JPH07242198A - Stern tube sealing device - Google Patents

Abstract

PURPOSE:To simplify the structure and a piping system of a stern tube sealing device in the rear part by arranging two elastic seal rings made of rubber or high polymer material on the low side and on the stern side individually, and introducing a pressurized air feeding pipe and a fluid discharging pipe into a space structured of these seal rings. CONSTITUTION:On the stern side, a seal ring 1 is arranged in the sea water sealing direction, while on the low side, a seal ring 4 is arranged in the stern tube lube oil sealing direction, so that two seal rings are respectively arranged as a whole. A pressurized air feeding pipe 7 arranged via a constant flow rate type pressure controlling valve unit and a fluid discharging pipe 11 are connected to a space which formed of the seal rings 1, 4 and serves as the first annular chamber 31. In this way, a piping system can be greatly simplified.

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 for ships.

[0002]

2. Description of the Related Art A conventional rear stern tube sealing device according to 1980 Utility Model Publication No. 148171 is shown in FIG. 5, and its piping system is shown in FIG. In this rear stern tube seal device, four elastic body seal rings 1, 2, 3, 4 are arranged, and a constant flow type pressure control valve unit 9 is interposed in a first annular chamber 31 between the seal rings 1 and 2. By supplying pressurized air higher than seawater pressure from the pressurized air supply pipe 7 and discharging this air into the outboard seawater from between the seal ring 1 at the rearmost portion and the propeller shaft liner 10, a sealing device is provided. It also prevents seawater from entering the stern tube. The air pressure in the first annular chamber 31, which is discharged into the outboard seawater from between the seal ring 1 at the rearmost portion and the propeller shaft liner 10, changes due to the action of the constant flow type pressure control valve unit 9 to the seawater pressure. Correspondingly, a state in which the pressure is constantly high by a constant pressure is automatically maintained, and the differential pressure applied to the seal ring 1 is always kept constant. First
Lubricating oil is fed and circulated from the oil sump tank to the second annular chamber 32 adjacent to the annular chamber 31 through the pressurized oil circulation pipe 15 to lubricate the sliding surfaces of the seal rings 2 and 3. There is. The hydraulic pressure in the second annular chamber 32 is controlled by the booster relay 19 which is a pressure adjusting valve provided in the air branch pipe 20 branching from the pressurized air supply pipe 7 to adjust the pressure of the pressurized air. From the control valve unit 9 to the first annular chamber 3
The pressure difference with the air pressure supplied to 1 is always kept constant, so that the pressure difference applied to the seal ring 2 is kept constant.
In addition, the fluid discharge pipe 11 is guided to the first annular chamber 31,
Even if seawater invades the annular chamber 31 or the lubricating oil leaks, this can be promptly recovered in the ship.

[0003]

In the conventional rear stern tube sealing device shown in FIG. 5, each of the four sealing rings has the following functions. The seal ring 3 is for preventing the seawater from finally entering the stern tube even if the seal ring 1 that seals the seawater is damaged.
The seal ring 2 is for preventing the lubricating oil from finally leaking out of the ship even when the seal ring 4 that seals the stern tube lubricating oil is damaged. However, in such a seal device, not only the number of seal rings is large and the entire device becomes complicated, but also the piping system becomes complicated as shown in FIG. 6, resulting in an expensive stern tube lubrication system. There is.

[0004]

According to the present invention, one seal ring for sealing seawater and one seal ring for sealing lubricating oil are provided, and an air chamber is provided between the two seal rings. Realizing a rear stern tube sealing device with a simple structure as a means of solving the problems of releasing air from between the seal ring and the liner in regret water and collecting seawater and lubricating oil from the air chamber into the ship The piping system was also simplified as much as possible.

[0005]

According to the experience and results of the stern tube sealing device so far, it is known that each seal ring is hardly damaged unless seawater enters the sealing device. Therefore, it is of utmost importance to prevent the intrusion of seawater into the sealing device by increasing the reliability of the seal ring at the rearmost part that comes into contact with seawater, and as long as the seal ring at the rearmost part is sound, the reliability of other seal rings is also high. Will be secured. In addition, even if the last seal ring is damaged, by collecting the seawater that has infiltrated into the sealing device into the ship, other seal rings will be damaged unless they directly contact the seawater. Almost never. In the rear stern tube sealing device according to FIG. 4, since air is constantly blown from the first annular chamber 31 through the seal ring 1 and the propeller shaft liner 10 toward the outboard seawater, the lip sliding of the seal ring 1 is performed. Since the moving surface hardly comes into direct contact with the outer peripheral surface of the propeller shaft liner 10 and the differential pressure between the air pressure and the seawater pressure is always kept constant, the seal ring 1 is used in a highly reliable state. Has been done. Therefore, the other seal rings 2, 3 and 4 have sufficient reliability without directly contacting with seawater, so that only one seal ring is required to seal the lubricating oil. Therefore, even if the preliminary seal rings 2 and 3 for the intrusion of seawater into the stern tube and the leakage of lubricating oil to the outside of the ship are omitted, the sealing action of seawater and lubricating oil is one each, and there are two seals in total. Since it can be reliably performed by the ring, the structure of the rear stern tube sealing device and its piping system can be simplified.

