JP2011093503A - Propulsion structure of twin-screw vessel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a propulsion structure of a twin-screw vessel, enhanced in propulsion performance. <P>SOLUTION: This propulsion structure includes: a first propeller structure 2-1 installed on a hull 6; and a second propeller structure 2-2 installed on the hull. Each includes: bossings 3-1, 3-2 extending rearward from a vessel bottom; propeller shafts 9-1, 9-2 rotatably supported by the bossing, and extended rearward; and propellers 4-1, 4-2 installed on the propeller shafts so as to generate a propulsion force accompanied by the rotation of the propeller shafts. At least one of the first propeller structure and the second propeller structure further includes: bearings 8-1, 8-2 arranged at rear of the propellers so as to support the propeller shafts; and bearing supports installed on the vessel bottom so as to support the bearings. The bearing supports are configured so as to generate a lift force with a forward directional component while receiving the water current of the propellers. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a propulsion structure for a twin-screw ship.

  The ship is provided with a propulsion structure in order to obtain a propulsive force. A propeller is usually used as the propulsion structure. As such a propulsion structure, a uniaxial system and a biaxial system are known. In the single shaft system, a single propeller shaft to which a propeller is attached is used. In the biaxial system, two propeller shafts extending in parallel are used, and a propeller is attached to each propeller shaft. In the single-shaft system, the propeller shaft must be rotated with a large work amount in order to obtain a desired driving force. As a result, cavitation tends to occur, and the propeller shaft vibration tends to increase. Since the vibration of the hull tends to increase, it tends to be disadvantageous in terms of ride comfort. On the other hand, in the biaxial system, the amount of work required to rotate each propeller can be reduced. As a result, cavitation can be suppressed and vibration can be reduced. This is advantageous in terms of ride comfort. Even if one of the propellers breaks down, the ship can be propelled by the other propeller.

  FIG. 1A is a schematic view of a ship using a biaxial system (hereinafter referred to as a biaxial ship) viewed from below. FIG. 1B is a side view of the biaxial ship. As shown in FIGS. 1A and 1B, this biaxial ship has a rudder 102 attached to the stern of a hull 101. Further, as the propulsion structure 100, the two main engines 106 (106-1, 106-2), the two bossings 103 (103-1, 103-2), and the two propeller shaft members 105 (105-1, 105-2). ) And two propellers 104 (104-1, 104-2). Each main engine 106 is a device for driving the propulsion structure 100 and is disposed inside the hull 101. Each propeller shaft member 105 is connected to each main engine 106 at one end, and extends toward the outside rear of the hull 101. Each bossing 103 is provided to support each propeller shaft member 105. Each bossing 103 protrudes rearward from the hull 101. Each bossing 103 is hollow, and each propeller shaft member 105 extends out of the boat through each bossing 103. The rear end portion of each propeller shaft member 105 protrudes from each bossing 103. Each propeller 104 is attached to a rear end portion of each propeller shaft member 105.

  Here, since the two propeller shaft members 105 are used in the biaxial ship, each propeller shaft member 105 is disposed at a position away from the central portion. The hull 101 is normally formed so that the bottom of the ship is deeper at the center and shallow at the part away from the center. Therefore, in each propeller shaft member 105, the length of the part arrange | positioned outside a ship becomes long. Accordingly, each bossing 103 also becomes longer. The bossing 103 disposed outside the ship becomes a resistance and lowers the propulsion performance. That is, biaxial ships are more likely to be disadvantageous than uniaxial ships in terms of propulsion performance. Therefore, it is desired to improve the propulsion performance in the twin-screw ship.

  Related technology is described in Patent Document 1 (WO 2006-095774). In Patent Document 1, in a ship equipped with an overlapping propeller, the waterline surface shape of the stern hull in the range of at least 0.4 R in the vertical direction of the axis of the propeller (R is the propeller radius) is the birth of the waterline surface. The vessel angle is set to be 15 degrees or less with respect to the hull center line, and the imaginary width (both widths) at the tip position when the waterline surface shape is extended to the tip is sharpened to 600 mm or less. The stern structure is described.

