JPH0653518B2 - Lubrication system for stern tube equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a lubrication system in a stern tube device of a ship.

[Conventional technology]

As an example of a conventional stern tube device, as shown in FIG. 2, bearings (3) are provided on the inner circumference of the stern tube (2) penetrating the ship body (1).
The propeller shaft (5) is rotatably supported via (4)
(3) The oil that lubricates the (4) part is sealed by the front seal device (6) and the rear seal device (7) that are arranged before and after the stern tube (2), and by the rear seal device (7). It is known to prevent entry of seawater. Multiple lip seals are commonly used for both seal devices (6) (7), especially rear seal devices.
A lip seal (7a) for lubricating oil and lip seals (7b), (7c) for seawater are arranged in parallel in (7) in mutually opposite directions.

In this stern tube device, the propeller shaft (5) is supported by two front and rear bearings (3), (4), but both of them support the propeller and the weight shaft (5) by their own weight, resulting in a considerably high load. Active supply of lubricating oil is essential. Further, it is customary to supply oil to the sealing device (6) in order to maintain good sealing performance. Therefore, the above device is provided with the following lubrication system.

That is, as shown in the figure, the oil stored in the tank (8) was fed from the pump (9) through the pipe (10a) into the stern pipe (2) to lubricate the bearings (3) (4). After that, it is recovered in the tank (8) through the pipe (10b or 10c). Some of the oil leaving the pump (9) is piped (1
1a) to branch, lubricate the front seal device (6), and pipe
Returned from (11b) to tank (8). In this lubrication system, the oil to be fed into the stern tube (2) is the rear seal device (7).
Since it is necessary to keep the pressure above the pressure corresponding to the stall depth of the ship in equilibrium with the seawater pressure, the valves (12) and (13) are selectively opened depending on the stall depth at that time. Is being adjusted. The lubricating oil pressure of the front seal device (6) is generally set to a low pressure of about 0.2 to 0.3 kg / cm ² irrespective of the water depth.

[Problems to be solved by the invention]

In the system according to the above conventional example, the lubricating oil for the bearings (3) (4) to be fed into the stern pipe (2) is set to a pressure corresponding to the depth of water of the ship or above by the rear seal device ( This is to prepare for this so that seawater can be prevented from invading at the time of damage in 7), but along with this, piping (10b) (10c) to a high place corresponding to the depth of stuttering is required, There is a problem that a high load is applied to the front seal device (6) during high-drinking water.

[Object of the Invention]

In view of the above points, it is an object of the present invention to reduce the cost and improve the durability of the front sealing device by simplifying (simplifying) the piping.

[Means for solving problems]

In order to achieve this object, the lubrication system of the present invention includes a stern tube that encloses a bearing that supports a propeller shaft and is supplied with lubricating oil, a rear sealing device that is arranged on the stern side of the stern tube, and the stern. A rear sealing device disposed on the bow side of the pipe, wherein the rear sealing device is between the stern pipe side anti-lubricating oil seal member and the rear anti-seawater seal member facing seawater. And a structure in which a high-pressure pressurized fluid is supplied by the pressure of seawater contacting the sealing member for seawater, and the front seal device comprises a plurality of seals for lubricating oil facing the stern tube side. In a stern tube device composed of a member, a pipe for circulating and supplying lubricating oil between a plurality of sealing members for lubricating oil of the front seal device, the discharge side of the pipe for circulating and supplying lubricating oil to the bearing on the inner circumference of the stern tube. To the discharge side of The pressure head of the lubricant due to the tube is obtained by the same.

The above-mentioned rear sealing device for feeding a pressurized fluid is the one for which the applicants previously applied for a patent and utility model registration (Japanese Patent Laid-Open No. 60-1
No. 61298 "Stan tube seal", No. 59-165300 "Stern tube shaft sealing device"), seawater pressure is applied by the pressurized fluid supplied between the seal member for lubricating oil and the seal member for seawater. And the bearing lubricating oil inside the rear sealing device and the seawater outside the rear sealing device are completely separated.

