JPH07310829A - Stern pipe seal device - Google Patents

Abstract

PURPOSE:To simplify structure, to ensure operation, and to improve reliability and durability. CONSTITUTION:A plurality of seal rings 6, 7, 8, and 9 coming into slide contact with the propeller shaft 1 side are disposed in a housing 4 in which the propeller shaft 1 is loosely fitted. A space formed with a pair of seal rings 7 and 8 forms an air chamber 10. The space on the inner side of a ship of the air chamber 10 forms oil chambers 13 and 14, the air chamber 10 and a compressed air tank 24 are interconnected through an air feed pipe 25, and the oil chambers 13 and 14 and the tank 24 having oil gravity are interconnected through oil feed pipes 31 and 32. By blowing air, contained in the compressed air tank 24, through a pipe 22 into water outside a ship, a pressure in the air chamber 10 follows a water pressure outside the ship to produce a stern pipe seal device. A check on-off valve 20 is located in a blowoff 19 for compressed air, and the valve 20 is operated in such a manner that when blowout of air is suspended, a valve body is closed under an owing weight or a water pressure to prevent entrance of outside water.

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 the stern tube, respectively.
A plurality of seal rings slidably contacting the propulsion shaft side are sequentially arranged from the outer side of the ship to the inner side of the ship, the space formed by the pair of seal rings is an air chamber, and the space on the inner side of the air chamber is an oil chamber. It is known that the chamber and the compressed air source are connected by an air supply pipe (for example, Japanese Utility Model Laid-Open No. 59-16530).
No. 0, Japanese Utility Model Publication No. 5-35249).

In order to improve the durability of the seal ring and prevent the marine pollution due to the outflow of lubricating oil, the sealing device constantly supplies compressed air to the air chamber, and the seal ring on the seawater side is provided from the rear side thereof. It is designed to push up and constantly blow out air toward the seawater side. Further, since the pressure in the air chamber is maintained at the draft pressure +0 to 0.2 kg / cm ² , the pressure difference 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 compressed air, the elastic function of the seal ring deteriorates over time, and a gap is created between the liner and the seal ring fitted on the propulsion shaft. However, there is a problem that outside water flows into the air chamber. Therefore, in order to solve the above problems, the applicant of the present application has already set the pressure of the air supplied to the air chamber to a level slightly lower than the draft pressure by connecting the air tank and the light gravity tank with an air connecting pipe. Provided is a stern tube sealing device in which an air pressure adjusting means for maintaining the value is provided and an oil gravity tank is arranged at a position where the oil chamber pressure becomes higher than the air chamber pressure.

The air pressure adjusting means keeps the pressure of the air chamber in the stern tube sealing device to follow the seawater pressure by constantly blowing out compressed air to the outside of the ship. An on-off valve is used. As shown in FIG. 8, the check valve 60 is provided with a valve seat 62 made of an elastic body such as rubber in a valve box 61, and a valve body 63 is constantly urged from a seawater side by a spring 64. Since it is opened by compressed air against the external water pressure and the urging force of the spring 64, the seawater is prevented from flowing backward.

[0006]

By the way, since the check valve 60 is mounted in seawater and in a system passage through which air is blown out, it is very likely to be corroded and organisms such as shellfish are easily attached thereto. Due to the fact that it is in the environment and the structure is complicated by the mounting of springs and the like, there are problems such as its short life and poor reliability.

The present invention has been made in view of the above situation, and an object thereof is to have a simple structure, reliable work, high reliability, and improved durability. The present invention provides a stern tube sealing device.

[0008]

In order to achieve the above object, the present invention takes the following technical means. That is, according to the present invention, in the housing in which the propulsion shaft is loosely fitted, a plurality of seal rings slidably contacting the propulsion shaft side are sequentially arranged from the outer side of the ship to the inner side of the ship, and the space formed by the pair of seal rings is air-sealed. Chamber, the space inside the air chamber of the ship is an oil chamber, the air chamber and the compressed air tank are connected by an air supply pipe, the oil chamber and the oil gravity tank are connected by an oil supply pipe, and the compressed air A stern tube seal device configured to cause the pressure in the air chamber to follow the outboard water pressure by blowing the air in the tank into the outboard water. A valve is provided, and the check valve is characterized in that the valve body is closed by its own weight or external water pressure when the blowing of air is interrupted.

