogonal to the longitudinal direction D1 and the width direction D2 is referred to as the height direction D3 for explanation. Further, hereinafter, the bow 3 side in the longitudinal direction D1 is taken as the front side and the front, and the stern 4 side in the longitudinal direction D1 is taken as the rear side and the rear.

[0012] The bottom 10 has a bottom center portion 11, a bow side bottom 12, and a stern side bottom 13. The bottom center portion 11 constitutes the lower region of the hull 2 in the height direction D3. The bottom center portion 11 extends in the longitudinal direction D1. The bow side bottom 12 extends from the bottom center portion 11 to the front side in the longitudinal direction D1 and is connected to the bow 3. The bow side bottom 12 is located on the front side in the longitudinal direction D1 with respect to the center C (midship) of the hull 2 in the longitudinal direction D1. The stern side bottom 13 extends from the bottom center portion 11 to the rear side in the longitudinal direction D1 and is connected to the stern 4. The stern side bottom 13 is located on the rear side in the longitudinal direction D1 with respect to the center C of the hull 2 in the longitudinal direction D1.

[0013] In the present embodiment, the stern side bottom 13 has a first portion 16, a second portion 17, and a boss portion 19.

[0014] The first portion 16 extends from the bottom center portion 11 to the rear side in the longitudinal direction D1. The first portion 16 is curved so as to be located on the upper side in the height direction D3 as it goes toward the rear side in the longitudinal direction D1.

[0015] The second portion 17 extends rearward from the end portion on the rear side in the width direction D2 of the first portion 16 and is connected to the stern 4. The second portion 17 extends along the horizontal plane. The second portion 17 has a storage chamber 18. The storage chamber 18 is recessed in the bottom 10 and opens to the lower side in the height direction D3. A jet propulsion unit 40 described later is stored in the storage chamber 18. In the present embodiment, the storage chamber 18 is formed directly above the propeller 20.

[0016] The boss portion 19 is provided on the first portion 16 of the stern side bottom 13. The boss portion 19 protrudes rearward in the fore-and-aft direction D1 from the stern side bottom 13. A propeller shaft 21 protruding rearward in the fore-and-aft direction D1 is provided on the boss portion 19. The propeller shaft 21 extends in the fore-and-aft direction D1. A propeller 20 is attached to the propeller shaft 21.

[0017] (Propeller) As shown in FIGS. 1 and 2, the propeller 20 is provided rearward of the center C in the fore-and-aft direction D1 of the hull 2. The propeller 20 has a hub 22 and blades 23. The hub 22 is attached to the tip of the propeller shaft 21. The hub 22 covers the outer peripheral surface of the propeller shaft 21. A plurality of blades 23 are provided in the circumferential direction of the propeller shaft 21. The plurality of blades 23 are radially arranged so as to extend in the radial direction of the propeller shaft 21 from the hub 22. The propeller 20 generates a water flow Wa toward the rear side in the fore-and-aft direction D1 by rotating around the propeller shaft 21. The water flow Wa generated by this propeller 20 generates a propulsive force in the fore-and-aft direction D1. In each drawing, the water flow Wa by the propeller 20 is illustrated by an arrow.

[0018] (Rudder) The rudder 30 is provided rearward of the propeller 20 in the fore-and-aft direction D1 of the hull 2. More specifically, the rudder 30 is provided rearward of the storage chamber 18 in the second portion 17 of the stern side bottom 13 in the fore-and-aft direction D1. Further, the rudder 30 is installed at a position overlapping the propeller 20 in the fore-and-aft direction D1 when viewed in the ship height direction D3.

[0019] The rudder 30 has a fixing portion 31, a rudder shaft 32, and a rudder plate 33. The fixing portion 31 is fixed to the bottom 10 of the ship. The fixing portion 31 extends in the fore-and-aft direction D1. The rudder shaft 32 is provided at the end portion of the fixing portion 31 on the front side in the fore-and-aft direction D1. The rudder shaft 32 extends downward from the bottom 10 of the ship in the ship height direction D3 and protrudes from the fixing portion 31. The rudder plate 33 is provided below the fixed part 31 in the ship height direction D3. The rudder plate 33 is a plate-shaped member extending in the ship height direction D3. The rudder plate 33 is connected to the fixed part 31 via a rudder shaft 32. The rudder shaft 32 is attached to the front end of the rudder plate 33 in the fore-and-aft direction D1 of the ship so as to be inserted from the upper side in the ship height direction D3. The rudder plate 33 is rotatable around the rudder shaft 32. Thereby, the rudder plate 33 can change its posture with respect to the fixed part 31. The water flow Wa of the propeller 20 hits the rudder plate 33, and the direction of the water flow Wa of the propeller 20 is changed. When the direction of the water flow Wa of the propeller 20 is changed, the direction of the propulsive force is also changed, and the traveling direction of the ship 1 is changed.