The present invention pays attention to this point and sets the pressure of the lubricating oil supplied to the bearing to a constant value regardless of the seawater pressure outside the rear sealing device, and at the same time, for the plural lubricating oils of the front sealing device. It is equal to the pressure of the lubricating oil supplied between the seal members, eliminating the need for high-place piping to obtain high pressure.
Plumbing for supply and discharge can be shared in many parts.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the rear sealing device (7) attached to the rear end of the stern tube (2) has an annular recess (7e) formed in the inner periphery of the casing (7d) to form a pair of segment seals ( 7f) and (7g) are inserted, and a seawater-side lip seal (7h) is provided on the seawater side of the segment seals (7f) and (7g), and a segment seal for lubricating oil (on the side of the bearing (inside the machine)). 7i) and lip seal (7
j) is provided. The pair of segment seals (7f) (7
In the annular recess (7e) that is substantially sealed by g), a pressurized fluid supply pipe (7k) for supplying a pressurized fluid (compressed air or the like) having a pressure equal to or higher than seawater pressure is opened, and It is connected to a source of pressurized fluid. During operation of this rear sealing device (7), in principle, a pressurized fluid is always fed so that the fluid faces the seawater. On the other hand, the front seal device (6) attached to the bow side of the stern tube (2) is a pair of lip seals (6a) (6a) (6a) (6a) facing the stern tube (2) side as a sealing member for lubricating oil.
b) is equipped.

The lubricating oil discharged from the tank (8) via the pump (9) is
It is supplied to the bearings (3) and (4) in the stern tube (2) through the pipe (10a) and between the lip seals (6a) and (6b) through the pipe (11a) branched from the pipe (10a). The lubricating oil discharged from the bearings (3) (4) through the pipe (10b) merges with the lubricating oil discharged through the pipe (11a) from between the lip seals (6a) and (6b), From a height of 2 to 3 m from the axis of the propeller shaft (5), the propeller shaft (5) is flown down to the tank (8) thereunder via a pipe (12). For this reason, the pressure of the lubricating oil in the stern tube (2) and the lip seal (6
The pressure of the lubricating oil between a) and (6b) has a constant low pressure value of 0.2 to 0.3 kg / cm ² by the same pressure head (h).

That is, in this rear lubrication system, in the rear seal device (7), the pressure of the pressurized fluid supplied between the segment seals (7f) and (7g) is made to oppose the seawater pressure outside the seawater lip seal (7h). Since it is not necessary to counteract the pressure of the lubricating oil supplied into the stern tube (2) with the seawater pressure, the lip of the front seal device (6) set to a relatively lower pressure than this seawater pressure. By equalizing the lubricating oil pressure between the seals (6a) and (6b), it is not necessary to install pipes at a high place as can be seen from a comparison with FIG. Not only can it be shared, but since there is no pressure difference before and after the rear lip seal (6a) of the front seal device (6), the lip seal (6a) is always kept in an idling state, and a preliminary seal for emergencies is created. Can be used as Further, the lip seal (6a) is removed, and the branch pipe (11
It is also possible to remove a) (11b).

〔The invention's effect〕

As described above, the lubrication system of the stern tube device according to the present invention does not require high-place piping for obtaining high pressure by reducing the lubricating oil pressure for bearings, and simplifies the piping. The cost can be reduced due to the reduction of the physical quantity. Further, since the lubricating oil pressure for the bearing and the lubricating oil pressure for the front seal device are made to be the same, the load on the seal device can be significantly reduced and the durability thereof can be improved. In addition, there is an advantage that the piping design can be facilitated in a narrow ship (engine room) by simplifying the piping, and the system maintenance can be reduced to reduce the burden on the crew.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a stern tube device according to an embodiment of a lubrication system of the present invention, and FIG. 2 is a schematic sectional view of a stern tube device showing an example of a conventional lubrication system. (1) …… Hull, (2) …… Stern tube, (3) (4) …… Bearing (5) …… Propeller shaft, (6) …… Front seal device (6a) (7h) (7j) …… Lip seal (7) …… Rear seal device (7f) (7g) (7i) …… Segment seal, (8) …… Tank (9) …… Pump (10a) (10b) (10c) (10d) (11a) (11b) …… Piping

Claims (1)

[Claims] 1. A stern tube containing a bearing for supporting a propeller shaft and supplied with lubricating oil, a rear sealing device arranged on the stern side of the stern tube, and a front part arranged on the stern side of the stern tube. And a rear sealing device between the stern tube side anti-lubricating oil seal member and the sea water opposing sea water sealing member behind the stern tube side sealing device. The stern tube device has a structure in which a pressurized fluid having a pressure higher than the pressure of seawater in contact is supplied, and the front seal device is a stern tube device composed of a plurality of anti-lubricating oil seal members facing the stern tube side. The discharge side of the pipe that circulates the lubricating oil to the bearing on the inner circumference of the stern pipe is joined to the discharge side of the pipe that circulates the lubricating oil between the plurality of anti-lubricating oil seal members of the front seal device. The same pressure head for the lubricating oil through the piping Lubrication system stern tube and wherein the.