JPH07119840A - Segment ring and segment seal - Google Patents

Abstract

PURPOSE:To restrain leaking out of segment end faces by letting a device be equipped with each inner circumferential ring formed out of a plurality of segment pieces, and with each elastic outer circumferential ring. CONSTITUTION:Paired combinations each of which is a combination of a segment ring R and a segment ring W, are provided in the inside of a casing C. Both the segment ring R and the segment ring W are mounted on a rotating shaft X, they are stopped in whirl by a whirl stop 4 provided for the casing C side, and concurrently they are pressed against each seal flange F of the casing C by a press spring 5. Each segment ring R is identical in structure to a so-called R ring, and each segment ring W is made up of an inner circumferential ring 2 formed of a plurality of segment pieces 20, and of an outer circumferential ring 1 mounted on the outer circumference of the inner circumferential ring 2. By this constitution, leaking can be restrained by the elastic outer circumferential ring 1 even if there occurs strain at the seal end face of the inner circumferential ring 2.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to segment rings and segment seals.

[0002]

2. Description of the Related Art In a segment seal, a segment ring fitted on a rotary shaft makes sliding contact with the rotary shaft to form a sliding seal surface, and an end face of the segment ring makes non-sliding contact with a seal flange. This is a device for sealing by forming a seal end face. The segment ring has multiple segments formed in a ring shape from the viewpoint of ease of mounting,
The structure is such that this is fastened with a garter spring. In order to bring the segment rings into close contact with each other and to bring them into close contact with the rotary shaft as well, high-precision machining is required. Therefore, a ring called an R ring and a ring called a C ring are usually used together. . That is, the R ring makes a gap between the segments instead of coming into contact with the rotating shaft, and leakage occurs from the gap. On the other hand, the C-ring, on the contrary, is designed to bring the segments into close contact with each other so that a gap is formed between the segment and the rotary shaft, so that leakage occurs between the segment and the rotary shaft. This R
A seal is usually formed by combining a ring and a C ring.

[0003]

However, even if the R ring and the C ring are combined, there is a problem that the sealing property is not sufficient. This is due in part to the above-described circumferential clearance between the segments of each R ring and the radial clearance between the rotation axis of the C ring. In order to make this gap small, make the radial gap of the C ring as close as possible to the axis,
Although it is conceivable to limit the flow path gap, when it comes into contact with the shaft, a gap is created in the circumferential direction like an R ring and leakage occurs. Further, as shown in FIG. 16, there is also a segment ring called a B ring in which the circumferential gap g between the segments 50 is closed by a small segment 51 to suppress leakage from the gap g. When received, there is a problem that the segment 50 and the small segment 51 are misaligned with each other, and a gap is created between them to cause leakage. Further, there is a problem that the thickness of the segment 50 and the small segment 51 is not uniform and distortion is likely to occur. The sliding seal surface fits into the outer peripheral surface of the rotating shaft as it is used by sliding with the rotating shaft, and the leakage from the sliding seal surface gradually decreases, but the segment end surface slides against the seal flange. Therefore, it does not fit in with the seal flange, and leakage does not decrease with use. On the contrary, the fact that the segment end faces are distorted due to the sliding heat generated at the sliding seal faces and the leakage from the segment end faces gradually increases is a major cause of the above gap. The above is the biggest drawback of the conventional general segment combination. The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide a segment ring having a novel structure and a segment seal using the segment ring.

[0004]

In order to achieve the above object, a segment ring of the present invention comprises an inner peripheral ring formed of a plurality of segment pieces, and an elastic outer periphery attached to the outer periphery of the inner peripheral ring. It is characterized by having a ring. A segment seal of the present invention is characterized by including the above-mentioned segment ring and a seal flange that comes into contact with an axial end face of the segment ring.

[0005]

Since the outer peripheral ring has elasticity, the close contact is high and the close contact can be maintained even if the seal end surface of the inner peripheral ring is distorted. Therefore, leakage is suppressed. Also, even if there is a gap between each segment of the inner ring due to the outer ring,
Leakage from here is suppressed.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a double seal structure in which a pair of a combination of a segment ring R and a segment ring W according to the present invention is provided inside a casing C. The segment ring R and the segment ring W are fitted on the rotating shaft X, and are provided on the casing C side to prevent rotation.
And is pressed against the seal flange F of the casing C by the pressing spring 5. The rotating shaft X has a sleeve L, and the segment ring W and the segment ring R are fitted through the sleeve L, but illustration and description of the sleeve L are omitted in the following description. Further, it is naturally possible to fit the rotary shaft X directly without providing the sleeve L.