[0020] (Jet propulsion unit) The jet propulsion unit 40 is provided on the ship bottom 10. The jet propulsion unit 40 generates a jet water flow Wc. The jet propulsion unit 40 is provided above the propeller 20 in the ship height direction D3. Further, it is provided at the same position as the propeller 20 in the fore-and-aft direction D1 of the ship, or on the rear side of the propeller 20 in the fore-and-aft direction D1. In each drawing, the water flow Wb by the jet propulsion unit 40 is illustrated by an arrow. Further, among the water flows Wb by the jet propulsion unit 40, the arrow indicating the jet water flow discharged from a discharge port 46 described later is assigned the symbol Wc.

[0021] In this embodiment, the entire jet propulsion unit 40 is housed in the storage chamber 18. Therefore, the lower surface of the jet propulsion unit 40 and the lower surface of the ship bottom 10 are arranged on substantially the same plane, and are in a so-called flush relationship.

[0022] Further, the jet propulsion unit 40 is provided above the propeller 20 in the ship height direction D3 and at the same position in the ship bow-stern direction D1 as the propeller 20. In other words, the jet propulsion unit 40 is provided at a position overlapping the propeller 20 in the ship height direction D3. In the present embodiment, the jet propulsion unit 40 is disposed directly above the propeller 20 and overlaps the hub 22 of the propeller 20 in the ship height direction D3. The jet propulsion unit 40 is installed so as to be rotatable 360 degrees about an axis O extending in the ship height direction D3.

[0023] As shown in FIGS. 3 and 4, the jet propulsion unit 40 of the present embodiment is a so-called pump jet. The jet propulsion unit 40 includes a housing 41, an impeller 42, and a lid portion 43.

[0024] The housing 41 has a space S capable of storing water therein. The outer shape of the housing 41 is formed in a columnar shape extending in the direction of the axis O. The housing 41 has an inner wall 44, a suction port 45, and a discharge port 46.

[0025] Hereinafter, the radial direction centered on the axis O may be simply referred to as the "radial direction", and the circumferential direction centered on the axis O may be simply referred to as the "circumferential direction" for explanation. The inner wall 44 is provided in the space S of the housing 41. The inner wall 44 is formed in a cylindrical shape extending upward from the lower surface of the inner surface of the housing 41 in the ship height direction D3 around the axis O. The upper end of the inner wall 44 is spaced downward from the upper surface of the inner surface of the housing 41. By this inner wall 44, the space S in the housing 41 is partitioned, and a flow path S1 is formed in the housing 41.

[0026] The suction port 45 is formed inside the radial direction of the inner wall 44, which was the lower surface of the housing 41. The suction port 45 opens downward in the ship height direction D3. The suction port 45 is formed in a circular shape centered on the axis O. The discharge port 46 is formed on the lower surface of the jet propulsion unit 40 in the ship height direction D3 and on the radially inner side of the inner wall 44. That is, the discharge port 46 is formed on the outer peripheral side of the suction port 45. Three discharge ports 46 are provided. Two of the three discharge ports 46 are opposed to each other in the radial direction centered on the axis O. Also, the remaining one of the three discharge ports 46 is sandwiched in the circumferential direction centered on the axis O by the other two discharge ports 46. All these three discharge ports 46 open in the same direction in the horizontal direction. The suction port 45 and the discharge port 46 are connected by a flow path S1.

[0027] The impeller 42 is housed inside the housing 41. The impeller 42 is disposed directly above the suction port 45 and on the radially inner side of the inner wall 44. When the impeller 42 rotates around the axis O, water outside the housing 41 is sucked into the flow path S1 from the suction port 45.

[0028] The lid portion 43 is attached to the suction port 45. The lid portion 43 has an outer frame 43a and a net portion 43b. The outer frame 43a is formed in an annular shape centered on the axis O. The outer frame 43a is fitted into the suction port 45. The net portion 43b is provided inside the outer frame 43a and is integrally formed with the outer frame 43a. The net portion 43b is formed in a lattice shape extending in the horizontal direction. The lid portion 43 allows the water sucked into the flow path S1 from the suction port 45 to pass through, and prevents dust and the like larger than the lattice of the net portion 43b from entering the flow path S1.

