Water flow generator and side thruster for vessel

Abstract

To provide a water flow generator for suppressing an occurrence of blade tip vortex cavitation.SOLUTION: A water flow generator 1 is a device for generating a water flow underwater. The water flow generator 1 includes a duct 2, a propeller 5, and a blade tip plate 6. The duct 2 conducts water in the direction of a shaft 3. The propeller 5 generates a water flow in the direction of the shaft 3 inside the duct 2. The blade tip plate 6 is provided on a tip 54 of the blade 50 of the propeller 5. The blade tip plate 6 projects from the tip 54 of the blade 50 to both of one side and the other side in the direction of the shaft 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a water current generating device and a marine side thruster. [Background technology]

[0002] A water current generating device typically includes a duct and a propeller disposed within the duct. The propeller rotates around the axis of the duct. Patent Document 1 describes a propeller having blade end plates at the tips of the blades. The blade end plates protrude from the blades in one direction (one axial direction). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-26186 Summary of the Invention [Problem to be solved by the invention]

[0004] The propeller described in Patent Document 1 uses blade end plates to somewhat suppress the occurrence of tip vortex cavitation. However, when the propeller described in Patent Document 1 is placed in a duct as a water flow generating device, the occurrence of tip vortex cavitation must be further sufficiently suppressed. This is because tip vortex cavitation in a duct can cause problems, such as damage to the inner surface of the duct, noise generation, and a reduction in the amount of water flow generated.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to provide a water flow generating device and a marine side thruster that can sufficiently suppress the occurrence of tip vortex cavitation. [Means for solving the problem]

[0006] A water flow generating device according to one aspect of the present invention includes a duct, a propeller, and a blade end plate. The duct guides water in an axial direction. The propeller generates a water flow in the axial direction within the duct. The blade end plate is provided at the tip of the propeller blade. The blade end plate protrudes from the tip of the blade on both sides in the axial direction.

[0007] A marine side thruster according to another aspect of the present invention generates a water current in the width direction of the hull. The marine side thruster includes the water current generating device according to one aspect of the present invention. The water current generating device is arranged so that its axial direction is in the width direction of the hull. [Effects of the Invention]

[0008] According to the water flow generating device and marine side thruster of the present invention, the occurrence of tip vortex cavitation can be sufficiently suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a water jet generating device according to a first embodiment. [Figure 2] 1 is a vertical cross-sectional view of a water jet generating device according to a first embodiment. [Figure 3] 3 is an enlarged cross-sectional view of the duct and the upper half of the propeller taken along line III-III of FIG. 2. FIG. [Figure 4] FIG. 10 is a perspective view of a water jet generating device according to a second embodiment. [Figure 5] FIG. 10 is a vertical cross-sectional view of a water jet generating device according to a second embodiment. [Figure 6] FIG. 10 is a schematic perspective view of a marine side thruster according to a third embodiment. [Figure 7] FIG. 10 is a vertical cross-sectional view showing details of a marine side thruster according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and description thereof will not be repeated.

[0011] In the following description, terms indicating specific positions and directions, such as "upper," "lower," "front," "rear," "left," and "right," may be used. However, these terms are used for convenience to facilitate understanding of the contents of the embodiments, and have no relation to the directions in which the embodiments are actually implemented. <Embodiment 1>

[0012] The water jet generating device 1 according to the first embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a perspective view of the water jet generating device 1 according to the first embodiment. Fig. 2 is a vertical cross-sectional view of the water jet generating device 1 according to the first embodiment.

[0013] As shown in Figures 1 and 2, the water current generating device 1 is a device that generates a water current in water. The water current generating device 1 is used, for example, in water jets and marine side thrusters. The water current generating device 1 includes a duct 2, a propeller 5, and a blade end plate 6.

[0014] The duct 2 guides water in the axial direction 3. The propeller 5 generates a water flow in the duct 2 in the axial direction 3. The blade end plate 6 is provided at the tip 54 of the blade 50 of the propeller 5. The blade end plate 6 protrudes from the tip 54 of the blade 50 to both one side and the other side in the axial direction 3. In other words, the blade end plate 6 protrudes in both directions from the tip 54 of the blade 50.

[0015] The blade end plates 6 protruding in both directions sufficiently suppress the occurrence of tip vortex cavitation in the propeller 5 compared to conventional blade end plates protruding in one direction. As a result, the water flow generating device 1 has the effects of suppressing damage to the inner surface 4 of the duct 2, reducing noise, and increasing the amount of water flow generated. Furthermore, the blade end plates 6 protruding in both directions can achieve the above-mentioned effects even when the rotation of the propeller 5 is reversed.

