JP2015074434A - Propulsion unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propulsion unit which includes a rudder plate with a valve and sufficiently improves the propulsion efficiency of a ship with an easy structure.SOLUTION: A propulsion unit 1 includes: a rudder plate 21 which is provided at the rear side of a propeller 11 so as to steer a hull; a valve 22 which is provided at the rudder plate facing a propeller boss; and a cover member 12 which is provided at the propeller boss 14 and covers a front end surface of the valve 22 expanding a diameter toward the rear side of the propeller. The cover member is curved into a dome shape so as to form a substantially fusiform surface with the valve.

Description

  The present invention relates to a propulsion device including a steering plate with a valve that improves the propulsion efficiency of a ship.

  As a propeller propulsion type propulsion device, in order to improve the propulsion efficiency of a ship, a propeller rear rudder plate provided with a substantially spindle-shaped valve (ladder valve) is known (for example, see Patent Document 1). . The valve described in Patent Document 1 is located on the axis of the propeller boss, and the inflow speed of water to the propeller is delayed by a substantially spindle-shaped bulge so that a large amount of water is guided to the blade surface. . Further, the valve reduces the vortex resistance by weakening the boss vortex by rectifying the boss vortex generated by the propeller boss along the surface of the valve.

  Further, as a propulsion device using a valve, there is known a device that fills a gap between a propeller and a valve provided on a steering plate in order to further improve the propulsion efficiency of a ship (see Patent Document 2). In the propulsion device described in Patent Document 2, a propeller nut that prevents the propeller from coming off is provided at the rear end of the propeller labs, and a gap between the propeller and the valve is filled with a propeller cap that covers the propeller nut. The propeller cap has a tapered surface that expands toward the rear, and the propelling efficiency is improved by delaying the flow flowing into the propeller by the increased tapered surface.

JP-A-5-39090 Japanese Patent No. 5162449

  However, in the valve described in Patent Document 1, the flow speed can be suppressed by receiving the wake of the propeller due to the substantially spindle-shaped bulge, but there is a limit to the improvement of propulsion efficiency because the valve is separated from the propeller. . On the other hand, the propeller cap described in Patent Document 2 can receive the wake of the propeller at a position close to the propeller, but the flow velocity cannot be sufficiently delayed on the tapered outer peripheral surface of the propeller cap. It has been difficult to improve the propulsion efficiency.

  This invention is made | formed in view of this point, and it aims at providing the propulsion apparatus which can fully improve the propulsion efficiency of a ship with a simple structure.

  The propulsion device of the present invention is a propulsion device for propelling a hull by a propeller provided with a plurality of blades on the outer periphery of the propeller, a rudder plate provided so as to be steerable with respect to the hull behind the propeller, A valve provided on the rudder so as to face the propeller boss, and a diameter increasing member that covers the front end surface of the valve by increasing the diameter toward the rear of the propeller. And a curved surface so as to form a substantially spindle-shaped surface.

  According to this configuration, since the wake of the propeller is received by the curved surface of the diameter-expanding member at a position close to the propeller, the inflow speed of water to the propeller can be delayed. Therefore, the propulsion efficiency of the ship can be sufficiently improved by a simple configuration in which the diameter-expanding member is provided.

  In the propulsion device of the present invention, the diameter-expanding member extends to the vicinity of the front edge of the rudder plate, and the front end surface of the valve is positioned near the front edge of the rudder plate. According to this configuration, since the rudder shaft is brought close to the front end surface of the valve, even if the rudder angle of the rudder plate is increased, the streamline formed by the enlarged member and the valve is not easily broken. Therefore, it becomes difficult for the water flow to separate at the boundary between the diameter-expanding member and the valve at the time of steering, and the resistance due to the flow separation can be reduced to suppress the reduction in propulsion efficiency.

  Moreover, the said propulsion apparatus of this invention WHEREIN: The said diameter expansion member is a propeller cap which covers the propeller nut which prevents the said propeller from falling out. According to this configuration, by using the propeller cap as the diameter-expanding member, it is not necessary to provide the diameter-expanding member separately from the propeller cap, and the number of parts can be reduced.

  Further, in the propulsion device according to the present invention, a propeller nut for preventing the propeller from being removed is covered with a propeller cap, and the diameter-expanding member is a cover member provided in the propeller boss so as to cover the propeller cap. is there. According to this configuration, since the propeller nut can be covered using the existing propeller cap, it is not necessary to newly design the propeller cap.

