JPH0537694U - Stern tube emergency seal - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the sealability and durability of the emergency seal in the stern tube sealing device. [Structure] A plurality of annular lips 12 or mesh lips having different inner diameters are provided on an inner peripheral surface 11a of a seal ring 11. The entire inner peripheral surface 11a of the seal ring 11 is a flat surface, a convex surface, a concave surface, a tapered surface, or a combination thereof. In an emergency, compressed fluid is supplied to the seal ring 11 to press the lip 12 closest to the shaft to prevent the inflow of seawater or the like. The other lip 12 is pressed against the shaft.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a stern tube emergency seal used as an auxiliary seal of a main seal of a stern tube sealing device.

[0002]

[Prior art]

 In the stern tube seal device, when the main seal breaks down or during maintenance, an emergency seal provided on the stern side of the main seal is activated to temporarily prevent seawater from entering the ship. In the meantime, repair, replace or perform maintenance checks on the main seal.

FIG. 4 shows an example of this type of stern tube sealing device. An emergency seal 3 is incorporated in a notch 2a of a casing 2 fixed to the stern tube body 1 and fixed by a side plate 4. The emergency seal 3 is attached to the stern side (left side in the figure; the same applies below) of the main seal 5, and normally, as shown in FIG. 7 and the like pass through, and when activated, as shown in Fig. 5 (b), they are pressurized by a compressed fluid such as air and come into pressure contact with the surface of the shaft 6, preventing the ingress of seawater 7 and the like. To do.

[0004]

[Problems to be solved by the device]

 However, in the conventional stern tube emergency seal 3 described above, as shown in the schematic view of FIG. 6 (a), during normal operation, the lips 3a and 3b are pressed against the surface of the shaft 6 to seal against seawater 7 and the like. However, if the stern side lip 3a is damaged or broken by marine products as shown in Fig. 6 (b) or the surface of the shaft 6 is corroded as shown in Fig. 6 (c), However, there was a problem that the sealing function deteriorates and the function as an emergency seal cannot be achieved.

Further, at the time of operating the emergency seal, the shaft 6 may be rotated at a low speed for reasons such as engine adjustment, so-called turning may be performed. At that time, since the emergency seal 3 is designed as a static seal, this When used dynamically like this, there is a problem that the lips 3a and 3b are greatly damaged and the function as an emergency seal is not fulfilled.

The present invention solves such a conventional problem, and an object thereof is to provide a stern tube emergency seal having high sealing performance and durability.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a plurality of annular lips or mesh lips having different inner diameters on the inner peripheral surface of a seal ring.

[0008]

[Action]

 Therefore, according to the present invention, when a compressed fluid is applied to an emergency seal to operate it, the contact state between the lip of the seal ring and the shaft surface is changed by changing the supply pressure, so that even a certain lip may be damaged. Even if the shaft surface is corroded, sealing performance can be secured by pressing another lip against the shaft surface.

[0009]

【Example】

 FIG. 1 shows some embodiments of the present invention. The emergency seal according to the present invention comprises a plurality of annular lips or mesh lips having different inner diameters on the inner peripheral surface of the seal ring. In FIG. 1, (a) shows that the inner peripheral surface 11a of the seal ring 11 is composed of one flat surface at the central portion and two tapered surfaces having gradually increasing inner diameters toward the outside on both sides thereof. A total of seven annular lips 12 are formed on each surface. In (b), the entire inner peripheral surface 11a of the seal ring 11 has a curved surface that is convex inward in the radial direction, and seven annular lips 12 are formed therein. In (c), the inner peripheral surface 11a of the seal ring 11 is composed of two tapered surfaces whose inner diameters gradually increase from the center toward both outer sides, and seven annular lips 12 are formed therein. In (d), the inner peripheral surface 11a of the seal ring 11 is composed of three flat surfaces having different inner diameters, and two annular lips 12 are formed on each of the three flat surfaces. In (e), the inner peripheral surface 11a of the seal ring 11 is one tapered surface having a gradually decreasing inner diameter, and six annular lips 12 are formed therein with gradually increasing intervals.

