JPH0118930Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an end seal device.

Mechanical seals are used where the rotating shaft of the device passes through the device's casing. For example, mechanical seals are used as stern tube seals to prevent seawater from leaking into the ship along the propulsion shaft. As shown in FIG. 1, this mechanical seal has conventionally been provided with a sliding ring 13 at the end of a diaphragm-shaped flexible part 3 made of a rubber-like elastic body fixed to the stern tube end face 9 via a retaining ring 12.
is attached, and the sliding ring is brought into sliding contact with a mating sliding ring fixed to the propulsion shaft 8, and surface pressure is applied to the sliding contact surface by the elasticity of the flexible portion 3. There is an end face sealing device. In such a conventional end face sealing device, since the rate of increase in the elastic pressing force of the flexible portion 3 with respect to the amount of movement of the propulsion shaft 8 toward the left in FIG.
The seal part is moved slightly to the left in the figure.
That is, the contact pressure on the sliding contact surface becomes considerably high, and therefore, when the amount of movement of the propulsion shaft 8 is large, there is a drawback that an appropriate contact pressure cannot be maintained.

An object of the present invention is to provide an end sealing device that eliminates the drawbacks of the conventional devices.

In FIG. 2, the end seal device according to the embodiment of the present invention is used as a mechanical seal for a stern tube. In the figure, the left side is the sealed liquid side, that is, the seawater side, and the right side is the inside of the ship. The end face sealing device includes a driven ring 1 attached to a casing 10 fixed to the end face 9 of the stern tube, and a sliding ring 13 of a seat ring 2 fixed to a two-split rotating ring 11 fixed to the propulsion shaft 8 as a rotation side portion. They mutually form a sealed end surface 7 and are in sliding contact to maintain sealing performance. The two-split rotating ring 11 is a movable member that rotates and moves in the axial direction together with the propulsion shaft 8. The seat ring 2 has a flexible portion 3 made of a rubber-like elastic body, and a support portion 4 in which a liquid passage 5 is formed on the sealed fluid side from the sealed end surface 7. The liquid passage 5 allows seawater around the propulsion shaft to pass through the sliding ring 1 when the support part 4 comes into contact with the driven ring 1.
It is designed to lead to the space below 3. The support part 4 is supported by the movable member, ie, the bisected rotating ring 11, and a sliding ring 13 is fixed to the free end of the seat ring 2. The flexible portion 3 is located between the support portion 4 and the sliding ring 13, and presses the sliding ring 13 toward the driven ring 1. The driven ring 1 is pressed toward the sliding ring 13 by a spring 6.

In the end face seal device described above, the propulsion shaft 8
moves to the left from the position shown in FIG. The force that presses the sliding ring 13 toward the driven ring 1 increases, and the surface pressure of the sealing portion between the sliding ring 13 and the driven ring 1 increases, but at this time, the driven ring 1 resists the spring 6. Since the rotary ring 11 moves a small amount to the left, the rate of increase in the surface pressure of the sealing portion relative to the amount of movement of the two-split rotary ring 11 is smaller than in the case of the prior art described above. Furthermore, when the amount of leftward movement of the split rotary ring 11 increases, the support portion 4 of the seat ring 2 comes into contact with the driven ring 1, and even if the split rotary ring 11 further moves to the left after that, The support part 4 is moved by the same amount as the amount of movement.
presses the driven ring 1 and moves it to the left, so the surface pressure of the sealed portion does not increase and is maintained at a constant value.

As is clear from the above, in the end face sealing device of the present invention, the amount of movement of the movable member supporting the support portion 4 of the seat ring 2 toward the driven ring reaches a predetermined value. In contrast, the surface pressure of the sealed portion increases at a small rate, and after the amount of movement of the movable member reaches a predetermined value, the surface pressure of the sealed portion is maintained at a constant value. Therefore, even when the movable member moves over a wide range, the surface pressure of the sealed portion does not become unduly high, and there is an advantage that the surface pressure of the sealed portion can always be maintained at an appropriate value.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a conventional end seal device, Figure 2
The figure is a sectional view of an end face sealing device according to an embodiment of the present invention used in a stern tube. 1... Driven ring, 2... Seat ring, 3...
...flexible part, 4...support part, 5...liquid passage, 6...
Spring, 7... Sealed end surface, 8... Propulsion shaft, 9
... Stern tube end face, 10 ... Casing, 11 ...
Two-split rotating ring (movable member), 12...presser ring, 13...sliding ring.

Claims (1)

[Scope of utility model registration request] An end surface that is designed to bring the sliding ring 13 provided on the seat ring 2 mounted on the movable member 11 into contact with the driven ring 1 to seal between the sliding ring and the driven ring. The sealing device includes a spring 6 that presses the driven ring toward the sliding ring, and the seat ring is supported by the movable member and faces the driven ring with a predetermined small gap, A support part 4 that comes into contact with the driven ring when the member moves a predetermined amount toward the driven ring, and a rubber-like elastic body between the support part and the sliding ring, and the sliding ring is connected to the driven ring. An end face sealing device characterized by having a flexible portion 3 that presses toward.