JPH1059286A - Variable pitch propeller for ship - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable pitch propeller for ship which has a simple structure, and is inexpensive. SOLUTION: A variable pitch propeller is provided with a propeller shaft 13 furnishing a screw 15 at the tip, a hub 17 to surround the outer periphery of the tip of the propeller shaft 13, propeller vanes 25 provided to plural positions in the peripheral direction of the hub 17 orthogonal to the propeller shaft 13, in which a propeller shaft 24 is installed rotatably to the hub 17, an eccentric arm 26 extending in the radial direction at the inner side end of the hub 17 of the propeller shaft 24, a variably slider 31 screwed to a screw part 15 inside the hub 17, an engaging member 33 furnishing the variably slider 31 to rotate the eccentric arm 26 by the movement of the variably slider 31 to the screw part 15, and return dampers 35a and 35b to move the variably slider 31 to near the middle part of the screw part 15 in the longitudinal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable pitch propeller for ships.

[0002]

2. Description of the Related Art Conventionally, a propeller generally used in a ship has a plurality of propeller blades 3 integrally fixed to a tapered shaft 1a formed at the tip of a propeller shaft 1, as shown in FIG. The boss 2 is fitted with a key groove and fastened with a nut 2b via a washer 2a.

As described above, in the propeller 4 in which the propeller shaft 1 and the propeller blade 3 are fixed, the pitch angle α of the propeller blade 3 is adjusted so that the maximum propulsion force is obtained when the propeller 4 is at the rated maximum rotation speed. Determined, generally 3
The pitch angle α is about 0 °.

[0004] However, in the propeller 4 in which the propeller shaft 1 and the propeller blades 3 are fixed as described above,
In particular, in the low-speed rotation range in the early stage of acceleration of the propeller 4, the large pitch angle α increases the resistance of the water received by the propeller 4, thereby increasing the power consumption for driving the propeller 4, and particularly accelerating and decelerating. However, there is a problem that fuel efficiency is poor, a problem that exhaust gas emission increases, and a problem that acceleration performance at a predetermined horsepower is low.

In order to solve such a problem, there has been proposed a variable pitch propeller capable of changing a pitch angle of a propeller blade with respect to a propeller shaft.

[0006] As shown in FIG. 4, a conventional variable pitch propeller has a hub 6 provided integrally with a propeller shaft 5.
In addition, a propeller shaft 8 of a propeller blade 7 is provided so as to penetrate in the radial direction, so that the propeller blade 7 can rotate about the propeller shaft 8. An eccentric arm 9 extending in the radial direction of the propeller shaft 8 is provided at an inner end of the propeller shaft 8 inside the hub 6. Further, inside the propeller shaft 5, there is provided an inflection rod 10 which can penetrate through the propeller shaft 5 and move in the axial direction of the propeller shaft 5. The crosshead 11 is integrally fixed, and the crosshead 11
Is provided with an engaging claw 12 for rotating the eccentric arm 9 by moving the crosshead 11 in the axial direction of the propeller shaft 5.

The propeller shaft 5 is driven to rotate as shown by an arrow A by an engine (not shown) provided on the right side in FIG.
Is moved as shown by arrows B and B 'by a push-pull cylinder (not shown) provided on the right side in FIG.

FIG. 4 shows a state in which the pitch angle α is the maximum pitch angle. From this state, when the inflection rod 10 is moved in the direction of arrow B by a push-pull cylinder (not shown), the inflection rod 10 and the inflection rod 10 are integrated. The cross head 11 also moves in the direction B, so that the engagement claw 12 rotates the eccentric arm 9 clockwise, and thereby the pitch angle α
Is reduced as shown by arrow C. When the inflection bar 10 is moved in the direction of arrow B ', the eccentric arm 9 is rotated counterclockwise, and the pitch angle α is increased in the direction opposite to the direction of arrow C.

In addition to the method of moving the inflection bar 10 in the directions B and B 'by the push-pull cylinder as described above, the inflection rod 10 is rotated as shown by arrows D and D', not shown. There is also a system in which the crosshead 11 is moved in the axial direction of the propeller shaft 5 via a screw, whereby the eccentric arm 9 is rotated via the engaging claw 12.

[0010]

However, in the conventional variable pitch propeller shown in FIG. 4, as described above, the variable rod 10 for changing the pitch angle α of the propeller blade 7 is provided with the propeller shaft 5. There is a problem that the structure is complicated due to the double-shaft structure provided by penetrating through the inside, and the drive for moving the inflection bar 10 in the direction of arrow B, B 'or D, D'. The need for the device further complicates and increases the size of the device, and further requires a control device for controlling the driving of the inflection bar 10,
There has been a problem that the device becomes very expensive.

The present invention has been made in view of such circumstances, and has as its object to provide a variable pitch propeller for boats which has a simple structure and can be implemented at low cost.

[0012]

SUMMARY OF THE INVENTION The present invention provides a propeller shaft having a threaded portion at the tip, a hub surrounding the outer periphery of the tip of the propeller shaft, and the propeller shaft at a plurality of circumferential positions of the hub. A propeller blade orthogonally disposed and a propeller shaft rotatably mounted on the hub, an eccentric arm extending radially to a hub inner end of the propeller shaft, and the screw portion inside the hub. A variable slider screwed into the screw portion; an engaging member provided on the variable slider so as to rotate the eccentric arm by movement of the variable slider with respect to the screw portion; and moving the variable slider to a position near the longitudinal center of the screw portion. A variable pitch propeller for ships, comprising: a return damper.

Further, in the present invention, the pitch angle of the propeller blade is adjusted by moving the variable slider by the inertial force of the propeller blade and the hub.

In the present invention, the variable slider is moved by utilizing the magnitude of the moment of inertia of the propeller blades and the hub, and the resistance to water for rotating the propeller blades.
Since the pitch angle was automatically adjusted, a variable rod for changing the pitch angle of the propeller blade was penetrated through the propeller shaft as in the conventional case to form a double shaft structure, or move the variable rod There is no need to provide a drive device for adjusting the pitch angle, the configuration is simple and small, and a variable pitch propeller can be provided at low cost.

Furthermore, the variable slider is moved by the inertial force of the propeller blades and the hub to adjust the pitch angle of the propeller blades, so that acceleration performance can be improved and fuel efficiency can be improved.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention.
A screw portion 15 is formed coaxially via a boss 14, and further, a shaft portion 16 is provided at a distal end portion of the screw portion 15, and is provided so as to cover the outer periphery of the distal end portion of the propeller shaft 13. A hub 17 is mounted via a bearing 18 provided on the boss 14 and the shaft 16.

A thrust plate 19 is fixed to a front end of the shaft portion 16 by a bolt 20 and a knock pin 21, and a nose cone 23 fixed to a tip end of the hub 17 by a bolt 22 and the hub 17. By holding the thrust plate 19, the hub 17
Is transmitted to the propeller shaft 13.

At a plurality of locations in the circumferential direction of the hub 17, propeller blades 25 are disposed at right angles to the propeller shaft 13 and have a propeller shaft 24 rotatably penetrated with respect to the hub 17 at equal intervals (FIG. 1). And only one is shown in FIG. 2), and an eccentric arm 26 extending in the radial direction of the propeller shaft 24 is provided at the inner end of the hub 17 of the propeller shaft 24. The hub 17 is split into two parts in the axial direction of the propeller shaft 13 at a position where the propeller shaft 24 penetrates, and a front hub 17 a and a rear hub 17 b are integrally assembled by bolts 27. The propeller blade 25 is attached to the hub 17 by an attachment plate 30 fixed to the hub 17 with bolts 29 so as to press a boss 28 provided on the propeller shaft 24.

The screw portion 15 is provided inside the hub 17.
Is provided with a variable slider 31 rotatably screwed therewith.

On the outer periphery of the variable slider 31, the longitudinal direction of the eccentric arm 26 (radial direction of the propeller shaft 24)
A pin-shaped engaging member 33 is provided which engages with the elongated hole 32 formed in the eccentric arm 26 to rotate the eccentric arm 26 by moving the variable slider 31 in the axial direction of the propeller shaft 13. I have.

Further, between the variable slider 31 and the boss 14, and between the variable slider 31 and the step 34 provided on the left inner side of the hub 17, the variable slider 31 is always in the longitudinal direction of the threaded portion 15. Return dampers (springs) 35a and 35b are provided to apply a force to return to the intermediate position in the direction.

In FIG. 1, reference numerals 36 and 37 denote stoppers formed on the hub 17 so as to regulate the movement width of the variable slider 31. The stopper 36 is provided when the variable slider 31 moves to the left side in FIG. The stopper 37 is provided so that the variable slider 31 moves to the right in FIG.
5 is defined so as not to be larger than a predetermined pitch angle. Reference numeral 38 denotes a seal ring, 39 denotes a gasket, and 40 denotes lubricating oil filled in the hub 17.

The operation of the above embodiment will be described below.

FIGS. 1 and 2 show that the variable slider 31 is located substantially at the center of the threaded portion 15 in the longitudinal direction. In this state, the pitch angle α (see FIG. 4) of the propeller blade 25 is a median value (for example, 30 °). ) Pitch angle.

Now, assuming that the speed of the engine is increased and the ship is accelerated, a case where the screw portion 15 is a right-hand screw and the propeller shaft 13 is driven to the right will be described.

When the clockwise rotation of the propeller shaft 13 is driven from the state shown in FIG. 1, the screw portion 15 also rotates clockwise, but the variable slider 31 and the hub 17 have a large moment of inertia, and the propeller blade 25 has a pitch angle. (For example, 30
°), and the variable slider 31 and the hub 17 try to stay at the same position because of the large resistance of water. For this reason, the screw portion 15 is screwed into the variable slider 31, and the rotation speed of the engine is increased.
When the screw portion 15 is screwed in, the variable slider 31 moves rightward in FIG. 1 so as to compress the return damper 35a, and the engaging member 33 engaged with the long hole 32 moves rightward in FIG. The eccentric arm 26 is rotated, and the pitch angle of the propeller blades 25 is increased from the state shown by the phantom line in FIG. 1 by the angle Z as shown by the solid line.

