JP2750270B2 - Stern tube sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stern tube sealing device.

[0002]

2. Description of the Related Art A stern tube sealing device, especially a stern side sealing device, is required to have a function of sealing water and lubricating oil in a stern tube, respectively.
A plurality of seal rings slidably contacting the propulsion shaft side are sequentially arranged from the outboard side to the inboard side, a space formed by the pair of seal rings is used as an air chamber, and a space on the inboard side of the air chamber is used as an oil chamber, It is known that a chamber and a compressed air source are connected by an air supply pipe (for example, Japanese Utility Model Application Laid-Open No. 59-16530).
0, Japanese Utility Model Publication No. 5-35249).

In order to improve the durability of the seal ring and prevent marine pollution due to the outflow of lubricating oil, the seal device constantly supplies compressed air to the air chamber, and seals the seawater side seal ring from the back. It pushes up and always blows air to the seawater side. Further, since the pressure in the air chamber is maintained at the draft pressure +0 to 0.2 kg / cm ² , there is an advantage that the differential pressure applied to the seal ring can be reduced and the lubricating oil and water can be separated.

However, since the seal ring on the outer side of the ship is constantly pushed up by the blowing of the compressed air, the elastic function of the seal ring is reduced due to aging, and a gap is generated between the liner externally fitted to the propulsion shaft and the seal ring. However, there is a problem that outside water flows into the air chamber. Therefore, the present applicant has connected, in order to solve the above problems, already with said air tank and the oil gravity tank by an air connecting pipe
And , the pressure of the air supplied to the air chamber is provided with air pressure adjusting means for maintaining a value slightly lower than the draft pressure, and the oil gravity tank is disposed at a position where the oil chamber pressure is higher than the air chamber pressure. Offers stern tube sealing device (Japanese Patent Application
See JP-A-5-261297) .

[0005] Before SL pressure adjusting means, the outlet air tube
By blowing compressed air outboard and above the center level of the propulsion shaft, the pressure in the air chamber in the stern tube sealing device is set to be lower than the draft pressure , always following changes in draft.
In Teisu shall, in this case, the outlet air tube check-off valve is used to prevent a reverse flow of sea water. As shown in FIG. 8, the check valve 60 is provided with a valve seat 62 made of an elastic material such as rubber in a valve box 61, and a valve body 63 is constantly urged by a spring 64 from the seawater side. Since the air is opened by the compressed air against the external water pressure and the urging force of the spring 64, the seawater does not flow backward.

[0006]

However, since the check valve 60 is attached to a blow-off air pipe through which air is blown into seawater , the check valve 60 is very susceptible to corrosion and is liable to adhere to living things such as shells. In addition, there is a problem that the life is short and the reliability is poor because the structure is complicated by the mounting of a spring or the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has as its object to improve the durability with a simple structure and reliable operation, high reliability and high durability. To provide a stern tube sealing device.

[0008]

According to the present invention, the following technical measures have been taken in order to achieve the above object. That is, the present invention is to form an air chamber between a pair of seal rings in sliding contact on the propulsion shaft side within a housing propeller shaft is loosely fitted
In both cases, an oil chamber is formed inside the air chamber,
Connecting an air supply pipe to the air chamber
The compressed air in the compressed air tank is
Blow-off air for blowing higher than the center level of the propulsion axis
A stern tube sealing device in which a trachea is connected to the tank , wherein a check valve is provided in an outlet of the blown air tube or in a pipe line thereof, and the check valve is interrupted to blow air. At times, the valve body is characterized in that it is closed by its own weight or external water pressure.

Further, the present invention is characterized in that the valve element of the check valve is spherical, hemispherical, conical or disk-shaped. Further, the present invention is characterized in that a lid having a water hole is provided at an outside water inlet of the check valve.

[0010]

According to the present invention, the air of the compressed air tanks, ship
To blow outside and above the center level of the propulsion axis
Since the water is blown out through a check valve provided in the blow-off air pipe , the outside water does not flow back to the air tank, and the pressure in the air tank is lower than the draft pressure while following the change in the draft pressure. also Ru held in slightly lower air pressure.

