JPS62268797A - Lubrication system for stern tube device - Google Patents

Abstract

PURPOSE:To enable the common use of lube oil approximately at the same pressure level for a bearing and a sealing device by applying the same low pressure to lube oil for the bearing built into a stern tube and for the sealing device. CONSTITUTION:Oil for lubricating bearings 3 and 4 is sealed with a forward sealing device 6 and an aft sealing device 7 located fore and aft of a stern tube 2. A lead pipe 10d for discharging oil after the lubrication of the bearings 3 and is provided at a position about 2-3m below the axial center of the stern tube 2, and made continuous to a discharge pipe 11b for lubricating the forward sealing device 6. Therefore, lube oil pressure for the bearings 3 and 4, and lubricating pressure for the forward sealing device 6 can be kept at the same low level in common.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a 1lII sliding system in a stern tube device of a ship.

[Conventional technology]

Conventionally, as an example of a stern tube device, as shown in Fig. 2, a propeller shaft (5) is attached to the inner periphery of a stern tube (2) installed through a ship body (1) via bearings (3) and (4). The stern tube (2
) is sealed by the front seal device (6) and the rear seal device (7) arranged before and after the same rear seal device (
7) There are known products that prevent seawater from entering.
Both seal devices (8) (?) Generally, multiple glue-tube seals are used, especially the rear seal device 2! In (7), a lubricating oil seal (7a) and a seawater seal (?b) (7c) are arranged side by side in opposite directions.

In this stern tube device, the propeller shaft (5) is supported by two front and rear bearings (3) and (4), but since both support the weight of the propeller and the weight of the shaft (5), the load is quite high. Proactive supply of lubricating oil is essential. It is also customary to supply oil to the sealing device (6) in order to maintain good sealing performance, and for this reason, the above-mentioned device is provided with the following lubrication system.

In other words, as shown in the figure, oil stored in the tank (8) was fed from the pump (9) through the pipe (10a) into the stern tube (2) to lubricate the bearings (3) and (4). After, piping (1
01+ or 10c) and collected in tank (8).

A part of the oil leaving the pump (9) is branched off by a pipe (lla) to lubricate the front sealing device (6) and then to a pipe (Ilb).
) and returned to the tank (8). In this lubrication system, the oil fed into the stern tube (2) must be maintained at a pressure equal to or higher than the water depth of the ship in order to balance the seawater pressure across the rear sealing device (7). Therefore, the pressure is adjusted by selectively opening the valves (12) and (13) depending on the depth of stifling at that time. The lubricating oil pressure of the front sealing device (8) is generally 0.2 to 0.0, regardless of the stuttering depth.
It is customary to use a low pressure of about 3 kg/c+w2.

[Problem that the invention seeks to solve]

In the conventional system described above, the reason why the lubricating oil for the bearings (3) and (4) fed into the stern tube (2) is set to a pressure higher than the pressure corresponding to the water depth of the ship is because the aft seal device ( 7
) to prevent seawater from entering in the event of breakage, but this requires piping (10b) (loc) to a high place corresponding to the stuttering depth, and There are problems such as a high load being applied to the front sealing device (8) during stasis.

[Purpose of the invention]

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

[Means for solving problems]

In order to achieve this objective, the lubrication system of the present invention includes a seal member for lubricating oil and a seal member for seawater, which are arranged side by side, and pressurized fluid for seal replenishment is supplied between the two seal members. In a stern tube device that has a rear seal device, the lubricating oil pressure of the bearing built in the stern tube is set to a low pressure that is approximately the same as the lubricating oil pressure of the front seal device, and the lubricating oil of both is shared at approximately the same pressure. I decided to do so.

The above-mentioned rear sealing device for supplying pressurized fluid was previously patented and registered as a utility model by the applicants of the present application (Japanese Patent Application Laid-Open No.
No. 0-181298 "Stun Tube Seal" and Utility Model Application No. 165300/1982 "Stern Tube Shaft Sealing Device") are configured to use pressurized fluid against seawater and reduce the burden on each seal member. It has the feature that the pressure of the lubricating oil (in-flight oil) can be set freely without any relation to seawater pressure.

The present invention focuses on this, and the lubricating oil pressure is adjusted to the lubricating oil pressure of the front seal device (0.2 to 0.3 kg/as described above).
The lubricating oil for both is shared at almost the same low pressure (set at can be shared in parts.

〔Example〕

Next, an embodiment of Suekkan IJII will be explained according to the drawings.

As shown in FIG. 1, the rear seal device (7) attached to the rear end of the stern tube (2) forms an annular recess (7e) on the inner periphery of the casing (7d) and has a pair of segment seals ( 7f) (7g) is inserted, and a glue lug seal (7h) for seawater is installed on the seawater side of the segment seal (?f) (7g), and a segment for pairing oil is installed on the same bearing (a) side. It has a seal (?i) and a knob seal (7j). Said pair of segment seals (7F) (7g)
A pressurized fluid supply pipe (7k) that supplies pressurized fluid (compressed air, etc.) with a pressure higher than seawater pressure is opened in the annular recess (7e) that is almost sealed by the pressurized air inside the ship. connected to a fluid supply source; During its operation, this rear sealing device (7) is in principle always supplied with pressurized fluid, which is brought into contact with the seawater. This allows the same sealing device (7
), the seal for seawater and the seal for lubricating oil are completely separated, and the lubricating oil pressure in the stern tube (2) can always be kept low regardless of the depth of the ship's stutter.

The lubrication system takes advantage of this advantage and the bearing (3) (
4) A piping (10d) for discharging the lubricated oil is installed at a low location (2 to 3 m height from the shaft center), and the front sealing device (
6) It merges with the lubrication discharge piping (llb) and provides lubricating oil pressure and front seal device (8) for bearings (3) and (4).
As can be seen from the comparison with the conventional example shown in Fig. 2, it eliminates the need to install piping at a high place and allows many parts of the discharge piping to be shared. Not only is this possible, but the pressure difference between the front and rear lip seals (8a) of the front seal installation (8) is eliminated, so the lip seals (6a) can be kept in an idling state at all times and used as a backup seal in case of an emergency. Can be done. Also, remove the lip seal (6a) and branch piping (lla) (ll
b) can also be removed.

〔Effect of the invention〕

Stern tube according to the present invention? As explained above, the lubrication system installed in the In addition, since the lubricating oil pressure for the bearing and the lubricating oil pressure for the front seal device are almost the same, the load on the seal device is significantly reduced and its durability is improved. be able to. In addition, by simplifying the piping, it is possible to easily design piping in a narrow ship (engine room), and it is also possible to reduce system maintenance and reduce the burden on the crew.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of a stern tube device according to an embodiment of the 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 (8) Front seal device (8a) (7h
) (7j) Lip seal (7) Rear seal device (7f) (7g) (7i) Segment seal (8)
Tank (9) pump

Claims (1)

[Claims] In a stern tube device, a stern tube device includes a seal member for lubricating oil and a seal member for seawater, and a rear seal device that supplies pressurized fluid for seal replenishment between the two seal members. A stern tube lubrication system characterized in that the lubricating oil pressure of the built-in bearing is set to a low pressure that is approximately the same as the lubricating oil pressure of the front seal device, and both lubricating oils are shared at approximately the same pressure.