[0006]

Embodiments of the present invention will be described below with reference to FIGS. 1, 2, 3 and 4. In the first embodiment of the rear stern tube sealing device shown in FIG. 1, 1 and 4 are elastic seal rings made of rubber or polymer material that are in sliding contact with the propeller shaft liner 10 and are fixed to the hull stern member 40. It is held by the housing member 22 of the device 30. The seal ring 1 is located on the stern side and is arranged toward the seawater side, and acts to seal the seawater. Also,
The seal ring 4 is arranged toward the stern tube and acts to seal the stern tube lubricating oil. The first annular chamber 31 formed by the seal rings 1 and 4 has a structure in which pressurized air is fed so that seawater and lubricating oil do not come into direct contact with each other. FIG. 2 is a first embodiment of the piping system according to the present invention. The pressurized air supplied from the pressure tank unit 8 which is an air source is supplied from the pressurized air supply pipe 7 through the constant flow rate pressure control valve unit 9 to the first annular chamber 3 of the sealing device 30 of FIG.
Guided to 1. The air supplied to the first annular chamber 31 is controlled by the flow rate type pressure control valve unit 9 so as to flow a certain amount, and is blown from the sliding portion between the seal ring 1 and the propeller shaft liner 10 into the outboard seawater. Therefore, the pressure also automatically changes according to the fluctuation of the seawater pressure, and the pressure difference from the seawater pressure can be kept constant. Further, a fluid discharge pipe 11 is connected to the first annular chamber 31 from the inside of the ship, and a part of the pressurized air supplied to the chamber is provided by an air vent pipe 13 provided with a drain tank 12 and a flow rate limiting device 14 such as a needle valve. Since it is constantly discharged into the ship, it is possible to promptly recover seawater or lubricating oil that has entered the same room. Lubricating oil is a pressure type oil sump tank 17 that is hermetically sealed.
From the oil pump 16 to the stern tube bearing chamber 34 of FIG. 1 by the pressurized oil circulation pipe 15, and again the oil sump tank 1
Return to 7. An air branch pipe 20 is branched from the pressurized air supply pipe 7, and an air communication pipe 18 is connected to an upper part of the oil sump tank 17 via a booster relay 19 which is a pressure adjusting valve.
The oil pressure in the oil sump tank 17 can be automatically adjusted by the booster relay 19 so that the lubricating oil pressure in the stern tube bearing chamber 34 is always increased by a constant pressure with respect to the air pressure in the first annular chamber 31. As described above, in the seal ring 1, air is blown from between the lip sliding surface and the propeller shaft liner 10 to seal seawater,
For this reason, the lip sliding surface hardly comes into direct contact with the propeller shaft liner 10 and the differential pressure between the pressurized air and seawater is also constant, so that a stable use condition is maintained and high reliability and longevity are provided. Is secured. Further, also in the seal ring 4, since the differential pressure between the lubricating oil and the pressurized air is made constant, a stable use state is maintained as in the seal ring 1, and high reliability and life are obtained. If seawater or lubricating oil intrudes into the first annular chamber 31 due to an unexpected accident, these are collected in the drain tank 12 through the fluid discharge pipe 11, and the seawater invades the stern tube bearing chamber 34. The leakage of lubricating oil into the outboard seawater is prevented. Furthermore, since the first annular chamber 31 is maintained as an air chamber by such a recovery function, the usage state of the seal ring 4 or 1 is maintained stable. FIG. 3 shows a second embodiment of the piping system according to the present invention. In this example, the lubricating oil pressure in the stern tube bearing chamber 34 is given by the gravity type head tank 42, and the lubricating oil pressure is in the first annular chamber 3
The pressure is constant without being interlocked with the pressure of the pressurized air of No. 1, and is otherwise the same as that of the first embodiment shown in FIG. Since the reliability of the sealing device 30 almost depends on the seal ring 1 at the rearmost portion, it is a practical piping system even if the differential pressure between the lubricating oil and the pressurized air applied to the seal ring 4 is not necessarily constant. Yes, simplification is achieved compared to the first embodiment. In addition, instead of the gravity type head pressurizing method of the lubricating oil by the head tank 42 in the second embodiment,
It goes without saying that a circulating pressurization method using an oil pump configured not to interlock with the pressure of the pressurized air in the first annular chamber 31 can be adopted. FIG. 4 shows a second embodiment of the rear stern tube sealing device according to the present invention. In order to protect the seal ring 1 for sealing seawater from foreign matters such as fishing nets, the fishing net intrusion prevention ring 50 is provided on the propeller side of the seal ring 1. I am wearing. The fishing net intrusion prevention ring 50 is fixed to the propeller shaft liner 10 by a garter spring 53 and rotates together, and the outboard arm portion 51 and the inboard arm portion 52 are in sliding contact with the casing member 22. The inboard arm portion 52 also has a function of sealing a liquid in addition to foreign matter such as a fishing net, and the pressurized air blown into the seawater annular chamber 54 is used for the casing member 2.
The air is discharged from the air outlet 55 into the outboard seawater through the space between the fishing rod 2 and the inboard arm 52 of the fishing net intrusion prevention ring 50. Therefore, the seawater is sealed in two stages by adding the fishing net intrusion prevention ring 50 to the seal ring 1, and the sealing device 3
The reliability of 0 is further enhanced. In addition, in the above rear sealing device, in addition to the seal ring 1, the seal ring 4
Also has a structure directed to the direction of sealing seawater, and the pressure of the lubricating oil in the stern tube bearing chamber 34 can be used as a pressure lower than the pressure of the pressurized air in the first annular chamber 31.

