JPS61193993A - Marine adjustable pitch propeller - Google Patents

Abstract

PURPOSE:To make each pitch of propeller blades automatically adjustable to each other according to a ship's wake current flowing in each propeller blade, by making the pitch of these propeller blades alterable with hydraulic cylinders. CONSTITUTION:An adjustable pitch propeller is provided with plural pitch- adjustable type propeller blades 15-1-15-4 being projectingly installed an and around a propeller boss 14 via rotary blocks 18. These blades are designed so as to make their pitches alterable by means of hydraulic cylinders 25-1-25-4 being installed inside the propeller boss. Respective hydraulic cylinders are interconnected with one another via an interconnecting pipe 26 which is connected to a pump 20. This pump 20 is designed so as to be controlled for its operating state by a control unit 21.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is directed to a variable pitch propeller provided at the stern of a ship.

[Conventional technology]

As a conventional variable pitch propeller, there is one as shown in FIG. A plurality of rotary tables 18 are provided, and each rotary table 18 is provided with a propeller blade 15 protruding from the rotary table 18.

On the other hand, a hydraulic cylinder 23 is provided in the propeller transport 11, and this hydraulic cylinder 23 is connected to the piston 16.
The piston 16 can be moved from side to side in FIG. 9 by appropriately supplying pressure oil from the bomb 20 to either oil chamber.

In addition, the piston 16 is connected to the rotary table 1) via the iron 16a.
The rotary table 18 is connected to a pin 17 with a piston 16, and as the piston 16 moves, the rotary table 18 can freely rotate. This allows the pitch angle of the propeller blades 15 to be changed as shown in FIGS. 10(a) and (+)).

In FIG. 9, reference numerals 12 and 13 indicate bearings, 19 an oil tank, 21 a pump control device, and 22 an oil groove.

, -noyo) 1, such a marine vessel can reduce fuel consumption by 1 mi.
There are advantages r'jf+ such as not having to place an undesirable load on the -B beach based on the sea-song state and the loading state of the ship, and also being able to select the pitch with the best propeller efficiency depending on the sailing state.

[Problem that the invention seeks to solve]

However, one of the major problems with such conventional marine variable pitch propellers is pressure fluctuation at the stern. One of the major causes of this pressure fluctuation is unsteady cavitation that occurs in the propeller. This is because when the propeller blade 15 rotates in the vicinity of the stern bottom surface 2, as shown by the arrow a, as shown in Figure 6, the propeller blade becomes excessively negative pressure due to the non-uniform flow in the stern part. This occurs on the rear surface (see the portion indicated by reference numeral l in FIG. 7). The occurrence or disappearance of such cavitation may cause vibration problems or collapse of the propeller blade 15 depending on various conditions! III Eronosine (lEro
(cavitation erosion): Hereinafter referred to as [cavitation erosion].

In addition, if the ship speed is V D + the part of the rotation angle of the propeller rotating part and the average flow velocity of that part is V, then
The average wake field according to the rotation angle is expressed as W=1(v/Vo). Based on the rotation angle θ of the propeller, the relationship between this θ and the wake rate is approximately 1
It will look like Figure 8. Here, as shown in figure fjS6, the point where the propeller blades are upward is defined as θ=0.

The present invention aims to solve the above-mentioned problems by making it possible to automatically adjust the pitch of each of a plurality of propeller blades according to the ship's wake flowing into the propeller blades, thereby reducing vibration and cavitation. An object of the present invention is to provide a marine variable pitch propeller that prevents erosion from occurring.

[Means for solving problems]

For this reason, the marine variable pitch propeller of the present invention includes a plurality of variable pitch propeller blades protruding around a propeller boss in a screw propeller installed at the stern of the ship, and a variable pitch propeller for changing the pitch of each of these propeller blades. It is equipped with a plurality of hydraulic cylinders, and responds to the ship's wake flowing into the propeller blades.
Automatically change the pitch of each propeller blade! ! In order to improve the system, the working chambers of each of the hydraulic cylinders are connected to each other via a communication pipe.

