JPS623357Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] Variable pitch propellers for ships can move forward or backward by changing the pitch of the propelling blades without changing the rotational direction or rotation speed of the propulsion shaft. Not only can you obtain thrust, but you can also adjust the thrust from 0 to 100% by adjusting the pitch angle of the propulsion blades.
It is a propulsion device that can be propelled steplessly. This invention relates to a boss mechanism for this type of variable pitch propeller.

[Conventional technology]

Conventional variable pitch propellers have a variable pitch mechanism built into the thruster boss, which has the disadvantage of making the boss hollow, making the boss wall thinner, and reducing its strength. Furthermore, since the propulsion blades are installed in the boss wall hollowed out using the blade bonding material, the center of gravity of the propulsion blades is higher than the axis.
The structure is completely weak against loads such as the lever action that occurs in proportion to the thrust of the propulsion blades, or the centrifugal force that occurs when the thrust is 0% or when spinning in rough weather.In order to withstand all of the above loads, the boss Due to the necessity of increasing the inner thickness of the wall, the diameter of the boss had to be larger than that of a fixed pitch propeller, which had the fateful drawback of poor propeller efficiency.

On the other hand, as shown in Figures 5 and 6,
A new blade root connecting shelf 15 is installed on the inner wall of the boss tail portion 13'' toward the propulsion shaft 12 side, and the blade roots 14 are connected to each other in the blade root connecting portion 17 to connect the propulsion blades 11 to each other, thereby reducing the centrifugal force generated by rotation. Propeller efficiency is improved by balancing the forces against each other, reducing the action on the boss wall 13', reducing the wall thickness of the boss wall 13', reducing the diameter of the boss 13, and reducing the boss ratio. An attempt was made to do so.

[Problem that the invention attempts to solve]

When using thrust, the propulsion blade 11 is the point of effort, and the boss 13
Using point P or P' in the figure as a fulcrum, connect the blade root joint 17.
The lever action load generated by the thrust is applied to the boss tail part 1 via the blade root connecting shelf 15 with
3″, to act on the boss wall 13, the boss tail 1
3'', the wall thickness of the boss wall 13 could not be reduced much, and the propeller efficiency was not improved as much as expected.Furthermore, the blade root coupling shelf 15 was removed from the boss tail 13''.
Due to the new planting on the inner wall, the center of gravity of the propeller moved closer to the 13'' side of the boss tail, which increased the mass of the propeller's oscillating motion, making it easier for the propeller and the hull to vibrate. .

[Means for solving problems]

The idea here is to erect a blade root receiving coupling shelf protruding from the end of the propulsion shaft in the variable pitch propeller boss toward the tail of the boss, and to provide a blade root fitting hole into which the blade root is inserted into the blade root coupling shelf. A connecting part is provided on the inner periphery of this blade root fitting hole and the outer periphery of the blade root, and the propelling blade is connected with a connecting material so that it can rotate in the circumferential direction of the blade root but cannot be displaced in the radial direction. The present invention proposes a variable pitch propeller boss mechanism, which has a variable pitch propeller boss mechanism.With this configuration, the lever action load generated by the centrifugal force and thrust generated by the rotation of the propeller blades is absorbed by the boss. The structure of the thruster is such that it does not act on the wall as much as possible, and the wall thickness of the boss wall 3' is made thinner.
The diameter of the propeller is made as small as possible to improve propeller efficiency, and the center of gravity of the propulsion device is moved as close to the propulsion shaft 2 as possible to reduce the mass of the propulsion device's oscillating motion, reducing vibrations and vibrations of the propulsion shaft system and the ship's hull. This is intended to reduce wear and tear on the stern tube bearing.

[Effect]

Next, this idea will be explained in detail.

As shown in FIGS. 1 and 2, a new blade root receiving coupling shelf 5 is installed at the end of the propulsion shaft 2' toward the boss tail 3'', and the blade root 4 is inserted into the blade root receiving coupling shelf 5. A blade root fitting hole 6 is provided, and the inner periphery of the blade root fitting hole 6 and the blade root 4
Connecting parts 7 are provided on the outer periphery of the blade roots 4 and the blade root receiving coupling shelf 5, and a connecting member 8 connects the blade roots 4 and the blade root receiving joint shelf 5 so that the propulsion blades 1 can rotate in the circumferential direction of the blade root 4 but cannot be displaced in the radial direction.
It is also a combination.

