JP3725525B2 - Pod prop structure of pod propulsion unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pod prop structure of a pod propulsion unit including a propulsion unit having a built-in drive motor and a prop that rotatably fixes the propulsion unit to a hull.
[0002]
[Prior art]
Conventionally, this type of pod prop structure of a pod propulsion unit is generally provided with a propulsion unit having a built-in drive motor and a single prop that fixes the propulsion unit to the hull so as to be rotatable. .
FIG. 8 is a side view showing the pod support structure of the conventional pod propulsion machine described above. FIG. 9 is a back view showing the pod support structure of the conventional pod propulsion machine described above. FIG. 10 is a diagram for explaining the flow of fluid by the pod support structure of the conventional pod propulsion machine described above.
[0003]
In these drawings, a pod prop structure 101 of a conventional pod propulsion unit includes a propulsion unit 105 disposed on a center line CL of a hull 103, and a propulsion unit 105 disposed on the center line CL. It is composed of a single column 107 that is fixed to be rotatable at a predetermined position. The propulsion device 105 includes a pod main body 105a that incorporates a drive motor and a propeller 105b that is rotated by the drive motor. Further, the column 107 has a cross-sectional shape that is formed in a right and left target wing shape, and the center line of the right and left target wing shape usually coincides with the center line CL of the hull 103.
[0004]
A pod prop structure of a pod propeller having a structure very similar to the pod prop structure of the conventional pod propeller described above (a pod prop structure of another conventional pod propeller) has been proposed (for example, see Patent Document 1). .
In the case of such a conventional pod prop structure of a pod propulsion unit and other pod prop structures, it is understood that the propeller surface force increases due to the influence of the wake and the blocking effect of the prop 105. Yes. Here, the “wake” refers to a flow of water that moves in the same direction because the water is viscous and the portion of water that is very close to the outer plate is dragged by the boat. This wake is the largest at the stern, especially in a single-shaft ship (one propeller shaft) at the upper end of the stern in the vicinity of the propeller, and decreases as it goes downward and toward the stern.
[0005]
If the ship speed is Vs, the wake is Vw and the propeller water speed is Va,
Va = Vs−Vw [1]
Given in.
Also, considering the wake coefficient w, the wake coefficient w is
w = Vw / Vs [2]
Given in.
[0006]
Therefore, when the water speed of the propeller is expressed by Va, the wake coefficient w, and the speed Vs of the ship,
Va = (1-w) Vs [3]
It becomes.
[0007]
Considering such a mathematical expression, when the wake coefficient w of the pod strut structure of the conventional pod propulsion device is taken as the wake distribution in the rotation direction of the propeller 105b of the pod 105a, the dotted line in FIG. Become a characteristic.
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-362487.
[0008]
[Problems to be solved by the invention]
Thus, according to the pod strut structure of the conventional pod propulsion unit described above and other conventional pod strut structures, as shown in FIG. 10, the wake from the hull 103 and the flow Ve flowing through the stern are propeller 105b. Due to the flow blocking effect by the pod strut 107 arranged at the back of the propeller, the flow Vc at the propeller tip portion is slowed and the flow Vf outside the propeller is accelerated, thereby increasing the propeller surface force that causes the hull vibration. There was a drawback of inviting.
An object of the present invention is to provide a pod prop structure of a pod propulsion unit that eliminates the above-described drawbacks of the pod prop structure of the conventional pod propulsion unit and reduces the propeller surface force.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a pod prop structure of a pod propulsion unit according to the invention of claim 1 includes a propulsion unit having a built-in drive motor and a prop that rotatably fixes the propulsion unit to a hull. In the pod prop structure of the pod propulsion unit, the two props are provided and the cross section of each prop is formed in a wing shape, and each prop is directed from the propulsion unit disposed on the hull center line toward the hull. In this case, the support pillars are arranged so as to spread at a predetermined angle with respect to the hull center line, and the support columns are arranged so as to face the wing-shaped streamline portion.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
1 to 4 are views for explaining a pod support structure of a pod propulsion device according to the first embodiment of the present invention. FIG. 1 is a side view showing the pod support structure of the pod propulsion device according to the first embodiment of the present invention. FIG. 2 is a rear view of the pod support structure of the pod propulsion device according to the first embodiment of the present invention. 3 is a top view of the pod support structure of the pod propulsion device according to the first embodiment of the present invention, and is a cross-sectional view taken along line AA of FIG.
