WO2011062463A2

WO2011062463A2 - Stern tube bush unit

Info

Publication number: WO2011062463A2
Application number: PCT/KR2010/008303
Authority: WO
Inventors: 최금식
Original assignee: 선보공업주식회사; 선보하이텍 주식회사
Priority date: 2009-11-23
Filing date: 2010-11-23
Publication date: 2011-05-26
Also published as: KR100940906B1; CN102069903A; WO2011062463A3

Abstract

The present invention relates to a stern tube bush unit. When assembling the stern tube bush unit onto a hull, the rear surface of the stern of the hull and the rear surface of a first bush housing are disposed on the same plane, for coupling, and a rubber sponge is mounted between the bush housing and the hull for retaining sealing resin. Therefore, it is possible to increase the use of space at the rear side of the stern of the hull, and increase the sealing force of the resin which is filled between the hull and the bush housing. In addition, it is possible to firmly mount the stern tube bush unit at the precise position in the hull through a stable structure in a short time.

Description

Sterntube Bush Unit

The present invention relates to a stern tube bushing unit installed between a propulsion shaft and a hull of a ship, and more particularly, can improve the space utilization of the rear side of the hull and increase the sealing effect of the resin filled between the hull and the bushing housing. The present invention relates to a stern tube bush unit that can be installed in a rigid, fast and stable structure with high construction quality at an accurate position in a hull.

In general, among the various bearings supporting the propulsion shaft of the ship, the bearing fitted to the stern tube is a bush type bearing (hereinafter referred to as the `` stern tube bush unit ''), and when the stern tube bush unit is constructed, a propeller acting on the prop shaft The axis system alignment is performed so that the contact pressure with the propulsion shaft is generated evenly over the length of the bearing in consideration of its own weight, seawater buoyancy and thrust moment.

Conventionally, the stern tube bushing unit is connected to the hull by welding, and before welding or during welding, it is necessary to check the welded area, remove the weld slag, maintain the welded site cleanness and the presence of weld defects. It is difficult to check at any time and to control the voltage, current, speed, etc. used in welding.After welding is completed, defects in the inside or surface of the weld during post-treatment due to welding heat deformation and during ship owner and class inspection. There was a hassle to check strictly.

In addition, the conventional stern tube bushing unit has a structure in which the rear flange of the bushing is protruded to the rear side of the hull of the hull when combined with the hull, so that the space utilization of the rear side of the hull is reduced and the overall length of the hull is also long. There was a problem lost.

The present invention has been made to solve the above-described problems, the present invention is arranged so that the rear of the hull and the rear of the bushing in a straight line when assembling the stern tube bushing unit on the hull and the resin (resin between the hull and the bushing) By installing a rubber sponge that can seal), it can improve the space utilization of the rear side of the hull and increase the sealing effect of the resin filled between the hull and the bushing housing, as well as the stern tube. It is an object of the present invention to provide a stern tube bushing unit that allows the bushing unit to be installed in a rigid, fast and stable structure with high construction quality at an accurate position in the hull.

The present invention for achieving the object as described above, in the stern tube bushing unit is inserted into the hull to support the propeller shaft, is installed inside the stern portion (propeller side, rear side) of the hull, rear of the stern portion of the hull A first bushing housing having a flange portion protruding radially from the first bushing housing; A second bushing housing installed inside a bow portion (engine side, front side) of the hull; A connecting tube integrally coupled between the first and second bushing housings; The second bushing housing and the front flange is provided in front of the fore portion of the hull, wherein the stern portion of the hull and the rear surface of the first bushing housing is formed to be on the same plane, the first bushing A rubber sponge is provided between the housing and the stern portion of the hull and between the second bushing housing and the bow portion of the hull to seal the resin filled therebetween.

Here, the present invention may further comprise a disk plate which is fixed to the stern portion of the hull and the rear portion of the first bushing housing at the same time fixed.

At this time, fixing grooves for fixing the installation position of the rubber sponge may be formed on the outer surfaces of the first and second bushing housing.

In addition, the present invention may further be provided with a spacing member for maintaining a constant axial spacing between the flange portion of the first bushing housing and the stern portion of the hull.

At this time, it is preferable that the gap holding member is coupled to the flange part by a screwing method so that the protrusion width from the flange part can be adjusted.