In each of the embodiments shown in FIG. 1, the entire inner peripheral surface 11a of the seal ring 11 is formed into a flat surface, a convex surface, a tapered surface or the like, and 6 to 7 annular lips of substantially the same height are formed therein. By arranging 1 and 2, a plurality of annular lips having different inner diameters can be obtained. As another example, the inner peripheral surface of the seal ring may be concave and a plurality of annular lips of substantially the same height may be arranged therein, or the inner peripheral surface of the seal ring may be flat and the height of the annular lip itself may be increased. By varying the height, it is possible to obtain a plurality of annular lips having different inner diameters.

FIG. 2 shows another embodiment of the present invention. In this embodiment, the entire inner peripheral surface 21a of the seal ring 21 is a curved surface that is convex inward in the radial direction, and the mesh lip 22 is formed there. In FIG. 2 (b), the large rhombus is the apex of the mesh lip and the small rhombus is the bottom. Also in this embodiment, the shape of the entire inner peripheral surface 21a of the seal ring 21 may be configured by a flat surface, a convex surface, a concave surface, a tapered surface, or a combination thereof.

Next, the operation of the embodiment of the present invention will be described with reference to the emergency seal shown in FIG. In this emergency seal, the inner peripheral surface 31a of the seal ring 31 is a curved surface that is convex inward in the radial direction, and five annular lips 32 are formed therein. In FIG. 3, (a) shows a non-operating state, in which the inner peripheral surface 31a of the seal ring 31 and the shaft 40 are separated from each other, and the seawater 50 can flow between them. (B) is a state at the time of normal operation, and the central lip 32a contacts the surface of the shaft 40 to prevent the ingress of seawater 50 from the stern side. (C) shows the operating state when the central lip 32a is damaged or broken, or the surface of the shaft 40 at that portion is roughened due to corrosion or the like. The supply pressure of the compressed fluid supplied to this emergency seal is shown in FIG. In this case, the lips 32b and 32c on both sides of the central lip 32a are brought into contact with the surface of the shaft 40. Prevent intrusion. (D) shows an operating state when these lips 32b and 32c are also damaged or the surface of the shaft 40 at that portion is roughened, and the supply pressure of the compressed fluid is further increased, and the lips on both sides thereof are further increased. The surfaces 32d and 32e are brought into contact with the surface of the shaft 40 to prevent the seawater 50 from entering by the stern side lip 32d or the cab side lip 32e in the case of a malfunction.

As described above, according to each of the above-described embodiments, even if the sealing performance is deteriorated by the lip during the normal operation, the supply pressure of the compressed fluid is increased to ensure the sealing performance by the new lip adjacent to the compressed fluid. Therefore, it is possible to realize an emergency seal with high sealing performance and durability.

[0014]

[Effect of the device]

 As described above, since the emergency seal according to the present invention has a plurality of annular lips or mesh lips having different inner diameters on the inner peripheral surface of the seal, the stern tube emergency seal having high sealing performance and durability. Can be realized.

[Brief description of drawings]

1 (a), (b), (c), (d) and (e) are sectional views of different embodiments having an annular lip of the present invention.

2A and 2B are a sectional view and a developed view of an embodiment having a mesh lip of the present invention.

3 (a), (b), (c) and (d) are schematic views showing the operation in one embodiment of the present invention.

FIG. 4 is a sectional view showing an example of a conventional stern tube sealing device.

5 (a) and 5 (b) are cross-sectional views showing a state of a conventional emergency seal during normal operation and during operation.

6 (a), (b) and (c) are schematic diagrams showing the action of a conventional emergency seal.

[Explanation of symbols]

 11, 21, 31 Seal ring 11a, 21a, 31a Inner peripheral surface 12, 22, 32 Lip 40 Shaft 50 Seawater

Claims (2)

[Scope of utility model registration request] 1. A stern tube emergency seal used as an auxiliary seal of a main seal of a stern tube sealing device, comprising a plurality of annular lips or mesh lips having different inner diameters on the inner peripheral surface of the seal ring. Tube emergency seal. 2. The stern tube emergency seal according to claim 1, wherein the entire inner peripheral surface of the seal ring is formed by a flat surface, a convex surface, a concave surface, a tapered surface or a combination thereof.