Underwater walking body

Abstract

To provide an underwater vessel capable of improving propulsion efficiency.SOLUTION: An underwater vessel 1 which is a machine body 2 having an outer periphery surface 2a forming a cylindrical surface with an axial line O as center and continuously extending in the axial direction has an entrance unit 11 opened over the whole periphery in one portion of an outer periphery surface in the axial direction and an exit unit 12 opened on a rear end of the machine body, and includes the machine body forming an annular channel 10 with a gradually shrinking diameter in at least one portion from an entrance unit and the exit unit, a propeller 3 provided in the annular channel and capable of being rotated around an axial line, and a driving unit 4 for rotating and driving the propeller.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to underwater vehicles. [Background technology]

[0002] Patent Document 1 discloses a submersible underwater vehicle equipped with a propulsion device at the rear end of the vehicle body (hull). The propulsion device of the underwater vehicle has a cylindrical shroud into which the rear end of the vehicle body is inserted, and a propeller disposed between the inside of the shroud and the outside of the rear end of the vehicle body and rotating around the axis of the shroud. As the propeller rotates, water is pumped inside the shroud to the rear of the vehicle body, allowing the underwater vehicle to travel underwater. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-280981 Summary of the Invention [Problem to be solved by the invention]

[0004] When an underwater vehicle travels underwater, water flows from the front to the rear of the vehicle along the surface of the vehicle, but a boundary layer is generated on the surface of the vehicle due to the viscosity of the water. The generation of a boundary layer is undesirable because it creates resistance to the propulsion of the underwater vehicle.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an underwater vehicle that can improve propulsion efficiency. [Means for solving the problem]

[0006] In order to solve the above problems, the underwater vehicle according to the present disclosure is a vehicle having a cylindrical surface centered on an axis and an outer peripheral surface that extends continuously in the axial direction, the vehicle having an inlet portion that opens around the entire circumference of the outer peripheral surface in the axial direction and an outlet portion that opens at the rear end of the vehicle, the vehicle having an annular flow path that gradually reduces in diameter in at least a portion from the inlet portion to the outlet portion; a propeller that is provided in the annular flow path and is rotatable around the axis; and a drive unit that rotationally drives the propeller. The diameter of an inner circumferential portion of the aircraft, which is an inner circumferential portion of the annular flow passage in the aircraft, decreases rearward from the propeller as it approaches the outlet portion and becomes zero at the outlet portion, and the aircraft further includes a momentum imparting device that is provided in an area rearward from the propeller on the inner circumferential surface of the annular flow passage made up of the inner circumferential portion of the aircraft, and that imparts momentum to the water on the inner circumferential surface toward the rear along the inner circumferential surface. do. [Effects of the Invention]

[0007] According to the present disclosure, the propulsion efficiency of an underwater vehicle can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of an underwater vehicle according to a first embodiment of the present disclosure. [Figure 2] 2 is a diagram illustrating the suction of a boundary layer generated on the outer peripheral surface of the underwater vehicle of FIG. 1. FIG. [Figure 3] FIG. 10 is a cross-sectional view of an underwater vehicle according to a second embodiment of the present disclosure. [Figure 4] FIG. 10 is a cross-sectional view of an underwater vehicle according to a third embodiment of the present disclosure. [Figure 5] 5 is a view of the rear strut provided on the underwater vehicle of FIG. 4 as viewed from the radial direction of the annular flow path. [Figure 6] FIG. 10 is a cross-sectional view showing a modified example of the underwater vehicle according to the third embodiment of the present disclosure. [Figure 7] FIG. 10 is a cross-sectional view of an underwater vehicle according to a fourth embodiment of the present disclosure. [Figure 8] FIG. 10 is an enlarged cross-sectional view showing a main part of an underwater vehicle according to a fifth embodiment of the present disclosure. [Figure 9] FIG. 10 is a cross-sectional view showing a main part of an underwater vehicle according to a sixth embodiment of the present disclosure. [Figure 10] FIG. 10 is a cross-sectional view showing an underwater vehicle according to a seventh embodiment of the present disclosure. [Figure 11]FIG. 13 is a cross-sectional view showing an underwater vehicle according to an eighth embodiment of the present disclosure. [Figure 12] FIG. 13 is a cross-sectional view showing an underwater vehicle according to a ninth embodiment of the present disclosure. [Figure 13] FIG. 10 is a cross-sectional view showing an underwater vehicle according to a tenth embodiment of the present disclosure. [Figure 14] FIG. 22 is a cross-sectional view showing an underwater vehicle according to an eleventh embodiment of the present disclosure. [Figure 15] FIG. 23 is a cross-sectional view showing an underwater vehicle according to a twelfth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment [Overall configuration of the underwater vehicle] Hereinafter, a first embodiment of the present disclosure will be described with reference to FIGS. As shown in FIG. 1, the underwater vehicle 1 includes a body 2, a propeller 3, and a drive unit 4.

[0010] [Aircraft] The vehicle body 2 has an outer peripheral surface 2a that is cylindrical and centered on the axis O and extends continuously in the direction of the axis O. The continuous extension of the outer peripheral surface 2a of the vehicle body 2 in the direction of the axis O means that the outer peripheral surface 2a extends in the direction of the axis O from the front end to the rear end of the vehicle body 2 so as to maintain a streamlined shape. A streamlined shape is a shape that is less likely to cause turbulence such as flow separation and vortices on the outer peripheral surface 2a when the underwater vehicle 1 travels generally in the direction of the axis O. The diameter of the outer peripheral surface 2a of the vehicle body 2 may gradually vary in the direction of the axis O of the vehicle body 2 as long as the streamlined shape is maintained. In this embodiment, the diameter of the outer peripheral surface 2a at the front part (front vehicle part) of the vehicle body 2 in the direction of the axis O is generally constant. The diameter of the outer peripheral surface 2a in the direction of the axis O, rearward of an inlet portion 11 of an annular flow path 10 (described later), gradually decreases toward the rear of the vehicle body 2.

[0011] [Annular flow path] An annular flow path 10 is formed in the airframe 2. The annular flow path 10 is formed in an annular shape, specifically a circular ring shape, centered on the axis O. The annular flow path 10 is located at the rear of the airframe 2 in the direction of the axis O (rear of the airframe). The annular flow path 10 has an inlet portion 11 and an outlet portion 12. The inlet portion 11 opens over the entire circumference at a portion of the outer circumferential surface 2a in the direction of the axis O. The outlet portion 12 opens at the rear end of the airframe 2 in the direction of the axis O. 1, the inlet 11 opens in a region of the outer peripheral surface 2a where the diameter of the outer peripheral surface 2a is constant, but this is not limiting. For example, the inlet 11 may open in a region of the outer peripheral surface 2a where the diameter of the outer peripheral surface 2a gradually decreases toward the rear of the fuselage 2.

[0012] It is sufficient that the region of the outer peripheral surface 2a of the airframe 2 that is aft of the inlet portion 11 in the direction of the axis O does not protrude radially outward of the airframe 2 relative to at least the region forward of the inlet portion 11 in the direction of the axis O. Furthermore, the diameter of the outer peripheral surface 2a at the rear end 11B of the inlet portion 11 may be equal to or smaller than the diameter of the outer peripheral surface 2a at the front end 11A of the inlet portion 11, for example. It is preferable that the difference between the diameter of the outer peripheral surface 2a at the front end 11A of the inlet portion 11 and the diameter of the outer peripheral surface 2a at the rear end 11B of the inlet portion 11 is small.