  Another related technique is described in Patent Document 2 (Japanese Patent Laid-Open No. 8-72797). Patent Document 2 discloses that two propeller shafts projecting rearward from the hull boshing on both left and right sides of the stern are provided with an extension shaft extending rearward from the propeller at the rear end, and the rear end of the extension shaft. It is described that the portion is supported by a bearing provided on the ladder horn. Thereby, since the conventional shaft bracket is abolished, it is described that the resistance of the hull is reduced.

WO2006-095774 JP-A-8-72797

  It is desired to further improve the propulsion performance of the biaxial ship. An object of the present invention is to provide a propulsion structure for a twin-screw ship capable of improving the propulsion performance.

  The means for solving the problem will be described below using the numbers used in the (DETAILED DESCRIPTION). These numbers are added to clarify the correspondence between the description of (Claims) and (Mode for Carrying Out the Invention). However, these numbers should not be used to interpret the technical scope of the invention described in (Claims).

  The propulsion structure (1) for a biaxial ship according to the present invention includes a first propeller structure (2-1) attached to the hull (6) and a second propeller structure (2) attached to the hull (6). -2). The first propeller structure (2-1) and the second propeller structure (2-2) are rotatably supported by a boshing (3) and a boshing (3), respectively, extending rearward from the ship bottom. A propeller shaft member (9) that extends rearward from the boshing (3) and attached to the propeller shaft member (9), rotates as the propeller shaft member (9) rotates, and generates a propeller water flow toward the rear. And a propeller (4) that generates a propulsive force that propels the hull (6) forward. At least one of the first propeller structure (2-1) and the second propeller structure (2-2) is further disposed rearward of the propeller (4), and supports the propeller shaft member (9). (10) and bearing support members (11, 12) attached to the ship bottom and supporting the bearing (10). The bearing support members (11, 12) are mounted so as to receive a propeller water flow and generate a lift having a forward direction component.

  According to the present invention, the rear end portion of the propeller shaft member (9) is supported by the bearing (10). Since the propeller shaft member (9) is supported by both the boshing (3) and the bearing (10), the load received by the boshing (3) can be reduced. As a result, the size of the boshing (3) can be reduced, and the resistance caused by the boshing (3) can be reduced. As a result, propulsion performance can be improved. In addition, according to the present invention, the bearing support members (11, 12) receive the propeller water flow and generate a lift having a forward direction component. This lifting force makes it possible to further improve the propulsion performance.

  The bearing support members (11, 12) are preferably inclined with respect to the direction in which the propeller shaft member (9) extends so that the cross-sectional shape of the plane parallel to the horizontal plane is a shape extending along the propeller water flow. .

  The bearing support members (11, 12) are disposed rearward of the propeller (4), and extend from the bracket (11), the bracket (11), and the bearing (10), so as to connect the ship bottom and the bearing. Are preferably provided with fins (12) extending vertically downward.

  Each of the bracket (11) and the fin (12) preferably extends along the propeller water flow.

  From one viewpoint, the bearing (10) and the bearing support members (11, 12) may be provided in both the first propeller structure (2-1) and the second propeller structure (2-2). preferable.

  The propeller (4-1) provided in the first propeller structure (2-1) is located behind the propeller (4-2) provided in the second propeller structure (2-2). Also good. In this case, the bearing (10) and the bearing support members (11, 12) may be provided only in the second propeller structure (2-2). The first propeller structure (2-1) includes a front bearing (16) disposed in front of the propeller (4-1), a front bearing (16) supported on the ship bottom, and extending to support the front bearing (16). A bearing support member (17) may be provided.

  In the first propeller structure (2-1) and the second propeller structure (2-2), the position where the propeller (4) is provided may be shifted in the front-rear direction. When viewed from the rear, a part of the circular region (14-1) occupied by the propeller (4-1) in the first propeller structure (2-1) during rotation is part of the second propeller structure (2-2). It is preferable that the propeller (4-2) in Fig. 4 overlaps with a part of the circular area (14-2) occupied during rotation.

  ADVANTAGE OF THE INVENTION According to this invention, the propulsion structure of the biaxial ship which can improve propulsion performance is provided.