[0029] The jet propulsion unit 40 operates the impeller 42 to suck water from the suction port 45 into the flow path S1. The water sucked into the flow path S1 becomes a swirling flow by the rotation of the impeller 42, and this swirling flow is converted into a jet water flow Wc without a swirling component in the process of flowing through the flow path S1. The jet propulsion unit 40 discharges the water sucked from the suction port 45 horizontally as the jet water flow Wc from the discharge port 46.

[0030] Furthermore, when the entire jet propulsion unit 40 rotates around the axis O, the orientation of the opening of the discharge port 46 is changed to an arbitrary orientation. As a result, the jet propulsion unit 40 can discharge the jet water flow Wc in an arbitrary horizontal direction from the discharge port 46. The jet water flow Wc of this jet propulsion unit 40 generates a propulsive force in the horizontal direction. Also, the jet propulsion unit 40 discharges the jet water flow Wc from the discharge port 46 above the rudder plate 33 in the ship height direction D3.

[0031] (Drive source) The drive source 7 is provided on the hull 2 and rotates the entire jet propulsion unit 40 around the axis O. The arrangement and structure of the drive source 7 can be changed as appropriate. The drive source 7 is, for example, housed in the storage chamber 18 together with the jet propulsion unit 40 and is arranged directly above the jet propulsion unit 40.

[0032] (Function and effect) The ship 1 with the above configuration can exhibit the following function and effect. In the present embodiment, the ship 1 is provided on the bottom 10 of the hull 2 and includes a jet propulsion unit 40 that generates a jet water flow. The jet propulsion unit 40 has a suction port 45 for sucking water and a discharge port 46 for discharging the water sucked from the suction port 45 as a jet water flow. The jet propulsion unit 40 can discharge the jet water flow in an arbitrary horizontal direction from the discharge port 46. The jet propulsion unit 40 is provided above the propeller 20 in the ship height direction D3 and is located at the same position in the ship bow - stern direction D1 as the propeller 20 or behind the propeller 20 in the ship bow - stern direction D1.

[0033] The jet propulsion unit 40 can discharge the jet water flow Wc in an arbitrary horizontal direction from the bottom 10 of the ship. The ship 1 can change its direction in an arbitrary horizontal direction by the propulsive force of this jet water flow Wc. Therefore, the jet propulsion unit 40 also serves as a thruster, eliminating the need to provide a thruster on the stern 4 side of the hull 2. In addition, the stance thruster is generally disposed below the propeller 20 in the ship height direction D3 and in front of the ship bow / stern direction D1. In contrast, the jet propulsion unit 40 is provided above the propeller 20 in the ship height direction D3. Therefore, it is difficult for debris on the bottom of the water to be sucked into the suction port 45 of the jet propulsion unit 40. In recent years, due to the influence of global warming, the growth speed of algae such as seaweed has been increasing. However, according to this aspect, it is also possible to suppress the algae from being sucked into the suction port 45. Thus, the jet propulsion unit 40 can operate well.

[0034] Furthermore, the jet propulsion unit 40 is provided at the same position as the propeller 20 in the ship bow / stern direction D1 or behind the propeller 20 in the ship bow / stern direction D1. Therefore, compared with the length from the center C in the ship bow / stern direction D1 of the hull 2 to the stance thruster when the stance thruster is provided on the hull 2 instead of the jet propulsion unit 40, the length from the center C in the ship bow / stern direction D1 of the hull 2 to the jet propulsion unit 40 becomes longer. Thus, compared with the case where the stance thruster is provided on the hull 2 instead of the jet propulsion unit 40, the turning moment by the jet propulsion unit 40 becomes larger, and the ship 1 is more likely to change direction. Thus, according to this embodiment, the maneuverability of the ship 1 can be improved.

[0035] Here, for example, in the case of an azimuthing thruster-equipped ship, the azimuthing thruster protruding from the bottom of the ship 10 is always used as the thruster. Therefore, not only does the added resistance increase, but also electric conversion loss is likely to occur. In contrast, in this embodiment, since the above-described jet propulsion unit 40 is provided, the electric conversion loss can be suppressed to the same extent as that of a thruster.

