JPS5814281Y2 - Seal ring shaft sealing device - Google Patents

Description

[Detailed description of the invention] This invention relates to a seal ring shaft seal arrangement that seals high-pressure gas with a seal ring that is housed in a holding box and fitted with the outer peripheral surface of the rotating shaft through a narrow gap. The first example of the conventional seal ring shaft sealing device described above is
This will be explained with reference to FIGS.

In FIGS. 1 and 2, 1 is a rotating shaft, 2 is a seal ring made of an integral annular ring, and 3 is a holding box for storing the seal ring 2, which is separated from an upper half 3a and a lower half 3b. The seal ring 2 is housed in the annular groove formed on the inner circumferential surface of the holding box 3, and the rotating shaft 1 is inserted into the holding box 3 with a gap between the seal ring 2 and the inner circumferential surface of the seal ring 2. A seal ring 2 is loosely fitted on the outer circumferential side.

Reference numeral 4 denotes a sealing oil inlet for sealing high-pressure gas, which is provided in several locations on the circumference of the seal ring 2 in the radial direction.

5 is a radial gap between the outer circumferential surface of the rotating shaft 1 and the inner circumferential surface of the seal ring 2φ, and 6a and 6b are side gaps between both sides of the seal ring 2 and the holding box 3 on the atmosphere side and the sealed gas side. It is.

In the seal ring shaft sealing device configured as described above, sealing oil is supplied from the injection port 4 and the side gaps 6a, 6b to seal high pressure gas.

The sealing oil forms an oil film in a narrow radial gap 5 between the rotating shaft 1 and the seal ring 2, and is discharged to both sides of the seal ring 2 through this gap 5.

The supply pressure of the sealing oil is slightly higher than that of the gas to be sealed, so that the sealing oil can completely cut off the gas to be sealed.

When the conventional seal ring shaft seal device as described above continues to operate, the holding box 3 becomes shaped as shown in FIG. 3 due to thermal deformation due to temperature rise, and the holding box 3
and the seal ring 2 come into contact with each other, and the seal ring 2 is restrained by the holding box 3.

Therefore, in such a case, the seal ring 2 becomes unable to follow the floating of the rotating shaft 1 or the vibration of the rotating shaft 1 due to the formation of a bearing oil film during rotation, and the seal ring 2 and the holding box 3
The drawback was that it lacked long-term reliability.

This invention was made in order to eliminate the above-mentioned drawbacks, and elastic bodies are provided on both sides of the seal ring between the seal ring and the holding box, and the outside m of these elastic bodies is
By providing an extensible part made up of a thin plate on the retaining box, when thermal deformation occurs in the retaining box, the seal ring comes into contact with the retaining box via the extensible part, thereby preventing the thermal deformation of the retaining box from expanding and contracting. The elastic body of the flexible part absorbs it and reduces the contact pressure, making it easier for the seal ring to float in the radial direction.It also prevents the seal ring from being scratched and can be expected to have a long service life. be.

An embodiment of this invention will be described below with reference to FIG.

In FIG. 4, reference numeral 7 indicates a rotating shaft, 2 indicates a seal ring, and 3 indicates a holding box in which the seal ring 2 is housed.

Elastic bodies 7a and 7b such as rubber are provided over the entire surface of both sides of the seal ring 2, and thin plates 8a and 8b are attached to the outer surfaces of these to form an elastic part, and the thin plates 8a and sb and the seal ring Holding box 3 fitted with 2
Gaps 6a and 6b are formed between the groove 3C and the side wall of the groove 3C.

Note that the configuration other than the above is the same as that of the conventional shaft seal device shown in FIGS. 1 and 2, and therefore a description thereof will be omitted.

Further, in FIG. 4, reference numeral 4 indicates a sealing oil injection port, and 5 indicates a gap between the outer circumferential surface of the rotating shaft 1 and the inner circumferential surface of the seal ring 2.

Next, the operation of the seal ring shaft sealing device configured as above will be explained.

Upper half 3a and lower half 3 forming holding box 3 during rotation
When b is thermally deformed as shown in FIG. 5, for example, the thermal deformation is absorbed by the elastic bodies 7a and 7b.
The total contact pressure P is smaller than the pressure that would occur if the holding box 3 and the seal ring 2 were in direct contact.

That is, since the restraining force P×μ (where μ is the coefficient of friction between the holding box and the thin plate) is reduced with respect to the floating blade F of the seal ring 2, the seal ring 2 can be easily floated.

The elastic body 7a is attached to the floating blade F of the seal ring 2,
7b also has the effect of causing shearing deformation as shown by the chain line in FIG. 5, which also facilitates floating and allows normal rotation of the rotating shaft 1 to be established.

When the thin plates 8a and 8b come into direct contact with the elastic bodies 7a and 7b when the holding box 3 is thermally deformed, stress is locally concentrated on the contact portions, causing the elastic bodies 7a to become concentrated.

The thin plate 8a is prevented from being permanently deformed or prematurely fatigued by exceeding the elastic limit of the thin plate 7b.

8b reduces the coefficient of friction with the holding box 3 compared to when the holding box 3 is in direct contact with the elastic bodies 7a and 7b, making it easier for the seal ring 2 to float.

Furthermore, since no excessive force is applied to the seal ring 2 and the holding box 3, a longer life and reliability can be expected than in the past.

In addition, in order to enhance the effect of this invention, the elastic body 7a,
The material used for 7b is preferably a material with a small elastic modulus, such as rubber.

Moreover, the elastic body 7a. It is preferable that the axial thicknesses H, H of 7b be as large as possible.

As explained above, according to the seal ring shaft sealing device of this invention, the seal ring can always be floated normally, and its life can be extended compared to the conventional one.

[Brief explanation of drawings]

FIG. 1 is a side sectional view showing an example of a conventional seal ring shaft sealing device, FIG. 2 is a sectional view taken along line II-n in FIG.
The figure is an enlarged sectional explanatory view showing the state in which the holding box of the shaft sealing device shown in Fig. 1 has been thermally deformed, Fig. 4 is a side sectional view showing an embodiment of this invention, and Fig. 5 is an embodiment of the shaft sealing device shown in Fig. 4. FIG. 3 is an enlarged cross-sectional explanatory view showing a state in which the holding box is thermally deformed. 1...Rotating shaft, 2...Seal ring,
3...Holding box, 4...Sealing oil inlet, 5...Gap between rotating shaft and seal ring, 6a
, 6b...Gap between seal ring and holding box, 7
a, 7b...Elastic body, 8a, sb...
・Thin plate. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A seal ring is housed through a narrow gap in an annular groove formed on the inner circumferential surface of the holding box, and the seal ring is inserted into the rotating shaft inserted into the holding box with a gap provided between the seal ring and the inner circumferential surface of the holding box. Fitting the seal ring with a narrow gap between the seal ring and the outer peripheral surface of the seal ring,
In a seal ring shaft sealing device that seals high-pressure gas by interposing sealing oil in a narrow gap between the seal ring, the annular groove side wall of the holding box, and the outer peripheral surface of the rotating shaft, elastic bodies are provided on both sides of the seal ring. A thin plate is provided on the outer surface of each of these elastic bodies to constitute a telescopic portion, and thermal deformation of the holding box is absorbed by the elastic body, so that the contact pressure between the seal ring and the holding box is reduced. A seal ring shaft sealing device characterized by: