JPH068882A - Stern pipe sealing device - Google Patents

Abstract

PURPOSE:To prevent the substitution of an oil lubricating a seal ring for air. CONSTITUTION:In a casing 3 which is freely fitted on a shaft 1, a plurality of sealing rings 4, 5, and 6 which slidingly contact the shaft 1 side are successively arranged on the vessel inside from the vessel outside, and the space formed by a pair of seal rings is formed to an air chamber 7 and an oil chamber 8 from the vessel outside, and the air chamber 7 and a compressed air source are connected, while, a pipe 11A for the connection and communication between the oil chamber 8 and an inside-vessel oil tank 10 is provided, and a stern pipe sealing device is constituted. An air pocket 3A is formed by forming the spread part in the diameter outside direction in the upper part of the oil chamber 8, and the oil tank 10 is installed so as to have the equal level to the oil level in the oil chamber 8 and/or the air pocket 3A formed in the oil chamber 8, and connected through the piping 11A, and further, the air pocket 3A and the upper part of the oil tank 10 are connected by other pipings 11.

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 As a stern tube sealing device with an air blowing device for a ship, there is a technique disclosed in Japanese Utility Model Publication No. 4-4567. As shown in FIG. 3, this conventional technique is such that, in a casing 3 having a liner 2 loosely fitted to a shaft 1, first to third seal rings 4, 5 and 6 slidably contacting the shaft 1 side are provided from the outside of the ship. The inner and outer seals are arranged one after another, and the first and second seal rings 4,
5 between the air chamber 7 and the second and third seal rings 5,
In the stern tube seal device in which the oil chambers 8 are provided between the first and second oil seals, the first seal ring 4 is provided with the rear surface facing the air chamber 7 so that the air from the air chamber 7 can be blown to the outside of the ship, and the second seal ring 4 is provided. The ring 5 is provided with the front side facing the air chamber 7 so that the lip portion is pressed against the shaft 1 side by the air pressure of the air chamber 7. According to this technique, the first and second seal rings 4, Since the rear side of both 5 faces the inside of the ship, it is only necessary to set the pressure of the oil chamber 8 to be lower than the seawater pressure, and it is not necessary to interlock with the air pressure of the air chamber 7.

The second seal ring 5 has an oil chamber on the back.
With 8 lubricating oils, it is difficult to damage even if a large differential pressure is applied due to shaft vibration. Even if the oil pressure in the oil chamber 8 fluctuates, the lip portion of the second seal ring 5 is constantly pressed by the air pressure to the shaft 1 side.
A large amount of air in 7 cannot leak into the oil chamber 8. A small amount of air can be removed from the oil supply pipe.

Furthermore, it is not necessary to constantly send air to the air chamber 7, and air can be supplied and blown out only when there is an abnormality such as oil leakage or seawater intrusion. The air supplied to the air chamber 7 passes through the first seal ring 4 and flows out to the seawater side. The second ring 5 normally seals the air supplied to the air chamber 7 and does not allow air to enter the oil chamber 8.

[0005]

However, when the second seal ring 5 is deteriorated and damaged, the sealing property of the ring 5 is deteriorated, and a part of the air supplied to the air chamber 7 becomes the second seal. There was a risk of passing through the ring 5 and entering the oil chamber 8. That is, when the sealing device was used for a long time, the second seal ring 5 could be sufficiently damaged.

When such a situation occurs, there is a large difference in the viscosity of the target fluid between sealing seawater or lubricating oil and sealing air, so that when the second seal ring 5 is damaged, the oil The amount of fluid flowing into the chamber 8 varies greatly depending on the type of fluid. Therefore, the second seal ring 5
If the oil is damaged, a large amount of air will enter the oil chamber 8 and the air will not be fully exhausted. Therefore, the oil chamber 8 is entirely replaced with the air chamber, and the lubrication conditions for the second and third seal rings 5 and 6 are replaced. Deteriorated and the second and third seal rings 5,
There was a risk of causing damage to item 6.

In particular, when the oil level of the oil chamber 8 is raised and all of the chamber 8 is filled with oil, the air that has entered the chamber 8 passes through the lines on both the top and bottom portions. The chamber 8
This oil was extruded into air and replaced with air, causing the above-mentioned problems. Therefore, in the present invention, by forming an air pocket on the top side of the oil chamber and connecting an oil pipe to the air pocket, even if the second seal ring is damaged and air enters the oil chamber, The purpose is to remove the air from the oil in the oil chamber and to ensure the lubrication performance by drawing the air into the ship through the oil pipe.

