Swivel Seal Assembly

Abstract

A composite seal for a swivel seal assembly includes an elastomeric sealing ring coupled to at least one anti-extrusion ring. The elastomeric sealing ring includes an outer annular recess formed along an outer diameter, the outer annular recess separating a first outer sealing annular interface from a second outer sealing annular interface. The first outer sealing annular interface is disposed adjacent to a first axial side surface, and the second outer sealing annular interface is disposed adjacent to the at least one anti-extrusion ring. The elastomeric sealing ring includes an inner annular recess formed along an inner diameter, the inner annular recess separating a first inner sealing annular interface from a second inner sealing annular interface. The first inner sealing annular interface is disposed adjacent to a first axial side surface, and the second inner sealing annular interface is disposed adjacent to the at least one anti-extrusion ring.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This international application claims priority to U.S. Patent Application No. 17 / 445,881, filed August 25, 2021, and U.S. Provisional Application No. 63 / 071,452, filed August 28, 2020, the entire contents of which are hereby incorporated by reference herein in their entirety.

[0002] explanation FIELD OF THE INVENTION The present invention relates generally to swivel seal assemblies and, more particularly, to a composite seal for a swivel seal assembly having a novel elastomeric ring coupled to at least one anti-extrusion ring.

[0003] Background of the Invention As is known in the prior art, for example from U.S. Pat. No. 10,619,774, swivel joints are commonly used in the oil field industry to form rigid, yet dynamically configurable, flow lines between various pieces of equipment. For example, in oil field pumping stimulation or fracturing operations, swivel joints are often used to connect multiple high-pressure pumping units to a manifold, which in turn connects to an injection wellhead.

[0004] These types of swivel joints typically include a tubular male member rotatably connected to a tubular female member. The male member includes a male race, which in turn includes a female race configured to receive the male race. When the male race is positioned within the female race, a plurality of outer annular grooves in the male race are aligned with corresponding inner annular grooves in the female race, thereby forming a plurality of bearing races. A plurality of bearing balls are received within the bearing races to rotatably connect the male member to the female member.

[0005] When the male and female components are connected together, an annular passage is formed between the male and female races. This annular passage is in fluid communication with a flow bore defined by the swivel joint. To contain the fluid within the flow bore while still allowing the male and female components to rotate relative to one another, the swivel joint typically includes a dynamic primary seal positioned between a protruding portion of the male race and an inner end portion of the female race.

[0006] However, if the primary seal fails, the flow of pressurized fracturing fluid through the annulus can rapidly erode the male protruding portion and / or the female inner end portion, thereby causing failure of the swivel joint. Pressurized fluid can also enter the annulus, creating end hydrostatic loads between the male and female races, which can lead to bearing race failure. Therefore, it is common practice to include a second seal to prevent failure of the entire assembly in the event of primary seal failure. However, better seal designs remain desirable. It is further desired that such improved seals could eliminate the need for a secondary seal, thereby reducing assembly cost and complexity.

[0007] Thus, there continues to be a need for improved seals. The present invention fulfills this need and provides other related advantages.

[0008] Summary of the Invention Referring now to the drawings, and more particularly to FIGS. 7 and 8 , an exemplary embodiment of a swivel seal assembly provided by the present invention is shown. The swivel seal assembly may be configured for axial sealing and, when assembled, rests against a metal surface to cover an existing extrusion gap between mating parts. The swivel seal assembly includes an elastomeric seal body coupled to an extrusion prevention device configured to reduce extrusion of the seal body into the extrusion gap when pressure is applied to the seal body. The swivel seal assembly may be used, for example, in systems where oil and high-pressure gases are present, such as hydraulic fracturing applications. The swivel seal assembly can be assembled and function without the need for intermediate adjustment or lubrication.

[0009] The seal body, as shown, may be in the shape of an annular ring and may be formed from a suitable elastomer, such as rubber or another type of resilient polymer. As best seen in cross section, the seal body may have an outer diameter surface corresponding to an outer diameter and an inner diameter surface corresponding to an inner diameter. In the illustrated embodiment, the seal body outer diameter may vary from 85.8 mm to 86.0 mm, the seal body inner diameter may be 73.74 mm, and the seal body has a maximum thickness of approximately 6.2 mm. Naturally, these values ​​may vary depending on the size of the gland into which the seal body will be assembled.

[0010] Referring now to FIG. 7 , the outer diameter surface and inner diameter surface may be mirror images of each other. Each of the outer diameter surface and inner diameter surface may have a first sealing interface formed adjacent to the exposed axial surface of the seal body and a second sealing interface formed adjacent to the anti-extrusion device. The seal body may have a nonlinearly variable thickness section between the exposed axial surface and the first sealing interface, in which the thickness of the seal body varies axially from the exposed axial surface to the first sealing interface. A third sealing interface between the anti-extrusion device and the second sealing interface extends from the elastomeric body to the mating surface to provide enhanced sealing. The thickness of the seal body may vary nonlinearly in the nonlinearly variable thickness section to provide a rounded contour on the outer diameter surface and inner diameter surface at the nonlinearly variable thickness section. A pair of linearly variable thickness sections may be provided between the nonlinearly variable thickness section and the second sealing interface. The linearly varying thickness section represents a section of the seal body where the seal body thickness varies linearly in the axial direction toward a minimum thickness region. The minimum thickness region includes a rounded recess where the seal body thickness is minimum, thereby enabling compressibility and enhancing sealing across a range of axial groove widths. Meanwhile, the first seal interface and the second seal interface may represent a maximum thickness region of the seal body that seals against the gland when assembled.

