KR20100036936A - Propulsion and steering arrangement - Google Patents

Abstract

PURPOSE: A propulsion and steering system is provided to improve the propeller efficiency by preventing the reduction of propeller slip stream. CONSTITUTION: A propulsion and steering system comprises a screw propeller(2) and a rudder(10) arranged and rotated behind the screw propeller. A fairing(4,6) of the propeller tail end and a bulb type main body(20) provided on a rudder blade form a continuous streamlined structure excluding a narrow gap between the fairing and the bulb type main body. The rudder comprises a twisted top leading edge(12) extended from a top end(17) thereof to the bulb type main body and a twisted bottom leading edge(13) extended from a bottom end(18) thereof to the bulb type main body.

Description

PROPULSION AND STEERING ARRANGEMENT}

The present invention relates to a propulsion and steering apparatus for ships. The device is in the form of a propeller, a rudder disposed behind the propeller, and a bulb-shaped body mounted to the rudder.

The most common means of propelling a ship is a screw propeller with two or more propeller blades. In order to reduce fuel consumption and emissions, the propulsion efficiency of the propeller, which is defined as the ratio between propulsion (or so-called effective power) and transmission power, should be as high as possible.

Estimation of propulsion efficiency for constant engine power is usually made through scale model testing. The prevailing opinion of the model test run at that time, which was developed more than 100 years ago, was proposed that ship propellers and hulls could be viewed and evaluated separately. In practice, however, the interaction between the propeller and the hull is a very important aspect. The propeller and hull should be integral and fitted together if optimal performance can be obtained. It is also valid for the interaction between propellers and attachments of hulls such as rudders.

In order to improve the interaction between the screw propeller and the rudder, GB 762, 445 discloses the positioning of the bulbous body behind the propeller in the extension of the propeller axis. In order to overcome the shrinkage of the propeller slip stream, it has been proposed to push the free protruding head of the bulb body close to the trailing edge of the propeller blade to overlap the propeller hub. In one embodiment, the front portion of the bulbous body is supported by a rudder post of an unbalanced rudder, while the tail or aft portion of the bulbous body is supported by a rudder blade. Supported, these parts of the bulbous body are articulated engagement. In another embodiment, the bulbous body is supported by a balanced rudder, and the propeller hub is attached to the protruding head of the bulbous body to allow the movement of the bulbous body relative to the propeller hub when the rudder is turned. Has a recess coupled by.

EP 0 852 551 A discloses a propulsion and steering device of a ship, which is a bulb body in which a transition ring screwed to the hub of a screw propeller is supported by a rudder horn of semi-spade rudder behind the propeller. To form a continuous streamlined body having a. The streamlined body is interrupted only by the narrow rotational gap between the transition ring and the bulbous body.

WO 2006/112787 A discloses a propulsion and steering device for a ship, which has a fairing hubcap integral with the hub of the screw propeller, with a full spade rudder at the rear of the propeller. Forming a continuous streamlined body having a supported bulbous body. The front end of the bulb body and the hub cap are designed such that the narrow gap between the bulb body and the hub cap remains constant when the rudder is turned. In addition, the rudder is designed to be very complex based on the simulation and optimization of the twisted leading edge form encountered with swirling water propagated backwards by the propeller when the propeller steers the ship in the fore direction. . The twist angle of the rudder is greatest in the region of the bulbous body and decreases away from the bulbous body. The twisted leading edge profile of the rudder increases the propeller efficiency by improving the propeller slip stream through the rudder region.

The object of the present invention is to improve the propulsion and steering devices disclosed in EP 0 852 551 A and WO 2006/112787 A.

According to a first aspect of the invention there is provided a propulsion and steering apparatus for a ship, the apparatus comprising a screw propeller and a pivotable rudder disposed behind the screw propeller. The bulbous body provided in the fairing and rudder provided at the rear end of the screw propeller forms a continuous streamlined body except for the narrow gap between the fairing and the bulbous body. The rudder has a twisted upper leading edge extending from the upper end of the rudder to the bulbous body and a twisted lower leading edge extending from the lower end of the rudder to the bulbous body. The rudder is characterized in that at least one of the upper leading edge and the lower leading edge has a constant twist angle, which makes the rudder much stronger and easier to manufacture than the complicated solution described in WO 2006/112787.

The applicant has found that the fuel consumption of the propulsion and steering device according to the invention can be reduced compared to the conventional propulsion and steering device of EP 0 852 551 A with a leading edge profile without twist.