Segment ring W and segment ring R
Has an inner peripheral surface in sliding contact with the rotating shaft X to form a sliding seal surface S2. The end surface of the segment ring W contacts the seal flange F to form a seal end surface S1, and the end surfaces of the segment ring W and the segment ring R contact to form an inter-ring seal surface S3. The sliding seal surface S2 and the inter-ring seal surface S3 are configured to perform sealing. Further, the casing C is provided with a purging fluid injection hole 6 for injecting a purging fluid such as air or gas, and a high-pressure fluid is blown from this to enhance the sealing effect.

As shown in FIGS. 2 and 4, the segment ring R has the same structure as a conventional so-called R ring. As shown in FIGS. 2 and 3, the segment ring W is composed of an inner peripheral ring 2 formed of a plurality of segment pieces 20 and an outer peripheral ring 1 mounted on the outer periphery of the inner peripheral ring 2.

In this embodiment, the outer ring 1 is made of an elastic synthetic resin material such as tetrafluoroethylene resin.
A band-shaped (band-shaped) material is wound around the outer circumference of the inner peripheral ring 2, and a garter spring 3 is attached and fastened to the outer circumference. By thus winding the band-shaped member, there is an advantage that the mounting work on the rotary shaft X becomes easy. In addition, as the material of the outer peripheral ring 1, it is possible to use resin such as ethylene trifluoride resin or synthetic rubber. As shown in FIG. 3, the outer peripheral ring 1 is mounted on the entire outer periphery of the inner peripheral ring 2, and the end portion of the outer peripheral ring 1 is an overlapping portion 15 which is superposed.
It has a structure that prevents leakage from the seam at the end. Further, when the overlapping portion 15 is provided in this way, there is an advantage that it is not necessary to align the outer peripheral ring 1 and the inner peripheral ring 2 as in the embodiment of FIG. 8 described later.

Each segment piece 20 of the inner peripheral ring 2 is in contact with the rotation axis X, and a circumferential gap 21 is formed between the segment pieces 20. By allowing this circumferential gap 21, the segment piece 20 may be low in precision, easy to process, and inexpensive to manufacture. Moreover, since the seamless outer peripheral ring 1 is wound around the inner peripheral ring 2, the circumferential gap 21
It is also possible to prevent leakage from.

As shown in FIG. 2, an outer peripheral surface of the outer peripheral ring 1 is circumferentially formed with a groove 19 for a garter spring for mounting the garter spring 3 substantially at the center thereof. Similarly, a pair of grooves 10 are formed on the sides in the circumferential direction. By forming the groove 10, the elastic piece 101 having greater elasticity is formed, and the sealing performance of the seal end surface S1 and the inter-ring seal surface S3 is improved. Further, as shown in FIG. 5, when the pressure inside the casing C is high, the elastic piece 101 is pressed against the seal flange F side and the segment ring R side due to the pressure being applied to the groove 10, and the seal end surface S1 and the ring. The sealing property of the inter-sealing surface S3 is further improved.

FIG. 6 shows an embodiment in which a taper 11 is formed on the end surface of the outer peripheral ring 1. That is, the taper 11 is a surface that bulges in the axial direction toward the outer peripheral side in the radial direction, thereby improving the contactability with the end face of the seal flange F and the segment ring R. In this embodiment groove 1
0 to form the elastic piece 101, and further taper 1 there
Since No. 1 is formed, a very large contact property is obtained, and a large improvement in sealing property can be obtained.

FIG. 7 shows the outer ring 1 in the embodiment of FIG.
FIG. 4 is an enlarged perspective view of the shape of the terminal portion of FIG. 1, in which a groove 12 is provided with a notch 12 as shown. The notch 12 further increases the elasticity of the elastic piece 101 at the end portion, and enhances the adhesion with the seal flange F and the segment ring R at the end portion. Such a notch 12 is more effective in the embodiment of FIG. 8 described below.