In addition, a guide bolt guided along the inner surface of the stern portion may be installed at a lower portion of the first bushing housing.

In addition, a center adjustment bolt for adjusting the first and second bushing housings to be positioned at each center portion of the stern portion and the bow portion may be provided outside the stern portion and the bow portion of the hull.

On the other hand, the present invention includes a plurality of split plates in close contact with each of the front and stern portion of the hull to prevent the rubber sponge from sliding; A support jig fixed to the front of the stern and the rear of the bow; A pressing bolt fastened to each support jig and pressurizing the split plate to be in close contact with the stern front and the fore part rear may be further installed.

Here, the rubber sponge is provided in plurality in close contact with each other, it is preferable to form so that the joint portions of the rubber sponge adjacent to each other are alternately disposed.

The present invention by the above-described configuration, by forming the rear surface of the stern portion of the hull and the rear surface of the first bushing housing on the same plane and by simultaneously engaging the disk plate against the rear portion of the stern portion and the first bushing housing The length of the first bushing is shorter than the conventional coupling structure in which the flange portion of the first bushing is protruded to the stern rear side of the hull, so that the length of the first bushing is shortened and the length of the hull is reared. There is an effect that can increase the space utilization of the side.

In addition, the present invention provides a rubber sponge between the first bushing housing and the stern portion of the hull and between the second bushing housing and the bow portion of the hull, thereby providing a rubber sponge between the first bushing housing and the stern portion of the hull. The resin filled between the two bushing housing and the bow portion of the hull can be effectively sealed, and the workability for sealing the resin can be improved.

In addition, the present invention by providing a fixing groove along the circumferential circumference on each outer surface of the first and second bushing housing, the rubber sponge can be accurately fixed in place without being pushed to the front side of the hull when installing the rubber sponge Therefore, workability and construction quality can be improved.

In addition, the present invention has the advantage of maintaining a constant axial spacing between the flange portion and the stern portion during the construction of the first bushing housing, by providing a separate spacing member in the flange portion of the first bushing housing, In addition, as the spacing member is coupled to the flange portion by screwing, the protrusion width of the spacing member can be adjusted so that the axial spacing between the flange portion and the stern portion can be freely adjusted to a desired spacing.

In addition, according to the present invention, when a separate guide bolt is installed at the bottom of the first bushing housing, the first bushing is easily moved by sliding along the inner surface of the stern through the guide bolt when the first bushing is pushed into the stern. There is an advantage that can be installed, and also, by adjusting the protrusion width of the guide bolt has the advantage of maintaining a constant distance between the first bushing housing and the stern portion.

In addition, the present invention has a center adjustment bolt that is fastened to the outside of the stern and the fore part of the hull, the first and second bushing housing can be adjusted to be precisely positioned in each center portion of the stern and the fore and the bush at the same time There is an advantage that can prevent sagging of the housing.

In addition, the present invention is a structure for fixing the rubber sponge to be installed on the front of the stern and the rear of the hull, by adopting a split plate, support jig, pressure bolt, when filling the resin on the front of the stern or the rear of the bow It is possible to prevent the rubber sponge from being pushed through the pressure-contacted split plate and to easily remove the split plate and the support jig by loosening the bolt after construction of the rubber sponge is completed.

In addition, the present invention is provided with a plurality of rubber sponges are installed to be in close contact with each other, but by arranging the joint portions of the adjacent rubber sponges to cross each other, the resin can be reliably blocked from leaking to the outside easily through the joint portion There is this.

In addition, the present invention uses the bushing assembly and the front flange of the first bushing housing, the second bushing housing, the connecting tube fastening and fixing through a plurality of bolts to the hull without applying welding as in the conventional method It can be installed firmly and stably. Accordingly, inspection of welding area, welding slag removal and maintenance of welding area, occasional confirmation of welding defects, control of voltage, current, speed, etc. used during welding, welding heat deformation According to the post-treatment and the owner and classification inspection process, there is an advantage that can be installed and applied to the hull more simply and quickly, without the need to strictly inspect the defects in the interior or surface of the weld.

1 is a sectional view showing the main portion of an embodiment of a stern tube bushing unit according to the present invention.

FIG. 2 is an enlarged view illustrating main parts of the hull portion of the hull in FIG. 1.

3 is a detail view of a portion “A” of FIG. 2;

FIG. 4 is a detailed view of FIG. 2 viewed in the X-X section direction. FIG.

