JPH01105070A - Split ring seal with slip joint - Google Patents

Abstract

PURPOSE: To provide resistance against damage by providing a mechanism of which the first end of a connecting element is fixedly attached to the first end of a split ring and the second end of the connecting element is slidable with respect to the second end of a split ring. CONSTITUTION: A connecting element 14 has a thickness less than that of a split ring seal 12. The end 52 of the connecting element 14 is fixedly attached to the free end 20 of the split ring seal 12 by tack welds 16 and 18. The end 54 of the connecting element 14 is received in the second free end 22 of the seal 12. The end 54 slides freely in the free end 22 with the contraction and expansion of the split ring seal assembly 10 caused by the varying temperature and pressure. In such a case, the split ring seal 12 expands and contracts freely, and the connecting element 14 is more resistant against damage as it is more resilient than the ring seal 12. As the ring seal has a double 'E' cross section, it provides excellent and durable sealing.

Description

[Detailed description of the invention] The present invention relates to a ring seal for pressurized fluid couplings.

More particularly, the present invention relates to split ring seals that expand and contract with abutting coupling members when subjected to varying temperatures and pressures.

Seals of various types and configurations are used to prevent fluid from escaping from fittings along fluid flow paths or within fluid containers. A joint within a flow path or container is, of course, formed whenever two or more members are brought together to form a continuous conduit or fluid container. One common type of seal is a ring seal that seals a fluid gap, thereby preventing fluid from escaping between two members. These two members often have grooves formed therein to accommodate ring seals.

These ring seals are elastic due to their material and shape, and the ring seals fill gaps between adjacent members forming a flow path. The desired result is for the ring seal to firmly abut both members at all points along the seal so that the gap is completely occluded by the ring seal.

While requiring fairly wide radial dimensions to achieve the desired flexibility, ring seals are sometimes designed to fit into extremely narrow annular spaces. This requirement, combined with the accumulation of manufacturing tolerances for seal and groove diameters and widths, creates undesirable compromises and problems. To overcome these problems, split ring seals were developed to give ring seals circumferential visibility. Because of this circumferential visibility, these split ring seals can be adjusted to fit into grooves just slightly wider than the radial dimension, thereby eliminating the effects of seal and groove diameter tolerances. Other advantages of the zero-split ring seal are its ability to compensate for the effects of differential thermal expansion between the seal and the members forming the joint (thus avoiding circumferential thermal stresses) and the ability to make the seal "elastic". The seal is capable of opening on parts with a larger diameter than the seal groove (just as the piston ring is expandable to slide over the outside diameter of the piston until it fits into the recessed groove). It can be assembled into

A split ring seal is basically a continuous ring seal with a portion removed along a transverse section so that the ring seal can be opened at the split section. Two free ends are formed by the split portion.

However, the split ring seal will not work if the split ring is expanded so that the free ends are no longer in contact.
A disadvantage is that a gap is formed between the free ends of the ring seal. Fluid therefore escapes through the gap. Thus, simple split ring seals cannot provide the complete seal that is often desired under all pressures and temperatures.

In response to this problem, split ring seals with slip joints were developed. In this seal, the split ring seal assembly is in the form of a split ring seal and the slidable element is a ring segment having approximately the same curvature as the split ring seal. A first end of the slidable element is secured to a first free end of the split ring seal. The second end of the slidable element is slidably received within the second free end of the split ring seal. In these split ring seal assemblies, the split ring seal assembly expands and contracts when subjected to varying temperatures and pressures, causing the second end of the slidable element to move within the split ring seal. Slide with.

An example of these ring seals is U.S. Pat.
It is disclosed in the specification of No. 86.

However, the ring seal assembly disclosed in U.S. Pat. No. 4,477,086 has a number of drawbacks and is unsuitable for a number of reasons. First, this patent indicates that the split ring seal and the slidable element are of the same material and of the same thickness.
The :L design is relatively difficult to compress, resulting in a slip joint that is not as resilient as desired.

