JPH07242197A - Stern tube sealing device - Google Patents

Abstract

PURPOSE:To simplify a piping system of a stem tube pipe sealing device in the rear part by adjacently arranging two elastic seal rings on the stem side, arranging an elastic seal ring on the bow side, and introducing a pressurized air feeding pipe and a fluid discharging pipe into a space which is constructed of the two seal rings and is adjacent to a stem tube bearing chamber. CONSTITUTION:On the stem side, seal rings 1, 3 are adjacently arranged in the sea water sealing direction. On the bow side, a seal ring 4 is arranged in the stem tube lubricating oil sealing direction, so that three seal rings are arranged as a whole. A space serving as the second annular chamber 32, which is adjacent to a stem tube bearing chamber 34, in a sealing device 30 is constructed of the seal rings 3, 4. A pressurized air feeding pipe 7 arranged via a constant flow rate type pressure control valve unit and a fluid discharging pipe 11 are connected to this space. 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 sealing device, not only the number of sealing rings is large and the entire device becomes complicated, but also between the first annular chamber 31 supplying pressurized air and the seawater outside the ship, Since only one seal ring 1 is arranged as the seal ring that is used in the state where it is most likely to be damaged by foreign matter outside the vessel because it directly seals seawater, the reliability of the entire sealing device is improved. It is a drawback in securing. Further, as shown in FIG. 6, the piping system connected to the rear stern tube sealing device becomes complicated, and the stern tube lubrication system must be expensive.

[0004]

In the present invention, two seal rings are arranged on the stern side in the direction of sealing seawater, and one seal ring is arranged on the bow side in the direction of sealing stern tube lubricating oil. Arranging the seal rings of the above and using the space adjacent to the stern tube bearing chamber constituted by the two seal rings as an air chamber to discharge air into the outboard seawater from between the two seal rings and the liner. As a means of solving the problem of recovering seawater and lubricating oil from the air chamber to the inside of the ship, we realized a highly reliable rear stern tube seal device with a simple structure and simplified the piping system 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 in contact with seawater, and as long as the seal ring at the rearmost part is sound, the reliability of other seal rings is As a result, the reliability of the entire sealing device is 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. 5, 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. Since the moving surface hardly makes 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. ing. However, the seal ring 1 that is in direct contact with seawater is in an environment where it is easily damaged by foreign matter outside the ship, which is a drawback in improving the reliability of the entire sealing device. Therefore, two seal rings are continuously arranged toward the seawater side, and pressurized air is blown into the outboard seawater from between the two seal rings and the propeller shaft liner, whereby the pressurized air chamber And the infiltration of seawater into the stern tube is sealed in two stages. Therefore, the reliability is further ensured as compared with the conventional rear stern tube sealing device, so that only one seal ring is required to seal the lubricating oil, and the structure and the structure of the rear stern tube sealing device The 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, 3 and 4 are elastic seal rings made of rubber or a polymer material that are in sliding contact with the propeller shaft liner 10, and the hull stern member 40
It is held by the housing member 22 of the sealing device 30 which is fixed to the. The seal rings 1 and 3 are on the stern side and are arranged toward the seawater side to perform the function of sealing the seawater. Further, the seal ring 4 is arranged toward the stern tube to perform an operation of sealing the stern tube lubricating oil. Seal ring 3,4
The pressurized air is supplied to the second annular chamber 32 formed by so that the seawater and the lubricating oil do not come into direct contact with each other. FIG. 2 shows the first piping system of the present invention.
This is an example. The pressurized air supplied from the pressure tank unit 8 which is an air source is supplied from the pressurized air feed pipe 7 through the constant flow rate pressure control valve unit 9 to the stern tube bearing chamber 34 so that the sealing device 30 of FIG. It is guided to the second annular chamber 32.
The air supplied to the second annular chamber 32 is controlled by the flow rate type pressure control valve unit 9 so as to flow in a constant amount, and the air is supplied from the sliding portion between the two seal rings 1 and 3 and the propeller shaft liner 10 to the first annular chamber. Since the gas is blown into the seawater outside the vessel while being decompressed each time it passes through the sliding portion between each seal ring and the propeller shaft liner 10 via the chamber 31, the first annular chamber 31 and the second annular chamber 32 Each 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 second annular chamber 32 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 flow restricting device 14 such as a drain tank 12 and 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. The lubricating oil is supplied to the stern tube bearing chamber 34 shown in FIG. 1 from the sealed pressurized oil sump tank 17 via the oil pump 16 by the pressurized oil circulation pipe 15 and returns to the oil sump tank 17 again. 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 portion of the oil sump tank 17 via a booster relay 19 which is a pressure regulating valve, whereby the second annular chamber 3
The oil pressure in the oil sump tank 17 can be automatically adjusted 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 of 2. As described above, in the seal rings 1 and 3, air is blown from between the lip sliding surface and the propeller shaft liner 10 to seal the seawater in two stages. The lip sliding surface hardly makes direct contact with the propeller shaft liner 10, and the pressure difference between the pressurized air in the second annular chamber and the first annular chamber and the pressurized air in the first annular chamber and the seawater. Since the differential pressure is also constant, stable usage is maintained and high reliability and longevity are secured. Further, also in the seal ring 4, since the differential pressure between the lubricating oil and the pressurized air is constant, a stable use state is maintained as in the seal rings 1 and 3, and high reliability and longevity are obtained. If seawater or lubricating oil intrudes into the second annular chamber 32 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 pipe bearing chamber 34. The leakage of lubricating oil into the outboard seawater is prevented.
Furthermore, since the second annular chamber 32 is maintained as an air chamber by such a recovery function, the usage state of the seal ring 4 or the seal rings 1 and 3 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 a constant pressure that is not interlocked with the pressure of the pressurized air in the second annular chamber 32. Other than this, it is the same as the first embodiment shown in FIG. Since the reliability of the seal device 30 depends almost on the two seal rings 1 and 3, it is not necessary to make the differential pressure between the lubricating oil and the pressurized air on the seal ring 4 constant, but it is a practical pipe. System, first
The simplification is achieved as compared with the embodiment. It should be noted that, instead of the method of pressurizing the lubricating oil by the gravity type head tank 42 in the second embodiment of the piping system, circulating pressurization by an oil pump configured not to be linked to the pressure of the pressurized air in the second annular chamber 32. It goes without saying that the method 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 rings 1 and 3 for sealing seawater from foreign matter such as fishing nets, a fishing net intrusion prevention ring 50 is attached to the propeller side of the seal ring 1. 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 boat inner arm 52 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 allows the boat inner arm of the casing member 22 and the fishing net intrusion prevention ring 50. 52 through which air is blown out 55
Released into the seawater outboard. Therefore, seawater is sealed in three stages in which the fishing net intrusion prevention ring 50 is added to the seal rings 1 and 3, and the reliability of the sealing device 30 is further enhanced. In the rear stern tube sealing device, the seal rings 4 and 3 have a structure directed in the direction of sealing seawater.
The pressure of the lubricating oil can be used as a pressure lower than the pressure of the pressurized air in the second annular chamber 32.