  In the propulsion device of the present invention, the diameter-expanding member is formed of FRP (Fiber Reinforced Plastics). According to this configuration, it is not necessary to use a welded structure unlike the configuration in which the diameter-expanding member is formed of a metal material, manufacturing costs can be reduced, and further weight reduction can be achieved.

  According to the present invention, it is possible to sufficiently improve the propulsion efficiency of the ship with a simple configuration by bending the diameter-expanding member provided in the propeller boss so as to form a substantially spindle-shaped surface together with the valve. it can.

It is a side view of the propulsion device concerning this embodiment. It is a partial section schematic diagram of the propulsion device concerning this embodiment. It is explanatory drawing at the time of steering of the propulsion device concerning this embodiment. It is a figure which shows the modification of the propulsion apparatus which concerns on this Embodiment.

  The propulsion device according to the present embodiment will be described below with reference to the accompanying drawings. FIG. 1 is a side view of the propulsion device according to the present embodiment. FIG. 2 is a partial cross-sectional schematic view of the propulsion device according to the present embodiment. In the following description, an example in which a cover member that covers a propeller cap as a diameter-expanding member is provided on the propeller is shown, but the present invention is not limited to this example.

  As shown in FIGS. 1 and 2, the propulsion device 1 propels the hull with a propeller 11 provided at the stern portion 2, and the hull is steered by a rudder plate 21 provided behind the propeller 11. It is configured. Further, the propulsion device 1 forms a so-called ladder valve by forming a substantially spindle-shaped curved surface behind the propeller 11 by the cover member 12 provided on the propeller 11 and the valve 22 provided on the steering plate 21. The hull propulsion efficiency is improved. The stern portion 2 of the hull is formed with a boss swelled rearward, and a propeller 11 is rotatably supported at the tip of the bossing 3 via a propeller shaft 13.

  The propeller 11 is formed by projecting a plurality (four in the present embodiment) of blades 15 on the outer periphery of a propeller boss 14 attached to the propeller shaft 13. The propeller shaft 13 is press-fitted into the shaft hole of the propeller boss 14, and the propeller boss 14 and the propeller shaft 13 are configured to be integrally rotatable. Each blade 15 is twisted so as to be inclined from the front edge to the rear edge in the rotation direction, and a relative driving force is generated between the blade 15 and the fluid by the rotational movement of the propeller 11. A propeller nut 16 is attached to the rear part of the propeller boss 14, and the propeller 11 is prevented from coming off from the propeller shaft 13.

  The propeller nut 16 is covered with a cylindrical propeller cap 17. A dome-shaped cover member 12 is provided at the rear portion of the propeller boss 14 so as to cover the propeller cap 17. The cover member 12 is formed of FRP (Fiber Reinforced Plastics), which is reduced in weight and has sufficient strength. The cover member 12 is formed to expand toward the rear of the propeller 11 and cover the front end face 25 of the valve 22 of the steering plate 21. Thus, the cover member 12 functions as the front side of the ladder valve, and receives the wake of the propeller 11 at the dome-shaped curved surface at a position close to the propeller 11. Thereby, the inflow speed of the water with respect to the propeller 11 is delayed, and the propulsion efficiency of the ship is improved.

  The rudder plate 21 is provided so as to be steerable with respect to the hull around the rudder shaft 23 extending in the vertical direction behind the propeller 11. The steering plate 21 is provided with a valve 22 having a circular shape in front view and a teardrop shape in side view so as to face the propeller boss 14 coaxially. The valve 22 protrudes from the front edge 24 of the rudder plate 21 toward the propeller 11, and the front end face 25 enters the inside of the cover member 12. Thus, the valve 22 functions as the rear side of the ladder valve, and is narrowed so that the wake of the propeller 11 flows smoothly along the outer surface of the valve 22.

  In the propulsion device 1 configured as described above, the wake generated by the rotation of the propeller 11 is received by the curved surface of the dome-shaped cover member 12 provided on the propeller cap 17, and is applied to the curved surface of the cover member 12. Rectified along. For this reason, the flow which flows into the propeller 11 becomes slow, and the propulsion efficiency is raised. Further, since the substantially spindle-shaped surface is formed by the cover member 12 and the valve 22, a stream line along the curved surface of the cover member 12 is formed to the rear of the valve 22. For this reason, generation | occurrence | production of a turbulent flow is suppressed and resistance becomes small.

