JPH06323443A - End-face sealing type seal ring for stern tube shaft seal device - Google Patents

Abstract

PURPOSE:To facilitate positioning at attaching of a seal ring and to maintain a proper sliding condition with a mating ring even when a propeller shaft is displaced in the axial direction. CONSTITUTION:A sliding collar part 12 having flexibility in which sliding faces 12a and 12b in close contact and sliding with an end face 3a of a mating ring 3 are formed and a ring-state block 13 opposed to the back face of the sliding collar part 12 through a ring-state clearance delta are provided integrally on an outer circumference of an inside diameter attaching part 11 to be attached on the side of a propeller shaft 2. Moreover, an end face 11a on the side of the mating ring 3 of the inside diameter attaching part 11 is formed largely retreating from the sliding faces 12a and 12b more than the width in the axial direction of the ring-state clearance delta in the state that the sliding faces 12a and 12b are in close contact with the end face 3a of the mating ring 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elastomeric sealing element for a stern tube shaft sealing device which is mounted on an end portion of a stern tube of a ship and axially seals the outer circumference of a propeller shaft. The present invention relates to an end face sealing type seal ring.

[0002]

2. Description of the Related Art Stern tube bearings for ships include oil-lubricated and water-lubricated ones. FIG. 3 shows a stern portion of a ship having a water-lubricated stern tube bearing. Reference numeral 100 is a water-lubricated stern tube bearing, and 110 is a propeller for pivotally supporting the stern tube bearing 100 to rotate a propeller 111. It is an axis. Since the water-lubricated stern tube bearing 100 has a lubrication structure in which seawater is sent from the inside of the ship to the bearing surface and discharged to the outside of the ship, the aft side of the stern tube bearing 100 is prevented from entering the engine room so that the seawater does not enter the engine room. A casing 120 provided so as to surround the outer peripheral space of the propeller shaft 110, and an elastomer seal ring 13 arranged in the inner peripheral space of the casing 120.
The stern tube shaft sealing device including 0 etc. is attached. Reference numeral 140 denotes an inflatable seal made of a hollow elastomer. In an emergency such as a breakage of the seal ring 130, a pressurized fluid is fed into the inflatable seal to inflate it and the inner peripheral surface thereof is brought into close contact with the outer peripheral surface of the propeller shaft 110 to seal water. It is something to do.

The seal ring 130 has a structure of end face sealing type, and conventionally, as shown in FIG. 4, a tightening force is applied by an annular garter spring 133 so that the seal ring 130 is tightly fitted to the outer peripheral surface of the propeller shaft 110. The fixed inner diameter boss portion 131 and the annular sliding surfaces 132a, 1 on the end surface on the bow side.
32b is composed of a sliding flange portion 132 formed concentrically, and is rotated together with the propeller shaft 110.
The a and 132b closely slide with the stern side end surface 121a of the mating ring ring 121 fixed to the casing 120, thereby providing a water sealing function.

[0004]

According to the above-mentioned conventional seal ring 130, in order to perform accurate positioning and mounting as shown in FIG. 4, it is necessary to use a dedicated mounting jig at the time of mounting. This is because, for example, when the seal ring 130 is installed so as to be unevenly distributed closer to the bow than the regular mounting position shown in FIG. 4, as shown in FIG.
The end surface 131a of No. 1 may be slid in a state of being strongly pressed against the mating ring ring 121, and in this state, the sliding flange portion 13 having low rigidity is formed.
2 is pushed back by the increase of the pressing reaction force, and the sliding surface 1
This is because 32a and 132b are not in the proper proper sliding state. The same problem occurs when the propeller shaft 110 is largely axially displaced toward the bow side due to thrust or the like.

The present invention has been made under the circumstances as described above, and its technical problem is to facilitate the positioning at the time of mounting the seal ring and to prevent the axial displacement of the propeller shaft. Even if there is, it is to maintain the proper sliding state with the mating ring.

[0006]

The above-mentioned technical problems are as follows.
The present invention can effectively solve the problem. That is, the end face sealing type seal ring for a stern tube shaft sealing device according to the present invention has a flexible sliding brim portion having a sliding surface that comes into close contact with the end face of the mating ring provided on the casing side. And an annular lump that faces the back surface of the sliding collar portion through an annular gap is integrally provided on the outer circumference of the inner diameter fitting portion that is fitted to the propeller shaft side. The end surface on the ring side is formed so as to recede largely from the sliding surface rather than the axial width of the annular gap in the state where the sliding surface and the end surface of the mating ring are in close contact with each other.