[0016] The axis 3 of the duct 2 is a line that coincides with the center of gravity of the cross section of the duct 2. In order to enhance the above-mentioned effects, it is preferable that the axis 3 of the duct 2 coincides with the axis of the propeller 5 (the duct 2 and the propeller 5 are coaxial).

[0017] The propeller 5 is not limited to the three blades shown in Figures 1 and 2, and may have other numbers of blades 50. To enhance the above-mentioned effects, the propeller 5 preferably has three or four blades, and most preferably has three blades.

[0018] The wing tip plates 6 protruding in both directions may be provided on the tips 54 of all of the wings 50, or on the tips 54 of any of the wings 50. In order to enhance the above-mentioned effect, it is preferable that the wing tip plates 6 protruding in both directions be provided on the tips 54 of all of the wings 50.

[0019] 2, the width of the wing tip plate 6 may be any width as long as it protrudes in both directions from the tip 54 of the wing 50. To enhance the above-mentioned effect, it is preferable that the width of the wing tip plate 6 protruding on one side is the same as the width of the wing tip plate 6 protruding on the other side.

[0020] The position and range where the blade end plate 6 is provided will be described in detail below with reference to Fig. 3. Fig. 3 is an enlarged cross-sectional view of the duct 2 and the upper half of the propeller 5 taken along the line III-III in Fig. 2.

[0021] 3, the propeller 5 has a rotating cylinder 7 in addition to the blades 50. The rotating cylinder 7 rotates the blades 50.

[0022] The blades 50 of the propeller 5 have a connecting portion 51, a leading edge 52, a trailing edge 53, and a tip 54. The connecting portion 51 is connected to the outer peripheral surface of the rotating barrel 7 of the propeller 5. The leading edge 52 and the trailing edge 53 extend from the rotating barrel 7 toward the duct 2. The leading edge 52 is the edge on the side that cuts through the water as the rotating barrel 7 rotates. The trailing edge 53 is the edge on the side that releases the water as the rotating barrel 7 rotates. The tip 54 is continuous with the leading edge 52 and the trailing edge 53.

[0023] The wing tip plate 6 is provided at any position and in any range of the tip 54 of the wing 50. The wing tip plate 6 does not have to extend over the entire range of the tip 54 of the wing 50, and may extend beyond the entire range of the tip 54 of the wing 50 to the leading edge 52 and the trailing edge 53. In order to enhance the above-mentioned effects, it is preferable that the wing tip plate 6 be provided over the entire range of the tip 54 of the wing 50.

[0024] The surface (outer peripheral surface 60) of the blade end plate 6 facing the duct 2 is aligned with the inner peripheral surface 4 of the duct 2. In other words, the outer peripheral surface 60 of the blade end plate 6 and the inner peripheral surface 4 of the duct 2 are equidistant from each other.

[0025] By providing an equal distance between the outer peripheral surface 60 of the blade end plate 6 and the inner peripheral surface 4 of the duct 2, the above-mentioned effect can be enhanced.

[0026] The distance between the outer peripheral surface 60 of the blade tip plate 6 and the inner peripheral surface 4 of the duct 2 can be set arbitrarily, but is preferably 3 mm or more and 5 mm or less. This is because, when the distance between the outer peripheral surface 60 of the blade tip plate 6 and the inner peripheral surface 4 of the duct 2 is 3 mm or more, high manufacturing precision is not required for the water flow generating device 1. Also, the smaller the distance between the outer peripheral surface 60 of the blade tip plate 6 and the inner peripheral surface 4 of the duct 2, the more enhanced the above-mentioned effect is. <Embodiment 2>

[0027] The water jet generating device 1 according to the second embodiment will be described below with reference to Fig. 4 and Fig. 5. Fig. 4 is a perspective view of the water jet generating device 1 according to the second embodiment. Fig. 5 is a vertical cross-sectional view of the water jet generating device 1 according to the second embodiment.

[0028] As shown in FIGS. 4 and 5, the water jet generating device 1 according to the second embodiment includes two propellers 5 and two blade end plates 6 according to the first embodiment in the duct 2 according to the first embodiment.

[0029] Specifically, the propeller 5 of the water flow generating device 1 according to the second embodiment has a first propeller 15 and a second propeller 25. The first propeller 15 is disposed at one end of the duct 2 in the axial direction 3. The second propeller 25 is disposed at the other end of the duct 2 in the axial direction 3.