  Further, since the propeller cap 17 is covered with the cover member 12, it is not necessary to form the propeller cap 17 in a dome shape. That is, the propeller cap 17 can be formed in a cylindrical shape so as to have a straight outer peripheral surface. For this reason, it is not necessary to make the propeller cap 17 into a two-piece structure or to increase the thickness, and it is possible to form the propeller cap 17 with a copper alloy as usual, and to reduce the cost.

  Further, since the cover member 12 is formed by FRP, it is not necessary to have a two-piece structure as in the case of being formed of a metal material such as a copper alloy, and the thickness of each member is increased in order to ensure strength. It is not necessary to have it. Therefore, the manufacturing cost of the cover member 12 is reduced and the weight is reduced. The diameter of the cover member 12 is preferably designed to be 1.0 to 2.5 times the boss diameter of the propeller boss 14 because the resistance becomes propulsive and the propulsion efficiency decreases when the cover member 12 is too large. It is preferable to be designed to be 1 to 2.0 times.

  Furthermore, since the cover member 12 constitutes the front side of the ladder valve, the protruding length of the valve 22 from the front edge 24 of the rudder plate 21 can be shortened. As a result, the distance between the front end face 25 of the valve 22 and the rudder shaft 23 is shortened, so that even if the rudder plate 21 is steered and the valve 22 is turned, the streamline formed by the cover member 12 and the valve 22 is reduced. It is hard to collapse.

  Hereinafter, the streamline collapse at the time of steering of the propulsion device will be described with reference to FIG. 3. FIG. 3 is an explanatory diagram during steering of the propulsion device according to the present embodiment. 3A and 3B show streamlines during steering of the propulsion device 9 according to the comparative example, and FIGS. 3C and 3D show streamlines during steering of the propulsion device 1 according to the present embodiment.

  As shown in FIG. 3A, in the propulsion device 9 according to the comparative example, the valve 42 protrudes larger than the front edge 44 of the rudder plate 41 as compared with the propulsion device 1 according to the present embodiment. The front end face 45 is brought close to the propeller 31. The cover member 32 extends to the front end surface 45 of the valve 42, and is formed to be shorter by an amount corresponding to the protrusion of the valve 42 on the axis of the propeller 31. Thus, in the propulsion device 9 according to the comparative example, the front end face 45 of the valve 42 is greatly separated from the rudder shaft 43. Therefore, when the rudder plate 41 is steered around the rudder shaft 43, the amount of movement of the front end face 45 of the valve 42 increases.

  When the rudder angle of the rudder plate 41 is sufficiently small, there is no large deviation between the center of the valve 42 and the center of the cover member 32, and the streamline is maintained by the valve 42 and the cover member 32. Therefore, the wake of the propeller 31 does not peel off at the boundary portion between the cover member 32 and the valve 42, and the rudder resistance does not increase. As shown in FIG. 3B, when the rudder angle reaches a predetermined angle Θ, the front end surface 45 of the valve 42 pivots greatly by the distance between the rudder shaft 43 and the front end surface 45 of the valve 42, and the center of the valve 42 and the cover are covered. A large deviation C1 occurs in the center of the member 32. The outer surface of the cover member 32 and the outer surface of the valve 42 are discontinuous, and the streamline between the valve 42 and the cover member 32 is broken. For this reason, the wake of the propeller 31 is separated at the boundary portion between the cover member 32 and the valve 42, and the lift is reduced and the rudder resistance is increased.

  On the other hand, as shown in FIG. 3C, in the propulsion device 1 according to the present embodiment, the valve 22 protrudes slightly from the front edge 24 of the steering plate 21 as compared with the propulsion device 9 according to the comparative example. The front end face 25 is brought close to the front edge 24 of the rudder plate 21. The cover member 12 extends to the front end face 25 of the valve 22, and the protrusion length of the valve 22 is formed to be shorter by the length of the cover member 12 formed on the axis of the propeller 11. Thus, in the propulsion device 1 according to the present embodiment, the front end face 25 of the valve 22 is brought closer to the rudder shaft 23 than the propulsion device 9 according to the comparative example. Therefore, even if the rudder plate 21 is steered around the rudder shaft 23, the front end face 25 of the valve 22 is not moved greatly.