[Effect]

In the variable pitch marine propeller of the present invention described above, the working chambers of the hydraulic cylinders for variable propeller pitch are connected to each other via the communication pipe, so each propeller blade can control the size of the ship's wake flowing into it. If the values are different,
Rotational force acts on each propeller blade depending on the size of this wake, so this force is transmitted through the communication pipe, and as a result, the pitch decreases where the wake is large, and the pitch decreases accordingly where the wake is small. Each propeller blade rotates so that it becomes slightly larger.

〔Example〕

Hereinafter, a marine variable pitch propeller will be described as an embodiment of the present invention with reference to the drawings. Fig. 1 is a sectional view schematically showing its schematic structure, and Fig. 2 shows the arrangement of its hydraulic cylinders. Schematic diagram showing Fig. 13.4 and fjs
Figures 5 (, ) are schematic diagrams for explaining the effect, and Figure 5 (1)) is a graph for explaining the effect. The same reference numerals as in the figure indicate substantially similar parts.

1st. :3 As shown in Fig. 1, this Or-shaped pinch propeller is installed on the bottom surface 2 of the stern ship, and around the propeller boss 14. ] Plural (for example, one) variable pitch type % type % protruding through the turntable 18 Also, multiple (4 in this example □) hydraulic pressure to change the pitch of each of these propeller blades. cylinder 25
1,25 2,25 3,25 4 are provided in the propeller boss 14, as shown in Fig. 1.2 and Fig. f55 (,). That is, each hydraulic cylinder 25-1, 25
The pistons 2, 253 and 25-4 are connected to the bins 17 of each rotary table 18a and 18a through separate cranks (link rods) 28, respectively.

Furthermore, the waste hydraulic cylinder 25-1.25-2゜25-3
．． 251 working chamber 27-1.27-2゜27-3.27
-4 are connected to each other through a communication pipe 26, and this communication pipe 26 is further connected to a common pipe 26', and this common pipe 26' is connected to the pump 2 through an oil groove 22.
Connected to 0.

Note that the operating state of the pump 20 is controlled by a pump control device 21.

With the above configuration, when changing the pinch of each propeller blade at the same time, the pump 20 connects each hydraulic cylinder 25-1°25-2.25 via the common pipe 26' and the communication pipe 26.
-3.25-4 working chamber 27-1゜27-2.27-3
．． What is necessary is to supply the required pressure oil to 27-4. As a result, each hydraulic cylinder 25-1゜25-2, 25 3.25
4 operate all at once, each rotary table 1)) A, 1 propeller blade 15-1.15-2゜1.5-3, I! '＋
4 rotates to change the pinch of the propeller blades.

By the way, if you rotate the C propeller at a certain pitch,
There are 4 cases in which we are at t2.

Life, Figure 4 [Propeller blade 15-1゜15-
2+15-3,15 The moment r that attempts to rotate 4 41 times is defined as M.

Generally, when a ship is moving at a constant speed, there is a wake at the stern, and this wake is represented by the dotted line characteristic WA in Figure 15(b).
Like KE, the propeller @1 (it is thought that the surroundings have changed.

Here, in FIG. 5(b), the symbols A, 13,
C and D are the propeller and g15-1, respectively, when the propeller blade 15-1 approaches the stern bottom surface 2.
The rotational position at 15-2.15-3.15-4 is shown.

By the way, when the wake is large, the water flow hitting the rear surface of the propeller blade is small and the pressure is low, resulting in a moment M acting to rotate the propeller blade, but the magnitude of this moment M is shown in Figure 5 (b). ) differs depending on each position as shown by the symbol M'.

