JP3104177U - Stern tube arrangement structure - Google Patents

Abstract

To provide a stern tube arrangement structure in which a ship does not generate a stress high enough to generate a crack between a partition wall, particularly an engine room wall, and a stern tube.
A stern tube (3) through which a propeller shaft (5) for transmitting a driving force from an internal combustion engine of a ship to a propeller is inserted, and an engine room wall (11a) facing the internal combustion engine, and the stern tube (3) is slidably inserted. And a seal box 25 having an O-ring groove for sealing between the stern tube and the stern tube.
[Selection] Figure 2

Description

  The present invention relates to a stern tube arrangement structure, and more particularly to a stern tube arrangement structure for supporting a propeller shaft that transmits power from an internal combustion engine of a ship to a propeller.

  A ship rotates a propeller shaft using a driving force generated by an internal combustion engine such as a diesel engine, and obtains a propulsion force by rotation of a propeller fixed ahead. The propeller shaft is housed in a tube called a stern tube or a stun tube, is supported by a bearing provided in the tube, and is driven to rotate.

The stern tube is usually fixed to the bulkhead of the hull by welding. However, since the propeller shaft passes through the stern tube, high precision is required for its arrangement. For this reason, a method of accurately arranging the stern tube using a piano wire or the like has been proposed (for example, see Patent Document 1).
JP 2001-63693 A

  2. Description of the Related Art In recent years, many fishing boats have been built that can carry fish while keeping them alive in a low-temperature fish tank between a fish ground and a market or a consumption area because of an emphasis on freshness. In such a fishing boat, the distance between the engine room in which the internal combustion engine is arranged and the stern is large, so that the propeller shaft and the stern tube are longer than those of a normal fishing boat. The length of the stern tube and the like greatly depends on the number and size of the fish tank. A normal fishing boat without a fish tank has a stern tube of about 1500 mm in length, whereas a typical fishing boat with a fish tank has a length of about 4500 mm.

  In a fishing boat with the above-mentioned fish tank, the long stern tube as described above is fixed to the wall of the engine room on the internal combustion engine side, the hull outer plate on the propeller side, and the partition wall between them, all by welding. . The longer the length of the stern tube, the more the bulkheads penetrate, and the middle portions are welded and fixed at each of the bulkheads.

  However, as described above, when the stern tube is three times as long as the conventional length, strain generated in the hull is transmitted to the stern tube over a wide range, and a very high stress concentration is generated in the stern tube. Further, a large stress is generated by thermal expansion and thermal contraction. This creates a large stress between the bulkhead and the stern tube, causing cracks in the bulkhead in some cases and in the stern tube itself in other cases. That is, cracks are generated on the side having the lower strength or durability. If the stern tube is cracked, not only can the propeller shaft not be supported with high accuracy and reliability, but also the seawater transmitted from the propeller to the propeller shaft cannot be sealed. In addition, when a crack occurs in the wall of the engine room, not only the stern tube cannot be supported at a predetermined position, but also the rigidity of a predetermined hull cannot be secured.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a stern tube arrangement structure that does not generate a stress high enough to cause a crack between a partition wall, particularly an engine room wall, and a stern tube.

  The stern tube arrangement structure of the present invention is fixed to a stern tube for inserting a propeller shaft for transmitting a driving force from a power engine of a ship to a propeller and an engine room wall facing the power engine so that the stern tube can slide. And a seal box having a seal mechanism for inserting the stern tube and sealing the stern tube.

  According to the above configuration, the stern tube and the engine room wall are not fixed. Therefore, the repeated deformation due to the large waves of the ship is not transmitted to the stern tube as it is. As a result, generation of a large stress between the stern tube and the engine room wall is prevented, and the occurrence of cracks is completely suppressed.

  The stern tube described above can slidably penetrate a partition wall provided on the ship.

  With this configuration, since the stern tube is not fixed to the bulkhead between the engine room and the stern, the repeated deformation of the hull is not transmitted to the stern tube as it is, and a large stress is applied between the stern tube and the middle bulkhead. Will not occur.

  Further, the stern tube may be fixed to the stern hull outer plate with a stern sheath portion through which the stern tube passes.

  The stern tube must be fixed somewhere on the ship, but at the stern end of the stern tube, with the stern sheath interposed to prevent high stress caused by hull deformation be able to. In addition, by fixing the hull skin and the stern sheath by welding, etc., and fixing the stern sheath and the stern tube, deformation of the hull is more stable than fixing the stern tube directly to the hull skin. The degree of transmission to the tube can be reduced. That is, the stern sheath has a buffering effect on the transmission of the deformation of the hull to the stern tube. Further, by fixing the stern tube only at the stern sheath portion as described above, deformation caused by thermal expansion and thermal contraction can be shifted by sliding at other partition walls, so that high stress is prevented from being generated. Can be.