[0011]
In these drawings, a pod prop structure 1 of a pod propulsion device according to an embodiment of the present invention includes a propulsion device 5 disposed on a center line CL of a hull 3 and the propulsion device 5 at a predetermined position on the bottom of the hull 3. And two struts 7s, 7p arranged in a predetermined shape while being rotatably fixed. Here, the propulsion unit 5 includes a pod main body 5a having a built-in drive motor, and a propeller 5b provided rotatably in the bow direction of the pod main body 5a.
[0012]
More specifically, in the pod strut structure 1 of the pod propulsion device according to the embodiment of the present invention, as already described, two struts 7s and 7p made of the steel plate are provided. Moreover, the cross-sectional shape of each said support | pillar 7s and 7p is formed in the wing | blade shape, as shown in FIG. As shown in FIG. 3, the wing shape refers to a shape in which one surface is substantially flat and the other surface is streamlined.
[0013]
Further, in the pod prop structure 1 of the pod propulsion unit according to the embodiment of the present invention, the props 7s and 7p are separated from the pod main body 5a of the propulsion unit 5 disposed on the center line CL of the hull 3. It is directed to the hull 3 and is set at the same plus or minus angle with respect to the center line CL so as to spread in a substantially V shape toward the hull 3. Further, as shown in FIG. 3, the struts 7s and 7p are arranged so as to confront the wing-shaped streamline portion. Thereby, the said support | pillars 7s and 7p are left-right object with respect to the centerline CL of the pod main body 5a. The support columns 7s and 7p are fixed and attached to the pod main body 5a in such an arrangement relationship.
[0014]
The operation of such a pod prop structure of the pod propulsion device will be described based on FIGS. 1 to 3 and with reference to FIG. FIG. 4 shows that the wake coefficient of the pod prop structure of the pod propeller according to the first embodiment of the present invention can be compared with the wake coefficient of the pod prop structure of the conventional pod propeller. In the figure, the horizontal axis represents the rotation direction θ [deg. ], And the vertical axis represents the wake coefficient w. Note that the wake coefficient w can be obtained by Equation 3 described above.
[0015]
In the pod prop structure 1 of this pod propulsion unit, the cross-sectional shape of the props 7s and 7p is formed into a wing shape, shifted from the center line CL of the hull 3 and toward the bottom of the hull 3 in a substantially V shape with respect to the center line CL. Since the arrangement is such that the wing-shaped streamlined portion is opposed to the wing shape, the flow Ve is caused by the generation of the circulation Γ around the wing as shown in FIG. The flow Vc in the region surrounded by the columns 7s and 7p) becomes faster and the flow Vh outside the columns 7s and 7p becomes slower.
[0016]
As a result, the flow Vc at the upper end of the propeller 5b becomes faster, and the wake at this portion is reduced. As a result, the wake coefficient above the propeller 5b decreases as indicated by the solid line portion indicated by the arrow Y in FIG.
Further, according to the pod prop structure 1 of the pod propulsion device according to the present embodiment, since it has the above-described structure, as shown by the solid line in FIG. 4, the lower end from the upper end (θ = 0 [deg.]) Of the propeller 5b. A characteristic that the wake coefficient w gradually changes toward (θ = 180 [deg.]) Can be obtained.
[0017]
On the other hand, according to the pod support structure of the conventional pod propulsion device, as shown by the dotted line in FIG. 4, the upper end (θ = 0 [deg.]) To the lower end (θ = 180 [deg.]) Of the propeller 5b. The wake coefficient w changes abruptly toward.
Therefore, by loosening the wake coefficient w above the propeller 5b in the pod prop structure 1 of the pod propulsion device, the behavior from the occurrence of propeller cavitation to the disappearance can be smoothly transferred, and the hull vibration The surface force that causes the problem can be reduced.
[0018]
[Second Embodiment]
5 to 7 are diagrams for explaining a pod support structure of a pod propulsion device according to the second embodiment of the present invention. FIG. 5 is a side view showing the pod support structure of the pod propulsion device according to the second embodiment of the present invention. FIG. 6 is a view of the pod support structure of the pod propulsion device according to the second embodiment of the present invention as viewed from the rear. FIG. 7 is a view of the pod support structure of the pod propulsion device according to the second embodiment of the present invention as viewed from above, and is a cross-sectional view taken along line BB in FIG.