It is the schematic which shows a biaxial ship. It is a side view of a biaxial ship. It is the schematic when the ship carrying the propulsion structure of the biaxial ship which concerns on embodiment is seen from the downward direction. It is the schematic which shows the side surface of a ship. It is a figure when seeing a propeller from back. It is the schematic which shows the structure of a bearing part. It is sectional drawing which shows a bracket and a propeller. It is sectional drawing which shows a fin and a propeller. It is a figure which shows the propulsion structure which concerns on a modification. It is a side view which shows a front bearing part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2A is a schematic view when a ship on which the propulsion structure 1 for a biaxial ship according to the present embodiment is mounted is viewed from below. FIG. 2B is a schematic view showing the side of this ship. 2A and 2B, the bow side is shown as the front, and the stern side is shown as the rear. Further, a line passing through the center portion of the hull 6 and extending from the front toward the rear is shown as the center line. As shown in FIG. 2A, a rudder 5 is attached to the stern of the hull 6. The propulsion structure 1 is provided at the stern of the hull 6. The hull 6 is formed deeper as it is closer to the center line, and shallower as it is far from the center line.

  The propulsion structure 1 has a first propeller structure 2-1 and a second propeller structure 2-2. The first propeller structure 2-1 and the second propeller structure 2-2 are arranged at positions that sandwich the center line.

  As shown in FIGS. 2A and 2B, the first propeller structure 2-1 includes a main machine 7 (7-1), a boshing 3 (3-1), a propeller shaft member 9 (9-1), and a propeller boss 13. (13-1), a propeller 4 (4-1), and a bearing portion 8 (8-1).

  The main machine 7-1 is provided to rotate the propeller shaft member 9-1. The main engine 7-1 is disposed inside the hull 6.

  The propeller shaft member 9-1 is a member that serves as a rotation shaft of the propeller 4-1. The propeller shaft member 9-1 is connected to the main machine 7-1 at one end. The propeller shaft member 9-1 extends rearward from the main engine 7-1 and protrudes outside the hull 6.

  The bossing 3-1 is provided to support the propeller shaft member 9-1. The boshing 3-1 extends from the hull 6 so as to protrude rearward. The boshing 3-1 is hollow, and the propeller shaft member 9-1 is disposed in the boshing 3-1. The rear end portion of the propeller shaft member 9-1 protrudes from the boshing 3-1.

  The propeller shaft member 9-1 is provided with a propeller boss 13-1 at a portion protruding from the boshing 3-1. The propeller boss 13-1 is provided to support the propeller 4-1, and reinforces the propeller shaft member 9-1 so as to obtain a strength capable of supporting the propeller 4-1.

  The propeller shaft member 9-1 extends further rearward from the portion where the propeller 4-1 and the propeller boss 13-1 are provided. The bearing portion 8-1 is disposed behind the propeller 4-1, and supports the rear end portion of the propeller shaft member 9-1. By providing the bearing portion 8-1, the propeller shaft member 9-1 can be supported by both the boshing 3-1 and the bearing portion 8-1. Therefore, it is possible to reduce the load to be supported by the bossing 3-1, and to reduce the strength required for the bossing 3-1. As a result, it is possible to reduce the size of the bossing 3-1. Thereby, the resistance which the ship to propel receives by the boshing 3-1 can be reduced, and the propulsion performance can be improved.

  In the first propeller structure 2-1, the main machine 7-1 rotates the propeller shaft member 9-1. Thereby, propeller 4-2 rotates and the propulsive force for propelling hull 6 is obtained.

  Similar to the first propeller structure 2-1, the second propeller structure 2-2 includes the main engine 7 (7-2), the boshing 3 (3-2), the propeller shaft member 9 (9-2), and the propeller boss. 13 (13-2), propeller 4 (4-2), and bearing 8 (8-2). The propeller shaft member 9-2 extends in parallel with the propeller shaft member 9-1.