FIG. 5 is a partial detail of “B” in FIG. 2; FIG.

6 to 8 are detailed views of FIG. 2 viewed in the Y-Y, Z-Z, and W-W section directions, respectively.

FIG. 9 is a partial detail of “C” in FIG. 2; FIG.

FIG. 10 is a detailed view of FIG. 2 viewed in the “V” section direction; FIG.

FIG. 11 is an exemplary view illustrating an arrangement form of a seam portion of the rubber sponge shown in FIG. 9. FIG.

12 to 14 is a cross-sectional view showing an embodiment of various forms in which the second bushing housing is installed inside the bow portion of the hull.

10 propeller shaft 21 stern part of hull

22: bow portion of the hull 110: first bushing housing

111: flange portion 120: second bushing housing

130: connection tube 150: front flange

250: nozzle 260: jack bolt

311,315,332: Rubber sponge 312: Disc plate

314: spacing member 316: support jig

317: fixing bolt 318: pressing bolt

319: split plate 320: guide bolt

330,335,340: Center adjustment bolt

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing a main part of an embodiment of the stern tube bushing unit according to the present invention, FIG. 2 is a main portion detail view showing an enlarged stern side installation structure of the hull in FIG. 1, and FIG. Part A is a detailed view, and FIG. 4 shows a view of FIG. 2 as viewed in the XX section direction. FIG. 5 is a detailed view of part “B” of FIG. 2, and FIGS. 6 to 8 show a view of FIG. 2 as viewed from the YY, ZZ, and WW sections, respectively, and FIG. 9 is a “C” of FIG. 2. Partial detail view. FIG. 10 is a detailed view of FIG. 2 viewed from the “V” section direction, and FIG. 11 is an exemplary view illustrating an arrangement form of a seam portion of the rubber sponge illustrated in FIG. 9.

1 to 11, the stern tube bushing unit according to the present invention relates to a stern tube bushing unit inserted into the hull 20 to support the propeller shaft 10, the stern portion 21 of the hull ( A first bushing housing 110 provided inside the propeller side and the rear side and having a flange portion 111 protruding radially from the rear of the stern portion 21 of the hull, and the bow portion 22 of the hull (engine Side, front side) the second bushing housing 120 is installed inside, the first and second bushing 110, the connecting tube 130 is integrally coupled between the housing and the second bushing housing ( 120 and the front flange 150 is installed in front of the hull part 22 of the hull.

The first bushing housing 110 and the second bushing housing 120 are inserted into the stern portion 21 and the bow portion 22 of the hull, respectively, and are integrally connected and connected by the connecting tube 130. To form a bush unit assembly.

The bush unit assembly and the front flange 150 including the first bushing housing 110, the second bushing housing 120, and the connection tube 130 may include a plurality of rear fixing bolts 210 and first and second front fixing bolts. Assembled by the fastening of the (221, 222), it is assembled in a rigid and stable structure to the stern portion 21 and the bow portion 22 of the hull without applying a welding process.

The first bushing 110 has a flange portion 111 protruding in a radial direction on the rear side, a plurality of rear fixing bolts 210 to the flange portion 111 of the first bushing 110 in the axial direction. The first bushing 110 is firmly fixed to the stern portion 21 of the hull by penetrating into the stern portion 21 of the hull.

At this time, the rear surface of the stern portion 21 of the hull is fixed to the rear fixing bolt 210 in a state that is disposed on the same plane as the rear surface of the flange portion 111 of the first bushing housing 110, as shown in FIG. Through the fastening operation is made.

In addition, a front flange 150 is installed in front of the second bushing housing 120 and the bow portion 22 of the hull, and the front flange 150 has a plurality of agents penetrating in the axial direction of the second bushing housing 120. The second bushing housing 120 is fastened to the bow portion 22 of the hull through the first front fixing bolt 221 and the second front fixing bolt 222, respectively. It is firmly fixed to (22). As described above, the present invention can stably fix the stern tube bushing unit to the hull 20 only by fastening bolts without undergoing a welding step.

On the other hand, as a characteristic configuration of the present invention, between the flange portion 111 of the first bushing housing 110 and the stern portion 21 of the hull, as shown in Figure 3, the stern portion 21 and A plurality of rubber sponges 311 for sealing the resin filled in the space between the first bushings 110 are installed.