The applicant has the same fuel savings as the conventional propulsion and steering apparatus of WO 2006/112787 A, in which the propulsion and steering apparatus according to the invention is reduced from the region of the bulb body to the upper or lower end of the rudder. I did not expect to get it. While theoretical propulsion efficiency tends to be higher for the propulsion and steering device of WO 2006/112787 A when the rudder is parallel to the axis of rotation of the propeller, the propulsion efficiency is in the present invention when the rudder is pivoted to steer the ship. There is a higher tendency for the propulsion and steering devices to follow. Considering that the rudder of the ship is often operated at sea against lateral winds and currents, in practice the total propulsion efficiency and fuel consumption will be substantially the same for both the propulsion and steering. If much manoeuvring is required, the total propulsion efficiency and fuel consumption will be more useful for the propulsion and steering device according to the invention.

The propulsion and steering device according to the invention has the further advantage because the manufacturing cost for the rudder with a constant twist angle is less than the manufacturing cost for the rudder of WO 2006/112787 A.

Preferably, both the upper leading edge and the lower leading edge have a constant twist angle.

At least one of the twist angles is preferably less than 15 °, more preferably less than 10 °, most preferably 5 ° to 10 °.

At least one of the twist angles decreases to 0 ° within the range defined by the pivot axis of each leading edge and rudder in the solid direction.

The bulb-shaped body is preferably provided on the rudder blade of the rudder so that the swinging movement of the bulb-shaped body with respect to pairing is allowed at the time of turning of the rudder. The rudder may be a full spade rudder or a semi spade rudder.

The propulsion efficiency and fuel savings of the propulsion and steering device according to the invention are more pronounced as the pivot axis of the rudder is positioned farther from the leading edge of the rudder, or the upper and lower leading edges of the rudder propellers for a given turning angle of the rudder. The further the displacement from the axis of rotation of the more pronounced.

For this reason, the pivot axis of the rudder is preferably 30 to 50% of the maximum rudder length, more preferably 35 to 50% of the maximum rudder length, most preferably the maximum rudder from the upper or lower leading edge in the solid direction. Located at 40-50% of the length.

According to a second aspect of the present invention, there is provided a vessel provided with the aforementioned propulsion and steering device.

Hereinafter, the present invention will be described in detail with reference to Figs. 1 to 6 which describe preferred embodiments of the present invention.

1st Embodiment

1 to 4 show a propulsion and steering device according to a first embodiment of the invention. This propulsion and steering system is mounted on the stern of the ship. The ship may be equipped with one or more propulsion and steering devices.

As shown in FIG. 1, the propulsion and steering apparatus according to the first embodiment includes a screw propeller mounted on a drive shaft of a ship (not shown), and a pivot axis with respect to a rudder stock (not shown) of the ship. A full spade rudder 10 mounted behind the screw propeller 2 in (P). In the present specification, the term "rear" refers to the foreign body direction of the ship as indicated by the arrow (F).

When the screw propeller 2 is driven by the drive shaft, the screw propeller 2 directs the ship in the foreign body direction F or in the opposite solid body direction. When the ship is advanced in the foreign material direction F by the screw propeller 2, the water passing through the screw propeller 2 forms a vortex slip stream moving toward the rudder 10.

The screw propeller 2 has a propeller hub 4 on which three propeller blades 8 are mounted. The propeller hub may have more or fewer blades. The screw propeller 2 is shown as a variable pitch propeller, but may also be a fixed pitch propeller.

The trailing end of the screw propeller 2 is formed by a fairing hub cap 6 which is screwed or heated on the propeller hub 4 so as to be integral with the propeller hub 4. The illustrated outer contour of the propeller hub 4 may be cast in a single part. The fairing hub cap 6 has a recess. This recess engages with the front end 22 of the bulbous body 20, which bulbous body 20 is rudder blade 10a of the rudder 10 by flange connection such that it is integral with the rudder blade 10a. Is attached to.

The front end 22 of the bulbous body 20 projects into the recess of the fairing hub cap 6 without contacting the recess. The recess of the fairing hub cap 6 and the front end 22 of the bulbous body 20 are the recess of the fairing hub cap 6 and the front end of the bulbous body 20 when the rudder 10 pivots. The narrow gap between the 22 is bent so as to remain constant. The bulbous body 20 and the pairing hub cap 6 form a continuous streamlined body interrupted only by a narrow gap. This streamlined body prevents shrinkage of the propeller slip stream, thereby increasing propeller efficiency.

Hereinafter, the design of the rudder 10 will be described in detail with reference to FIGS. 2 to 4. FIG. 2 shows the full spade rudder 10 of FIG. 1 together with the top face of the top end 17 of the rudder 10 and the bottom face of the bottom end 18 of the rudder 10. 3 and 4 show the top and bottom surfaces in more detail.