[0036] Furthermore, the jet propulsion unit 40 is housed in a storage chamber 18 recessed in the bottom of the ship 10 so as to open downward in the ship height direction D3.

[0037] As a result, the jet propulsion unit 40 can be attached without protruding from the bottom 10 of the ship. Thereby, the jet propulsion unit 40 does not become an appendage resistance, and an increase in the hull resistance can be suppressed.

[0038] In addition, in the case of a ship equipped with an azimuth thruster, when only the azimuth is equipped as a thruster, a skeg is required to ensure the course-keeping performance. On the other hand, in the present embodiment, since the jet propulsion unit 40 is arranged in addition to the propeller 20 and the rudder 30, the course-keeping performance is ensured, so that the skeg becomes unnecessary.

[0039] In addition, in the present embodiment, the jet propulsion unit 40 is provided in the second part 17 of the stern side bottom 13 on the rear side in the fore-and-aft direction D1 of the propeller 20 in the bottom 10 of the ship. The second part 17 extends along the horizontal plane.

[0040] As a result, a storage chamber 18 for installing the jet propulsion unit 40 in the second part 17 can be formed without changing the ship shape.

[0041] In addition, in the present embodiment, the jet propulsion unit 40 is provided at a position overlapping the propeller 20 in the ship height direction D3.

[0042] According to the above configuration, the jet propulsion unit 40 is installed directly above the propeller 20. As a result, the so-called damping effect in which the exciting force of the propeller 20 is suppressed by the weight of the jet propulsion unit 40 can be exhibited. By this damping effect, the vibration of the hull 2 caused by the propeller 20 can be alleviated. In addition, the restriction on the exciting force of the propeller 20 can be relaxed, and the design upper limit value of the exciting force of the propeller 20 can be increased. Thereby, the efficiency of the propeller 20 can be improved and the propulsion performance can be improved.

[0043] In addition, in the present embodiment, the rudder 30 includes a fixing portion 31 fixed to the bottom 10 of the ship, and a rudder plate 33 provided below the fixing portion 31 in the ship height direction D3, which is capable of changing its attitude with respect to the fixing portion 31 and against which the water flow Wa of the propeller 20 impinges. The jet propulsion unit 40 discharges a jet water flow Wc from the discharge port 46 above the rudder plate 33 in the ship height direction D3.

[0044] Thereby, it is possible to prevent the jet water flow Wc from hitting the rudder plate 33. Therefore, the influence of the jet water flow Wc on the operation of the rudder 30 can be significantly reduced.

[0045] In addition, in the present embodiment, the case where the jet propulsion unit 40 is provided when there is one propeller 20 has been described. Even if the propeller 20 breaks down, the ship can return to port by navigation due to the propulsion force of the jet propulsion unit 40, and redundancy can be provided to the ship 1.

[0046] In the present embodiment, it is assumed that the jet propulsion unit 40 is provided directly above the propeller 20, but the present invention is not limited to this. For example, as shown in FIG. 5, the jet propulsion unit 40 may be provided on the rear side of the propeller 20 in the ship's bow-stern direction D1.

[0047] <Second Embodiment> (Configuration of Ship) Hereinafter, a ship 201 according to a second embodiment of the present disclosure will be described with reference to FIG. 6. Among the present embodiments, the same configurations as those in the above-described embodiments will be denoted by the same names and the same reference numerals, and the description thereof will be appropriately omitted.

[0048] As shown in FIG. 6, the ship 201 of the present embodiment is a two-shaft ship equipped with two propellers 20 and two rudders 30. The hull 202 is not provided with the boss portion 19 in the bottom 10 of the ship in the first embodiment, and two propeller shafts 21 extend from the second portion 17 of the bottom 13 on the stern side to the rear side in the ship's bow-stern direction D1. The two propeller shafts 21 are provided to face each other in the ship width direction D2.

[0049] The propellers 20 are attached to the respective propeller shafts 21. Two propellers 20 are provided facing each other in the ship width direction D2. The rudders 30 are provided behind the respective propellers 20. Two rudders 30 are provided facing each other in the ship width direction D2.

[0050] Two jet propulsion units 40 are provided facing each other in the ship width direction D2. One jet propulsion unit 40 is provided directly above each propeller 20. That is, each jet propulsion unit 40 is provided above the corresponding propeller 20 in the ship height direction D3 and at the same position in the ship bow - stern direction D1 as the corresponding propeller 20. In other words, each jet propulsion unit 40 is provided at a position overlapping the corresponding propeller 20 in the ship height direction D3.