The embodiment shown in FIG. 8 has a structure in which the outer peripheral ring 1 is mounted on the inner peripheral ring 2 by opening a predetermined separating portion 16 without overlapping the end portions of the outer peripheral ring 1. The spacing portion 16 is mounted so as to be displaced from the position of the circumferential gap 21 between the segment pieces 20. In the case of such a configuration, leakage is likely to occur in the circumferential direction of the seal end surface S1 or the inter-ring seal surface S3 through the spacing portion 16, and therefore the above-described notch 12 formed at the end portion of the outer peripheral ring 1 has a large leak prevention effect. . That is, when the notch 12 is formed in the groove 10 at the terminal end of the outer peripheral ring 1 as shown in FIG. 7, the elasticity of the notch end is enhanced and the sealing property is improved. Further, as shown in FIGS. 9 and 10, when the pressure inside the casing C is high, the pressure is applied inside the notch 12, and the elastic piece 101 is pressed against the seal flange F or the segment ring R side, and the sealing performance is further improved. . Therefore, it is possible to prevent leakage from the separating portion 16 in the circumferential direction.

FIG. 11 shows another embodiment. In this embodiment, the garter springs 3 mounted on the outer circumference of the outer peripheral ring 1 are not used, but the end portions of the outer peripheral ring 1 are connected by a connecting spring 17, and the spring of the connecting spring 17 and the outer peripheral ring 1 itself. The outer ring 1 is configured to be fastened to the inner ring 2 by elasticity. This structure eliminates the need for the garter spring 3 and has the advantages that the structure is simple and the mounting work is easy. It is also possible that the outer peripheral ring 1 itself has sufficient elasticity and elasticity so that the inner peripheral ring 2 is fastened only by the outer peripheral ring 1.

In FIG. 12, a groove 22 is formed in the circumferential direction at the center of the outer peripheral surface of the inner ring 2, and the ridge 1 fitted in the groove 22.
3 shows a configuration in which 3 is provided on the inner peripheral surface of the outer peripheral ring 1.
With this configuration, the outer peripheral ring 1 is easily aligned with the inner peripheral ring 2, and the mounting is facilitated. Moreover, there is an effect that the positions of the outer peripheral ring 1 and the inner peripheral ring 2 do not shift.

In the above construction, the segment piece 20 is first mounted on the rotary shaft X to form the inner peripheral ring 2, and the outer peripheral ring 1 is wound around the inner peripheral ring 2 to be mounted, and the garter spring groove 19 is further mounted. The spring 3 is attached and the inner ring 2 and the outer ring 1 are fastened to assemble the segment ring W. Assembling work can be easily performed by using the assembling pin 9 shown in FIGS. 13 and 14. The assembling pins 9 are simply inserted into the holes 91 provided in the seal flange F as shown in the figure, and are installed at four places as shown in FIG. 14, and the garter springs 3 are wound around them. . Then, when the outer ring 1 is attached to the outer circumference of the inner ring 2, the assembling pin 9 is in this state.
Are removed in order and the garter spring 3 is mounted on the outer peripheral ring 1. The segment ring R is also attached by the same operation. An engaging groove 90 is formed in the assembling pin 9 so that the garter spring 3 can be reliably engaged.
Further, the assembling pin 9 does not fall out of the hole 91 due to the spring force of the garter spring 3.

In the above embodiment, the segment ring W
However, the present invention is not limited to this, and the combination of the segment ring W and the segment ring W or the combination of the segment ring W and any one or more of the rings may be possible. is there. Further, it is also possible to use the segment ring W alone.

According to the configuration described above, the outer peripheral ring 1
The gap between the segment pieces 20 of the inner peripheral ring 2 is sealed by the above, and the elasticity of the outer peripheral ring 1 enhances the contactability with the seal flange F and the segment ring R, and seals at the seal end surface S1 and the inter-ring seal surface S3. The property is improved. Further, by providing the groove 10, the taper 11 and the notch 12, the sealing property is further improved, and particularly the casing C
When the inside of the casing C has a high pressure such as when a purging fluid is introduced into the inside, the effect of the groove 10 and the notch 12 becomes large. Further, by providing the overlapping portion 15 as shown in FIG. 3, it is possible to prevent leakage from the end portion of the outer peripheral ring 1. Furthermore, FIG.
In the first embodiment, it is not necessary to mount the garter spring 3 on the outer circumference of the outer circumference ring 1, and the structure is simple and the assembling work is easy.