[0013] 1, the annular flow path 10 gradually reduces in diameter from the inlet portion 11 to the outlet portion 12, but this is not limited thereto. The annular flow path 10 only needs to gradually reduce in diameter in at least a portion from the inlet portion 11 to the outlet portion 12. By forming the annular flow path 10 in this manner, the outlet portion 12 is located more inward than the inlet portion 11 in the radial direction of the fuselage 2. Moreover, the annular flow path 10 of this embodiment is also formed in an annular shape at the outlet portion 12. Therefore, at the rear end of the fuselage 2 corresponding to the outlet portion 12, a flat rear end surface 2b is formed that is located radially inside the annular flow path 10 and perpendicular to the axis O.

[0014] Since the annular flow path 10 is formed in the body 2, the outer body portion 22, which is the outer peripheral portion of the annular flow path 10 in the body 2, is separated from the inner body portion 21, which is the inner peripheral portion of the annular flow path 10 in the body 2.

[0015] [Strut] The fuselage 2 has a strut that connects the fuselage outer periphery 22 and the fuselage inner periphery 21. The strut in this embodiment is a front strut 23 that connects the front end of the fuselage outer periphery 22 and the front end of the fuselage inner periphery 21 in the direction of the axis O. The front struts 23 are arranged at intervals in the circumferential direction of the fuselage 2 around the axis O at the inlet 11 of the annular flow path 10. It is preferable that the front struts 23 are arranged at equal intervals in the circumferential direction. When viewed from the direction of the axis O, each front strut 23 is formed in a plate shape with its thickness direction perpendicular to the radial direction of the fuselage 2. This prevents the front struts 23 from reducing the opening area of ​​the inlet 11. 1 is formed so as to maintain the streamlined shape of the outer peripheral surface 2a of the fuselage 2. In other words, the front strut 23 does not protrude radially outward from the outer peripheral surface 2a of the fuselage 2, but is formed so as to smoothly connect the outer peripheral surface 2a from the front end 11A to the rear end 11B of the inlet 11. Note that the front strut 23 may also be formed so as to be recessed radially inward from the outer peripheral surface 2a of the fuselage 2, for example.

[0016] [propeller] The propeller 3 is provided in the annular flow path 10 and is rotatable about an axis O. Specifically, the propeller 3 is rotatably attached to the inner circumferential portion 21 of the aircraft. The propeller 3 has a plurality of blades 31 arranged at intervals in the circumferential direction of the annular flow path 10 around the axis O. Each blade 31 extends in the radial direction of the annular flow path 10 from an inner surface 13 of the annular flow path 10 to an outer surface 14 of the annular flow path 10. Here, the "inner surface 13 of the annular flow path 10" corresponds to the outer surface 13 of the inner circumferential portion 21 of the aircraft. Furthermore, the "outer surface 14 of the annular flow path 10" corresponds to the inner surface 14 of the outer circumferential portion 22 of the aircraft. When the propeller 3 rotates, the blades 31 of the propeller 3 positioned in the annular flow path 10 force water from the inlet 11 to the outlet 12 of the annular flow path 10 (that is, toward the rear of the aircraft body 2).

[0017] [Drive unit] The drive unit 4 drives and rotates the propeller 3. The drive unit 4 is provided on the outer periphery of the aircraft body 22. The drive unit 4 in this embodiment is a motor that drives and rotates the propeller 3 when supplied with electric power.

[0018] [Drive source] The underwater vehicle 1 has a drive source 5 that supplies drive force to the drive unit 4. The drive source 5 is provided inside the vehicle body 20, which includes the vehicle inner peripheral portion 21 of the vehicle body 2. The drive source 5 is preferably disposed on the front side of the vehicle inner peripheral portion 21 of the vehicle body 20. This allows the diameter dimension of the vehicle inner peripheral portion 21 to be kept small. The driving source 5 in this embodiment is a power supply device that supplies power to the driving unit 4. The power supply device may be a battery, a power generation device, or the like. The driving unit 4 and the driving source 5 are connected by an electrical wiring 61. The electrical wiring 61 extends from the driving source 5 via the front strut 23 to the driving unit 4 provided on the outer periphery 22 of the aircraft body.

[0019] [Action and effect] The underwater vehicle 1 can navigate underwater by rotating the propeller 3. That is, when the propeller 3 rotates around the axis O, the blades 31 of the propeller 3 located in the annular flow path 10 pressurize the water in the annular flow path 10 rearward. Then, a forward thrust force is generated in the propeller 3 as a reaction force to the pressurized water. This thrust force is transmitted to the body 2, causing the underwater vehicle 1 to propel.

[0020] In the underwater vehicle 1 of the first embodiment, an inlet 11 of an annular flow path 10 opens on the outer peripheral surface 2a of the body 2, which extends continuously in the direction of the axis O. As a result, when the underwater vehicle 1 travels underwater, as shown in FIG. 2 , a boundary layer BL generated on the outer peripheral surface 2a of the body 2 forward of the inlet 11 (on the left side in FIG. 2 ) is sucked into the annular flow path 10 from the inlet 11. This makes it possible to suppress the development of the boundary layer BL on the outer peripheral surface 2a of the body 2 rearward of the inlet 11. Furthermore, because the outer peripheral surface 2a of the body 2 extends continuously before and after the inlet 11, which corresponds to the direction of the axis O, water can flow smoothly at a high speed along the outer peripheral surface 2a of the body 2 rearward of the inlet 11. This improves the propulsion efficiency of the underwater vehicle 1.

[0021] Furthermore, in the underwater vehicle 1 of the first embodiment, the propeller 3 is provided in an annular flow path 10 formed inside the body 2. This limits the direction in which sound (noise) generated by the propeller 3 is emitted outside the body 2. Specifically, the sound of the propeller 3 is limited to the inlet portion 11 and outlet portion 12 of the annular flow path 10. This allows the underwater vehicle 1 to be made quieter.

[0022] Furthermore, in the underwater vehicle 1 of the first embodiment, the drive unit 4 is provided on the outer circumferential portion 22 of the vehicle body. This makes it possible to form the annular flow path 10 between the outer circumferential portion 22 of the vehicle body and the inner circumferential portion 21 of the vehicle body while preventing the diameter of the vehicle body 2 from becoming larger, compared to when the drive unit 4 is provided on the inner circumferential portion 21 of the vehicle body. This point will be described below.

[0023] When the drive unit 4 is provided in the inner circumferential portion 21 of the fuselage, it is necessary to secure space for installing the drive unit 4 in the inner circumferential portion 21 while forming the annular flow path 10 in the fuselage 2, which increases the diameter of the inner circumferential portion 21. In contrast, when the drive unit 4 is provided in the outer circumferential portion 22 of the fuselage, it is possible to set the diameter of the inner circumferential portion 21 to be smaller even if the annular flow path 10 is formed in the fuselage 2. This makes it possible to prevent the diameter of the fuselage 2 from becoming larger. Furthermore, since the annular flow path 10 is formed so as to gradually reduce in diameter, the dimensions of the outer circumferential body portion 22 tend to increase in the radial direction, and therefore the drive unit 4 can be easily provided on the outer circumferential body portion 22 .