  Next, the positional relationship between the propeller 4-1 provided in the first propeller structure 2-1 and the propeller 4-2 provided in the second propeller structure 2-2 will be described. As shown in FIG. 2A, the propeller 4-1 is disposed behind the propeller 4-2. Moreover, FIG. 2C is a figure when the propeller 4-1 and the propeller 4-2 are seen from the back. As shown in FIG. 2C, a part of the circular area 14-1 occupied when the propeller 4-1 is rotated overlaps a part of the circular area 14-2 occupied when the propeller 4-2 is rotated. ing. That is, the propulsion structure 1 according to the present embodiment has a so-called overlapping propeller structure. By adopting such a configuration, the propeller shaft member 9-1 and the propeller shaft member 9-2 can be disposed close to each other. That is, each propeller shaft member 9 can be disposed at a position close to the center line. As a result, the length of the portion where each propeller shaft member 9 protrudes out of the ship can be shortened, and the length of each bossing 3 can be shortened. Therefore, resistance due to the boshing 3 can be reduced, and propulsion performance can be improved.

  Here, in the present embodiment, the configuration of the bearing portion 8 is devised in order to obtain higher propulsion performance. Below, the structure of the bearing part 8 is explained in full detail.

  FIG. 3 is a schematic diagram showing the configuration of the bearing portion 8 (8-1, 8-2). As shown in FIG. 8, the bearing portion 8 is provided with a bracket 11, a bearing 10, and fins 12. The bracket 11 is provided to support the bearing 10. The upper end of the bracket 11 is connected to the hull 6. The bracket 11 is connected to the bearing 10 at the lower end and supports the bearing 10. The bearing 10 supports the propeller shaft member 9 to be rotatable. The fins 12 are attached to generate lift with a forward component. The fin 12 is connected to the bearing 10 and extends vertically downward from the bearing 10.

  FIG. 4A is a cross-sectional view along AA ′ shown in FIG. 3 and shows the cross-sectional shapes of the bracket 11 and the propeller 4. In FIG. 4A, the direction in which the propeller shaft member 9 extends is shown as the axial direction. The directions in which the propeller 4 rotates are shown as the rotation direction and the circumferential direction. The propeller 4 generates a propeller water flow backward when rotating. This propeller water flow is a swirl flow, and is inclined with respect to the axial direction at the position where the bracket 11 is disposed. In FIG. 4A, the flow velocity and direction of the propeller water flow at the position where the bracket 11 is provided are shown as a combined flow velocity W. The bracket 11 is disposed to be inclined along the axial direction by an angle θ so as to extend along the combined flow velocity W. The angle θ is, for example, 10 ° or less. Thus, by arranging the bracket 11 so as to extend along the propeller water flow, the backward force that the bracket 11 receives from the propeller water flow can be reduced.

  Here, the combined flow velocity W can be divided into an axial flow velocity Vx along the axial direction and a circumferential flow velocity Vt along the circumferential direction. The cross-sectional shape of the bracket 11 is a streamlined type so as to generate the lift L upon receiving the circumferential flow velocity Vt. This lift L has a forward direction component. A force obtained by subtracting a backward direction component of the drag D (a force received by the bracket 11 by the axial flow velocity Vx) from the forward direction component of the lift L acts on the bracket 11 as the thrust Ts. With this thrust Ts, the propulsion performance of the ship can be improved.

  4B is a cross-sectional view taken along BB ′ shown in FIG. 3 and shows the cross-sectional shapes of the fins 12 and the propeller 4. Similarly to the bracket 11, the cross-sectional shape of the fin 12 is inclined by an angle θ with respect to the axial direction, and extends along the propeller water flow. The fins 12 are also streamlined, and are configured to receive a propeller water flow to generate lift L and to obtain thrust Ts.

  As described above, according to the present embodiment, the bearing portion 8 receives the propeller water flow and generates a lift having a forward direction component. Thereby, the thrust which faces a forward direction can be obtained and the propulsion performance of a ship can be improved.

  In the present embodiment, the propulsion structure having the overlapping propeller structure has been described. However, the present invention is not limited to the overlapping propeller structure. The propulsion structure 1 according to the present invention can also be applied to other biaxial ships.

  Moreover, in this embodiment, the case where the bearing part 8 was attached with respect to each of the two propeller shaft members 9 (9-1, 9-2) was demonstrated. However, the bearing portion 8 does not necessarily have to be attached to each of the two propeller shaft members 9 (9-1, 9-2), and as shown in a modification described below, one of the propeller shaft members The bearing portion 8 may be attached only to 9.