[0008]

SUMMARY OF THE INVENTION According to the present invention, a plurality of sealings 4, 5 and 6 slidably contacting the shaft 1 are sequentially arranged from the outer side to the inner side of a ship in a casing 3 loosely fitted to the shaft 1 to form a pair. The space formed by the seal ring is formed from the outside of the ship to the air chamber 7 and the oil chamber 8, and the air chamber 7 and the compressed air source are connected, while the oil chamber 8 and the inboard oil tank 10 are connected and communicated. Plumbing 11A
In order to achieve the above-mentioned object, the stern tube sealing device including the following technical means is taken.

That is, the present invention relates to the oil chamber 8
An air pocket is formed by forming a radially enlarged portion on the top of the
3A, the oil tank 10 is installed so as to be at the same level as the oil level in the oil chamber 8 and / or the air pocket 3A formed in the oil chamber 8, and the pipe 11
Besides connecting by A, air pocket 3A and oil tank 10
It is characterized in that it is connected to the upper part of the pipe by another pipe 11.

[0010]

According to the present invention, even if the air in the air chamber 7 enters the oil chamber 8 due to the damage of the second seal ring 5, the invading air escapes to the inside of the ship through the pipe 11 to replace the air with the oil. To prevent.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In addition, the same parts as those of the conventional example described above are denoted by common reference numerals. In FIGS. 1 and 2, an oil tank 10 provided in a ship for lubricating oil is not elongated and has a large cross-sectional area, and the top portion of the oil chamber 8, specifically, the upper surface of the liner 2 is shown. Oil level slightly above
10A is set, and increasing the cross-section area
The change of 10A is difficult to change, which makes the oil chamber
An air chamber 8A is formed in the top part of 8.

The casing 3 corresponding to the air chamber 8A in the oil chamber 8 is formed with an air expanding portion in the radially outer direction to form an air pocket 3A, and the oil supply pipe 11 is provided in the air pocket 3A.
Is connected to the oil tank 10 together with the bottom side pipe 11A. Therefore, in the normal state, the second and third seal rings 5,
The sliding portion of 6, that is, the lip portion is filled with the lubricating oil, and even if a small amount of oil leakage occurs, the oil level fluctuation of the oil chamber 8 and the oil tank 10 is reduced.

Here, even if the air in the air chamber 7 enters the oil chamber 8 due to damage to the second seal ring 5, it escapes from the pipe 11 through the piping 11 via the air chamber 8A on the top side and the air pocket 3A. Prevent the replacement of air and oil. That is, the present invention forms an air pocket 3A by forming an enlarged portion in the radial direction on the upper part of the oil chamber 8, and forms the oil surface in the oil chamber 8 and / or the air pocket 3A formed in the oil chamber 8. The oil tank 10 is installed so as to be at the same level and connected by the pipe 11A, and the air pocket 3A and the upper part of the oil tank 10 are connected by another pipe 11.

In FIG. 1, 12 is a compressed air supply device, 13 is a leakage oil recovery device, 14 is an oil drain, 15 is a tank air vent, and 16 is a third S seal ring.

[0015]

The present invention is as described above. Even if the second seal ring is damaged and the air in the air chamber enters the oil chamber, the intruding air can be extracted into the ship by the oil supply pipe on the top side. It is possible to eliminate the replacement of oil with air in the oil chamber and maintain the lubricating performance.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 is a configuration diagram of a conventional example.

[Explanation of symbols]

 1 Shaft 3 Casing 3A Air pocket 4 1st seal ring 5 2nd seal ring 6 3rd seal ring 7 Air chamber 8 Oil chamber 8A Air chamber 10 Oil tank 10A Tank oil level 11 Oil supply pipe

Claims (1)

[Claims] 1. A casing (3) loosely fitted to a shaft (1).
Inside, there are multiple sealings (4) that slide on the shaft (1) side.
(5) (6) are sequentially arranged from the outer side of the vessel to the inner side of the vessel, and the space formed by a pair of seal rings is formed from the outer side of the vessel to the air chamber (7) and the oil chamber (8). ) With a compressed air source, while the oil chamber
A stern tube sealing device comprising a pipe (11A) for connecting and communicating between (8) and an onboard oil tank (10), wherein an air pocket is formed by forming an enlarged radially outward portion at the upper part of the oil chamber (8). (3A), the oil chamber (8)
And / or install the oil tank (10) so that it is at the same level as the oil level in the air pocket (3A) formed in the oil chamber (8) and connect it by piping (11A), and also in the air pocket (3A) A stern tube sealing device, characterized in that the oil tank (10) and the upper part of the oil tank are connected by a separate pipe (11).