[0024] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to Fig. 3. In the following description, configurations common to those already described will be assigned the same reference numerals and redundant description will be omitted.

[0025] [Horizontal rudder] As shown in FIG. 3, the underwater vehicle 1C of the second embodiment further includes a horizontal rudder 7 compared to the underwater vehicle 1 of the first embodiment. The horizontal rudder 7 is provided rearward of the inlet portion 11 on the outer peripheral surface 2a of the vehicle body 2. The horizontal rudder 7 is fixed to the outer peripheral portion 22 of the vehicle body. When viewed from the direction of the axis O, the horizontal rudder 7 is formed in a plate shape with the plate thickness direction being a direction perpendicular to the radial direction of the outer peripheral surface 2a. Multiple horizontal rudder 7 are arranged at intervals in the circumferential direction of the outer peripheral surface 2a. It is preferable that the multiple horizontal rudders 7 are arranged at equal intervals in the circumferential direction. 3, the horizontal rudder 7 does not protrude radially outward from the outer peripheral surface 2a at the rear end 11B of the inlet 11 of the annular flow path 10. This makes it possible to reduce water resistance when the underwater vehicle 1C is propelled. Note that the horizontal rudder 7 may protrude slightly radially outward from the outer peripheral surface 2a at the rear end 11B of the inlet 11 of the annular flow path 10, for example.

[0026] The underwater vehicle 1C of the second embodiment provides the same effects as the first embodiment. Furthermore, in the underwater vehicle 1C of the second embodiment, as described in the first embodiment, the water flow velocity is high when the underwater vehicle 1C travels through water on the rear side of the inlet portion 11 of the outer peripheral surface 2a where the horizontal rudder 7 is provided. In other words, the horizontal rudder 7 is provided in a portion of the body 2 where the water flow velocity is high. This can improve the stability of the underwater vehicle 1C when it travels through water.

[0027] Third Embodiment Next, a third embodiment of the present disclosure will be described with reference to Figures 4 and 5. In the following description, configurations that are common to those already described will be assigned the same reference numerals, and duplicated description will be omitted.

[0028] [Rear strut] As shown in FIG. 4, the underwater vehicle 1D of the third embodiment further includes a rear strut 24 compared to the underwater vehicle 1 of the first embodiment. In FIG. 4, the electrical wiring 61 (see FIG. 1) connecting the drive unit 4 and the drive source 5 is omitted. The rear strut 24 is provided rearward of the propeller 3 in the annular flow path 10, and together with the front strut 23, forms a strut that connects the outer circumferential body portion 22 and the inner circumferential body portion 21. That is, the rear strut 24 extends from the outer circumferential surface 13 of the inner circumferential body portion 21 that forms the annular flow path 10 to the inner circumferential surface 14 of the outer circumferential body portion 22. As shown in FIG. 5, the rear strut 24 is formed in a wing shape in a cross section perpendicular to the radial direction of the annular flow path 10, with a leading edge on the inlet portion 11 side of the annular flow path 10 and a trailing edge on the outlet portion 12 side of the annular flow path 10. In the underwater vehicle 1D shown in Fig. 4, a plurality of rear struts 24 are arranged at intervals in the circumferential direction of the vehicle body 2 centered on the axis O. It is preferable that a plurality of front struts 23 are arranged at equal intervals in the circumferential direction.

[0029] [Rudder] As shown in Figures 4 and 5, the rear portion 24B of the rear strut 24 located on the outlet 12 side serves as a rudder 8 (flap). The rudder 8 is attached to the fuselage 2 and the front portion 24A of the front strut 23 located on the inlet 11 side so as to be rotatable about an axis perpendicular to the longitudinal and circumferential directions of the annular channel 10. The rudder 8 rotates relative to the fuselage 2 to change or adjust the flow direction of water from the propeller 3 toward the outlet 12 of the annular channel 10. The front portion 24A of the rear strut 24 is fixed to the fuselage 2.

[0030] [Rudder drive unit] As shown in Figure 4, the rudder 8 is rotationally driven by a rudder drive unit 80. The rudder drive unit 80 is provided on the fuselage inner circumferential portion 21. The rudder drive unit 80 is a motor that is rotationally driven when supplied with electric power, and is connected to the drive source 5 via an electric wiring 62.

[0031] The underwater vehicle 1D of the third embodiment provides the same effects as the first embodiment. Furthermore, in the underwater vehicle 1D of the third embodiment, the rear strut 24 is provided behind the propeller 3. Therefore, the swirling flow generated by the propeller 3 can be collected by the rear strut 24. This reduces the swirling flow loss behind the rear strut 24. Therefore, the propulsion efficiency of the underwater vehicle 1D can be further improved.

[0032] Furthermore, in the underwater vehicle 1D of the third embodiment, the rudder 8 is provided behind the propeller 3. Therefore, the rudder 8 changes the direction of the water flow accelerated by the propeller 3 in the annular flow path 10 (i.e., the water flow with a high flow velocity). This makes it possible to provide an underwater vehicle 1D with a greater deflection force.

[0033] In a third embodiment, the entire rear strut 24 may be configured as a rudder 8, as shown in FIG.

[0034] In the third embodiment, for example, the rear strut 24 may not include the rudder 8 , and the entire rear strut 24 may be fixed to the fuselage 2 .

[0035] The rear strut 24 of the third embodiment may be applied to the second embodiment.

[0036] <Fourth embodiment> Next, a fourth embodiment of the present disclosure will be described with reference to Fig. 7. In the following description, configurations common to those already described will be assigned the same reference numerals and redundant description will be omitted.

[0037] [Variable nozzle] As shown in Figure 7, the underwater vehicle 1E of the fourth embodiment further includes a variable nozzle 9, as compared to the underwater vehicle 1 of the first embodiment. In Figure 7, the electrical wiring 61 (see Figure 1) connecting the drive unit 4 and the drive source 5 is omitted. The variable nozzle 9 is provided at the rear end of the vehicle body 2 where the outlet 12 of the annular flow path 10 opens. Specifically, the variable nozzle 9 is provided at the rear end of the vehicle body outer circumferential portion 22.

[0038] The variable nozzle 9 is composed of multiple panels 91 arranged in the circumferential direction of the vehicle 2's outer periphery. Each panel 91 is rotatably attached to the rear end of the vehicle 2's outer periphery around an axis that corresponds to the circumferential direction of the vehicle 2, and extends generally rearward from the rear end of the vehicle 2's outer periphery. When each panel 91 rotates relative to the rear end of the vehicle 2's outer periphery, the leading end of each panel 91 moves radially relative to the vehicle 2's outer periphery. By appropriately rotating the multiple panels 91 arranged in the circumferential direction of the vehicle 2's outer periphery, relative to the rear end of the vehicle 2's outer periphery, the orientation of the outlet 12 and the opening area of ​​the outlet 12 can be changed. By changing the orientation of the outlet 12, the traveling direction of the underwater vehicle 1E can be changed. Furthermore, by changing the opening area of ​​the outlet 12, the underwater vehicle 1E can be rapidly accelerated or decelerated.

[0039] [Nozzle drive unit] The multiple panels 91 of the variable nozzle 9 are individually driven to rotate by a nozzle drive unit 90. The nozzle drive unit 90 is provided on the outer circumferential portion 21 of the machine body. The nozzle drive unit 90 is a motor that is driven to rotate when supplied with power, and is connected to a drive source 5 via electrical wiring 63. The nozzle drive unit 90 is connected to the multiple panels 91 provided on the outer circumferential portion 22 of the machine body via a drive shaft 92.