[0007]

When the seal ring is displaced in the direction closer to the mating ring than the regular mounting position, the reaction of the pressing force against the mating ring causes
When the sliding collar portion is relatively displaced so as to be pushed back toward the annular mass behind it, and when the displacement becomes the size of the annular gap between the sliding collar part and the annular mass, the back surface of the sliding collar part becomes annular. Since it comes into contact with the lump, relative displacement of the sliding brim portion is prevented at this point, and displacement to the mating ring side is prevented due to the generation of shear stress between the annular lump and the inner diameter fitting portion. Further, since the end surface of the inner diameter fitting portion on the mating ring side is formed at a position larger than the axial width of the annular gap and retracted from the sliding surface, it is held in non-contact with the end surface of the mating ring. In the case where the displacement is performed by axial displacement of the propeller shaft, for example, when the rearward displacement of the seal ring is prevented by the back surface of the sliding collar contacting the annular mass, the inner diameter fitting portion is Since it slips in the axial direction with respect to the outer peripheral surface of the propeller shaft, the contact pressure between the sliding surface of the sliding collar and the mating ring does not increase more than a predetermined value.

[0008]

1 is a sectional view showing a mounted state of an end face sealing type seal ring 10 for a stern tube shaft sealing device according to the present invention, and FIG. A casing 3 provided on the bow side of a bearing (not shown) so as to surround the outer peripheral space of the propeller shaft 2 is a mating ring which is watertightly fixed to the end of the casing 1 on the bow side. The seal ring 10, which is entirely formed of an elastomer, includes an inner diameter fitting portion 11 that is tightly fitted to the outer peripheral surface of the propeller shaft 2, and a sliding collar portion 12 on the bow side and a stern side formed on the outer periphery thereof. The rear surface of the sliding collar 12 on the stern side and the projecting end on the bow side of the annular mass 13 are formed to face each other with a slit-shaped annular gap δ open to the outer diameter side.

When the seal ring 10 is not mounted, the sliding flange 12 is inclined toward the bow side (the mating ring 3 side) as shown in FIG. 2, and the end face on the bow side is In the mounted state of FIG. 1, annular sliding surfaces 12a and 12b that are watertightly contacted with the stern side end surface 3a of the mating ring 3 are concentrically formed. Flushing water having a pressure higher than the seawater pressure to be sealed is preferably supplied to the annular groove 12c between the sliding surfaces 12a and 12b through a pressure introducing passage (not shown) formed in the mating ring 3. Further, the end surface 11a of the inner diameter fitting portion 11 on the bow side (the mating ring 3 side) is formed so as to recede toward the stern side with respect to the sliding surfaces 12a and 12b of the sliding collar portion 12, and the receding width thereof. Is larger than the axial width of the annular gap δ in the mounted state of FIG.

The axial thickness of the annular mass 13 is sufficiently larger than the axial thickness of the sliding collar portion 12, and therefore the sliding collar portion 12 is easily flexible in the axial direction. While it is displaceable, the annular mass 13 is not easily displaceable in the axial direction. A garter spring 14 is attached to the annular recess 13a formed on the outer peripheral surface of the annular lump 13,
An appropriate tightening force is applied to the inner diameter fitting portion 11 via the annular mass 13 against the outer peripheral surface of the propeller shaft 2.

In the above-mentioned structure, the seal ring 10 rotates together with the propeller shaft 2 and the sliding surface 12 of the sliding collar 12 is rotated.
The a and 12b closely slide on the end face 3a of the mating ring 3 to prevent the ingress of seawater reaching the inside space S of the casing 1 to the bow side. In the normal mounted state shown in FIG. 1, the elastic force of the sliding collar 12 in a state in which it is flexibly displaced so as to be relatively retracted from the unmounted state shown in FIG. The sliding surfaces 12a and 12b are pressed against the end surface 3a of the mating ring 3 by the seawater pressure in the space S acting on the back surface of the mating ring 12.

From this state, when the propeller shaft 2 is axially displaced toward the bow side by, for example, the thrust of the propeller, the seal ring 10 fitted to the outer peripheral surface of the propeller shaft 2 also follows the propeller shaft 2 toward the bow side. It is displaced, and the sliding flange 12
The annular gap δ behind is reduced. And the annular mass 13
When the tip end of the bow of the contact part comes into contact with the back surface of the sliding collar part 12, at that time, the end face 11a of the inner diameter fitting part 11 on the bow side is
The stern side end surface 3a of the mating ring 3 is not in contact with the mating ring 3 via the inner diameter fitting portion 11 that is about to be displaced to the bow side together with the propeller shaft 2 and the sliding collar portion 12. The shearing stress generated between the inner diameter fitting portion 11 and the annular lump 13 whose displacement toward the bow side is restricted acts to prevent the inner diameter fitting portion 11 from displacing toward the bow side. Therefore, when the pressing force of the sliding surfaces 12a and 12b against the mating ring 3 is increased to some extent by the annular mass 13,
The inner diameter fitting portion 11 slips relatively to the outer peripheral surface of the propeller shaft 2 toward the stern side, and the excessive deformation of the sliding collar portion 12 toward the stern side is prevented by the annular mass 13. 1
2a and 12b maintain elastic close contact with the mating ring 3 and the end surface 1 of the inner diameter fitting portion 11 on the bow side.
The pressure contact between 1a and the mating ring 3 is also prevented.