  When the rudder angle of the rudder plate 21 is sufficiently small, there is no large deviation between the center of the valve 22 and the center of the cover member 12, and the streamline is maintained by the valve 22 and the cover member 12. Therefore, the wake of the propeller 11 does not peel off at the boundary portion between the cover member 12 and the valve 22, and the rudder resistance does not increase. As shown in FIG. 3D, as with the propulsion device 9 according to the comparative example, even if the rudder angle increases to a predetermined angle Θ, the rudder shaft 23 and the front end surface 25 of the valve 22 are brought close to each other. The surface 25 is not moved greatly. Therefore, the deviation C2 between the center of the valve 22 and the center of the cover member 12 is smaller than that of the propulsion device 9 according to the comparative example, and the streamline between the valve 22 and the cover member 12 is not disrupted.

  As described above, the propulsion device 1 according to the present embodiment shortens the distance from the rudder shaft 23 to the front end surface 25 of the valve 22, thereby reducing the amount of movement of the front end surface 25 of the valve 22 during steering of the rudder plate 21. Thus, it is difficult to break the streamline due to the valve 22 and the cover member 12. Since the stall angle is designed to be larger than that of the propulsion device 9 according to the comparative example, even if the rudder plate 21 is steered greatly, a reduction in lift of the rudder plate 21 is suppressed and the rudder resistance does not increase.

  As described above, in the propulsion device 1 according to the present embodiment, since the wake of the propeller 11 is received by the dome-shaped curved surface of the cover member 12 at a position close to the propeller 11, the flow flowing into the propeller 11 is delayed. be able to. Therefore, the propulsion efficiency of the ship can be sufficiently increased by a simple configuration in which the dome-shaped cover member 12 is provided on the propeller cap 17. Furthermore, since the existing propeller cap 17 can be used to cover the propeller nut 16, it is not necessary to newly design the propeller cap 17.

  The present invention is not limited to the above embodiments, and can be implemented with various modifications. In the above-described embodiment, the size, shape, and the like illustrated in the accompanying drawings are not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.

  For example, the propulsion device 1 only needs to have the cover member 12 curved so as to form a substantially spindle-shaped surface together with the valve 22, and is not limited to the above-described configuration. For example, a propulsion device as shown in each modification of FIG. 4 may be used. FIG. 4 is a view showing a modification of the propulsion device according to the present embodiment. In FIG. 4, the propeller 11 is omitted for convenience of explanation.

  In the first modification shown in FIG. 4A, the valve 22a protrudes from the front edge 24a of the rudder plate 21a, and the dome-shaped cover member 12a is formed so as to be shorter in the axial direction. Further, the valve 22a is formed in a substantially conical shape, and the valve 22a is smoothly connected to the rudder plate 21a.

  In the second modified example shown in FIG. 4B, the front end face 25b of the valve 22b is positioned near the front edge 24b of the rudder plate 21b, and the dome-shaped cover member 12b is formed so as to be longer in the axial direction. Further, the valve 22b is formed in a substantially conical shape, and the valve 22b is smoothly connected to the rudder plate 21b.

  In the third modification shown in FIG. 4C, the front end face 25c of the valve 22c is positioned near the front edge 24c of the rudder plate 21c, and the dome-shaped cover member 12c is formed longer in the axial direction. The cover member 12c has a substantially half portion on the propeller 11 side formed in a cylindrical shape, and a substantially half portion on the valve 22c side swelled in the radial direction and formed in a dome shape. Further, the valve 22c is formed in a substantially conical shape, and the valve 22c is smoothly connected to the rudder plate 21c.

  In the fourth modified example shown in FIG. 4D, the valve 22d protrudes from the front edge 24d of the rudder plate 21d, and the dome-shaped cover member 12d is formed so as to be shorter in the axial direction. Further, the valve 22d swells outward from the first to third modifications, and is formed long from the middle of the rudder plate 21d to the front of the front edge 24d.

  In the fifth modification shown in FIG. 4E, the valve 22e protrudes from the front edge 24e of the rudder plate 21e, and the dome-shaped cover member 12e is formed shorter in the axial direction. Further, the valve 22e swells outward from the first to third modifications, extends from the front side of the steering plate 21e to the front of the front edge 24e, and is shorter than the fourth modification. Is formed.