Therefore, the pressure in the air chamber formed by the pair of seal rings is also maintained at a pressure slightly lower than the draft pressure following the change in the draft pressure, that is, the differential pressure acting on the seal ring changes with the draft. Regardless, air is not blown out of the space between the seal ring and the propulsion shaft. Then, the valve element of the check-off valve, the balloon of air is interrupted, smoothly and reliably closed by the valve body to its own weight or external water pressure, even when the air blowing rate becomes significantly less,
Outside water pressure is accurately detected, and the outside water does not flow backward and flow into the ship. In addition, the structure of the check valve is simple and does not include a conventional spring, so that the function is not stopped due to the adhesion of organisms, and the reliability and durability are improved.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.
Is the ship's propulsion shaft, 3 is the liner externally fitted to the propulsion shaft 1, 2
Is a stern tube housing, 4 is a stern tube bearing on which the propulsion shaft 1 is loosely fitted, and 5 is a stern tube bearing. In the housing 4, first to fourth seal rings slidingly contacting the outer peripheral surface of the propulsion shaft 1 6, 7, 8, and 9 are sequentially arranged from the outboard side to the inboard side.

The space formed by the second and third seal rings 7 and 8 is a compressed air chamber 10, and the space formed by the first and second seal rings 6 and 7 is a third oil chamber 11
The space formed by the third and fourth seal rings 8 and 9 is a fourth oil chamber 12, and the space inside the fourth oil chamber 12 on the hull is the second oil chamber 13 and the stern. A first oil chamber 14 is formed on the inner side of the pipe bearing 5, and the first and second oil chambers 1 are formed.
4 and 13 are communicated by the space between the bearing 5 and the propulsion shaft 1.

The housing 4 is provided with an air supply port 15 and a drain discharge port 16 communicating with the air chamber 10, and a lubricating oil supply port 17 and a discharge port 18 communicating with the fourth oil chamber 12 . Further, on the upper surface of the flange ring 4A of the housing 4, a compressed air outlet 19 having an upper end opening upward and in contact with outside water (seawater) is provided, and a check on / off valve 20 is attached, and air passing through the valve 20 is provided. A blowing path 21 is provided, and a blowing air pipe 22 is connected to the path 21.

The lip portions 6A to 9A are pressed against the outer periphery of the propulsion shaft 1 by the seal rings 6 to 9 outwardly from the air chamber 10 side, that is, by the outboard pressure or the lubricating oil pressure. In the air chamber 10 is minimized. As shown in FIG. 2, the check valve 20 includes a valve box 20A having a substantially funnel-shaped cross section, a spherical valve body 20B fitted in the valve box 20A, and a grid-shaped upper lid 20C. It is made of a material which has excellent corrosion resistance and does not easily adhere to marine microorganisms. And the upper lid 20
C is provided to prevent the valve body 20B from jumping out and to prevent infiltration of underwater floating substances such as dust.

Since the valve body 20B is provided so as to close the air blowing hole 23 of the valve box 20A from the upper side, the valve body 20B is pressed against the valve seat 20D by the weight of the valve body 20B and the external water pressure. . Therefore, when the blowing of air is stopped, the valve body 20B completely closes the hole 23 by the external water pressure in addition to its own weight, and completely prevents the external water from entering the air blowing hole 23.

The on-off valve 20 is made of a material which has a simple structure, operates smoothly and reliably, and is excellent in corrosion resistance and abrasion resistance and hardly adheres to marine microorganisms.
The function is not impaired by aging, the durability is greatly improved, and the function can be maintained for a long time without maintenance. Reference numeral 24 denotes a compressed air tank.
Is compressed by pressure from the compressed air source
Air is stored. The compressed air tank 24 is connected to the air supply port 1 of the housing 4 by a compressed air pipe 25.
5 to supply compressed air to the air chamber 10. Further, the outlet air pipe 22 is connected to the tank 24 via an on-off valve 26.
Oil gravity tank 27 and drain tank 28 containing lubricating oil
The air communication pipes 29 and 30 are connected.

The air pressure in the compressed air tank 24 is
It is always maintained at a pressure determined by the difference (C-b) between the draft pressure C (the height from the center level L of the propulsion shaft 1 to the draft WL) and the height b of the air outlet 19 from the level L. Further, the air pressure in the air chamber 10 connected to the compressed air tank 24 becomes equal to the pressure determined by the same (C−b) as the pressure in the tank 24, and the differential pressure acting on the second seal ring 7 is:
The difference between the draft pressure C and the pressure in the air chamber 10, that is, b, is always constant regardless of the change in the draft pressure.

The position of the air outlet 19 is
Since it is set at a position higher than the center level L of the propulsion shaft 1, the pressure acting on the outer water side of the first seal ring 6 becomes higher than the pressure inside the air chamber 10, and the first seal ring 7 and the propulsion Air does not blow out to the outside of the ship from between the shaft 1 and the outer peripheral surface. The third oil chamber 11 is filled with a substance having excellent lubricity such as lubricating oil and grease.