As shown in FIGS. 2 to 4, the rudder 10 has an upper leading edge 12 extending from the upper end 17 of the rudder 10 to the bulbous body 20, the lower end 18 of the rudder 10. And trailing extending from the upper end 17 of the rudder 10 to the lower end 18 of the rudder 10 behind the lower leading edge 13 and the bulbous body 20. A streamlined profile with edges 15. The upper leading edge 12 has a first twist angle α (8 °) constant with respect to the centerline C of the rudder 10 in the port-side direction, while the lower leading edge 13 is It has a second twist angle β (6 °) that is constant with respect to the centerline C of the rudder 10 in the starboard direction. These twist angles α and β may have different values, but are preferably less than 15 ° in each direction.

The twist of the above-mentioned upper and lower leading edges 12, 13 is reduced to 0 ° in the solid direction in the range defined by the pivot axis P of each leading edge 12, 13 and the rudder 10. Therefore, the trailing edge 15 extends straight without being twisted. In addition, the twist can be reduced to 0 ° within the range defined by the pivot axis P and the trailing edge 15, or the twist is such that the trailing edge 15 is formed such that a fishtail rudder is formed. Can be continued.

When the screw propeller 2 steers the vessel in the foreign body direction F, the twisted leading edges 12, 13 face a vortex which is advanced rearward by the screw propeller 2. The twisted leading edge profile of the rudder 10 improves the propeller slip stream through the rudder region, thereby increasing the propeller efficiency.

As best shown in FIG. 1, the pivot axis P of the rudder 10 shown is located at about 45% of the maximum rudder length L from the upper leading edge 12 in the solid direction. do. Further, the pivot axis P can be located at other points, but preferably at a point of 35 to 50% of the maximum rudder length L in order to obtain a good balance of the rudder 10.

If the pivot axis P of the illustrated rudder 10 is located within the above-mentioned range of the maximum rudder length L, the leading edges 12, 13 of the rudder 10 from the axis of rotation of the screw propeller 2. The displacement of is large for the small turning angle of the rudder 10. Under such large displacements, the constant twist angles (α, β) correspond to the conventional leading edge profiles of WO 2006/112787 A which have a large twist angle close to the bulbous body and a small twist angle close to the upper and lower ends of the rudder. In comparison, the propeller efficiency is increased.

In addition, the manufacturing cost of the rudder 10 with constant twist angles α and β is less than the manufacturing cost of the rudder of WO 2006/112787 A in which the twist angle changes.

2nd Embodiment

5 shows a propulsion and steering device according to a second embodiment of the invention mounted to the stern of a ship.

As shown in FIG. 5, the propulsion and steering apparatus according to the second embodiment includes a screw propeller 2 mounted on the drive shaft 30 of the ship, and a semi spade mounted on the hull of the ship behind the propeller 2. Rudder (semi spade rudder: 10 '). This semi spade rudder 10 'comprises a leading head 10d fixed to the hull and a pivotable rudder blade 10a to which the bulbous body 20 is flanged.

The leading head 10d is provided with the leading head 10d. The lower main bearing 10e supports the rudder head 32 on which the rotatable rudder blade 10a is mounted.

The screw propeller 2 has a propeller hub 4 on which four propeller blades 8 are mounted. The propeller hub may also have more or fewer blades. The screw propeller 2 is shown as a variable pitch propeller, but may also be a fixed pitch propeller.

The propeller hub 4 is cast in a single part to have a pairing shape. Alternatively, the fairing may be a hub cap that is screwed or heated on a propeller hub. The propeller hub 4 has a recess that engages the front end of the bulbous body 20 without contacting the recess. The bulbous body 20 and the propeller hub 4 are continuous, interrupted only by a narrow gap to allow rocking movement of the bulbous body 20 relative to the propeller hub 4 when the rudder blade 10a is pivoted. To form a streamlined body. This streamlined body prevents shrinkage of the propeller slip stream, thereby increasing propeller efficiency. The recess of the propeller hub 4 and the front end of the bulbous body 20 are bent so that the narrow gap is kept constant when the rudder blade 10a is pivoted.

Similar to the full spade rudder 10 according to the first embodiment, the semi spade rudder 10 'according to the second embodiment has a twisted upper leading edge 12, a twisted lower leading edge 13, and a twist And a streamlined profile with trailing edges 15 extending straight. The upper leading edge 12 extends from the upper end of the leading head 10d to the lower end of the leading head 10d. The lower leading edge 13 extends from the lower end 18 of the rudder blade 10a to the bulbous body 20. The upper leading edge 12 has a constant first twist angle with respect to the center line of the rudder 10 'in the starboard direction, while the lower leading edge 13 is at the center line in the port-side direction. Has a constant second twist angle with respect to. These twist angles have a value of less than 15 °, preferably less than 10 °, more preferably 5 ° to 10 ° in each direction. The twist of the upper leading edge 12 decreases to 0 ° towards the rudder stock 32 in the solid direction. The twist of the lower leading edge 13 decreases to 0 ° in the solid direction within the range defined by the pivot axis P of the lower leading edge 13 and the rudder blade 10a. The range between the pivot axis P and the trailing edge 15 can be twisted.