[0051] (Function and effect) Since the ship 201 of the present embodiment has the same configuration as that of the first embodiment, it can exhibit the same function and effect as the first embodiment.

[0052] Also, in the present embodiment, two jet propulsion units 40 are provided on the ship bottom 10.

[0053] Thereby, even if one of the jet propulsion units 40 fails, the other jet propulsion unit 40 can be operated, ensuring redundancy. Here, the case where two jet propulsion units 40 are provided has been described, but a plurality of three or more jet propulsion units 40 may be provided.

[0054] Also, in the present embodiment, it is assumed that one jet propulsion unit 40 is provided directly above each propeller 20, but it is not limited to this. For example, as shown in FIG. 7, each jet propulsion unit 40 may be provided on the rear side of the corresponding propeller 20 in the ship bow - stern direction D1.

[0055] Further, for example, as shown in FIG. 8, the jet propulsion unit 40 may be provided only at the center position in the ship width direction D2 of the two propellers 20 when viewed in the ship height direction D3. In this case, the jet propulsion unit 40 overlaps with the tips of the blades 23 of the two propellers 20 in the ship height direction D3.

[0056] Further, for example, as shown in FIG. 9, the jet propulsion unit 40 may be provided only at the center position in the ship width direction D2 of the two propellers 20 and on the rear side in the ship head-tail direction D1 with respect to the two propellers 20 when viewed in the ship height direction D3.

[0057] <Third Embodiment> (Configuration of Ship) Hereinafter, the ship 301 according to the third embodiment of the present disclosure will be described with reference to FIGS. 10 and 11. Among the present embodiment, for the configurations similar to those of the above-described embodiments, the description will be appropriately omitted by attaching the same names and the same reference numerals.

[0058] As shown in FIGS. 10 and 11, the ship 301 of the present embodiment includes one propeller 20 and two rudders 330. The rudder 330 of the present embodiment is of a so-called gate ladder type. The two rudders 330 are provided so as to sandwich the propeller 20 from both sides in the ship width direction D2.

[0059] The rudder 330 has a fixed portion 331, a rudder shaft 332, and a rudder plate 333. The fixed portion 331 is fixed to the ship bottom 10. The fixed portion 331 is provided directly above the propeller 20. The rudder shaft 332 is provided at the end portion on the front side in the ship head-tail direction D1 of the fixed portion 331. The rudder shaft 332 extends downward in the ship height direction D3 from the ship bottom 10 and protrudes from the fixed portion 331.

[0060] The rudder plate 333 is provided below the fixed portion 331 in the ship height direction D3. The rudder plate 333 is connected to the fixed portion 331 via the rudder shaft 332. The rudder plate 333 is rotatable around the rudder shaft 332. The rudder plate 333 has a mounting portion 333a, a connecting portion 333b, and a rudder plate body 333c. The mounting portion 333a is in contact with the fixing portion 331 from below. The mounting portion 333a is fixed to the lower end of the rudder shaft 332. The connecting portion 333b extends downward from the fixing portion 331 in the ship height direction D3. The connecting portion 333b is formed so as to be located outside in the ship width direction D2 as it goes downward in the ship height direction D3. The rudder plate body 333c extends downward from the lower end of the connecting portion 333b in the ship height direction D3. The rudder plate body 333c is located outside the ship width direction D2 of the propeller 20. The two rudder plate bodies 333c are provided so as to sandwich the propeller 20 from both sides in the ship height direction D3.

[0061] In the present embodiment, the jet propulsion unit 40 is provided on the rear side in the ship's bow and stern direction D1 with respect to the propeller 20 and the rudder 330.

[0062] (Function and effect) Since the ship 301 of the present embodiment has the same configuration as that of the first embodiment, it can exhibit the same functions and effects as those of the first embodiment.

[0063] Also, in the present embodiment, the jet propulsion unit 40 is provided on the rear side in the ship's bow and stern direction D1 with respect to the propeller 20.

[0064] When the rudder 330 is a gate rudder as in the present embodiment, for example, the rudder 330 is installed above the propeller 20. Thus, even when an additional object is installed above the propeller 20, according to this aspect, the jet propulsion unit 40 can be installed.

[0065] (Other embodiments) As described above, the embodiments of the present disclosure have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present disclosure are also included.