  In the sixth modification shown in FIG. 4F, the valve 22f protrudes from the front edge 24f of the rudder plate 21f, and the dome-shaped cover member 12f is formed to be shorter in the axial direction. Further, the valve 22f is recessed inward than the first to third modifications, and extends from the front side of the steering plate 21f to the front of the front edge 24f, so that the valve 22f is shorter than the fourth modification. Is formed.

  In the seventh modification shown in FIG. 4G, the front end face 25g of the valve 22g is positioned near the front edge 24g of the rudder plate 21g, and the dome-shaped cover member 12g is formed so as to be longer in the axial direction. The valve 22g swells outward from the first to third modifications, and is formed from the middle of the rudder plate 21g to the vicinity of the front edge 24g.

  In the eighth modification shown in FIG. 4H, the front end face 25h of the valve 22h is positioned near the front edge 24h of the rudder plate 21h, and the dome-shaped cover member 12h is formed longer in the axial direction. Further, the valve 22h swells outward from the first to third modifications, extends from the front side of the rudder plate 21h to the vicinity of the front edge 24h, and is formed to be the shortest of the modifications. .

  Also in the modified examples shown in FIGS. 4A to 4H, the propulsion efficiency of the ship is sufficiently increased by the simple configuration in which the dome-shaped cover member 12 is provided on the propeller cap 17 as in the propulsion device 1 according to the present embodiment. It is possible to improve.

  Moreover, in this Embodiment, although the diameter expansion member was comprised by the cover member 12, it is not limited to this structure. The diameter-expanding member may be composed of a propeller cap 17. That is, the propeller cap 17 itself may be formed in a dome shape. With such a configuration, it is not necessary to provide a diameter-expanding member separately from the propeller cap 17, and the cost can be reduced by suppressing the number of parts. Further, the diameter-expanding member can be formed by forming the rear end portion of the propeller boss 14 in a dome shape, or may be configured to be provided directly on the propeller boss 14.

  Moreover, in this Embodiment, although it was set as the structure by which the cover member 12 is shape | molded by FRP, it is not limited to this structure. The material of the cover member 12 is not particularly limited, and may be formed of a metal material such as a copper alloy.

  In the present embodiment, the cover member 12 is formed so as to cover the front end face 25 of the valve 22, but the cover member 12 may be formed so as to cover the substantially front half of the valve 22. In this case, a gap is secured between the outer surface of the valve 22 and the inner surface of the cover member 12 such that the outer surface of the valve 22 does not contact the inner surface of the cover member 12 when the rudder plate 21 is steered.

  As described above, the present invention has an effect that the propulsion efficiency of a ship can be sufficiently improved with a simple configuration, and is particularly useful for a propulsion device that improves the propulsion efficiency of a large-sized ship.

DESCRIPTION OF SYMBOLS 1 Propulsion apparatus 2 Stern part 3 Boshing 11 Propeller 12 Cover member (diameter expansion member)
13 Propeller shaft 14 Propeller boss 15 Blade 17 Propeller cap 21 Rudder plate 22 Valve 23 Rudder shaft 24 Front edge 25 Front end face

Claims (5)

In a propulsion device that propels the hull by a propeller provided with a plurality of blades on the outer periphery of the propeller boss,
A rudder plate provided so as to be steerable with respect to the hull behind the propeller;
A valve provided on the rudder so as to face the propeller boss,
A diameter increasing member that increases the diameter toward the rear of the propeller and covers the front end surface of the valve;
The propulsion device, wherein the diameter-expanding member is curved so as to form a substantially spindle-shaped surface together with the valve.   2. The propulsion device according to claim 1, wherein the diameter-expanding member extends to the vicinity of a front edge of the rudder plate, and a front end surface of the valve is positioned near a front edge of the rudder plate.   The propulsion device according to claim 1 or 2, wherein the diameter-expanding member is a propeller cap that covers a propeller nut that prevents the propeller from coming off.   2. A propeller nut for preventing the propeller from falling off is covered with a propeller cap, and the diameter-expanding member is a cover member provided in the propeller boss so as to cover the propeller cap. Or the propulsion apparatus of Claim 2.   The propulsion device according to any one of claims 1 to 4, wherein the diameter-expanding member is formed of FRP (Fiber Reinforced Plastics).

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