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

[0010]

According to the present invention, since the air in the compressed air tank is blown out by pushing open the valve body against which the external water pressure of the check opening / closing valve directly acts, against the external water pressure, the external water is discharged. It does not flow back into the air tank, and the pressure in the air tank is maintained at an air pressure slightly lower than the draft pressure that follows changes in the draft pressure of the outside water, and thus, in the air chamber formed by the pair of seal rings. The pressure is also maintained at a pressure slightly lower than the draft pressure that follows changes in draft pressure, that is, the differential pressure acting on the seal ring becomes constant regardless of changes in draft, and air flows between the seal ring and the propulsion shaft. It does not blow out overboard.

The valve body of the check valve is smoothly and surely closed by the weight of the valve body or the external water pressure when the blowing of air is interrupted.
The external water pressure is accurately detected, and the external water does not flow back into the ship. Moreover, since the structure of the check valve is simple and the conventional spring is not provided, the function and the durability are improved without causing the functional stop due to the adhesion of living organisms.

[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 a propulsion shaft of the ship, 2 is a liner fitted over the propulsion shaft 1, 3
Is a propeller, 4 is a stern tube housing in which the propulsion shaft 1 is supported by loose fitting, and 5 is a stern tube bearing. In the housing 4, first to fourth seal rings are slidably in contact with the outer peripheral surface of the propulsion shaft 1. 6, 7, 8, and 9 are sequentially arranged from the outside of the ship to the inside of the ship.

The space formed by the second and third seal rings 7, 8 is a compressed air chamber 10, and the space formed by the first and second seal rings 6, 7 is a third oil chamber 11
The space formed by the third and fourth seal rings 8 and 9 is the fourth oil chamber 12, and the space inside the fourth oil chamber 12 is the second oil chamber 13 and the stern. The first oil chamber 14 is formed inside the tube bearing 5 and the first and second oil chambers 1 are formed.
4, 13 are communicated with each other by a 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 which communicate with the air chamber 10, and a lubricating oil supply port 17 and a discharge port 18 which communicate with the fourth oil chamber 12. The upper surface of the flange ring 4A of the housing 4 is provided with a compressed air blowing port 19 whose upper end opens upward and is in contact with outside water (seawater), a check opening / closing valve 20 is attached, and an air blowing leading to the valve 20 is provided. A passage 21 is provided, and an outlet air pipe 22 is connected to the passage 21.

Each of the seal rings 6 to 9 is pressed outwardly from the air chamber 10 side, that is, by the ship pressure or the lubricating oil pressure, to press the lip portions 6A to 9A against the outer peripheral surface of the propulsion shaft 1, and the external water and the lubricating oil. The invasion of air into 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 lattice-shaped upper lid 20C. It is made of a material that has excellent corrosion resistance and does not allow marine microorganisms to adhere. And the upper lid 20
C is provided in order to prevent the valve body 20B from popping out and prevent entry of suspended matter in water such as dust.

Further, 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 its own weight and the external water pressure. . Therefore, when the blowing of the 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 opening / closing section 20 is made of a material having a simple structure, smooth and reliable operation, and excellent in corrosion resistance and abrasion resistance so that microorganisms in the sea hardly adhere to it.
The function is not impaired over time, the durability is significantly improved, and the function can be maintained for a long time without maintenance. Compressed air is supplied to 24, and an air supply port 15 of the housing 4 is provided by a compressed air pipe 25.
The compressed air is supplied to the air chamber 10. Further, the outlet air pipe 22 is connected to the tank 24 via an opening / closing valve 26, and air communication pipes 29, 30 for connecting a light gravity tank 27 and a drain tank 28 filled with lubricating oil are connected. There is.

The air pressure in the compressed air tank 24 is
The pressure is always maintained at a pressure determined by the difference (C-b) between the draft pressure C (the height from the central 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 inside 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 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 in the air chamber 10, and the first seal ring 7 and the propulsion are conducted. Air does not blow out to the outside of the ship from between the outer peripheral surface of the shaft 1. In the third oil chamber 11, a substance having excellent lubricity such as lubricating oil or grease is enclosed.

The light and heavy tank 27 is installed at a height a above the center level L of the propulsion shaft 1, is connected to the first oil chamber 14 by means of lubricating oil supply pipes 31, 32, and supplies the same. A supply pipe 33, one end of which is connected to the lubricating oil supply port 17 of the fourth oil chamber 12, is connected to the pipe 31 through an opening / closing valve 34, and one end of the supply pipe 32 has one end in the fourth oil chamber 12
The return oil pipe 35 connected to the discharge port 18 is connected via the on-off valve 36, and the lubricating oil can be supplied into the oil chambers 12, 13, 14 by its gravity.