[0066] In the above-described embodiments, the case where the jet propulsion unit 40 is a pump jet with an integrated suction port 45 and discharge port 46 has been described, but the present invention is not limited thereto. For example, the jet propulsion unit 440 may be a water jet pump as shown in FIG. 14. The jet propulsion unit 440 includes a suction port 445 and a discharge port 446 provided at spaced positions. In the illustrated example, the suction port 445 is provided at the same position in the fore-and-aft direction D1 as the propeller 20, and the discharge port 446 is provided on the rear side of the propeller 20 in the fore-and-aft direction D1 and on the front side of the rudder 30 in the fore-and-aft direction D1. In this case, by rotatably installing the discharge port 446 about the axis O extending in the ship height direction D3 with the center C, the jet propulsion unit 440 can discharge the jet water flow Wc in an arbitrary horizontal direction from the discharge port 446. Also, the arrangement of the suction port 445 and the discharge port 446 is not limited to the illustrated example and can be changed as appropriate.

[0067] <Supplementary Note> The ships 1, 201, 301, 401 described in each embodiment are understood as follows, for example.

[0068] (1) The ships 1, 201, 301, 401 according to the first aspect include a hull 2, a propeller 20 provided on the rear side of the center C of the hull 2 in the fore-and-aft direction D1 and generating a water flow Wa toward the rear side in the fore-and-aft direction D1, rudders 30, 330 provided on the rear side of the propeller 20 in the hull 2 in the fore-and-aft direction D1, and jet propulsion units 40, 440 provided on the bottom 10 of the hull 2 and generating a jet water flow Wc. The jet propulsion units 40, 440 have a suction port 45, 445 for sucking water and a discharge port 46, 446 for discharging the water sucked from the suction port 45, 445 as the jet water flow Wc. The jet water flow Wc can be discharged in an arbitrary horizontal direction from the discharge port 46, 446. The jet propulsion units 40, 440 are provided above the propeller 20 in the ship height direction D3 and at the same position in the fore-and-aft direction D1 as the propeller 20 or on the rear side of the propeller 20 in the fore-and-aft direction D1.

[0069] The jet propulsion units 40 and 440 can discharge the jet water flow Wc in any horizontal direction from the bottom of the ship 10. The ships 1, 201, 301, and 401 can change their directions in any horizontal direction by the propulsive force of this jet water flow Wc. Furthermore, the jet propulsion units 40 and 440 are provided above the propeller 20 in the ship height direction D3. Therefore, it is difficult for debris on the bottom of the water to be sucked into the suction ports 45 and 445 of the jet propulsion units 40 and 440. Also, in recent years, due to the influence of global warming, the growth speed of algae such as seaweed has become faster. However, according to this aspect, it is also possible to suppress the algae from being sucked into the suction ports 45 and 445. Thus, the jet propulsion units 40 and 440 can operate well. Also, the jet propulsion units 40 and 440 are provided at the same position in the ship head-tail direction D1 as the propeller 20 or on the rear side of the propeller 20 in the ship head-tail direction D1. For this reason, the length from the center C of the ship 2 in the ship head-tail direction D1 to the jet propulsion units 40 and 440 becomes longer. Therefore, the turning moment by the jet propulsion units 40 and 440 becomes larger, and the ships 1, 201, 301, and 401 are more likely to change their directions.

[0070] (2) The ships 1, 201, 301 of the second aspect are the ships 1, 201, 301 of the first aspect, wherein the bottom of the ship 10 has a storage chamber 18 formed with a recess so as to open downward in the ship height direction D3, and the jet propulsion unit 40 may be stored in the storage chamber 18.

[0071] Thereby, the jet propulsion units 40 and 440 can be attached without protruding the jet propulsion unit 40 from the bottom of the ship 10. Thereby, the jet propulsion unit 40 does not become additional resistance, and an increase in the hull resistance can be suppressed.

[0072] (3) The ships 1, 201 of the third aspect are the ships 1, 201 of the first or second aspect, wherein the jet propulsion unit 40 may be provided at a position overlapping the propeller 20 in the ship height direction D3.

[0073] According to the above configuration, the jet propulsion unit 40 is installed directly above the propeller 20. Thereby, the so-called damping effect can be exerted, in which the vibration exciting force of the propeller 20 is suppressed by the weight of the jet propulsion unit 40.