[0040] The underwater vehicle 1E of the fourth embodiment provides the same effects as those of the first embodiment. Furthermore, in the underwater vehicle 1E of the fourth embodiment, a large deflection force can be obtained by the variable nozzle 9, and the underwater vehicle 1E can also be rapidly accelerated and decelerated.

[0041] The variable nozzle 9 of the fourth embodiment may be applied to the second and third embodiments.

[0042] Fifth Embodiment Next, a fifth embodiment of the present disclosure will be described with reference to Fig. 8. In the following description, configurations common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0043] An underwater vehicle 1F of a fifth embodiment shown in FIG. 8 has the same components as the underwater vehicle 1 of the first embodiment. In FIG. 8, the drive source 5 and the electrical wiring 61 (see FIG. 1) connecting the drive unit 4 and the drive source 5 are omitted. In the fifth embodiment, as shown in FIG. 8, in a cross section including the axis O, two propeller mounting areas 14A, 13A on the outer peripheral surface 14 and the inner peripheral surface 13 of the annular flow path 10 of the vehicle body 2, where the propellers 3 are mounted, extend linearly and are not curved. The first propeller mounting area 14A on the outer peripheral surface 14 is an area where the blades 31 of the propeller 3 contact the outer peripheral surface 14 in a cross section including the axis O. Similarly, the second propeller mounting area 13A on the inner peripheral surface 13 is an area where the blades 31 of the propeller 3 contact the inner peripheral surface 13 in a cross section including the axis O. The two propeller mounting areas 14A, 13A are inclined with respect to the axis O. Specifically, the propeller mounting areas 14A, 13A are inclined so as to approach the axis O toward the outlet portion 12. In FIG. 8, the two propeller mounting areas 14A, 13A are parallel to each other, but may also be inclined with respect to each other, for example.

[0044] In a cross section including the axis O, an adjacent region 14B (first adjacent region 14B) of the outer peripheral surface 14 that is adjacent to the first propeller mounting region 14A on the side of the inlet 11 of the annular flow path 10 extends linearly from the first propeller mounting region 14A. The first adjacent region 14B is not inclined with respect to the first propeller mounting region 14A. In a cross section including the axis O, the length of the first adjacent region 14B may be any length, but is preferably, for example, at least half the length of the first propeller mounting region 14A. Similarly, in a cross section including the axis O, an adjacent region 13B (second adjacent region 13B) on the inner peripheral surface 13 adjacent to the second propeller mounting region 13A on the side of the inlet 11 of the annular flow passage 10 extends linearly from the second propeller mounting region 13A. The second adjacent region 13B is not inclined with respect to the second propeller mounting region 13A. The length of the second adjacent region 13B in a cross section including the axis O may be any length, but is preferably, for example, at least half the length of the second propeller mounting region 13A.

[0045] The underwater vehicle 1F of the fifth embodiment provides the same effects as those of the first embodiment. Furthermore, in the underwater vehicle 1F of the fifth embodiment, the first and second propeller arrangement regions 14A, 13A of the annular flow path 10 extend linearly in a cross section including the axis O. That is, the propeller 3 is provided in the linearly extending portion of the annular flow path 10. This allows the propeller 3 to accelerate water passing through the annular flow path 10 with high efficiency. This further improves the propulsion efficiency of the underwater vehicle 1F.

[0046] Furthermore, in the underwater vehicle 1F of the fifth embodiment, in a cross section including the axis O, the two adjacent regions 14B, 13B that are respectively adjacent to the front of the two propeller arrangement regions 14A, 13A extend linearly without inclining relative to the respective propeller arrangement regions 14A, 13A. That is, in the underwater vehicle 1F of the fifth embodiment, the portion of the annular flow path 10 that is adjacent to the front (upstream side) of the propeller 3 also extends linearly. This allows the propeller 3 to accelerate the water passing through the annular flow path 10 with even higher efficiency. If the length of the two adjacent regions 14B, 13B in a cross section including the axis O is more than half the length of each of the propeller arrangement regions 14A, 13A, the efficiency of water acceleration by the propeller 3 can be further increased.

[0047] In the fifth embodiment, the propeller arrangement areas 14A and 13A may extend linearly along the axis O in a cross section including the axis O, for example.

[0048] In the fifth embodiment, the adjacent regions 14B and 13B may be curved in a cross section including the axis O, for example.

[0049] Sixth Embodiment Next, a sixth embodiment of the present disclosure will be described with reference to Fig. 9. In the following description, configurations common to those already described will be assigned the same reference numerals and redundant description will be omitted.

[0050] As shown in FIG. 9, in the underwater vehicle 1G of the sixth embodiment, the propeller arrangement regions 14A, 13A of the annular flow path 10 extend linearly in a cross section including the axis O, similar to the underwater vehicle 1F of the fifth embodiment. In the sixth embodiment, the propeller mounting areas 14A, 13A extend linearly along the axis O in a cross section including the axis O. Furthermore, rear end areas 14G, 13G (first rear end area 14G, second rear end area 13G) from the rear ends of the propeller mounting areas 14A, 13A to the outlet portion 12 on the outer peripheral surface 14 and the inner peripheral surface 13 of the annular flow path 10 in the airframe 2 also extend linearly along the axis O in a cross section including the axis O, similar to the propeller mounting areas 14A, 13A.

[0051] The underwater vehicle 1G of the sixth embodiment provides the same effects as the fifth embodiment. Furthermore, in the underwater vehicle 1G of the sixth embodiment, the portion of the annular channel 10 from the propeller 3 to the outlet 12 extends linearly along the axis O. Therefore, the water pressure-fed rearward by the propeller 3 flows out rearward from the outlet 12 of the annular channel 10 parallel to the axis O. As a result, the forward propulsion force obtained as a reaction force to the pressure-fed water is also parallel to the axis O. Therefore, the propulsion efficiency of the underwater vehicle 1G can be further improved compared to when water flows out rearward from the outlet 12 of the annular channel 10 at an angle with respect to the axis O of the vehicle body 2.

[0052] The structures of the underwater vehicles 1F, 1G of the fifth and sixth embodiments may be applied to the second to fourth embodiments.

[0053] Seventh Embodiment Next, a seventh embodiment of the present disclosure will be described with reference to Fig. 10. In the following description, configurations common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0054] As shown in Fig. 10, the underwater vehicle 1H of the seventh embodiment has the same components as the underwater vehicle 1 of the first embodiment. In Fig. 10, the drive source 5 and the electrical wiring 61 (see Fig. 1) connecting the drive unit 4 and the drive source 5 are omitted. In the underwater vehicle 1H of the seventh embodiment, the diameter of the inner circumferential portion 21 of the vehicle decreases rearward of the propeller 3 and toward the outlet portion 12. The diameter of the inner circumferential portion 21 is zero at the outlet portion 12. In other words, the inner circumferential portion 21 is formed in a tapered shape with the outlet portion 12 as its apex. As a result, the outlet portion 12 of the annular flow path 10 is formed in a circular shape rather than an annular shape when viewed from the direction of the axis O.