The sum of the internal pressure (C-b) of the compressed air tank 24 and the lubricating oil head pressure a (C-b + a) acts on the lubricating oil in the oil chambers 12, 13, and 14. Therefore, the third seal ring 8 is provided with C from the air chamber 10 side.
The air pressure of −b acts, and as a result, the differential pressure [(C−b + a) − (C−b) = a] between the lubricating oil pressure and the air pressure always acts, and this differential pressure a is the oil gravity tank 27. Since it is determined by the height of the draft, it is always constant regardless of the change in the draft WL.

The drain tank 28 collects water and lubricating oil that have entered and accumulated in the air chamber 10. The drain tank 28 is connected to the drain discharge port 16 of the housing 4 by a drain recovery pipe 37, and drains are discharged. The pipe 38 is connected via an on-off valve 39. Since the inside of the drain tank 28 communicates with the compressed air tank 24 through the air communication pipe 30, the pressure inside the compressed air tank 24 and inside the air chamber 10 is the same, and the on-off valve 39 is opened to drain the drain. Discharge pipe 3
Even if the drain containing water and oil is discharged from 8, the air chamber 1
The air pressure in 0 does not change and can be easily discharged.

According to the first embodiment described above, the air pressure supplied into the air chamber 10 follows the change of the draft WL by the check valve 20 and becomes a constant pressure set slightly lower than the draft pressure C. Since the lubricating oil pressure in each oil chamber 12, 13, 14 is set higher than the pressure in the air chamber 10 by the amount corresponding to the lubricating oil head pressure, the compressed air is compressed by each seal ring 6-9. Since it does not blow out to the outside and the inside of the ship and the differential pressures a and b are set to be small, it is possible to extend the life of the seal rings 6 to 7, that is, improve the durability.

Further, the structure of the check valve 20 is simple and only the valve body 20B moves up and down, so the operation is reliable. Even if the air flow rate is remarkably reduced, the
The outside water pressure is accurately detected, and when the blowing of air is stopped, the valve body 20B is smoothly and surely closed by its own weight and the outside water pressure, and inflow of outboard water is blocked. Then, although the lubricating oil slightly enters the air chamber 10, the external water slightly flows into the air chamber 10, so that the lubricating oil does not flow out of the air chamber 10 to the outside of the ship, which may cause marine or river pollution. Instead, the drain of water and oil that entered the air chamber 10
It can flow into the drain recovery tank 28 and collect, and can be easily discharged and recovered.

3 to 6 show another embodiment of the check valve 20. In FIG. 3, the valve body 20B has a hemispherical shape and 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 an air passage 40 is formed in the center of the lower surface.
1 is provided. In FIG. 5, the valve body 20B has a conical shape, and a guide bar 41 that forms an air passage 40 is provided at the center of the upper surface.

In FIG. 6, the valve body 20B is a disk made of an elastic body such as rubber or synthetic resin, and one end thereof is fixed to the valve box 20A by a fixture 42 such as a bolt. This valve body 2
0B is designed to be thin so that its thickness can be easily bent by the air pressure to blow out air,
When the blowing of the air is stopped, the blowing hole 23 is easily closed by the outside water pressure, and the outside water pressure is sufficiently endured.

The constituent materials of the on-off valve 20 shown in FIGS. 3 to 5 and the constituent materials other than the valve body 20B shown in FIG.
Similar to the on-off valve 20 shown in (1), a material is set that has excellent corrosion resistance and abrasion resistance and is resistant to adhesion of underwater microorganisms. Similarly to the valve shown in FIG. 2, the check 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 period of time. Note that the check valve 20 shown in FIG. 6 can also be provided with an upper lid having lattice-shaped water passage holes, and the upper lid 20C can be made of a perforated plate.

FIG. 7 shows a second embodiment of the present invention, which is different from the first embodiment in that an air pressure adjusting means 43 is provided in place of the air blowing port 19, and the air pressure adjusting means 43 is provided. The vertical air pipe 22 having one end connected to the compressed air tank 24 is connected to the vertical cylinder 44 by the three check opening / closing valves 45 and 4.
6, 47 are connected. The air pressure adjusting means 42 includes the vertical tube 44 with the upper and lower ends closed, and the vertical tube 4
An outside water (for example, seawater) intake pipe 49 connected to the lower end of 4 through an on-off valve 48, and three blown air branch pipes 50, 51, 52 each having one end connected to the blown air pipe 22. ,
The on-off valves 53, 54, 55 connected to the respective branch pipes 50 to 52 and located above the central level L of the propulsion shaft 1 of the vertical cylinder 44 at the respective heights of b1, b2, b3, and The check valve 45-47.