The rubber sponge 311 is a sealing member made of a rubber material having a ring shape in which a portion thereof is broken, and a plurality of rubber sponges 311 are arranged in close contact with each other on the outer circumferential surface of the flange part 111.

At this time, the fixing groove 111a for fixing the installation position of the rubber sponge 311 is formed on the circumferential surface of the flange portion 111 of the first bushing 110, the fixing groove 111a is a flange portion 111 It is formed in the form recessed along the circumferential direction of the.

The fixing groove 111a guides the rubber sponge 311 so that the rubber sponge 311 can be accurately fixed in position without being drawn in the front side of the hull when the rubber sponge 311 is installed. Accordingly, it is possible to increase the construction work and construction quality of the rubber sponge 311.

In the same manner, a plurality of rubbers having the same shape as described above also exist in the space between the first bushing housing 110 and the front side of the stern portion 21 and the space between the second bushing housing 120 and the bow portion 22 of the hull.

Sponges

315 and 332 are installed in the same manner.

The

rubber sponges

311, 315, 332 are disposed in the space between the first bushing housing 110 and the stern portion 21 of the hull, and in the space between the second bushing housing 120 and the bow portion 22 of the hull. It effectively seals the filled resin.

Meanwhile, as shown in FIG. 3, the rubber sponge 311 is inserted between the flange portion 111 of the first bushing housing 110 and the stern portion 21 of the hull through a disc plate. It is fixed so as not to escape to the outside.

That is, the first bushing housing 110 is inserted into the stern portion 21 of the hull so that the rear surface of the stern portion 21 and the rear surface of the flange portion 111 of the first bushing housing 110 are in line with each other. By arranging the disk plate 312 having a ring shape in the arranged state to the rear surface of the flange portion 111 and the rear portion of the stern portion 21 at the same time, the rubber sponge 311 is fastened and fixed through the bolt 313. It is fixed so as not to escape to the outside.

As described above, the length of the first bushing housing may be shorter than the coupling method of the first bushing housing in which the flange portion of the first bushing housing is protruded to the rear side of the stern portion, so that the entire length of the hull can be shortened. The advantage of reducing the length can be obtained. In addition, there is an additional advantage that can effectively utilize the space behind the stern portion 21 of the hull.

In addition, the rubber sponge is formed such that the joint portions E1, E2, E3 of the

rubber sponges

315a, 315b, 315c which are adjacent to each other are arranged in a staggered form as illustrated in FIG. It is preferable. In this case, even if a resin filled inside is leaked between the seam portions of one rubber sponge, it is effectively blocked through another rubber sponge adjacent to the resin, thereby stably blocking the external leakage of the resin.

Meanwhile, in the present invention, as shown in FIGS. 2 and 5, the axial spacing between the front surface of the flange portion 111 of the first bushing 110 and the inner surface of the stern portion 21 rear side of the hull can be kept constant. A spacing member 314 is provided to make it possible.

The space maintaining member 314 is a structure that performs a kind of stopper function, is coupled to the front side of the flange portion 111 by a screwing method.

As such, when the gap retaining member 314 is installed on the front surface of the flange portion 111 of the first bushing housing 110, when the first bushing housing 110 is installed inside the stern portion 21, the gap is provided. The holding member 314 touches the rear inner surface of the stern portion 21 so that the axial spacing between the front surface of the flange portion 111 and the inner surface of the stern portion 21 is equal to the protruding width of the spacing holding member 314. It is always kept constant.

In addition, since the gap holding member 314 is coupled to the front surface of the flange portion 111 by a screwing method, if necessary, the gap holding member 314 is rotated in a clockwise or counterclockwise direction of the flange portion 111. Since the protruding width of the spacing member 314 can be freely adjusted from the front side, there is an advantage in that the axial spacing between the flange portion 111 and the stern portion 21 can be freely adjusted to a desired proper spacing.

Meanwhile, as shown in FIG. 8, two guide bolts 320 symmetrically disposed on the lower side of the first bushing housing 110 are provided in the present invention.

The guide bolt 320 is composed of a bolt body 320a having a screw thread formed on an outer circumferential surface thereof, and a nut 320b integrally coupled to the bolt body 320a. In addition, the end portion of the bolt body (320a) is formed to have a rounded curved surface in contact with the inner surface of the stern portion 21 of the hull to facilitate sliding.