[0007]

The rear stern tube sealing device of the present invention does not impair the functions required as a stern tube sealing device.
The structure is such that one seal ring for sealing seawater and one seal ring for sealing stern pipe lubricating oil are arranged, so that the structure can be remarkably simplified compared to the conventional stern pipe sealing device. There is. In addition, along with this, the piping system is greatly simplified, which can contribute to a reduction in piping work. Furthermore, by installing a fishing net intrusion prevention ring having a liquid sealing function, not only is the seal ring protected, but seawater is also sealed in two stages, further increasing the reliability of the sealing device. You can

[Brief description of drawings]

FIG. 1 is a half sectional view showing a first embodiment of a rear stern tube sealing device of the present invention.

FIG. 2 is a first embodiment of the piping system of the rear stern tube sealing device of the present invention.

FIG. 3 is a second embodiment of the piping system of the rear stern tube sealing device of the present invention.

FIG. 4 is a half sectional view showing a second embodiment of the rear stern tube sealing device of the present invention.

FIG. 5 is a half cutaway view showing a conventional rear stern tube sealing device.

FIG. 6 is a first embodiment of a piping system in a conventional rear stern tube sealing device.

[Explanation of symbols]

 1, 2, 3, 4 Seal ring 7 Pressurized air supply pipe 8 Pressure air tank 9 Constant flow type pressure control valve unit 10 Propeller shaft liner 11 Fluid discharge pipe 12 Drain tank 13 Air vent pipe 14 Needle valve 15 Pressurized oil circulation Pipe 16 Oil pump 17 Oil sump tank 18 Air connection pipe 19 Booster relay 20 Air branch pipe 22 Housing member 24 Communication hole 25 Pipe joint 30 Seal device 31 First annular chamber 32 Third annular chamber 33 Third annular chamber 34 Stern tube bearing Chamber 40 Hull stern member 41 Stern tube bearing 42 Head tank 50 Fishing line intrusion prevention ring 51 Outer side arm portion 52 Outer side arm portion 53 Garter spring 54 Seawater annular chamber 55 Air outlet hole

Claims (4)

[Claims] 1. A rear stern tube sealing device attached to the outer side of a stern tube of a ship, wherein one stern side seals seawater and the stern side seals stern tube lubricating oil. One elastic seal ring made of rubber or polymer material is arranged in each direction, and pressurized air is supplied to the space formed by these seal rings via the constant flow rate pressure control valve unit. A stern tube seal device comprising a pipe and a fluid discharge pipe. 2. A constant flow type pressure control valve unit
The pressure that adjusts the pressure of the pressurized air in the middle of this branch pipe by branching the pipe from the pressurized air supply pipe installed in the space formed by the book seal ring and guiding it to the pressure type oil sump tank The stern tube sealing device according to claim 1, further comprising a regulating valve. 3. The fishing net intrusion prevention ring that rotates together with a propeller shaft liner is provided on the propeller side of the rearmost seal ring, and the fishing net invasion prevention ring has a liquid sealing function. Stern tube sealing device. 4. The stern tube seal according to claim 1, wherein the two elastic seal rings made of rubber or polymer material are oriented in a direction of sealing seawater. apparatus.