  Next, the best mode for carrying out the invention will be described with reference to the drawings. FIG. 1 is a schematic view showing an arrangement structure of a stern tube according to an embodiment of the present invention. An internal combustion engine 6 such as a diesel engine is disposed in an engine room 15. The internal combustion engine 6 and a propeller 7 disposed at the stern are connected to each other to transmit rotational driving force from the internal combustion engine to the propeller 7. A propeller shaft 5 is provided. The propeller shaft 5 extends through the stern tube 3. The stern tube 3 slidably penetrates the engine room wall 11a and the intermediate partition 11b on the internal combustion engine side. As will be described later, the stern tube 3 is fixed to a stern sheath portion 19 fixed to a hull skin 18 at the stern. A rudder (rudder) 8 is arranged behind the propeller 7.

  Further, the above-mentioned stern tube arrangement structure is arranged below the fish tank 13 located between the engine room 15 in which the internal combustion engine 6 is arranged and the stern. In this case, the propeller shaft 5 and the stern tube 3 are much longer than a ship without a fish tank, and have a length of about 4500 mm.

  FIG. 2 is a view showing the stern tube 3 in a state where the propeller shaft 5 is inserted. The end of the propeller shaft 5 on the side of the internal combustion engine is gripped by a coupling (connector) 6a, and a rotational force is applied from the internal combustion engine. The stern tube 3 is arranged on the outer periphery of the propeller shaft 5, and the propeller shaft is rotatably held by a bearing (not shown) provided in the stern tube. A seal box 25 is fixed to the wall 11a of the engine room where the internal combustion engine is arranged. The seal box 25 includes a reinforcing plate 21, a seal base 22, and a seal body 23. Of these, the reinforcing plate 21 is fixed to the engine room wall 11a by a welded portion w, and the seal base 22 is fixed to the reinforcing plate 21 by a welded portion w. The seal main body 23 has a structure that can be divided as described later, and each is fixed to the seal main body 23 with a bolt.

  The stern tube 3 slidably penetrates the inside of the seal body. At the end of the stern tube 3 on the side of the internal combustion engine, a stern tube end 3a is provided in a flange shape, and a propeller shaft seal mechanism 27 for preventing intrusion of seawater transmitted along the propeller shaft is provided at the stern tube end 3a. .

  At the stern, the stern tube 3 passes through the stern sheath 19. The stern sheath portion 19 is fixed to the hull outer plate 18 at the stern by a welded portion w. Further, the stern tube 3 is similarly fixed to the stern sheath portion 19 by the welded portion w.

FIG. 3 is a view showing the vicinity of the penetrating portion of the engine room wall 11a of the stern tube. The stern tube 3 is not connected to the hole inner surface 51 of the engine room wall 11a and the shield box inner diameter surface 55, and is slidable with the hole inner surface 51 and the inner diameter surface 55 in accordance with expansion and contraction of the stern tube. It is in. Both the engine room wall 11a and the reinforcing plate 21 and the reinforcing plate 21 and the seal base 22 are connected by a welded portion w. Welding is performed by fillet welding. The seal body 23 is provided with an O-ring groove 23a to form a seal with the outer periphery of the stern tube. Therefore, even if there is seawater traveling along the outer periphery of the stern tube, the O-ring prevents the seawater from entering the engine room. The fixing of the seal main body 23 to the seal base 22 is performed by a bolt 26 that penetrates through the seal main body and is screwed into a female screw provided on the seal base.

  As described above, the seal mechanism can be formed by the O-ring groove and the O-ring housed therein and wound around the outer periphery of the stern tube, and a highly reliable seal mechanism can be obtained with a simple structure.

  The stern tube 3 long connected by the welded portion w has a flange-like end 3a, and a propeller shaft seal mechanism 27 for preventing seawater traveling along the outer periphery of the propeller shaft from entering the engine room is provided therein. Can be The propeller shaft sealing mechanism 27 is formed by a bolt screwed into a female screw provided at the end 3a of the stern tube.

  The stern tube 3 is welded and fixed to the stern sheath portion 19 at the end on the stern side as described above, but is not fixed to the engine room wall 11a and the seal box 25. For example, the hull and the stern tube are connected to each other by the stern tube. The relative positional relationship can be shifted along the longitudinal direction. For this reason, the deformation of the hull is not transmitted to the stern tube as it is, but is alleviated by a shift in the relative positional relationship between the stern tube and the large stress concentration does not occur between the stern tube and the engine room wall.