The oil gravity tank 27 is installed at a position above the center level L of the propulsion shaft 1 and at a height a, and is connected to the first oil chamber 14 by lubricating oil supply pipes 31 and 32. A supply pipe 33 having one end connected to the lubricating oil supply port 17 of the fourth oil chamber 12 is connected via an on-off valve 34 to the supply pipe 31.
A return oil pipe 35 connected to the second discharge port 18 is connected via an on-off valve 36 so that lubricating oil can be supplied into the oil chambers 12, 13, 14 by its gravity.

The lubricating oil in the oil chambers 12, 13, 14 is acted on by the sum of the pressure (Cb) in the compressed air tank 24 and the lubricating oil head pressure a (Cb + a). Therefore, the third seal ring 8 is provided with C from the air chamber 10 side.
-B air pressure acts, and as a result, the differential pressure [(Cb + a)-(Cb) = a] between the lubricating oil pressure and the air pressure always acts, and this differential pressure a is applied to the oil gravity tank 27. Is always constant regardless of changes in the draft WL.

The drain tank 28 collects water and lubricating oil that have accumulated in the air chamber 10 and is connected to the drain discharge port 16 of the housing 4 by a drain recovery pipe 37. A pipe 38 is connected via an on-off valve 39. Since the inside of the drain tank 28 is in communication with the compressed air tank 24 through the air communication pipe 30, the pressure inside the compressed air tank 24 and the pressure inside the air chamber 10 are the same. Discharge pipe 3
Even if the drain containing water and oil is discharged from
The air pressure in 0 does not change and can be easily discharged.

According to the first embodiment, the air pressure supplied into the air chamber 10 follows a change in the draft WL by the check valve 20 and becomes a constant pressure set slightly lower than the draft pressure C. Also, since the lubricating oil pressure in each of the oil chambers 12, 13, and 14 is set to be higher than the pressure in the air chamber 10 by an amount corresponding to the lubricating oil head pressure, compressed air is supplied to each of the seal rings 6-9. , And the differential pressures a and b are set small, so that the service life of the seal rings 6 to 7, that is, the durability can be improved.

Further, the structure of the check valve 20 is simple and only the valve body 20B moves up and down, so that the operation is reliable. Even if the air flow rate is extremely reduced, the air blows out.
When the outside water pressure is accurately detected and the blowing of the air is stopped, the valve body 20B is smoothly and reliably closed by its own weight and the outside water pressure, and the outflow of outboard water is prevented. Although the lubricating oil slightly enters the air chamber 10, the outside water slightly flows into the air chamber 10, so that the lubricating oil does not flow out of the air chamber 10 outboard and may cause ocean or river pollution. Without, the drainage of water and oil that has entered the air chamber 10
It can flow into and accumulate in the drain collection tank 28 and be easily discharged and collected.

FIGS. 3 to 6 show another embodiment of the check valve 20. FIG. 3 shows a valve element 20B having a hemispherical shape, which slides with the air blowing hole 23 as a guide and forms an air passage 40. A guide bar 41 is provided. FIG. 4 shows a guide bar 4 in which the valve body 20B has a disk shape and forms an air passage 40 in the center of the lower surface.
1 is provided. In FIG. 5, a valve bar 20B is conical and provided with a guide bar 41 forming an air passage 40 at the center of the upper surface.

FIG. 6 shows that the valve body 20B is a disk made of an elastic material such as rubber or synthetic resin, and one end of the valve body 20B is fixed to the valve box 20A by a fixture 42 such as a bolt. This valve 2
OB is designed to be thin so that its thickness can be easily bent by the air pressure to be blown out and blow out the air.
When the blowing of the air is stopped, the blowing hole 23 is easily closed by the external water pressure, and is sufficiently resistant to the external water pressure.

The constituent materials of the on-off valve 20 shown in FIGS. 3 to 5 and the constituent materials other than the valve element 20B shown in FIG.
A material having excellent corrosion resistance and abrasion resistance and hardly adhering to underwater microorganisms and the like is set in the same manner as the on-off valve 20 shown in FIG. The check on / off valve 20 shown in FIGS. 3 to 6 is extremely simple, operates smoothly and reliably, and can maintain its function without maintenance for a long time, similarly to the valve shown in FIG. In addition, also in the check valve 20 shown in FIG. 6, an upper lid having a lattice-shaped water passage hole can be provided, and the upper lid 20C can be made of a perforated plate.