[0055] The underwater vehicle 1H of the seventh embodiment provides the same effects as those of the first embodiment. Furthermore, in the underwater vehicle 1H of the seventh embodiment, the outlet 12 of the annular flow path 10 is formed in a circular shape rather than an annular shape when viewed from the direction of the axis O. This makes it possible to suppress or prevent the flow velocity distribution of the water flowing rearward from the outlet 12 of the annular flow path 10 from becoming doughnut-shaped, thereby reducing fluid mixing loss. This point will be explained below.

[0056] When the outlet 12 of the annular flow path 10 is annular (i.e., when the inner circumferential portion 21 of the aircraft has a rear end surface 2b (see FIG. 1) corresponding to the outlet 12), the flow velocity distribution of the water flowing rearward from the outlet 12 is donut-shaped. The donut-shaped flow velocity distribution of the water behind the outlet 12 means that regions where the flow velocity of the water flowing rearward from the outlet 12 is high are distributed in a donut shape. In this case, regions where the flow velocity is high and regions where the flow velocity is low mix together behind the outlet 12, resulting in large fluid mixing loss.

[0057] On the other hand, if the outlet 12 of the annular flow path 10 is circular (i.e., if the inner circumferential portion 21 does not have the rear end surface 2b corresponding to the outlet 12), the flow velocity distribution of the water flowing rearward from the outlet 12 will not be doughnut-shaped, but will tend to be circular. This reduces or eliminates mixing of regions with high and low flow velocities behind the outlet 12, thereby reducing fluid mixing loss.

[0058] Eighth Embodiment Next, an eighth embodiment of the present disclosure will be described with reference to Fig. 11. In the following description, configurations common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0059] [Momentum imparting device] 11 , in the underwater vehicle 1I of the eighth embodiment, similar to the underwater vehicle 1H of the seventh embodiment, the inner circumferential portion 21 of the body is formed in a tapered shape with the outlet portion 12 as an apex, and the outlet portion 12 of the annular flow path 10 is formed in a circular shape when viewed from the direction of the axis O. The underwater vehicle 1I of the eighth embodiment further includes a momentum imparting device 100. The momentum imparting device 100 is provided in a region of the inner peripheral surface 13 of the annular flow path 10 formed by the inner circumferential portion 21 of the aircraft, which is rearward of the propeller 3. The momentum imparting device 100 imparts momentum to the water on the inner peripheral surface 13 in a rearward direction along the inner peripheral surface 13.

[0060] The momentum imparting device 100 is composed of a roller 101. The roller 101 is formed in a cylindrical shape. The roller 101 is arranged so that a portion of its outer circumferential surface in the circumferential direction is exposed to the inner circumferential surface 13 of the annular flow path 10 and so that the axis of the roller 101 is perpendicular to the axis O and radial directions of the inner circumferential portion 21. The region of the outer circumferential surface of the roller 101 exposed to the inner circumferential surface 13 of the annular flow path 10 constitutes a portion of the inner circumferential surface 13 of the annular flow path 10. The roller 101 is rotatable relative to the inner circumferential portion 21 so that the region of the outer circumferential surface exposed to the inner circumferential surface 13 moves toward the outlet portion 12 of the annular flow path 10. In FIG. 11 , the roller rotates in the direction indicated by the arrow. A plurality of rollers 101 are arranged in the circumferential direction of the inner circumferential portion 21.

[0061] The roller 101 is rotationally driven by a roller drive unit (not shown), which may be, for example, a motor that is rotationally driven by power supplied from the drive source 5 illustrated in FIG.

[0062] In the momentum imparting device 100, the roller 101 rotates so that the area of ​​the outer surface of the roller 101 exposed to the inner surface 13 moves toward the outlet 12 of the annular flow channel 10. This allows the water on the inner surface 13 to be imparted with momentum moving backward along the inner surface 13.

[0063] The underwater vehicle 1I of the eighth embodiment provides the same effects as those of the seventh embodiment. Furthermore, in the underwater vehicle 1I of the eighth embodiment, the momentum imparting device 100 imparts rearward momentum along the inner peripheral surface 13 to the water flowing along the inner peripheral surface 13 of the annular flow path 10 behind the propeller 3. This makes it possible to prevent the rearward flow of water along the inner peripheral surface 13 from separating from the inner peripheral surface 13. This point will be described below.

[0064] In the underwater vehicle 1I of the eighth embodiment, the diameter of the inner circumferential portion 21 behind the propeller 3 decreases as it approaches the outlet portion 12. Therefore, the water flowing rearward along the inner circumferential surface 13 of the annular flow path 10 behind the propeller 3 tends to separate from the inner circumferential surface 13. In response to this, the momentum imparting device 100 imparts rearward momentum to the water on the inner circumferential surface 13 behind the propeller 3, thereby suppressing this separation. By suppressing separation of the water flow from the propeller 3 toward the rear in the annular flow path 10, it is possible to reduce fluid mixing loss.

[0065] In the eighth embodiment, the momentum imparting device 100 can impart momentum to the water on the inner surface 13 in a backward direction along the inner surface 13 using not only the roller 101 but also other momentum imparting devices.

[0066] The configurations of the underwater vehicles 1H, 1I of the seventh and eighth embodiments may be applied to the second to fifth embodiments.

[0067] Ninth Embodiment Next, a ninth embodiment of the present disclosure will be described with reference to Fig. 12. In the following description, configurations common to those already described will be assigned the same reference numerals and redundant description will be omitted.

[0068] [Sound absorbing materials, vibration damping materials] As shown in FIG. 12 , compared to the underwater vehicle 1 of the first embodiment, the underwater vehicle 1J of the ninth embodiment further includes sound-absorbing material 111 and / or vibration-damping material 112 provided on the inner surface of the annular channel 10. In FIG. 12 , the drive source 5 and the electrical wiring 61 (see FIG. 1 ) connecting the drive unit 4 and the drive source 5 are omitted. One or both of the sound-absorbing material 111 and the vibration-damping material 112 are provided on the inner surface of the annular channel 10. The sound-absorbing material 111 and the vibration-damping material 112 absorb sound generated by the propeller 3. In FIG. 12 , the inner surface of the annular channel 10 on which the sound-absorbing material 111 and / or the vibration-damping material 112 is provided is the outer peripheral surface 14 of the annular channel 10, but may also be, for example, the inner peripheral surface 13. The sound absorbing material 111 may be a porous sound absorbing material such as urethane foam, glass wool, or felt, or may be a resonator type sound absorbing material including a resonator with an opening formed in a cavity. The vibration isolating material 112 may be rubber, for example.

[0069] The underwater vehicle 1J of the ninth embodiment provides the same effects as those of the first embodiment. Furthermore, in the underwater vehicle 1J of the ninth embodiment, the sound absorbing material 111 and the vibration isolating material 112 absorb the sound generated in the propeller 3. This makes it possible to prevent the sound generated in the propeller 3 from being emitted to the outside of the vehicle body 2 from the inlet portion 11 and the outlet portion 12 of the annular flow path 10. Therefore, the underwater vehicle 1J can be made even quieter.