The check valves 45 to 47 have the construction shown in FIGS. 2 to 6. The outside water intake pipe 49 has a water intake port penetratingly attached to the hull outer plate S below the propulsion shaft center level L. Further, the upper end surface of the vertical cylinder 44 is located at a position considerably higher than the draft WL and is connected to the air vent pipe 56, and the water level in the vertical cylinder 44 is the same as the draft WL and the propulsion shaft center level. It is located at the height of the draft pressure C from L. Therefore, the air pressure in the compressed air tank 24 is always C
-It is kept at a pressure determined by b1 (or b2, b3).

In the second embodiment as well, the same effect as that of the first embodiment can be expected. Particularly, in the second embodiment, the opening / closing valves 53 to 55 are selected to be opened / closed, so that the pressure in the air tank 24, That is, the pressure in the air chamber 10 can be easily adjusted with respect to changes in the condition of the external water pressure acting on the first seal ring 6. Therefore, the same parts as those in the first embodiment are designated by the same reference numerals as those in FIG. 1 and their detailed description is omitted.

The present invention is not limited to the above embodiment, and 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]

As described above, according to the present invention, a plurality of seal rings, which are in sliding contact with the propulsion shaft side, are sequentially arranged from the outer side to the inner side of the ship in the housing in which the propulsion shaft is loosely fitted. The space formed by the ring is an air chamber, the space inside the air chamber is an oil chamber, the air chamber and the compressed air tank are connected by an air supply pipe, and the oil chamber and the oil gravity tank are supplied with oil. A stern tube sealing device which is connected by a pipe and blows out the air in the compressed air tank into the outboard water so that the pressure in the air chamber follows the outboard water pressure, and the compressed air is blown out. A check opening / closing valve is provided in a mouth or a system passage, and the check opening / closing valve is characterized in that, when the blowing of air is interrupted, the valve body is closed by its own weight or external water pressure. Therefore, the structure of the check valve is It is simple and operates reliably, and it does not adhere to underwater microorganisms, so it is highly reliable and can improve durability.In addition, even if the air flow rate is remarkably reduced, the outside water pressure can be accurately controlled by blowing air. It can be detected well and the pressure in the air chamber can always be kept constant irrespective of changes in the draft, and even if the air blowout stops (interrupts), the check valve will close smoothly and the outside water will flow back into the ship. There is no inflow.

Further, according to the present invention, since the lid having the water passage is provided at the outer water inlet of the check opening / closing valve, dusts and the like flow into the check opening / closing valve. It is possible to maintain the non-return function for a long period of time without any maintenance.

[Brief description of drawings]

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

FIG. 2 is a portion A of FIG. It is an expanded sectional view.

FIG. 3 shows another structural example of the check valve, where a is a central sectional view and b is an enlarged sectional view taken along line BB of a.

FIG. 4 shows another structural example of the check valve, where 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 cross-sectional view showing another structural example of the check valve.

FIG. 6 is a central vertical cross-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 sectional view showing a check valve of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Propulsion shaft 4 Housing 6 1st seal ring 7 2nd seal ring 8 3rd seal ring 9 4th seal ring 10 Air chamber 11 3rd oil chamber 12 4th oil chamber 13 2nd oil chamber 14 1st oil chamber 19 Compression Air outlet 20 Check valve 20B Valve body 20C Lid 22 Blow-off air pipe 24 Compressed air tank 25 Air supply pipe 27 Oil gravity tank 31 Oil supply pipe 32 Oil supply pipe 33 Oil supply pipe 45 Check open / close valve 46 Check open / close Valve 47 Check valve

Claims (3)

[Claims] 1. A plurality of seal rings, which are in sliding contact with the propulsion shaft side, are sequentially arranged from the outside of the ship to the inside of the ship in a housing in which the propulsion shaft is loosely fitted, and a space formed by a pair of seal rings is formed in an air chamber. The space inside the air chamber of the ship is an oil chamber, the air chamber and the compressed air tank are connected by an air supply pipe, the oil chamber and the oil gravity tank are connected by an oil supply pipe, and the compressed air tank A stern tube sealing device configured to cause the pressure in the air chamber to follow the outboard water pressure by blowing the air in the outboard water into the outboard water, wherein a check opening / closing valve is provided in the compressed air blowing port or system passage. The stern tube sealing device, wherein the check opening / closing valve is configured such that the valve body is closed by its own weight or external water pressure when air blowing is interrupted. 2. A valve body of the check valve is spherical, hemispherical,
The stern tube sealing device according to claim 1, wherein the stern tube sealing device has a conical shape or a disk shape. 3. A lid having a water passage hole is provided at an outer water inlet of the check opening / closing valve.
Stern tube sealing device.