[0019]
In the pod strut structure of the pod propulsion apparatus according to the second embodiment shown in these drawings, the same components as those of the first embodiment are denoted by the same reference numerals and detailed descriptions thereof are given. Description is omitted.
In these drawings, a pod prop structure 1A of a pod propulsion unit according to the second embodiment of the present invention is characterized by the propulsion unit 5A, and other configurations are the same as those of the first embodiment. Therefore, in the pod support structure of the pod propulsion unit according to the second embodiment, the propulsion unit 5A will be mainly described.
[0020]
That is, in the pod prop structure 1A of the pod propulsion unit according to the second embodiment of the present invention, the propulsion unit 5A includes a pod main body 5a having a built-in drive motor and the pod main body as shown in FIGS. a structure 5a of being fixed to the drive shaft comprising a propeller 5b which is rotatable, is characterized in that the propeller 5b are so arranged to face the stern side, the other structures are first This is the same as the embodiment.
[0021]
More specifically, in the pod strut structure 1A of the pod propulsion unit according to the second embodiment of the present invention, the cross-sectional shapes of the two struts 7s and 7p manufactured of the steel plate are as shown in FIG. It is formed into a shape. The respective struts 7s, 7p are set from the pod body 5a of the propulsion unit 5A arranged on the center line CL of the hull 3 toward the hull 3 and at the same plus or minus angle with respect to the center line CL. In such a manner, it is arranged so as to expand in a substantially V shape toward the hull 3. And each said support | pillar 7s and 7p is arrange | positioned so that the streamline part of a wing | blade shape may oppose as shown in FIG.
[0022]
Similarly to the pod prop structure 1 of the pod propulsion unit according to the first embodiment, the pod prop structure 1A of the pod propulsion unit according to the second embodiment having the above-described structure
As shown by the solid line in FIG. 4, the wake coefficient w gradually changes from the upper end (θ = 0 [deg.]) To the lower end (θ = 180 [deg.]) Of the propeller 5b. The same effects as those of the first embodiment are obtained.
[0023]
【The invention's effect】
As described above, according to the present invention, two struts are provided, each strut cross section is formed into a wing shape, and each strut is disposed on the hull center line from the propulsion device toward the hull. Since it is arranged to spread at a predetermined angle with respect to the center line of the hull, and each strut is arranged so that the wing-shaped streamline part faces each other, the change of the wake coefficient at the top of the propeller can be moderated, Propeller cavitation generation and extinction behavior can be smoothed, and the surface force that causes hull vibration can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view showing a pod support structure of a pod propulsion device according to a first embodiment of the present invention.
FIG. 2 is a view of the pod support structure of the pod propulsion device according to the first embodiment of the present invention as viewed from the stern side.
FIG. 3 is a view of the pod support structure of the pod propulsion device according to the first embodiment of the present invention as viewed from the line AA in FIG. 2;
FIG. 4 is a diagram showing that the wake coefficient by the pod strut structure of the pod propulsion device according to the first embodiment of the present invention can be compared with the wake coefficient by the pod strut structure of the conventional pod propulsion apparatus. .
FIG. 5 is a side view showing a pod support structure of a pod propulsion device according to a second embodiment of the present invention.
FIG. 6 is a view of a pod support structure of a pod propulsion device according to a second embodiment of the present invention as viewed from the stern side.
7 is a view of the pod support structure of the pod propulsion device according to the first embodiment of the present invention as seen from the line BB in FIG. 6;
FIG. 8 is a side view showing a pod support structure of a conventional pod propulsion device.
FIG. 9 is a view of a conventional pod prop structure of a pod propulsion device as viewed from the stern side.
FIG. 10 is a diagram for explaining the flow of fluid by the pod strut structure of a conventional pod propulsion device.
[Explanation of symbols]
1,1A Pod prop structure of pod propeller 3 Hull 5,5A Propeller 5a Pod body 5b Propeller 7s, 7p Prop

Claims (1)

In a pod prop structure of a pod propulsion unit comprising a propulsion unit having a built-in drive motor and a prop that rotatably fixes the propulsion unit to the hull,
Two pillars are provided, and each pillar cross section is formed in a wing shape, and each pillar is predetermined with respect to the hull center line from the propulsion device disposed on the hull center line toward the hull. A pod strut structure for a pod propulsion unit, wherein the struts are arranged so as to expand at an angle, and the struts are arranged opposite to a wing-shaped streamlined portion.

Images