Note that the bonding method is not limited to the bonding materials shown in the figures; in FIGS. 1 and 2, a filled ball is used as the bonding material 8, in FIG. 3, a screw ring is used as the bonding material 8', and in FIG. An example is shown in which a fitting ring is used for each member 8''.

As described above, in this invention, the inner periphery of the blade root fitting hole 6 of the blade root receiving coupling shelf 5 and the joint part 7 provided on the outer periphery of the blade root 4 are filled with a bonding material 8, and the propulsion blades 1 are connected to each other. The centrifugal force generated in the propulsion blade 1 due to the rotation of the propeller is transferred to the blade root support connection shelf 5.
to prevent the boss wall 3' and the boss tail 3'' from acting on the propeller blade 1.
is the point of force, the vicinity of point P or P' of the boss 3 is the fulcrum, and the lever action load generated with the blade root receiving joint 7 and the blade root fitting hole 6 as the application points is applied to the blade root receiving joint shelf 5. Although the load is pushed in the direction of the boss tail 3' or the propulsion shaft 2, the load is released to the propulsion shaft 2 on which the blade root receiver coupling shelf 5 is erected, so that it does not act on the boss wall 3' and the boss tail 3''. Furthermore, a blade root receiving coupling shelf 5 is installed at the end 2' of the propulsion shaft to move the center of gravity of the propulsion device toward the propulsion shaft 2 side, thereby reducing the mass of the swinging motion of the propulsion device.
This reduces vibrations to the propulsion shaft system and hull.

[Effect of idea]

1 Balance the centrifugal force acting on the propulsion boss wall 3' between the propulsion blades 1 via the blade root receiving shelf 5,
By adopting a structure that does not act on the boss wall 3', the thickness of the boss wall 3' can be reduced.
Improved propeller efficiency.

2 By releasing the leverage load generated on the propulsion blade 1 due to thrust and acting on the blade root receiver coupling shelf 5 to the propulsion shaft 2, the wall thickness of the boss wall 3' and the boss tail 3'' can be increased by a large amount. This reduced the boss ratio and dramatically improved propeller efficiency.

3. The center of gravity of the propulsion device is moved to the propulsion shaft 2 side by installing the blade root receiver coupling shelf 5 at the end of the propulsion shaft 2' and by reducing the wall thickness of the boss tail 3'' by a large amount. The mass of the thruster's oscillating motion becomes smaller,
Vibration of the shaft system and hull is reduced, reducing wear and tear on the stern tube bearing.

[Brief explanation of the drawing]

In the drawings, FIGS. 1 and 2 are side sectional views and front vertical sectional views of the boss mechanism of this invention, FIGS. 3 and 4 are front vertical sectional views showing examples of partial changes, and FIGS. FIG. 6 is a side sectional view and a front vertical sectional view of the conventional example. In the figure, 1...propulsion blade, 2...propulsion shaft, 2'...propulsion shaft end, 3...variable pitch propeller boss, 3''...boss tail, 4...blade root, 5...
...Blade root connecting shelf, 6...Blade root fitting hole, 7...Connecting portion, 8, 8', 8''...Binding material.

Claims (1)

[Scope of utility model registration request] Propulsion shaft end 2' in variable pitch propeller boss 3
A blade root receiving coupling shelf 5 is planted protrudingly toward the boss tail portion 3'' side, and a blade root fitting hole 6 into which the blade root 4 is inserted is provided in the blade root coupling shelf 5. A connecting portion 7 is provided on the inner periphery of the blade root 4 and the outer periphery of the blade root 4, respectively, and a connecting member 8 connects the propulsion blade 1 so that it can rotate in the circumferential direction of the blade root 4 but cannot be displaced in the radial direction. Variable pitch propeller boss mechanism.