Also, since the split ring seal and the slidable element are of the same thickness, the slidable element is subjected to higher stresses than the ring seal due to the shorter dimensions of the slidable element, pushing its elastic limit. It is easily compressed. This is undesirable because it results in loosening of the coupling elements which causes increased leakage through the slip coupling.

Ring seals having an "E" cross-section are known in the art (e.g., U.S. Pat. (See Dutley Day Taylor, U.S. Pat. No. 3,857,572 entitled "E-Ring Seal Assembly," issued December 31, 1974).

For many applications, these ring seals with an E-shaped cross section are preferred because they can provide a more effective strong seal between the members that make up the flow path. Additionally, E-shaped cross-section seals may be constructed of relatively thin metal or other materials so that the loads required to deflect and compress the seal are lower than for other shapes of ring seals, and may also be constructed from relatively thin metal or other materials. As the pressure provides a seal between the E-section outer flange and the intermediate arm, the fluid actually helps the seal accomplish its function.

A need exists for a ring seal that can expand and contract to compensate for design tolerances when subjected to changing pressures and temperatures, and that provides an effective durable seal to prevent fluid from escaping from the fitting. There is also a clear need for expansion joints that remain fully elastic and resist creep and loosening at elevated temperatures. The stresses must be low enough to avoid problems due to fatigue resulting from periodic axial deflections to which the seal accommodates. The present invention meets this need in the art and from the description herein. This takes into account other demands that may arise. Generally, the present invention provides a ring seal having a split ring having first and second ends forming a gap, the split ring having a resilient transverse cross section, and the material forming the split ring having a thickness T. a connecting element having first and second ends and having a resilient transverse cross-section substantially identical to but smaller than the transverse cross-section of the split ring, the material forming the connecting element having a thickness the connecting element is received within the split ring cross-section to span the gap, the first end of the connecting element being disposed within the first end of the split ring, and the connecting element having a thickness T' that is less than T; a second end of the element is disposed inwardly of the second end of the split ring and has a mechanism for tightly coupling the first end of the connecting element to the first end of the split ring; The present invention provides a ring seal characterized in that the second end is slidable relative to the second end of the split ring.

In some embodiments of the invention, the split ring and the connecting element are metallic, each consisting of a single sheet of metallic material.

In another embodiment of the invention, the split ring and the coupling element have an E-shaped transverse cross section that fits into the split ring and the coupling element is designed such that the coupling element fits into the split ring.

In a further embodiment of the invention, the transverse cross-section of the split ring consists of a first part having at least two curved parts and a second part spaced apart from the first part, and the cross-section of the connecting element has a mating contains parts.

In a further embodiment of the invention, the coupling means are arranged in the area of lowest stress in the cross section of the ring seal and the connecting element. When the ring seal and the connecting element have mating E-shaped transverse internal □ faces, the coupling means is “E”.
” located at the end of the external leg of the

In other embodiments of the invention in which the ring seal and the coupling element have mating E-shaped transverse cross-sections, the cross-section may include two external flanges and a medial loop forming an intermediate flange of σ"E" , the external flange may include at least a concavely curved portion and a convexly curved portion, these portions being formed continuously such that a longitudinal line of reversing curvature is formed between these two portions. Ru.

The coupling means may be placed in the line of reverse curvature.

In yet another embodiment of the invention, the joint means are at least two separate tack welds.

The ring seal of the present invention has a number of advantages over prior art ring seals that can be used under the same environmental conditions.The ring seal of the present invention is more resistant to damage. . This is because the ring seal is free to expand and contract and the connecting element is more elastic than the ring seal. This allows the slidable element to experience less stress than a ring seal, which is desirable. In some embodiments, this is accomplished by a slidable element having a thickness less than that of the ring seal. Additionally, the ring seals of the present invention are stronger and more durable than prior art ring seals. These ring seals are more effective due to the incorporation of a double "E" cross-section. The ring seal closes the gap more completely than prior art ring seals with a ring seal and reduces leakage through the gap filled by the ring seal.