  FIG. 4 is a diagram showing the stern tube 3 penetrating the partition wall 11b below the fish tank between the stern and the engine room. A tubular intermediate sheath 33 is fixed to each partition 11b by a welded portion w, and the stern tube 3 is slidably inserted through the intermediate sheath 33. Therefore, large stress concentration does not occur between the stern tube and the bulkhead 11b between the stern and the engine room.

  FIG. 5 is a plan view showing the seal body 23. The seal body 23 is divided into two parts 23x and 23y. To make one, a bolt is inserted into the hole 23d and fastened with a nut. By dividing into two in this manner, the O-ring can be housed in the O-ring groove 23a, and a seal by the O-ring can be formed while passing a stern tube (not shown) through the inner diameter 23f. When fixing the seal main body 23 to the seal base, a bolt is inserted into the bolt hole 23c, and the bolt is screwed into a female screw provided in the seal base to be fixed.

  FIG. 6 is a view of the VI-VI line in FIG. That is, it is one part of the seal body. In this seal body, three O-ring grooves are provided, which is useful for stable holding of the stern tube.

  When the stern tube is fixed to the engine room wall, a large stress is generated between the engine room wall and the stern tube, and a crack is generated in the weaker one. Even in a ship having a fish tank as described above, as described above, the stern tube has a structure in which the seal box fixed to the engine room wall is freely slidably inserted. No stress is generated.

  By using the above stern tube arrangement structure, for example, even if the stern tube becomes long, the stern tube and the engine room wall are not fixed, so that the deformation of the hull is not transmitted to the stern tube as it is, and the engine room wall and the stern tube are not fixed. Can shift the relative positional relationship with each other. For this reason, large stress concentration does not occur on the stern tube and the engine room wall, and the occurrence of cracks can be prevented. Further, the stern tube is not fixed to the partition wall between the stern and the engine room, and is arranged so as to cause a relative displacement. Therefore, the stress does not increase even with other partition walls. In particular, since the stern tube is only fixed to the hull outer plate with the stern sheath portion provided at the stern interposed, it is equivalent to being fixed at one place. Therefore, not only deformation of the hull but also thermal expansion and contraction can be released, and generation of large stress can be prevented. For this reason, especially in a ship having a fish tank, a stern tube with high durability can be arranged.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to the embodiments of the present invention. The scope of the present invention is indicated by the description of the utility model registration claims, and further includes all changes within the meaning and scope equivalent to the description of the utility model registration claims.

  In the stern tube arrangement structure of the present invention, the stern tube is not fixed to the engine room wall or the bulkhead but is fixed to the hull substantially at one place, so that the deformation repeatedly occurring on the hull is not transmitted to the stern tube as it is. The relative positional relationship can be shifted from each other. For this reason, a large stress is prevented from being generated between the stern tube and the hull, and the occurrence of cracks can be completely suppressed. As a result, in a vessel equipped with a fish tank which has to have a long stern tube, the stern tube arrangement structure according to the present invention particularly effectively acts to reduce stress, so that it is widely used in ships in this field. Be expected.

It is a figure showing an outline of a stern tube arrangement structure in an embodiment of the present invention. It is the schematic diagram which looked at the stern tube arrangement structure of FIG. 1 from below. FIG. 3 is a diagram showing a stern tube arrangement structure near an engine room wall in FIG. 2. It is a figure which shows the stern tube which penetrates the partition between a stern and an engine room. It is a top view which shows a seal main-body part. FIG. 6 is a view taken along line VI-VI of FIG. 5.

Explanation of reference numerals

  3 Stern tube, 3a end, 5 propeller shaft, 6 internal combustion engine, 6a coupling (coupler), 7 propeller, 8 rudder, 11a engine room wall, 11b partition wall, 13 fish tank, 15 engine room, 18 hull outer panel , 19 stern sheath part, 21 reinforcing plate, 22 seal base, 23 seal body, 23a O-ring groove, 23c hole for fixing to seal base, 23d hole for fastening two divided parts, 23f inner diameter, 23x, 23y seal body One-sided parts, 25 seal box, 26 bolts, 27 propeller shaft seal mechanism, 33 middle sheath, 51 engine room hole, 55 seal box inner diameter, w welded part.

Claims (3)

A stern tube for inserting a propeller shaft for transmitting driving force from a power engine of the ship to the propeller,
A stern tube arrangement structure, comprising: a seal box fixed to an engine room wall facing the power engine, slidably penetrating the stern tube, and having a seal mechanism for sealing between the stern tube and the stern tube.   The stern tube arrangement structure according to claim 1, wherein the stern tube slidably penetrates a partition wall provided in the ship.   3. The stern tube arrangement structure according to claim 1, wherein the stern tube is fixed to the hull outer plate of the stern with a stern sheath portion through which the stern tube is inserted. 4.

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