[0030] The blade end plate 6 according to the second embodiment has a first blade end plate 16 and a second blade end plate 26. The first blade end plate 16 is provided at the tip 54 of the blade 50 of the first propeller 15. The second blade end plate 26 is provided at the tip 54 of the blade 50 of the second propeller 25.

[0031] The first blade end plate 16 and the second blade end plate 26 protrude from the tips 54 of the blades 50 of the first propeller 15 and the second propeller 25 on both sides in the direction of axis 3. That is, the first blade end plate 16 protrudes in both directions from the tips 54 of the blades 50 of the first propeller 15. The second blade end plate 26 protrudes in both directions from the tips 54 of the blades 50 of the second propeller 25.

[0032] The water flow generating device 1 is equipped with a first propeller 15 and a second propeller 25 each provided with a first blade end plate 16 and a second blade end plate 26, and therefore can further enhance the above-mentioned effects compared to when there is only one propeller 5.

[0033] The first propeller 15 has a first rotating cylindrical body 17 which is the rotating cylindrical body 7 to which the blades 50 are connected. The second propeller 25 has a second rotating cylindrical body 27 which is the rotating cylindrical body 7 to which the blades 50 are connected. <Embodiment 3>

[0034] The marine side thruster 30 according to the third embodiment will be outlined below with reference to Fig. 6. Fig. 6 is a schematic perspective view of the marine side thruster 30 according to the third embodiment.

[0035] As shown in Fig. 6, a marine side thruster 30 according to the third embodiment is provided on a hull S and includes the water jet generating device 1 according to the second embodiment. The water jet generating device 1 is disposed so that the direction of its axis 3 is in the width direction of the hull.

[0036] The marine side thruster 30 has the aforementioned effects because the axis 3 of the water current generating device 1 is disposed in the hull width direction. That is, the marine side thruster 30 sufficiently suppresses tip vortex cavitation of the propeller 5 compared to conventional products in which the blade end plates of the propeller 5 protrude in only one direction. As a result, the marine side thruster 30 has the effects of suppressing damage to the inner surface 4 of the duct 2, reducing noise, and increasing the amount of water current generated. Furthermore, because the blade end plates 6 protrude in both directions, the aforementioned effects can be achieved even when the rotation of the propeller 5 is reversed.

[0037] Next, details of the marine side thruster 30 according to the third embodiment will be described with reference to Fig. 7. Fig. 7 is a vertical cross-sectional view showing details of the marine side thruster 30 according to the third embodiment.

[0038] As shown in FIG. 7, the marine side thruster 30 includes a duct 2, a first propeller 15, a second propeller 25, a first end plate 16, and a second end plate .

[0039] The duct 2 guides water in the direction of axis 3, which is the width direction of the hull. That is, the direction in which the duct 2 guides water is from port to starboard and from starboard to port. From the viewpoint of enhancing the above-mentioned effects of the marine side thruster 30, the inner diameter of the duct 2 is preferably any size between 150 mm and 3000 mm, more preferably any size between 200 mm and 1500 mm, and most preferably any size between 250 mm and 500 mm.

[0040] The first propeller 15 and the second propeller 25 are identical except that the first rotating cylinder 17 and the second rotating cylinder 27 are oriented in opposite directions. The first rotating cylinder 17 and the second rotating cylinder 27 are coaxial with the duct 2. The first propeller 15 and the second propeller 25 rotate in the same direction, generating a water current in the direction of axis 3.

[0041] The first blade end plate 16 and the second blade end plate 26 protrude by the same width on both sides in the direction of axis 3 from the tips 54 of the blades 50 of the first propeller 15 and the second propeller 25, respectively. In other words, the first blade end plate 16 and the second blade end plate 26 protrude by the same width in both directions from the tips 54 of the blades 50 of the first propeller 15 and the second propeller 25, respectively.

[0042] The marine side thruster 30 further includes a pair of propeller covers 38, a hydraulic motor 31, a vertical drive unit 32, and a horizontal drive unit 34.

[0043] The pair of propeller covers 38 are arranged at an opening on one end side and an opening on the other end side within the duct 2. Of the pair of propeller covers 38, one propeller cover 38 is located closer to the one end side than the first propeller 15, and the other propeller cover 38 is located closer to the other end side than the second propeller 25.

[0044] The hydraulic motor 31 is driven by hydraulic pressure. The hydraulic motor 31 is connected to hydraulic piping (not shown). The driving direction of the hydraulic motor 31 can be reversed by reversing the direction of the hydraulic pressure supplied from the hydraulic piping.

[0045] The vertical drive unit 32 rotates a built-in vertical shaft 33 by transmitting power from the driven hydraulic motor 31 .