The guide bolt 320 having such a structure is formed with a tab 320c on the outer surface of the first bushing housing 110 and then coupled to the tab 320c by a screwing method, wherein the first bushing housing 110 is formed. When the construction is inserted into the stern portion 21, the first bushing 110 easily slides along the lower inner surface of the stern portion 21 through the curved outer surface of the end portion of the guide bolt 320. There is an advantage that can be moved by construction.

Along with this, the guide bolt 320 is a user can turn the nut 320b portion to adjust the protrusion width of the guide bolt 320 from the outer surface of the first bushing 110, the guide bolt 320 By appropriately adjusting the protrusion width of the) there is an advantage that the gap between the first bushing housing 110 and the stern portion 21 can be easily adjusted.

Meanwhile, in the present invention, the first and

second bushing housings

110 and 120 have the first and

second bushing housings

110 and 120 at the center of the stern portion 21 and the bow portion 22 of the hull.

Center adjustment bolts

330, 335 and 340 that can be adjusted to be accurately positioned at the part are provided.

The

center adjusting bolts

330, 335, 340 are installed at the front and rear sides of the hull portion 21 of the hull, respectively, and one at the center of the bow portion 22, and the stern portion 21 of the hull. The center adjustment bolt 330 is installed at the rear side at the top and bottom of the first bushing housing 110, as shown in Figure 6 are installed at regular intervals, the stern portion 21 front side of the hull Two center adjustment bolts 335 to be installed are installed only in the lower portion of the first bushing 110, as shown in FIG. In addition, four center adjustment bolts 340 installed at the center of the bow portion 22 of the hull are installed to have an arrangement form as shown in FIG.

Center adjustment bolt

330, 335, 340 is installed in such an arrangement structure is to be adjusted by fastening the operator from the stern 21 and the bow portion 22, the first and second bush By supporting the outer surface of the

housing

110, 120, it is possible to easily perform the center adjustment work of the first and

second bushing housing

110, 120 from the stern portion 21 or the bow portion 22 outside. Here, in particular, the center adjustment bolt 335 which is fastened to the front side of the first bushing housing 110 is the central portion of the bush unit assembly, that is, connected from the first bushing housing 110 to the second bushing housing 120. In addition, the front side portion of the first bushing housing 110 has a function of preventing sagging in the downward direction by its own weight.

On the other hand, in the present invention, the rubber sponge push so as to suppress the axial rolling of the

rubber sponge

315, 332 provided on the front side of the first bushing housing 110 and the rear side of the second bushing housing 120 Prevention means are provided.

As shown in FIG. 9, the rubber sponge rolling prevention means includes a support jig 316 formed by bending a rectangular plate in a '-' shape, and the support jig 316 being stern 21. A fixing bolt 317 fixed to the front surface of the head), a plurality of split plates 319 contacting the rubber sponge 315 and the stern portion 21 of the hull at the same time, and the support jig 316. It is fastened to the end of the) is composed of a pressing bolt 318 for pressing the split plate 319 in close contact with the front of the stern portion (21). Rubber sponge rolling prevention means having the configuration as described above is installed in the same structure on the rear side of the hull portion 22 of the hull by the installation method as shown in Figure 9, after installing the rubber sponge between the hull and bushing housing between the hull and bushing housing The resin is filled in the space of the space and then separated and removed again.

Meanwhile, FIGS. 12 to 14 show various embodiments of the second bushing housing 120 installed inside the bow portion 22 of the hull.

12 is a hull non-fixed type in which the second bushing housing 120 and the front flange 150 are not fixed to the bow portion 22 of the hull. The nozzle 250 is mounted on the front flange 150. Next, after the stern tube unit is inserted into the bow portion 22 of the hull, the second bushing housing 120 and the front flange 150 are connected through the front fixing bolt 221. After the installation of the front flange 150 is completed, the split plate 319 is fixed to the front of the bow portion 22 of the hull using the support jig 316 and the pressure bolt 318. In this case, when the resin is injected between the bow portion 22 and the second bushing 120, it is possible to prevent the rubber sponge from being pushed out.