[0074] (4) The ships 1, 201, 301 of the fourth aspect are any one of the ships 1, 201, 301 of the first to third aspects, and the jet propulsion unit 40 may be provided on the rear side of the propeller 20 in the fore-and-aft direction D1.

[0075] Even when an additional object is installed above the propeller 20, according to this aspect, the jet propulsion unit 40 can be installed.

[0076] (5) The ships 1, 201, 301, 401 of the fifth aspect are any one of the ships 1, 201, 301, 401 of the first to fourth aspects, and the rudders 30, 330 include fixed parts 31, 331 fixed to the ship bottom 10, and are provided below the fixed parts 31, 331 in the ship height direction D3 and can change their postures with respect to the fixed parts 31, 331, and rudder plates 33, 333 against which the water flow Wa of the propeller 20 impinges. The jet propulsion units 40, 440 may discharge the jet water flow Wc from the discharge ports 46, 446 above the rudder plates 33, 333 in the ship height direction D3.

[0077] Thereby, it is possible to prevent the jet water flow Wc from hitting the rudder plates 33, 333. For this reason, the influence exerted by the jet water flow Wc on the operation of the rudders 30, 330 can be significantly reduced.

[0078] (6) The ships 1, 201, 301, 401 of the sixth aspect are any one of the ships 1, 201, 301, 401 of the first to fifth aspects, and a plurality of the jet propulsion units 40, 440 may be provided on the ship bottom 10.

[0079] Accordingly, even if one of the jet propulsion units 40 and 440 fails, the other jet propulsion units 40 and 440 can be operated, ensuring redundancy.

Explanation of Signs

[0080] 1…Ship 2…Hull 3…Bow 4…Stern 5…Side 6…Upper deck 7…Drive source 10…Bottom of ship 11…Central part of bottom of ship 12…Bow side bottom of ship 13…Stern side bottom of ship 16…First part 17…Second part 18…Storage room 19…Boss part 20…Propeller 21…Propeller shaft 22…Hub 23…Blade 30…Rudder 31…Fixed part 32…Rudder shaft 33…Rudder plate 40…Jet propulsion unit 41…Housing 42…Impeller 43…Cover part 43a…Outer frame 43b…Mesh part 44…Inner wall 45…Suction port 46…Discharge port C…Center D1…Lengthwise direction of ship D2…Width direction of ship D3…Height direction of ship O…Axis Wa…Water flow Wb…Water flow Wc…Jet water flow WL…Water surface 201…Ship 202…Hull 301…Ship 330…Rudder 331…Fixed part 332…Rudder shaft 333…Rudder plate 333a…Mounting part 333b…Connecting part 333c…Rudder plate body 401…Ship 440…Jet propulsion unit 445…Suction port 446…Discharge port

Claims

1. A hull, a propeller provided rearward of the center of the hull in the fore-and-aft direction and generating water flow toward the rear in the fore-and-aft direction, a rudder provided rearward of the propeller in the fore-and-aft direction on the hull, a jet propulsion unit provided on the bottom of the hull and generating a jet water flow, characterized in that it comprises: the jet propulsion unit has a suction port for sucking water and a discharge port for discharging the water sucked from the suction port as the jet water flow, and the jet water flow can be discharged from the discharge port in an arbitrary horizontal direction, the jet propulsion unit is provided above the propeller in the vertical direction of the ship and is located at the same position in the fore-and-aft direction as the propeller or is provided rearward of the propeller in the fore-and-aft direction.

2. The bottom of the hull has a storage chamber formed with a recess so as to open downward in the vertical direction of the ship, and the jet propulsion unit is stored in the storage chamber in the ship according to Claim 1.

3. The ship according to Claim 1 or 2, wherein the jet propulsion unit is provided at a position overlapping the propeller in the vertical direction of the ship.

4. The ship according to Claim 1 or 2, wherein the jet propulsion unit is provided rearward of the propeller in the fore-and-aft direction.

5. The rudder has a fixing part fixed to the bottom of the hull, and a rudder plate provided below the fixing part in the vertical direction of the ship, capable of changing its attitude with respect to the fixing part and against which the water flow of the propeller impinges, characterized in that it comprises: the ship according to Claim 1 or 2, wherein the jet propulsion unit discharges the jet water flow from the discharge port above the rudder plate in the vertical direction of the ship.

6. The ship according to Claim 1 or 2, wherein a plurality of jet propulsion units are provided on the bottom of the hull.

Images