That is, compared to position A (position of propeller blade 15-1), position B
, the moment is smaller at the D position (propeller blade 15-2, 15-4 position), and furthermore the moment is smaller at the C position (propeller blade 31 position).
5-3), the moment M is the smallest. However, through the communication pipe 26, each working chamber 27-1.27-2.2
7-3.27-4 are in communication, so even if the moment differs depending on the position as described above, each propeller blade 1
5-1.15-2゜15 3.15 4 is each working chamber 27
-1.27-2°27-3.27-4 Move so that the pressure within them becomes uniform, that is, the rotational moments M match.

As a result, the pitch of the propeller becomes small in high wake areas [such as A position 1 in Figure 5 (b)] - low H1 wake areas [such as B, C, and D positions 1 in Figure 5 (b)] Then, the pitch becomes more intense. That is, the propeller blades 15-1°15-2.15-3.
Each pitch of 15-4 can be automatically adjusted to 151g.

Each propeller blade at this time 15-1.15-2゜15-3
．． 15-4 and each hydraulic cylinder 25-1゜25 2
, 25-3 and 25-4 are shown in Figure 5(a).
become that way.

Due to this action, near the stern, especially when the propeller blade approaches the bottom surface 2 of the stern, the pitch angle of the approaching propeller blade becomes smaller than that of other propeller blades, which causes the cavity to become relatively small. Silane is less likely to form.

As a result, various problems associated with vibration and cavitation can be prevented.

〔Effect of the invention〕

As detailed above, according to the marine variable pitch propeller of the present invention, the screw propeller installed at the stern of the ship is provided with a plurality of variable pitch propeller blades protruding around the propeller boss, and the propeller blades of these propeller blades are It is equipped with a plurality of hydraulic cylinders for changing the pitch, and the working chambers of each of the hydraulic cylinders are connected to each other via a communication pipe, so that the ship's wake flowing into the propeller blades is The pitch of each of the above propeller blades can be mutually automatically adjusted according to the
This has the advantage of sufficiently preventing the occurrence of vibrations and cavity noise.

[Brief explanation of drawings]

Figures 1 to 5 show a marine variable pitch propeller as an embodiment of the present invention. Figure 1 is a sectional view schematically showing its schematic structure, and Figure 2 shows the arrangement of its hydraulic cylinders. The schematic diagrams shown in Figures 3, 4, and 5 (a) are all schematic diagrams for explaining the effect, and Figure 5 (b) is a graph for explaining the effect. Fig. 10 shows a conventional marine variable pitch propeller, Fig. 6 is a schematic diagram showing the relationship between this propeller and the bottom of the stern, Fig. 7 is a schematic diagram showing how cavitation occurs, and Fig. 8 The figure is a graph showing the relationship between the propeller rotation angle and the wake rate, Fig. 9 is a cross-sectional view schematically showing its schematic configuration, and Figs. 10 (a) and (1)) respectively show its effect. It is a schematic diagram for explanation. 11...Propeller shaft, 12.13...Les catcher, 14...Propeller boss, 15-1,15 2,15 3゜15-4
・・Propeller 1.17・・Bin, 18・・Rotary stand, 19
...Oil tank, 20..Pump, 21..Pump control device, 22..Oil groove, 25-1, 25-2
, 25 3, 25-4...Hydraulic cylinder, 26...Communication pipe, 26'...Common pipe, 27-1.27-2.27
-3.27-4... Working chamber, 28... Crank. Sub-Agent Patent Attorney Yoshi Iinuma 4 Figure 1 Figure 2 Figure 3 Figure 4 Figure 6 Figure 8 Figure 10

Claims (1)

[Claims] The screw propeller installed at the stern is equipped with a plurality of variable-pitch propeller blades protruding around the propeller boss, and a plurality of hydraulic cylinders for changing the pitch of each of these propeller blades.
The working chambers of each of the hydraulic cylinders are connected to each other through a communication pipe in order to mutually automatically adjust the pitch of each of the propeller blades according to the ship's wake flowing into the propeller blade. A marine variable pitch propeller.