Further, when the seal ring 10 is mounted, even when the seal ring 10 is pushed toward the mating ring 3 side from the regular mounting position shown in FIG. 1, the sliding surfaces 12a and 12b are attached to the end surface 3a of the mating ring 3. After the contact, the tip of the ring-shaped lump 13 on the bow side comes into contact with the back surface of the sliding collar portion 12 to prevent the seal ring 10 from moving, so that the end face 11a of the inner diameter fitting portion 11 on the bow side is prevented. The mating ring 3 can be mounted in an appropriate state without being pressed against it.

The maximum surface pressure of the sliding surfaces 12a and 12b when the seal ring 10 is displaced toward the mating ring 3 side from the regular mounting position is the inner diameter fitting portion of the outer peripheral surface of the propeller shaft 2. It can be arbitrarily set by the tightening margin of 11 and the frictional force with the outer peripheral surface of the propeller shaft 2 due to the tightness of the garter spring 14 or the like. It is also preferable that the annular mass 13 is formed of a material having high rigidity other than elastomer and is integrated with the outer circumference of the inner diameter fitting portion 11.

[0015]

According to the end face sealing type seal ring for the stern tube shaft sealing device of the present invention, even if the seal ring is displaced in the direction closer to the mating ring than the normal mounting position, the reaction force of the pressing force against the mating ring causes a reaction. When the rear surface of the sliding collar that is displaced relative to the inner diameter fitting portion comes into contact with the annular mass behind it, movement of the seal ring to the mating ring side is blocked, and the end of the inner diameter fitting portion is Since it is held in non-contact with the end face of the mating ring, it is easy to position during mounting, and when the seal ring is displaced to the mating ring side by the axial displacement of the propeller shaft, the sliding collar When the rear surface of the sliding portion contacts the annular mass, the following displacement is blocked, and the inner diameter fitting portion slips with the outer peripheral surface of the propeller shaft. Contact pressure between it without having to increase more than a predetermined and thus to ensure the proper sliding state, it is possible to improve the sealing property and durability.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a mounted state of a preferred embodiment of an end face sealing type seal ring for a stern tube shaft sealing device according to the present invention.

FIG. 2 is a sectional view showing an unmounted state of the embodiment.

FIG. 3 is a sectional view showing a stern portion of a ship having a water-lubricated stern tube bearing.

FIG. 4 is a cross-sectional view showing a mounted state of a typical conventional example of an end face sealing type seal ring for a stern tube shaft sealing device.

FIG. 5 is a cross-sectional view showing a deformed state of the conventional seal ring due to axial displacement.

[Explanation of symbols]

 1 casing 2 propeller shaft 3 mating ring 10 seal ring 11 inner diameter fitting portion 12 sliding flange portions 12a, 12b sliding surface 13 annular mass

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takashi Omura, 1-1 Takanoura-cho, Nagasaki-shi, Nagasaki Nagasaki Shipyard, Mitsubishi Heavy Industries, Ltd. (72) Masami Akatsu, 1500 Katayanagi, Sakado-shi, Saitama Eagle Industrial Co., Ltd. Inside the Saitama Factory (72) Inventor Kiyoshi Uchiyama 1500 Katayanagi, Sakado City, Saitama Prefecture Eagle Industrial Co., Ltd.In Saitama Factory (72) Inventor Yuji Chiyoda 1500 Katayanagi, Sakado City, Saitama Eagle Industry Co., Ltd. Saitama Factory

Claims (1)

[Claims] 1. A flexible sliding brim portion having a sliding surface that closely slides with an end surface of a mating ring provided on the casing side, and a sliding brim portion of the sliding brim portion via an annular gap. An annular lump facing the back surface is integrally provided on the outer circumference of the inner diameter fitting portion fitted to the propeller shaft side, and the end surface of the inner diameter fitting portion on the mating ring side is mated with the sliding surface. An end face sealing type seal ring for a stern tube shaft sealing device, characterized in that the seal ring is formed so as to recede largely from the sliding surface in comparison with the axial width of the annular gap in a state where the ring end face is in close contact with the ring gap.