This assembly method is a dual type that is assembled using the second bushing housing 120 and the front flange 150 as in the first embodiment described above, and a separate front flange 150 is required. In addition, a jack bolt 260 is installed on the outer surface of the second bushing 120 to adjust the center. Therefore, after inserting the second bushing 120 into the bow portion 22 of the hull, the tool is inserted through the space between the bow portion 22 and the second bushing 120 to allow the second bolt through the jack bolt 260. A center adjustment work of the bushing 120 is performed.

The shape shown in FIG. 13 is a single type assembled without using the front flange 150 of FIG. 12 described above, and the hull of the second bushing housing 120 is not directly fixed to the bow portion 22 of the hull. It is a non-fixed type.

In this case, the support jig 316 is fixed to the front part 22 using the bolt 317, and the split plate 319 is fixed to the front part 22 by the support jig 316. . In this case, when the resin is injected between the bow portion 22 and the second bushing 120, the rubber sponge may be prevented from being pushed out.

In this assembly method, the installation of the second bushing 120 in the hull part 22 of the hull is completed and the nozzle 250 is directly installed in front of the second bushing 120. Otherwise, the material cost is reduced because no additional front flange is required. And, as in FIG. 12 described above, by installing a jack bolt 260 for center adjustment on the outer surface of the second bushing 120, the second bush through the jack bolt 260 inside the hull. The center of the housing 120 can be adjusted.

14 is a dual type that fixes the second bushing housing 120 to the bow portion 22 of the hull using the front flange 150, and the front flange 150 to which the nozzle 250 is coupled. ) Is fixed to the front of the hull part 22 and the second bushing 120 of the hull using the front fixing bolts (221, 222). In this type, since the nozzle 250 is first coupled to the front flange 150 and then the front flange 150 is fixed to the hull and the bushing housing, the mounting of the nozzle 250 is easy.

The present invention has been described with reference to preferred embodiments of the present invention, but the present invention is not limited to these embodiments, and the claims and detailed description of the present invention together with the embodiments in which the above embodiments are simply combined with existing known technologies. In the present invention, it can be seen that the technology that can be modified and used by those skilled in the art are naturally included in the technical scope of the present invention.

Claims

In the stern tube bushing unit inserted into the hull to support the propeller shaft,

A first bushing housing installed inside the stern portion (propeller side, rear side) of the hull and provided with a flange portion protruding radially from the stern portion of the hull;

A second bushing housing installed inside a bow portion (engine side, front side) of the hull;

A connecting tube integrally coupled between the first and second bushing housings;

Including the front flange is installed in front of the bow portion of the second bushing housing and the hull,

The stern rear of the hull and the rear of the first bushing housing are formed to lie on the same plane,

A rubber sponge is provided between the first bushing housing and the stern portion of the hull and between the second bushing housing and the bow portion of the hull to seal the resin filled therebetween.

Stern tube bushing unit, characterized in that the guide bolt is guided along the inner surface of the stern portion in the lower portion of the first bushing housing.
The method of claim 1,

The stern tube bushing unit further comprises a disk plate which is fixed to the stern portion of the hull and the rear portion of the first bushing housing at the same time.
The method of claim 1,

Stern tube bushing unit, characterized in that the fixing groove for fixing the installation position of the rubber sponge is formed on the outer surface of the first and second bushing housing.
The method of claim 1,

The stern tube bushing unit of claim 1, further comprising a spacing member for maintaining a constant axial spacing between the flange portion of the first bushing housing and the stern portion of the hull.
The method of claim 4, wherein

Stern tube bushing unit is characterized in that the spacing member is coupled to the flange portion by a screwing method to enable adjustment of the protrusion width from the flange portion.
The method of claim 1,

The stern tube bushing unit, characterized in that the center adjustment bolt for adjusting the first and second bushing housing to be located at each center portion of the stern portion and the fore and aft portion outside the stern portion and the bow portion of the hull.
The method of claim 1,

A plurality of split plates in close contact with the stern front of the hull and the rear of the bow so as to prevent the rubber sponge from being pushed;

A support jig fixed to the front of the stern and the rear of the bow;

Stern tube bushing unit is fastened to each support jig and pressurizing bolts for pressing the split plate in close contact with the stern front and the back of the bow portion is further installed.
The method of claim 1,

Wherein the rubber sponge is a plurality of dogs are installed in close contact with each other, the stern tube bush unit, characterized in that the joint portion of the rubber sponge adjacent to each other formed so as to be alternately arranged.