[0070] Tenth Embodiment Next, a tenth embodiment of the present disclosure will be described with reference to Fig. 13. In the following description, configurations common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0071] [First propeller, second propeller] As shown in Fig. 13, the underwater vehicle 1K of the tenth embodiment has the same components as the underwater vehicle 1 of the first embodiment. In Fig. 13, the drive source 5 and the electrical wiring 61 (see Fig. 1) connecting the drive unit 4 and the drive source 5 are omitted. The underwater vehicle 1K of the tenth embodiment is provided with two propellers 3 in the direction of the axis O. That is, the propellers 3 include a first propeller 3A and a second propeller 3B that are arranged in order from the inlet 11 side toward the outlet 12 side of the annular flow path 10. The rotation directions of the first propeller 3A and the second propeller 3B are opposite to each other. That is, the first propeller 3A and the second propeller 3B constitute contra-rotating propellers with opposite rotation directions.

[0072] [Drive unit] Similar to the first embodiment, the two drive units 4 that respectively rotate and drive these two propellers 3A, 3B are provided on the outer periphery of the aircraft body 22. Similar to the first embodiment, these two drive units 4 are motors that are rotated when supplied with electric power from a drive source 5 (see FIG. 1).

[0073] According to the underwater vehicle 1K of the tenth embodiment, the same effects as those of the first embodiment are achieved. Furthermore, in the underwater vehicle 1K of the tenth embodiment, the first propeller 3A and the second propeller 3B rotate in opposite directions. This allows the second propeller 3B to recover the swirling flow generated by the first propeller 3A. This reduces the swirling flow loss behind the second propeller 3B. This further improves the propulsion efficiency of the underwater vehicle 1K.

[0074] Eleventh Embodiment Next, an eleventh embodiment of the present disclosure will be described with reference to Fig. 14. In the following description, configurations common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0075] As shown in Fig. 14, the underwater vehicle 1L of the eleventh embodiment has a first propeller 3A and a second propeller 3B that rotate in opposite directions, similar to the underwater vehicle 1K of the tenth embodiment. Also, similar to the tenth embodiment, the underwater vehicle 1L of the eleventh embodiment has two drive units 4 (4A, 4B) that rotationally drive the two propellers 3A, 3B, respectively. Similar to the first embodiment, these two drive units 4A, 4B may be motors that are rotationally driven by power supplied from a drive source 5 (see Fig. 1).

[0076] [First drive unit, second drive unit] In the eleventh embodiment, of the two drive units 4A, 4B, the first drive unit 4A that rotationally drives the first propeller 3A is provided on the airframe outer periphery 22. On the other hand, of the two drive units 4A, 4B, the second drive unit 4B that rotationally drives the second propeller 3B is provided on the airframe inner periphery 21. The second drive unit 4B is connected to the second propeller 3B via a drive shaft 42 that extends rearward from the second drive unit 4B. The second drive unit 4B may be disposed, for example, on the airframe 2 forward of the airframe inner periphery 21.

[0077] According to the underwater vehicle 1L of the eleventh embodiment, the same effects as those of the tenth embodiment are achieved. Moreover, in the underwater vehicle 1L of the eleventh embodiment, the first drive unit 4A is provided on the vehicle body outer peripheral portion 22, and the second drive unit 4B is provided on the vehicle body inner peripheral portion 21. Therefore, compared to when both the first and second drive units 4A, 4B that drive the two propellers 3A, 3B are provided on the vehicle body outer peripheral portion 22, more space can be provided for installing the drive unit 4A (first drive unit 4A) on the vehicle body outer peripheral portion 22. In other words, the first and second drive units 4A, 4B can be easily installed on the vehicle body 2. Furthermore, since the drive unit provided on the outer periphery 22 of the aircraft is more expensive than the drive unit provided on the inner periphery 21 of the aircraft, by providing the second drive unit 4B on the inner periphery 21 of the aircraft, the manufacturing cost of the underwater vehicle 1L can be reduced.

[0078] In the eleventh embodiment, for example, a first drive unit 4A provided on the outer periphery 22 of the aircraft may drive the second propeller 3B to rotate, and a second drive unit 4B provided on the inner periphery 21 of the aircraft may drive the first propeller 3A to rotate.

[0079] The configurations of the underwater vehicles 1K, 1L of the tenth and eleventh embodiments may be applied to the second to ninth embodiments.

[0080] Twelfth Embodiment Next, a twelfth embodiment of the present disclosure will be described with reference to Fig. 15. In the following description, configurations common to those already described will be assigned the same reference numerals and duplicated description will be omitted.

[0081] [Propulsion unit, main unit] As shown in FIG. 15, the underwater vehicle 1M of the twelfth embodiment has the same components as those of the eleventh embodiment. However, in the twelfth embodiment, the aircraft body 2 is divided into a propulsion device section 27 and a main device section 28. The propulsion device section 27 includes an annular flow path 10, propellers 3 (3A, 3B), and drive sections 4 (4A, 4B). The propulsion device section 27 forms the rear portion (rear body section) of the aircraft body 2, i.e., includes an aircraft outer peripheral section 22 and an aircraft inner peripheral section 21. On the other hand, the main device section 28 includes the drive source 5. The main device section 28 constitutes the front part of the machine body 2 (machine body front part).

[0082] By coupling the propulsion device unit 27 and the main device unit 28, the drive unit 4 and the drive source 5 are connected. Specifically, a connection terminal 271 (front end connection terminal 271) connected to the drive unit 4 of the propulsion device unit 27 is provided at the front end of the propulsion device unit 27. The drive unit 4 and the front end connection terminal 271 are connected via electrical wiring 61, 64. Meanwhile, a connection terminal 281 (rear end connection terminal 281) connected to the drive source 5 of the main device unit 28 via electrical wiring 65 is provided at the rear end of the main device unit 28 opposite the front end of the propulsion device unit 27. Note that the drive source 5 and the rear end connection terminal 281 may be directly connected, for example. When the propulsion device unit 27 and the main device unit 28 are coupled, the front end connection terminal 271 and the rear end connection terminal 281 are connected, and the drive unit 4 and the drive source 5 are connected.

[0083] According to the underwater vehicle 1M of the twelfth embodiment, the same effects as those of the eleventh embodiment are achieved. Furthermore, in the underwater vehicle 1M of the twelfth embodiment, various types of underwater vehicles can be easily manufactured simply by combining multiple types of propulsion device units 27 with various characteristics with the same type of main device unit 28. The types of propulsion device units 27 include, for example, those that prioritize speed performance, those that prioritize turning performance, those that prioritize quietness, etc.

[0084] The underwater vehicle 1M of the twelfth embodiment may be applied to the tenth embodiment in which, for example, two drive units 4 for driving the two propellers 3A, 3B respectively are provided on the outer circumferential part 22 of the vehicle body.

[0085] The underwater vehicle 1M of the twelfth embodiment is also applicable to an underwater vehicle having, for example, one propeller 3, that is, it is also applicable to the first to ninth embodiments.

[0086] The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configurations are not limited to these embodiments and also include design changes and the like within the scope that does not deviate from the gist of the present disclosure.

[0087] <Additional Notes> The underwater vehicles 1, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, and 1M described in the above-described embodiments can be understood, for example, as follows.

[0088] (1) The underwater vehicle 1, 1C to 1M of the first aspect is an underwater vehicle 1, 1C to 1M comprising a body 2 having an outer peripheral surface 2a that is cylindrically shaped and centered on an axis O and extends continuously in the direction of the axis O, with an inlet portion 11 that opens around the entire circumference of the outer peripheral surface 2a in a portion of the direction of the axis O and an outlet portion 12 that opens at the rear end of the body 2, and in which an annular flow path 10 is formed that gradually reduces in diameter in at least a portion from the inlet portion 11 to the outlet portion 12, a propeller 3 that is provided in the annular flow path 10 and can rotate around the axis O, and a drive unit 4 that rotationally drives the propeller 3.