[0046] The horizontal drive unit 34 rotates a built-in horizontal shaft 37 by receiving power from the vertical drive unit 32. The horizontal shaft 37 is coaxially connected to the first rotating cylinder 17 and the second rotating cylinder 27. Therefore, the horizontal drive unit 34 rotates the first rotating cylinder 17 and the second rotating cylinder 27 in the same direction.

[0047] The blades 50, which rotate together with the first rotating cylindrical body 17 and the second rotating cylindrical body 27, create areas of low water pressure. Areas of low water pressure can generate water currents, but they can also potentially generate tip vortex cavitation. In response to this, the first blade end plate 16 and the second blade end plate 26 adequately suppress the occurrence of tip vortex cavitation. Sufficiently suppressing the occurrence of tip vortex cavitation also eliminates problems caused by tip vortex cavitation. Problems caused by tip vortex cavitation include damage to the inner surface 4 of the duct 2, noise generation, and a reduction in the amount of water current generated. Therefore, the marine side thruster 30 can achieve the effects described above.

[0048] Like conventional marine side thrusters, the marine side thruster 30 can reverse the direction of the water flow by reversing the direction of the hydraulic pressure supplied to the hydraulic motor 31. That is, the marine side thruster 30 can generate a water flow from port to starboard, or from starboard to port. Here, because the first wing end plate 16 and the second wing end plate 26 protrude in both directions (toward port and starboard) from the tip 54 of the wing 50, the marine side thruster 30 can achieve the above-mentioned effects regardless of the direction of the water flow.

[0049] Above, Embodiments 1 to 3 of the present invention have been described with reference to the drawings. However, Embodiments 1 to 3 are illustrative in all respects and are not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims. Of the configurations described in the embodiments, those other than those described as the invention of the first aspect in "Means for Solving the Problem" are optional configurations and can be deleted or modified as appropriate.

[0050] Incidentally, the marine side thruster 30 according to the third embodiment has been described as including the water current generating device 1 according to the second embodiment, but it may also be one including the water current generating device 1 according to the first embodiment.

[0051] Furthermore, in the marine side thruster 30 according to the third embodiment, the first propeller 15 and the second propeller 25 are described as being identical, but the first propeller 15 and the second propeller 25 may have a contra-rotating structure. The first propeller 15 and the second propeller 25 have blades 50 with an opposite twist to each other. Because the first propeller 15 and the second propeller 25 have a contra-rotating structure, they are coaxially driven in opposite rotations to each other, generating water currents in the same direction. This enhances the effects described above.

[0052] Furthermore, although not described in detail in the third embodiment, as shown in Fig. 7, the duct 2 may have a central bottom upper portion 20 on the inner circumferential surface 4. The central bottom upper portion 20 is a raised portion at the bottom of the inner circumferential surface 4, between the first propeller 15 and the second propeller 25. The marine side thruster 30 can further enhance the above-mentioned effects due to the synergistic effect of the central bottom upper portion 20 and the first and second end plates 16 and 26 that protrude in both directions. [Industrial Applicability]

[0053] The present invention provides a water current generating device and a marine side thruster, and has industrial applicability. [Explanation of symbols]

[0054] 1. Water flow generator 2 ducts 3-axis 4 Inner surface 5 propellers 6 Wingtip 15 No. 1 Propeller 16 First wing end plate 25 No. 2 propeller 26 Second wing end plate 30 Marine side thruster 50 wings 54 Tip

Claims

1. a duct for guiding water in an axial direction; a propeller that generates a water flow in the duct in the axial direction; a blade tip provided at the tip of the propeller blade; Equipped with The water flow generating device, wherein the blade end plate protrudes from the tip of the blade to both one side and the other side in the axial direction.

2. The water flow generating device according to claim 1 , wherein the surface of the blade end plate facing the duct is aligned along the inner circumferential surface of the duct.

3. The propeller is a first propeller disposed at one end in the duct in the axial direction; a second propeller disposed at the other end of the duct in the axial direction; and The wing tip plate is a first blade end plate provided at the tip of a blade of the first propeller; a second blade end plate provided at the tip of the blade of the second propeller; and 3. The water flow generating device according to claim 1, wherein the first blade end plate and the second blade end plate protrude from the blade tips of the first propeller and the blade tips of the second propeller to both one side and the other side in the axial direction.

4. A marine side thruster that generates a water flow in the width direction of a hull, The water jet generating device according to claim 1 or 2 is provided, The water current generating device is disposed so that the axial direction is in the width direction of the hull.

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