JPS6335918Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a stern tube shaft sealing device.

Conventionally, an end surface contact type as shown in Fig. 1 has been widely known as a stern tube shaft sealing device.
The seal ring a is fitted onto the rotating shaft c by the tightening force of a garter spring b, and the large diameter side rear end surface of the seal ring a is fixed to a mating ring e fixed to the casing d. The seal ring a is brought into sliding contact with the front end surface of the seal ring a to form a sealing sliding surface f to prevent seawater existing on the front end side (left side in the figure) of the seal ring a from leaking into the atmosphere.
However, according to the stern tube shaft sealing device having such a configuration, since the surface load of the sealing sliding surface f depends only on the hydraulic pressure, the amount of thrust direction movement of the rotating shaft c is When there are many
The seal ring a, which is made of rubber, has poor conformability and has the drawback of reduced sealing performance.

In view of the above points, the present invention has a hollow ring interposed on the front side of the stationary side sealing ring which is fitted onto the stationary side member and rotates sealingly with the rotating side sealing ring on the rear end surface,
By providing a pressure adjustment mechanism that introduces and exhausts air into the hollow part of the hollow ring, the pressure adjustment mechanism adjusts the surface pressure on the sealing sliding surface, ensuring excellent sealing performance at all times regardless of the atmosphere. This is what we do.

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 2. In the figure, reference numeral 1 denotes a fixed-side sealing ring which is fitted and fixed in an annular recess 3a formed in the rear end surface of a casing 3, which is a fixed-side member. The end face of the fixed side seal ring 1 on the rear end large diameter portion 1a side is the front end of the rotating side sealing ring 2, which is fitted onto the rotating shaft 4, which is the rotating side member, via a split clamp ring 5. The sealing sliding surface 6 prevents seawater present in the left direction in the figure from leaking to the atmosphere side (inside the aircraft). Also,
7 in the figure is a hollow ring inserted into the front side of the large diameter portion 1a at the rear end of the fixed side sealing ring 1, and a hole 7a formed in the outer peripheral wall of the hollow ring 7 and a hole in the casing 3 is provided. A communication hole 7b is provided to communicate the air holes 3b, and the ventilation hole 3b communicates with a pressure adjustment mechanism (not shown). The pressure adjustment mechanism introduces and discharges compressed air into the hollow portion 7a of the hollow ring 7, and increases or decreases the volume of the hollow ring 7 made of a rubber-like elastic material, and increases or decreases the volume of the hollow ring 7 on the rear end side of the hollow ring 7. The pressing force on the rear end large diameter portion 1a of the fixed side sealing ring 1 is increased or decreased, thereby adjusting the surface pressure of the sealing sliding surface 6. Further, in the figure, 8 is an inflatable seal for emergency sealing, and 9 is an O-ring.

According to the stern tube shaft sealing device configured as above,
The surface pressure of the sealing sliding surface 6 formed between the sealing rings 1 and 2 on the fixed side and the rotating side can be easily adjusted by simply increasing or decreasing the amount of compressed air filled into the hollow ring 7. In addition, by providing an automatic synchronization mechanism to synchronize with the ship's water pressure,
It is also possible to automatically obtain a surface pressure suitable for the atmosphere.

As explained above, according to the stern tube shaft sealing device of the present invention, by operating the pressure adjustment mechanism, it is possible to always apply the optimum surface pressure to the sealing sliding surface, thereby achieving excellent sealing performance. Furthermore, the present invention has features such as being simple in structure and contributing to a reduction in maintenance costs, and the practical effects of the present invention are extremely large.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a front sectional view of a conventional stern tube shaft sealing device, and FIG. 2 is a half-cut sectional view of the main part of the stern tube shaft sealing device of the present invention. . 1...Fixed side sealing ring, 1a...Rear end large diameter part, 2
...Rotating side sealing ring, 3...Casing, 3a...
Annular recess, 3b...ventilation hole, 4...rotating shaft, 5...
... Clamp ring, 6 ... Sealing sliding surface, 7 ... Hollow ring, 7a ... Hollow part, 7b ... Communication hole, 8
...Inflatable seal, 9...O ring.

Claims (1)

[Scope of utility model registration request] A rotating side seal that is fitted and fixed in an annular recess formed in the rear end surface of a stationary side member such as a casing, and that is fitted onto a rotating side member such as a rotating shaft at the rear end surface of a rear end large diameter portion that projects from the annular recess. It has a fixed side sealing ring that sealsly slides on the front end surface of the ring, and a hollow ring is filled and fitted into the annular recess on the front side of the rear large diameter portion of the fixed side sealing ring, and A stern tube shaft sealing device characterized by being provided with a pressure adjustment mechanism for introducing and extracting air into a hollow portion.