FIG. 7 shows a second embodiment of the present invention. The difference from the first embodiment is that an air pressure adjusting means 43 is provided in place of the air outlet 19, and The blow-off air pipe 22 having one end connected to the compressed air tank 24 is connected to the vertical cylinder 44 by three check valves 45 and 4.
6 and 47 are connected. The air pressure adjusting means
43 is the vertical cylinder 44 whose upper and lower ends are closed, and the vertical cylinder 4
An outside water (for example, seawater) intake pipe 49 connected to the lower end of 4 via an on-off valve 48, and three blow-off air branch pipes 50, 51, 52 each having one end connected to the blow-off air pipe 22. ,
Opening / closing valves 53, 54, 55 connected to the branch pipes 50 to 52 and located above the center level L of the propulsion shaft 1 of the vertical cylinder 44 and connected at respective heights b1, b2, b3, and It comprises check valves 45-47.

The check valves 45-47 have the constructions shown in FIGS. The external water intake pipe 49 has a water intake port penetratingly attached to the hull outer plate S at a position lower than the propulsion shaft center level L. The upper end surface of the vertical cylinder 44 is located at a position considerably higher than the draft WL and is connected to an air vent pipe 56. The water level in the vertical cylinder 44 is the same as the draft WL and the level of the center of the propulsion shaft. It is located at a height of the draft pressure C from L. Therefore, the air pressure in the compressed air tank 24 is always C
The pressure is maintained at -b1 (or b2, b3).

In the second embodiment, the same operation and effect as the first embodiment can be expected. In particular, in the second embodiment, by selecting the opening and closing of the on-off valves 53 to 55, the pressure in the air tank 24 can be reduced. That is, the pressure in the air chamber 10 can be easily adjusted with respect to a change in the state of the external water pressure acting on the first seal ring 6. Therefore, portions common to the first embodiment are denoted by the same reference numerals as in FIG. 1, and detailed description is omitted.

The present invention is not limited to the above embodiment. For example, the first and fourth seal rings 6 and 9 are eliminated to provide a seal device without the third and fourth oil chambers 11 and 12. The design can be changed as appropriate.

[0032]

According to the present invention, a and simple structure of the check-off valve actuated reliably, since water microorganisms do not adhere, Ki de is possible to improve the high addition durability reliability
You. Furthermore, even if the air flow rate is extremely small, the outside water pressure can be accurately detected by blowing air to keep the pressure in the air chamber constant regardless of changes in draft, and the blowing of air is stopped (interrupted). However, the check valve is closed smoothly and the outside water does not flow backward and flow into the ship.

Further, the present invention is characterized in that a lid having a water passage hole is provided at an outside water inlet of the check valve, so that dusts enter the check valve. The non-return function can be maintained for a long time without maintenance.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a section A of FIG. 1; It is an expanded sectional view.

3A and 3B show another structural example of the check valve, wherein a is a central sectional view, and b is an enlarged sectional view taken along line BB of a.

4A and 4B show another example of the structure of the check valve, wherein a is a central longitudinal sectional view, and b is an enlarged sectional view taken along line CC of a.

FIG. 5 is a partially broken sectional view showing another example of the structure of the check valve.

FIG. 6 is a central longitudinal sectional view showing still another structural example of the check valve.

FIG. 7 is a configuration diagram showing a second embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a conventional check valve.

[Explanation of symbols]

 Reference Signs List 1 propulsion shaft 4 housing 6 first seal ring 7 second seal ring 8 third seal ring 9 fourth seal ring 10 air chamber 11 third oil chamber 12 fourth oil chamber 13 second oil chamber 14 first oil chamber 19 compression Air outlet 20 Check valve 20B Valve body 20C Lid 22 Blow air tube 24 Compressed air tank 25 Air supply tube 27 Oil gravity tank 31 Oil supply tube 32 Oil supply tube 33 Oil supply tube 45 Check valve 46 Check open / close Valve 47 Check valve

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-268797 (JP, A) JP-A-4-4567 (JP, U) JP-A-6-62267 (JP, U) JP-A-62-267 155097 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) F16J 15/16 B63H 23/36

Claims (3)

(57) [Claims] 1. A form an air chamber between a pair of seal rings propeller shaft is in sliding contact on its <br/> propulsion shaft side in a housing that is loosely fitted
And an oil chamber is formed inside the air chamber ,
Connect the air supply pipe to the compressed air tank to the air chamber.
And the compressed air in the compressed air tank is
And to blow out above the center level of the propulsion axis
A stern tube sealing device in which the blow-off air pipe is connected to the tank , wherein a check valve is provided in the blow-out port of the blow-off air pipe or in a pipe line thereof, and the check valve is configured to blow air. Wherein the valve element is closed by its own weight or external water pressure when the operation is interrupted. 2. The check valve according to claim 2, wherein the check valve is spherical, hemispherical,
2. The stern tube sealing device according to claim 1, wherein the stern tube sealing device has a conical shape or a disk shape. 3. The non-return valve according to claim 1, further comprising a lid having a water hole at an outside water inlet of the check valve.
Stern tube sealing device.