Next, the present invention will be explained with reference to the drawings.

Referring to FIG. 1, there is shown a split ring seal assembly 10 having a slip fitting. It has double welds 16 and 18.

Split ring seal 12 is a ring seal having a transverse cross-sectional cut to form a split ring. The split ring seal has two free ends 20 and 22.

The gap G is formed between the ends 20 and 22. The 0-split ring seal 12 is made of an elastic material and is constructed from a sheet of metal material pressed into the shape shown in FIGS. 3-5. You can.

Referring to FIG. 5, a lateral cross-section of the split ring seal 12 is shown. This transverse cross section is E-shaped,
two external flanges or arms 24 and 26 forming the top and bottom flanges of "E" and an intermediate arm 28 forming the intermediate flange of "E", II E II
two curved rear portions 30 and 3 forming the back of the
2 and has.

The outer flange 24 consists of a recess 34 and a projection 36. Similarly, the outer flange 26 has a recess 38 and a projection 40.
has. The recesses 34 and 38 are continuous with the protrusions 36 and 40, respectively, forming a sinusoidal leg of the general shape of an S curve. The lowermost ends of protrusions 36 and 40 are connected and continuous with portions 30 and 32, respectively.

Lines of reversing curvature 48 and 50 are formed between the respective connections of protrusions 36 and 40 and recesses 34 and 38.
is a line whose curvature changes from concave to convex and vice versa.

Intermediate arm 28 has an upper curved section 42 and two straight sections 44 and 46 that extend downwardly from opposite ends of upper curved section 42 and connect to rear sections 30 and 32, respectively. .

Split ring seal 12 has a relatively constant thickness T (see FIG. 5).

Connecting element 14 consists of a single sheet of resilient metallic material formed in the cross-section shown in FIGS. 3, 4 and 6. Connecting element 14 may be the same material as split ring seal 12, but is preferably made of a more flexible material than the material from which split ring seal 12 is constructed. Connecting element 14
forms a partial ring segment having approximately the same curvature as the ring seal 12.

Connecting element 14 has ends 52 and 54.

The transverse section of the connecting element 14 has the same parts as the split ring seal 12 (see FIG. 6), these parts being the outer flanges or arms 24' and 26°, the intermediate arm 28', the rear 30° and 32'. , Part 34 and 3
8′, convex portions 36° and 40°, an upper curved portion 42° and straight portions 44° and 46′, all of which are complementary to and fit with the correspondingly numbered portions of the split ring seal 12. do. Similarly, line 4 of reverse curvature
8'' and 50' are formed by recesses 34° and 38° and protrusions 36° and 40°, respectively.

The connecting element 14 has a thickness T'' which is preferably less than the thickness T of the split ring seal 12.

Tack welds 16 and 18 rigidly connect end 52 of coupling element 14 to free end 20 of split ring seal 12.

The tack welds are preferably placed in the areas of lowest stress within the split ring seal 12 and connecting element 14. In the embodiment shown in the Figures, these areas are the bottom ends of the outer legs (see Figure 4). (see welds 16 and 18 in FIG. 4) or along lines of reverse curvature 48.48'', 50 and 50° (see weld 16° in FIG. 4).

Typically, a tack weld need only be in one of these areas, but not both, and the tack weld will reduce the stresses placed on the split ring seal and the connecting element 14 due to the connection between them. located in low stress areas to reduce the amount of stress.

As shown in the figures, the end 54 of the connecting element 14 is received within the second free end 22 of the split ring seal 12. End 54 contracts (as split ring seal assembly 10 contracts and expands due to changing temperatures and pressures).
(see solid and dotted line position of end 54 in FIG. 3), - free to slide into free end 22.

The split ring seal assembly 10 includes two parts that define a fluid flow path.
used by inserting the assembly between two members. Such elements may be flanges of two pipes carrying pressurized fluid, two ring parts of a gas turbine engine, etc., where the seal is placed between the parts and the parts are connected to the split ring seal 12 and the connecting element. A ring seal 12 is optionally placed around one or both of the members for the ability to crack open so that the parts 14 are compressed and compressed. In use, the ends 54 of the connecting elements 14 slide relative to the free ends 22 of the split ring seal 12 as the seal assembly 10 and adjacent members contract and expand under varying temperatures and pressures. do.

Although the invention has been described with particular reference to ring seals and coupling elements having E-shaped cross-sections, other cross-sections may also be used. Preferably, the cross section has at least two members with curved portions.

Preferably, the split ring and connecting element are made from a nickel alloy. For a ring having an outside diameter of approximately 30.370 inches (77 cm), the thickness T of the material forming the split ring is approximately 0.010 inches ± 0.0 prior to formation.
0.01 inch (0.025 cm ± 0.0025 cm), and the thickness To of the material forming the connecting element is approximately 0.00 inch ± 0.001 inch (0.0170 cm) before formation.
In this configuration, the gap G is approximately 0.490-0.530 inches (1,2-1,
3C).

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway plan view of a ring seal assembly of the present invention. 2 is an enlarged view of the lower portion of the ring seal assembly shown in FIG. 1; FIG. FIG. 3 is a partially cutaway perspective view of the ring seal assembly shown in FIGS. 1 and 2. FIG.
It is a partial sectional view taken along line 4-'4'f in the figure. FIG. 5 is a partial cross-sectional view of the split ring shown in FIGS. 1-4. FIG. 6 is a partial cross-sectional view of the connecting element shown in FIGS. 1-4. '10...Split ring seal assembly, -12...
- Split ring seal, 14... Connecting element, 16.18... Tack welding, 20.22... Free end, 24.26... External flange, 28... Intermediate arm, 30.32 ... Rear part, 34... Concave portion, 36... Convex portion, 38... Concave portion, 40... Convex portion, 52... End portion, -54... End portion. ,,′

Claims (1)