As described above, when the variable slider 31 compresses the return damper 35a and moves rightward, the rotational force of the propeller shaft 13 is transmitted to the variable slider 31 by the frictional force of the screw portion 15, and By being transmitted from the engaging member 33 to the propeller shaft 24 via the eccentric arm 26, the rotation of the hub 17 and the propeller blades 25 is gradually increased, and the thrust generated by the rotation of the propeller blades 25 is reduced by the propeller. The information is transmitted to the shaft 13.

Therefore, the rotation of the engine is accelerated while the pitch angle of the propeller blades 25 is maintained in the low-speed rotation range at the beginning of the acceleration of the propeller, so that the power consumption during acceleration is reduced. As described above, by using the inertia force of the hub 17 and the like to suppress the load ratio at the time of low torque at the time of low rotation at the initial stage of engine acceleration, the engine rotation can be accelerated. Therefore, especially for ships that repeatedly accelerate and decelerate, fuel efficiency can be significantly reduced,
Further, the emission amount of exhaust gas can be reduced, and the acceleration performance at a predetermined horsepower can be improved.

As the rotational speed of the propeller shaft 13 increases, the rotational resistance of the propeller blades 25 against water increases, but the variable slider 31 is engaged with the propeller shaft 13 via the screw portion 15. Therefore, the pitch angle is not reduced. In the state where the pitch angle of the propeller blades 25 is increased in this manner, at the rated maximum speed, FIG.
As shown by the solid line, the maximum pitch angle (for example, 30 ° or more) can be maintained.

At the time of deceleration of the ship, the rotation speed of the propeller shaft 13 also decreases with a decrease in the engine rotation speed. However, the rotation speed of the propeller blades 25 and the hub 17 immediately decreases due to a large moment of inertia. Therefore, the variable slider 31 moves to the left in FIG. 1, contrary to the acceleration, so that the pitch angle of the propeller blades 25 is reduced from the state of the phantom line in FIG. Resistance to water is reduced.

When the ship is moved backward in the direction opposite to the propulsion direction by the variable pitch propeller shown in FIG. 1, the propeller shaft 13 is driven to rotate in the reverse direction.

According to the present invention described above, the magnitude of the moment of inertia of the propeller blade 25 and the hub 17 and the like and the propeller blade 25
The pitch angle is automatically adjusted by using the resistance to water for rotating, so that the propeller shaft has a double-shaft structure in which an inflection bar penetrates as in the past, There is no need to provide a drive device for adjusting the pitch angle by moving the inflector bar, and a small-sized variable-pitch propeller for boats with a simple configuration can be provided at low cost.

It should be noted that the present invention is not limited to the above-described embodiment, but that the eccentric arm and the engaging member may employ various structures, such as the position of the return damper and the position of the return damper. Can be variously changed, and of course, various changes can be made without departing from the gist of the present invention.

[0035]

According to the present invention, the variable slider is moved using the magnitude of the moment of inertia of the propeller blades and the hub and the resistance to water for rotating the propeller blades, and the pitch angle is automatically adjusted. Because it was set to be adjusted to
It is no longer necessary to have a dual-shaft structure in which an inflection rod penetrates the propeller shaft as in the past, or to provide a drive device for adjusting the pitch angle by moving the inflection rod,
An excellent effect that a small-sized variable pitch propeller having a simple configuration can be provided at low cost can be obtained.

Further, since the variable slider is moved by the inertial force of the propeller blades and the hub to adjust the pitch angle of the propeller blades, acceleration performance can be improved and fuel efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a cut-away side view showing an example of an embodiment of the present invention.

FIG. 2 is a cross-sectional view in the II direction of FIG.

FIG. 3 is a side view showing an example of a conventional propeller.

FIG. 4 is a side view showing an example of a conventional variable pitch propeller.

[Explanation of symbols]

 13 Propeller Shaft 15 Thread 17 Hub 24 Propeller Shaft 25 Propeller Blade 26 Eccentric Arm 31 Variable Slider 33 Engaging Member 35a, 35b Return Damper

Claims (2)

[Claims] 1. A propeller shaft having a threaded portion at a tip, a hub surrounding the outer periphery of the tip of the propeller shaft, and a propeller shaft disposed at a plurality of circumferential positions of the hub at right angles to the propeller shaft. A propeller blade rotatably mounted on a hub, an eccentric arm extending radially to a hub inner end of the propeller shaft, and a variable slider screwed to the screw portion inside the hub, An engagement member provided on the variable slider to rotate the eccentric arm by movement of the variable slider with respect to the screw portion;
And a return damper for moving the variable slider near the middle of the screw portion in the longitudinal direction. 2. The variable pitch for a marine vessel according to claim 1, wherein the pitch of the propeller blade is adjusted by moving the variable slider by the inertial force of the propeller blade and the hub. propeller.