FIG. 15 shows the relationship between the leak amount and the seal pressure of the segment seal having the structure shown in FIG. 1 in comparison with the conventional example. The conventional example uses a combination of an R ring and a C ring as a segment ring. As is clear from this graph, in the configuration of FIG. 1, the leakage amount is extremely small regardless of the seal pressure. On the other hand, the conventional one has a large amount of leakage,
In particular, the larger the seal pressure, the larger the amount of leakage.

[0021]

As described above, the segment ring of the present invention comprises the inner peripheral ring formed of a plurality of segment pieces and the outer peripheral ring having elasticity attached to the outer periphery of the inner peripheral ring. Therefore, the closeness at the end face is high and the sealing effect is high. Further, since the segment seal of the present invention includes the above-mentioned segment ring and the seal flange that comes into contact with the axial end surface of the segment ring, the seal flange has high close contact with the seal flange and the adjacent ring, and the sealability is improved. . Further, even if there is a gap between the segments of the inner ring due to the outer ring, there is an effect that leakage from this is suppressed.

[Brief description of drawings]

FIG. 1 is a half sectional view showing an embodiment of the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a segment ring W according to an embodiment of the present invention.
Enlarged view of.

FIG. 4 is a segment ring R according to one embodiment of the present invention.
Enlarged view of.

FIG. 5 is an operation explanatory view of the groove 10 according to the embodiment of the present invention.

FIG. 6 is an explanatory view showing another embodiment of the outer peripheral ring in the present invention.

FIG. 7 is an enlarged perspective view of an outer peripheral ring end portion according to an embodiment of the present invention.

FIG. 8 is an enlarged view of a segment ring W according to another embodiment of the present invention.

9 is an enlarged view of the end portion of the outer peripheral ring in the embodiment of FIG.

10 is an explanatory view of the operation of the end portion of FIG.

FIG. 11 is an enlarged view of a segment ring W according to another embodiment of the present invention.

FIG. 12 is a partially enlarged view of a segment ring W according to still another embodiment of the present invention.

FIG. 13 is an explanatory side view of the assembling method using the assembling pin 9.

14 is a front view of FIG.

FIG. 15 is a graph showing the relationship between the leak amount and the seal pressure in the embodiment of FIG.

FIG. 16 is an explanatory diagram of a conventional B ring.

[Explanation of symbols]

1: Outer ring, 2: Inner ring, 3: Garter spring, 4: Rotation stop, 5: Press spring, 6: Purge fluid injection hole, 9: Assembly pin, 10: Groove, 11: Taper, 12: Notch, 13: ridge, 15: overlapping part, 1
6: Separation part, 17: Connection spring, 19: Groter spring groove, 20: Segment piece, 21: Circumferential gap, 22: Groove, 50: Segment, 51: Small segment, 90: Locking groove, 91: Hole, 101: elastic piece.

Claims (11)

[Claims] 1. A segment ring comprising an inner peripheral ring formed of a plurality of segment pieces, and an outer peripheral ring having elasticity attached to the outer periphery of the inner peripheral ring. 2. A segment ring comprising: a plurality of segment pieces forming an inner peripheral ring; and a band-shaped elastic outer peripheral ring wound around the outer periphery of the inner peripheral ring and mounted. 3. The segment ring according to claim 2, wherein both end portions of the band-shaped outer peripheral ring are wound around and mounted on the inner peripheral ring so as to overlap each other. 4. The segment ring according to claim 2, wherein both end portions of the band-shaped outer peripheral ring are mounted by being wound around the inner peripheral ring with a predetermined distance therebetween. 5. The segment ring according to claim 2, 3 or 4, wherein a notch extending in a circumferential direction is provided in at least one of the end portions of the band-shaped outer peripheral ring. 6. The outer peripheral surface of the outer peripheral ring is circumferentially provided with 1
Alternatively, the segment ring according to claim 1, wherein two or more grooves are formed. 7. The segment ring according to claim 1, wherein a taper surface is formed on an axial end surface of the outer peripheral ring so as to project in the axial direction toward the outer side in the radial direction. 8. The segment ring according to claim 1, wherein an elastic fastening ring is attached to the outer circumference of the outer circumference ring. 9. The segment ring according to claim 1, wherein the end portions of the outer peripheral ring are mounted on the inner peripheral ring with a predetermined distance therebetween, and the end portions are connected by a fastening elastic body. 10. The segment ring according to claim 1, wherein the outer peripheral ring has elasticity for fastening the inner peripheral ring. 11. A segment ring according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10, and a seal flange contacting an axial end surface of the segment ring. Segment seal.