[0089] In the underwater vehicles 1, 1C to 1M configured as described above, the inlet 11 of the annular flow path 10 opens on the outer peripheral surface 2a of the vehicle body 2, which extends continuously in the direction of the axis O. As a result, when the underwater vehicle travels underwater, the boundary layer BL generated on the outer peripheral surface 2a of the vehicle body 2, forward of the inlet 11, is sucked into the annular flow path 10 from the inlet 11. This makes it possible to suppress the development of the boundary layer BL on the outer peripheral surface 2a of the vehicle body 2, rearward of the inlet 11. Furthermore, because the outer peripheral surface 2a of the vehicle body 2 extends continuously before and after the inlet 11, which corresponds to the direction of the axis O, water can flow smoothly at a high speed along the outer peripheral surface 2a of the vehicle body 2, rearward of the inlet 11. This improves the propulsion efficiency of the underwater vehicle.

[0090] Furthermore, in the underwater vehicles 1, 1C to 1M configured as described above, the propeller 3 is provided in an annular flow path 10 formed inside the body 2. This limits the direction in which sound (noise) generated by the propeller 3 is emitted outside the body 2. Specifically, the sound of the propeller 3 is limited to the inlet 11 and outlet 12 of the annular flow path 10. This allows the underwater vehicle 1 to be made quieter.

[0091] (2) The underwater vehicle 1, 1C to 1M according to the second aspect is the underwater vehicle 1, 1C to 1M described in (1) in which the drive unit 4 is provided on the outer periphery 22 of the vehicle body, which is the outer periphery of the annular flow path 10 in the vehicle body 2.

[0092] In the underwater vehicles 1, 1C to 1M configured as described above, the drive unit 4 that rotates the propeller 3 is provided on the outer circumferential body portion 22 located on the outer circumferential side of the annular flow path 10. This makes it possible to form the annular flow path 10 between the outer circumferential body portion 22 and the inner circumferential body portion 21 while preventing the diameter of the vehicle 2 from becoming larger, compared to when the drive unit 4 is provided on the inner circumferential body portion 21 located on the inner circumferential side of the annular flow path 10.

[0093] (3) The underwater vehicle 1C according to a third aspect is the underwater vehicle 1C described in (1) or (2) that includes a horizontal rudder 7 provided rearward of the inlet portion 11 on the outer peripheral surface 2a.

[0094] As described above, in the underwater vehicle 1C having the above configuration, the water flow velocity when the underwater vehicle 1C travels underwater is high on the rear side of the inlet portion 11 of the outer peripheral surface 2a where the horizontal rudder 7 is provided. In other words, the horizontal rudder 7 is provided in a part of the body 2 where the water velocity is high. This can improve the stability of the underwater vehicle 1C when it travels underwater.

[0095] (4) The underwater vehicle 1D according to a fourth aspect is the underwater vehicle 1D according to any one of (1) to (3), which is provided with a rudder 8 provided behind the propeller 3 in the annular flow path 10.

[0096] In the underwater vehicle 1D configured as described above, the rudder 8 is provided behind the propeller 3. Therefore, the rudder 8 changes the direction of the water flow accelerated by the propeller 3 in the annular flow path 10 (i.e., the water flow with a high flow velocity). This makes it possible to provide the underwater vehicle 1D with a greater deflection force.

[0097] (5) The underwater vehicle 1E according to the fifth aspect is an underwater vehicle 1E described in any one of (1) to (4) that is equipped with a variable nozzle 9 provided at the rear end of the body 2 where the outlet portion 12 opens.

[0098] In the underwater vehicle 1E configured as described above, a large deflection force can be obtained by the variable nozzle 9, and the underwater vehicle 1E can also be rapidly accelerated and decelerated.

[0099] (6) The underwater vehicle 1F, 1G according to the sixth aspect is an underwater vehicle 1F, 1G described in any one of (1) to (5), in which the propeller arrangement areas 14A, 13A, in which the propeller 3 is arranged, on the outer surface 14 and the inner surface 13 of the annular flow path 10 of the body 2, extend in a straight line in a cross section including the axis O.

[0100] In the underwater vehicles 1F, 1G configured as described above, the propeller 3 is provided in a linearly extending portion of the annular flow path 10. This allows the propeller 3 to accelerate the water passing through the annular flow path 10 with high efficiency. This further improves the propulsion efficiency of the underwater vehicles 1F, 1G.

[0101] (7) The underwater vehicle 1G of the seventh aspect is the underwater vehicle 1G described in (6) in which the propeller arrangement areas 14A, 13A extend in a straight line along the axis O in a cross section including the axis O, and the rear end areas 14G, 13G of the outer surface 14 and inner surface 13 of the annular flow path 10 in the body 2, which extend from the rear end of the propeller arrangement areas 14A, 13A to the outlet portion 12, also extend in a straight line along the axis O in a cross section including the axis O.

[0102] In the underwater vehicle 1G configured as described above, the water pressure-fed rearward by the propeller 3 flows out rearward from the outlet 12 of the annular flow path 10 parallel to the axis O of the vehicle body 2. As a result, the forward thrust obtained as a reaction force to the pressure-fed water by the propeller 3 is also parallel to the axis O. Therefore, the propulsion efficiency of the underwater vehicle can be further improved compared to when the water flows out rearward from the outlet 12 of the annular flow path 10 at an angle to the axis O of the vehicle body 2.

[0103] (8) The underwater vehicle 1H, 1I according to the eighth aspect is an underwater vehicle 1H, 1I described in any one of (1) to (6) in which the diameter dimension of the inner circumferential portion 21 of the vehicle body 2, which is the inner circumferential portion of the annular flow path 10, becomes smaller rearward of the propeller 3 as it approaches the outlet portion 12, and becomes zero at the outlet portion 12.

[0104] In the underwater vehicles 1H, 1I configured as described above, the outlet 12 of the annular flow path 10 is formed in a circular shape rather than an annular shape when viewed from the direction of the axis O. This suppresses or prevents the flow velocity distribution of the water flowing rearward from the outlet 12 of the annular flow path 10 from becoming doughnut-shaped, thereby reducing fluid mixing loss.

[0105] (9) The underwater vehicle 1I according to the ninth aspect is the underwater vehicle 1I described in (8) and equipped with a momentum imparting device 100 that is provided in a region of the inner surface 13 of the annular flow path 10 consisting of the inner circumferential portion 21 of the aircraft, rearward of the propeller 3, and that imparts momentum to the water on the inner surface 13 in a rearward direction along the inner surface 13.

[0106] In the underwater vehicle 1I configured as described above, the momentum imparting device 100 imparts rearward momentum along the inner peripheral surface 13 to the water flowing along the inner peripheral surface 13 of the annular flow path 10 behind the propeller 3. This makes it possible to prevent the rearward flow of water along the inner peripheral surface 13 from separating from the inner peripheral surface 13. This makes it possible to reduce fluid mixing loss.

[0107] (10) The underwater vehicle 1J according to the tenth aspect is an underwater vehicle 1J described in any one of (1) to (9) that is provided with sound-absorbing material 111 and / or vibration-proof material 112 provided on the inner surface of the annular flow path 10.

[0108] In the underwater vehicle 1J having the above configuration, the sound (noise) generated by the propeller 3 is absorbed by the sound absorbing material 111 and the vibration isolating material 112. This makes it possible to further reduce the noise of the underwater vehicle.

[0109] (11) The underwater vehicle 1K to 1M according to the eleventh aspect is an underwater vehicle 1K to 1M described in any one of (1) to (10), in which two propellers 3 (3A, 3B) are provided in the direction of the axis O, and the rotation directions of the two propellers 3A, 3B are opposite to each other.

[0110] In the underwater vehicles 1K to 1M configured as described above, contra-rotating propellers are configured in which the rotation directions of the two propellers 3A, 3B are opposite to each other. Therefore, the swirling flow generated by the upstream propeller 3A can be collected by the downstream propeller 3B. This reduces the swirling flow loss behind the downstream propeller 3B. This further improves the propulsion efficiency of the underwater vehicle.

[0111] (12) The underwater vehicle 1L, 1M according to the 12th aspect is the underwater vehicle 1L, 1M described in (11), in which a first drive unit 4A that rotates one of the propellers 3A of the drive unit 4 is provided on the outer periphery 22 of the body, which is the outer periphery of the annular flow path 10 in the body 2, and a second drive unit 4B that rotates the other propeller 3B of the drive unit 4 is provided on the inner periphery 21 of the body, which is the inner periphery of the annular flow path 10 in the body 2.

[0112] In the underwater vehicles 1L, 1M configured as described above, compared to when both the first and second drive units 4A, 4B that drive the two propellers 3A, 3B are provided on the vehicle outer periphery 22, more space can be provided for installing the drive unit 4A (first drive unit 4A) on the vehicle outer periphery 22. In other words, the first and second drive units 4A, 4B can be easily installed on the vehicle 2. In addition, since the drive unit provided on the outer periphery 22 of the aircraft is more expensive than the drive unit provided on the inner periphery 21 of the aircraft, by providing the second drive unit 4B on the inner periphery 21 of the aircraft, the manufacturing costs of the underwater vehicle can be reduced.

[0113] (13) The underwater vehicle 1M according to the thirteenth aspect is an underwater vehicle 1M described in any one of (1) to (12), in which the body 2 is divided into a propulsion unit 27 including the annular flow path 10, the propeller 3, and the drive unit 4, and a main unit 28 including a drive source 5 that supplies driving force to at least the drive unit 4 and is coupled to the propulsion unit 27 to connect the drive unit 4 and the drive source 5.

[0114] In the underwater vehicle 1M configured as described above, various types of underwater vehicles can be easily manufactured simply by connecting a plurality of types of propulsion device units 27 having various characteristics to the same type of main device unit 28. [Explanation of symbols]

[0115] 1, 1C, 1D, 1E, 1F, 1G, 1H, 1I, 1J, 1K, 1L, 1M...underwater vehicle, 2...airframe, 2a...outer surface, 2b...rear end surface, 3...propeller, 3A...first propeller, 3B...second propeller, 4...drive unit, 4A...first drive unit, 4B...second drive unit, 5...drive source, 7...horizontal rudder, 8...rudder, 9...variable nozzle, 10...annular flow path, 11...inlet portion, 11A...front end, 11B...rear end, 12...outlet portion, 13...inner surface, 13A...second propeller arrangement region (propeller arrangement region), 13B...second adjacent region (adjacent region), 13G...second aft end region (rear end region), 14...outer surface, 14A...first propeller arrangement region (propeller arrangement area), 14B...first adjacent area (adjacent area), 14G...first aft end area (aft end area), 20...airframe body, 21...airframe inner periphery, 22...airframe outer periphery, 23...forward strut, 24...aft strut, 24A...forward portion, 24B...aft portion, 27...propulsion unit, 28...main unit, 31...blades, 42...drive shaft, 61, 62, 63, 64, 65...electrical wiring, 80...rudder drive unit, 90...nozzle drive unit, 91...panel, 92...drive shaft, 100...momentum imparting device, 101...roller, 111...sound absorbing material, 112...vibration damping material, 271...forward end connecting terminal, 281...aft end connecting terminal, BL...boundary layer, O...axis

Claims

1. a fuselage having an outer peripheral surface that is cylindrically shaped about an axis and extends continuously in the axial direction, the outer peripheral surface having an inlet portion that opens over the entire circumference at a portion in the axial direction of the outer peripheral surface, and an outlet portion that opens at the rear end of the fuselage, the inlet portion having an annular flow path that gradually reduces in diameter at least in a portion from the inlet portion to the outlet portion; a propeller provided in the annular flow path and rotatable about the axis; a drive unit that drives the propeller to rotate; Equipped with a diameter dimension of an inner circumferential portion of the airframe, which is an inner circumferential portion of the annular flow path in the airframe, decreases toward the outlet portion rearward of the propeller and becomes zero at the outlet portion; The underwater vehicle further comprises a momentum imparting device that is provided in a region of the inner surface of the annular flow path that is formed by the inner circumferential portion of the aircraft, rearward of the propeller, and that imparts momentum to water on the inner surface in a rearward direction along the inner surface.

2. The underwater vehicle according to claim 1 , wherein the drive unit is provided on an outer periphery of the vehicle, which is a portion of the vehicle on the outer periphery of the annular flow path.

3. 3. The underwater vehicle according to claim 1, further comprising a horizontal rudder provided on the outer circumferential surface rearward of the inlet portion.

4. 3. The underwater vehicle according to claim 1, further comprising a rudder provided rearward of the propeller in the annular flow path.

5. 3. The underwater vehicle according to claim 1, further comprising a variable nozzle provided at a rear end of the vehicle body where the outlet portion opens.

6. 3. The underwater vehicle according to claim 1, wherein a propeller arrangement area in which the propeller is arranged on an outer peripheral surface and an inner peripheral surface of the annular flow path in the aircraft body extends linearly in a cross section including the axis.

7. The propeller arrangement region extends linearly along the axis in a cross section including the axis, 7. The underwater vehicle according to claim 6, wherein the rear end regions of the outer and inner surfaces of the annular flow path in the aircraft body, from the rear end of the propeller arrangement area to the outlet portion, also extend linearly along the axis in a cross section including the axis.

8. 3. The underwater vehicle according to claim 1, further comprising a sound absorbing material and / or a vibration isolating material provided on the inner surface of the annular flow path.

9. Two propellers are provided in the axial direction, 3. The underwater vehicle according to claim 1 or 2, wherein the two propellers rotate in opposite directions.

10. a first drive unit that rotationally drives one of the propellers of the drive units is provided on an outer periphery of the airframe that is an outer periphery of the annular flow path in the airframe, The underwater vehicle according to claim 9 , wherein a second drive unit that rotationally drives the other of the drive units is provided on an inner circumferential portion of the vehicle body that is an inner circumferential portion of the annular flow path.

11. 3. The underwater vehicle according to claim 1 or 2, wherein the airframe is divided into a propulsion device section including the annular flow path, the propeller, and the drive section, and a main device section including a drive source that supplies drive force to at least the drive section, and which is coupled to the propulsion device section to connect the drive section and the drive source.

Images