[Claims] (1) A ring seal having a split ring having first and second ends forming a gap, the split ring having a compressible, elastic and discontinuous transverse cross section. and the material forming said split ring has a substantially uniform thickness T, has first and second ends, and is compressible having a shape substantially identical to but smaller than the transverse cross section of said split ring. ,
a connecting element having an elastic and discontinuous transverse cross-section, the material forming the connecting element having a substantially uniform thickness T' that is less than the thickness T, and the thin thickness T' making the connecting element said split ring is more elastic, such that said thinner thickness T' does not exceed its elastic limit before said split ring exceeds its elastic limit when both are subjected to a transverse compressive force; reducing stresses on the element, thereby delaying the onset of fatigue from periodic deflections of the connecting element in an axial direction, the connecting element being accommodated within the split ring cross-section to span the gap; The first end of the connecting element is located within the first end of the split ring, and the second end of the connecting element is located within the second end of the split ring. and means for rigidly coupling a first end of the connecting element to a first end of the split ring, the second end of the connecting element being slidable relative to the second end of the split ring. A ring seal characterized by being flexible. 2. A ring seal according to claim 1, wherein the split ring and the connecting element have mating E-shaped transverse cross sections. (3) The ring seal according to claim 2, wherein the split ring and the connecting element are made of metal. (2) The ring seal according to claim 2, wherein the split ring and the connecting element are made of the same material. 5. A ring seal according to claim 2, wherein said connecting element is made of a material that is more elastic than said split ring. (6) The ring seal according to claim 1, wherein a transverse cross section of the split ring comprises a first portion having at least two connected curved portions and a second portion separated from the first portion, and the connecting element A ring seal characterized in that a cross section of the ring seal has a mating portion. 7. A ring seal according to claim 1, wherein said split ring is comprised of a single sheet of material. 8. A ring seal according to claim 7, wherein said connecting element comprises a single sheet of material. 9. A ring seal according to claim 1, characterized in that the coupling means are arranged in the lowest stress region of the cross-section of the ring seal and the connecting element. 10. A ring seal according to claim 9, wherein said coupling means is at least two separate tack welds. 11. The ring seal of claim 1, wherein the split ring and the connecting element have mating transverse cross-sections, the cross-sections forming an "E" and having two external flanges and an intermediate arm. A ring seal according to claim 1, wherein the intermediate arm has a free end and is formed by a curved loop, and the coupling means are arranged at the free end of the intermediate arm. 12. The ring seal of claim 1, wherein the split ring and the connecting element have mating E-shaped transverse cross-sections having two outer flanges and an intermediate loop, the outer flange having at least a recessed curved portion and a middle loop. comprising a convex curved portion, said portions being formed continuously such that a line of curvature to be reversed is formed between said portions, said coupling means being disposed on said line of curvature to be reversed; A ring seal characterized by: 13. A ring seal according to claim 12, wherein said coupling means is at least two separate tack welds. (14) A ring seal having a split ring having first and second ends forming a gap, the split ring having a compressible, elastic and discontinuous transverse cross section; a compressible material having a substantially uniform thickness T, having first and second ends, and having a shape substantially identical to but smaller than the transverse cross-section of the split ring;
a connecting element having an elastic and discontinuous transverse cross-section, the material forming the connecting element having a substantially uniform thickness T' that is less than the thickness T, and the thin thickness T' making the connecting element said split ring is more elastic, such that said thinner thickness T' does not exceed its elastic limit before said split ring exceeds its elastic limit when both are subjected to a transverse compressive force; reducing stresses on the element, thereby delaying the onset of fatigue from periodic deflections of the connecting element in an axial direction, the connecting element being accommodated within the split ring cross-section to span the gap; The first end of the connecting element is located within the first end of the split ring, and the second end of the connecting element is located within the second end of the split ring. and means for rigidly coupling a first end of the connecting element to a first end of the split ring, the second end of the connecting element being slidable relative to the second end of the split ring. the split ring and the connecting element are fitted in a lateral direction E;
having a shaped cross-section, said cross-section having sinusoidal legs forming the external arms of an "E", each of said legs having a free end, and said coupling means being attached to said free end of one of said legs. A ring seal is arranged. (15) A ring seal having a split ring having first and second ends forming a gap, the split ring having a compressible, elastic and discontinuous transverse cross section; a compressible material having a substantially uniform thickness T, having first and second ends, and having a shape substantially identical to but smaller than the transverse cross-section of the split ring;
a connecting element having an elastic and discontinuous transverse cross-section, the material forming the connecting element having a substantially uniform thickness T' that is less than the thickness T, and the thin thickness T' making the connecting element said split ring is more elastic, such that said thinner thickness T' does not exceed its elastic limit before said split ring exceeds its elastic limit when both are subjected to a transverse compressive force; reducing stresses on the element, thereby delaying the onset of fatigue from periodic deflections of the connecting element in an axial direction, the connecting element being accommodated within the split ring cross-section to span the gap; The first end of the connecting element is located within the first end of the split ring, and the second end of the connecting element is located within the second end of the split ring. the connecting element and the split ring have mating E-shaped transverse cross-sections including two external flanges, the external flanges having at least a concave curved portion and a convex curved portion, the portions comprising: the connecting element being continuously formed so that a line of reversing curvature is formed between said portions, and having means for rigidly connecting a first end of said connecting element to a first end of said split ring; A ring seal according to claim 1, characterized in that the second end of the element is slidable relative to the second end of the split ring, and the coupling means are arranged on a line of reversing curvature. (16) In the ring seal according to claim 1, the thickness T
' is a ring seal characterized by being approximately 30% thinner than the thickness T. (17) The ring seal according to claim 14, wherein the thickness T' is about 30 percent thinner than the thickness T. (18) The ring seal according to claim 15, wherein the thickness T' is about 30 percent thinner than the thickness T.