[0007]

The rear stern tube sealing device of the present invention does not impair the functions required as a stern tube sealing device.
Since two seal rings for sealing seawater are arranged adjacent to each other in two stages, the sealing effect for seawater, which requires the most reliability, is significantly enhanced, and a seal ring for sealing stern pipe lubricating oil is also provided. Since one structure is provided, there is an effect that the structure can be simplified as compared with the conventional stern tube sealing device. In addition, along with this, the piping system is greatly simplified, which can contribute to a reduction in piping work. further,
By mounting the fishing net intrusion prevention ring having the liquid sealing function, not only the seal ring is protected but also seawater is sealed in three stages, which can further increase the reliability of the sealing device. .

[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 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 Room 40 Stern member 41 Stern tube bearing 42 Head tank 50 Fishing net intrusion prevention ring 51 Outer arm 52 Outer arm 53 Garter spring 54 Seawater annular chamber 55 Air outlet hole

Claims (4)

[Claims] 1. In a rear stern tube sealing device attached to the outer side of a stern tube of a ship, two elastic seal rings made of rubber or a polymer material are adjacent to each other in a direction of sealing seawater on the stern side, and , A total of three units are arranged on the bow side in the direction of sealing the stern tube lubricating oil, and a constant flow rate pressure control valve unit is installed in the space formed by two seal rings and adjacent to the stern tube bearing chamber. A stern tube sealing device, characterized in that a pressurized air supply pipe and a fluid discharge pipe are installed through the stern pipe. 2. A pipe is branched from a pressurized air supply pipe installed in a space adjacent to the stern tube bearing chamber via a constant flow rate pressure control valve unit and led to a pressurized oil sump tank. The stern tube sealing device according to claim 1, wherein a pressure adjusting valve for adjusting the pressure of the pressurized air is provided in the middle of the branch pipe. 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 all of the three elastic body seal rings made of rubber or polymer material are oriented in a direction for sealing seawater. apparatus.