  An example of the propulsion structure 1 in which the bearing portion 8 is provided only on one propeller shaft member 9 will be described as a modification. FIG. 5 is a view showing a propulsion structure 1 according to this modification. As shown in FIG. 5, in the propulsion structure 1 according to the first modified example, the first propeller 4-1 is disposed behind the second propeller 4-2. And only the 2nd propeller structure 2-2 is provided with the bearing part 8 in the rear end. Instead, a front bearing portion 15 is provided on the propeller shaft member 9-1 in front of the propeller 4-1. FIG. 6 is a side view showing the front bearing portion 15. As shown in FIG. 6, the front bearing portion 15 includes a bracket 17 and a bearing 16. The bearing 16 supports the propeller shaft member 9-1 in a rotatable manner. The bracket 17 connects the hull 6 and the bearing 16 and supports the bearing 16. The front bearing portion 15 is not configured to generate a thrust upon receiving a propeller water flow like the bearing portion 8, and is attached only to support the propeller shaft member 9-1.

  Even if the configuration as in the above-described modification is adopted, in the second propeller structure 2-2, since the lift having the forward direction component is generated by the bearing portion 8 as described above, the propulsion performance is improved. Is possible.

DESCRIPTION OF SYMBOLS 1 Propulsion structure 2-1 1st propeller structure 2-2 2nd propeller structure 3 Boshing 4 Propeller 5 Rudder 6 Hull 7 Main engine 8 Bearing part 9 Propeller shaft member 10 Bearing 11 Bracket 12 Fin 13-1 Propeller boss 13-2 Properlabus 14-1 Circular Occupied Area 14-2 Circular Occupied Area 15 Front Bearing 16 Front Bearing 17 Front Bearing Support Member (Bracket)
DESCRIPTION OF SYMBOLS 100 Propulsion structure 101 Hull 102 Rudder 103 Boshing 104 Propeller 105 Propeller shaft member 106 Main engine

Claims (7)

A first propeller structure attached to the hull;
A second propeller structure attached to the hull;
Comprising
The first propeller structure and the second propeller structure are respectively
Bossing that extends backward from the bottom of the ship,
A propeller shaft member rotatably supported by the boshing and extending rearward from the boshing;
A propeller that is attached to the propeller shaft member, rotates with the rotation of the propeller shaft member, generates a propeller water flow toward the rear, and generates a propulsive force that propels the hull forward;
At least one of the first propeller structure and the second propeller structure further includes:
A bearing disposed behind the propeller and supporting the propeller shaft member;
A bearing support member attached to the ship bottom and supporting the bearing;
The bearing support member is a propulsion structure for a twin-screw ship configured to receive the propeller water flow and generate lift having a forward direction component. A propulsion structure for a twin-screw ship according to claim 1,
The propulsion structure for a twin-screw ship, wherein the bearing support member is inclined with respect to a direction in which the propeller shaft member extends so that a cross-sectional shape by a plane parallel to a horizontal plane extends along the propeller water flow. A propulsion structure for a twin-screw ship according to claim 2,
The bearing support member is
A bracket disposed rearward of the propeller and extending to connect the ship bottom and the bearing;
A propulsion structure for a twin-screw ship including fins extending from the bracket toward a vertically lower side than the bearing. A propulsion structure for a twin-screw ship according to claim 3,
Each of the bracket and the fin is a propulsion structure for a twin-screw ship that extends along the propeller water flow. A propulsion structure for a twin-screw ship according to any one of claims 1 to 4,
The bearing and the bearing support member are a propulsion structure for a twin-screw ship provided in both the first propeller structure and the second propeller structure. A propulsion structure for a twin-screw ship according to any one of claims 1 to 4,
The propeller included in the first propeller structure is located behind the propeller included in the second propeller structure;
The bearing and the bearing support member are provided only in the second propeller structure,
The first propeller structure is:
A front bearing disposed in front of the propeller;
A propulsion structure for a twin-screw ship, comprising: a forward bearing support member that is supported by the ship bottom and extends to support the forward bearing. A propulsion structure for a twin-screw ship according to any one of claims 1 to 6,
The first propeller structure and the second propeller structure are displaced from each other at the position where the propeller is provided;
When viewed from the rear, a part of the circular area occupied by the propeller in the first propeller structure overlaps with a part of the circular area occupied by the propeller in the second propeller structure. The propulsion structure of a biaxial ship.

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