When the screw propeller 2 steers the ship in the foreign body direction, the twisted leading edges 12, 13 face a vortex which is driven rearward by the screw propeller 2. The twisted leading edge profile of the rudder 10 'improves the propeller slip stream through the rudder region, thereby increasing the propeller efficiency.

The illustrated rudder 10 'has a constant rudder length in the foreign material and solid direction. The pivot axis P of the rudder blade 10a is located at about 41% of the rudder length from the upper or lower leading edges 12, 13 in the solid direction. The pivot axis P can also be located at other points, but preferably at a point of 35 to 50% of the rudder length in order to obtain a good balance of the rudder 10 '.

If the pivot axis P of the illustrated rudder 10 'is located within the above range of the maximum rudder length, the displacement of the lower leading edge 13 of the rudder blade 10a from the axis of rotation of the screw propeller 2 is rudder. Large for small turning angles of (10 '). Under this large displacement, the constant twist angle of the lower leading edge 13 increases the propeller efficiency compared to the lower leading edge with a large twist angle close to the notch and a small twist angle close to the lower end of the rudder blade.

In addition, the manufacturing cost of the semi spade rudder 10 'having a constant twist angle is less than the manufacturing cost of the semi spade rudder in which the twist angle changes.

1 shows a propulsion and steering device according to a first embodiment of the invention.

2 shows an upper end and a lower end of the rudder of FIG. 1;

3 shows an upper end of FIG. 2.

4 shows the lower part of FIG. 2.

5 shows a propulsion and steering apparatus according to a second embodiment of the invention mounted on the stern of a ship.

<Explanation of symbols for main parts of drawing>

2: screw propeller 4: propeller hub

6: pairing hub cap 8: propeller blades

10, 10 ': rudder 10a: rudder blade

10d: leading head 12: upper leading edge

13: lower leading edge 15: trailing edge

17: upper end of the rudder 18: lower end of the rudder

20: bulb body L: maximum rudder length

P: pivot axis α, β: twist angle

Claims (9)

As propulsion and steering device for ships, The apparatus comprises a screw propeller 2 and a swivelable rudder 10; 10 ′; 10 ′ disposed behind the screw propeller 2, The fairing bodies 4 and 6 provided at the rear ends of the screw propellers 2 and the bulbous body 20 provided in the rudders 10 and 10 'provide a narrow gap between the pairing and the bulbous body 20. Except that it forms a continuous streamlined body, The rudder 10; 10 ′ is a twisted upper leading edge 12 and the rudder 10; 10 ′ extending from the upper end 17 of the rudder 10; 10 ′ to the bulb-shaped body 20. In the marine propulsion and steering apparatus having a twisted lower leading edge 13 extending from the lower end 18 to the bulb-shaped body 20, At least one of the upper leading edge (12) and the lower leading edge (13) has a constant twist angle (α, β). The method of claim 1, A propulsion and steering apparatus for ships, characterized in that both the upper leading edge (12) and the twisted lower leading edge (13) have a constant twist angle (α, β). The method according to claim 1 or 2, At least one of the twist angles (α, β) is less than 15 °, preferably less than 10 °, more preferably between 5 ° and 10 °. The method according to any one of claims 1 to 3, At least one of the twist angles α, β is reduced to 0 ° within a range defined by the pivot axis P of each leading edge 12, 13 and the rudder 10; 10 ′ in the solid direction. Ship propulsion and steering device characterized in that. The method according to any one of claims 1 to 4, The bulbous body 20 is a rudder blade of the rudder 10; 10 ′ such that the swinging movement of the bulbous body 20 with respect to the fairing 6 is allowed upon pivoting of the rudder blade 10a. Propulsion and steering apparatus for ships, characterized in that installed in (10a). The method of claim 5, The rudder (10) is a propulsion and steering apparatus for ships, characterized in that the full spade rudder. The method of claim 5, The rudder (10 ') is a propulsion and steering apparatus for ships, characterized in that the semi spade rudder. The method according to any one of claims 1 to 7, The pivot axis P of the rudder 10; 10 ′ is 30-50% of the maximum rudder length L, preferably the maximum rudder length, from the upper or lower leading edges 12, 13 in the solid direction. A propulsion and steering apparatus for ships, characterized in that it is located at a point of 35-50% of L), more preferably 40-50% of the maximum rudder length (L). A ship provided with the propulsion and steering apparatus according to any one of claims 1 to 8.

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