[0011] To reduce the risk of the seal body being extruded into the extrusion gap, the anti-extrusion device may include a pair of backup rings. The backup rings may be coupled to the seal body and may rest against the sealing interface. The backup rings may be formed from a material having a higher rigidity than the seal body. This material may include, but is not limited to, a metal, such as stainless steel, and / or a rigid polymer, such as polyetheretherketone (PEEK). In some embodiments, the backup rings comprise the same material, although the backup rings may be formed from different materials.

[0012] Each backup ring may rest against a rounded axial extension of the seal body, thereby clamping the axial extensions together. The axial extensions may, for example, define an axial length greater than their thickness. The axial extensions may have an axial length slightly greater than the corresponding axial length of each backup ring, thereby including portions that extend axially further than the exposed axial surfaces of both backup rings. In this regard, the backup rings may define a gap between them that is substantially filled by the axial extension of the seal body, with a portion of the axial extension extending beyond the gap. In this regard, the portion of the axial extension that extends beyond the gap may contact a portion of the gland in which the swivel seal assembly is disposed. The exposed axial surfaces of the seal body and the backup ring may extend substantially parallel to each other, as shown.

[0013] The radiused axial extension of the seal body is compressed during assembly of the tubular male and female members. When assembled, the radiused axial extension of the seal is aligned with the backup ring, so that all axial faces of the seal are in full contact with the mating groove surfaces, eliminating any clearance.

[0014] The overall axial length of the swivel seal assembly may be 9.93 mm to 10.13 mm, the seal body having an axial face-to-face length of approximately 6.1 mm, and the backup ring having an axial length of approximately 3.7 mm. In some embodiments, the axial length of the backup ring may be a portion of the overall seal length, e.g., 1 / 3 to 1 / 2 of the overall seal length. The portion of the axial extension extending beyond the backup ring may have an axial length of approximately 0.1 mm to 0.3 mm. The swivel seal assembly may define a total thickness of 6.0 mm to 6.2 mm. Of course, these dimensions are merely exemplary and may be varied for various applications and gland dimensions.

[0015] Referring now to FIG. 8, another exemplary embodiment of a swivel seal assembly provided by the present invention is shown. Similar to the previously described swivel seal assemblies, the swivel seal assembly of FIG. 8 also includes an elastomeric seal body coupled to an anti-extrusion device. Both the seal body and the anti-extrusion device may have an annular ring shape, as shown, although the shape of either element may be tailored to fit the gland into which the swivel seal assembly will be assembled. The exemplary swivel seal assembly may have an overall outer diameter of 85.37 mm to 86.39 mm and an inner diameter of 73.69 mm. Of course, these values ​​may vary depending on the application and the size of the gland into which the swivel seal assembly will be assembled.

[0016] Unlike the previously described seal body shown in FIG. 7 , the seal body of the swivel seal assembly shown in FIG. 8 has inner and outer diameter surfaces that are not mirror images of one another with multiple variable thickness sections. The seal body may have an exposed axial surface having a linearly variable thickness. The seal body may have a first section of variable thickness adjacent to the exposed axial surface. In the first section of variable thickness, the inner diameter surface defines a relatively flat surface, while the outer diameter surface defines a surface having a rounded profile. In a second section of variable thickness adjacent to the first section of variable thickness, the outer diameter surface may have a rounded profile extending to the first sealing interface and a linearly tapered profile, while the inner diameter surface has a linearly tapered profile through the second section of variable thickness. In the third section of variable thickness, the outer diameter surface may have a linearly tapered profile, while the inner diameter surface may have a rounded profile including a plateau defining the region where the inner diameter of the seal body is largest. In the fourth section of variable thickness, the outer diameter surface may have a rounded profile including a depression defining the region where the outer diameter of the seal body is smallest, and the inner diameter surface may have a rounded profile. This allows for compressibility and enhances sealing across a range of axial groove widths. As can be seen, the depression on the outer diameter surface and the plateau on the inner diameter surface may be radially offset from one another. In the fifth section of variable thickness, both the outer diameter surface and the inner diameter surface may have a linearly tapered profile that terminates in a constant thickness section adjacent where the seal body is coupled to the anti-extrusion device.

[0017] The anti-extrusion device may be provided in the form of a backup ring bonded to the axial surface of the seal body. As shown, the axial surface of the backup ring may be bonded to the axial surface of the seal body such that the backup ring and the seal body are in surface contact. The thickness of the backup ring may be constant and may be equal to the thickness of the seal body in the constant-thickness section. Similar to the anti-extrusion device described above, the backup ring may comprise a material that is more rigid than the elastomeric material of the seal body. This material may include, but is not limited to, metals, such as stainless steel, and / or rigid polymers, such as PEEK. The backup ring may be bonded to the seal body by any suitable means for bonding the backup ring and the seal body together, including, but not limited to, adhesive bonding and / or thermal bonding. The backup ring has an exposed axial surface opposite the axial surface that contacts the seal body. This axial surface extends substantially perpendicular to the inner and outer diameter surfaces of the backup ring. The exposed axial surface of the seal body may extend at an angle to, and not parallel to, the exposed axial surface of the backup ring due to the variable thickness of the exposed axial surface of the seal body.

[0018] The swivel seal assembly may define an overall axial length of 9.91 mm to 10.16 mm, the seal body having an axial length of 6.48 mm, and the backup ring having an axial length of 3.56 mm. The backup ring may define a constant thickness of 5.97 mm to 6.22 mm, with the seal body having a variable thickness in different sections of variable thickness as previously described. Of course, all of the above dimensions are merely exemplary and may be adjusted depending on the application and the size of the gland into which the swivel seal assembly is assembled.

[0019] Referring to Figures 1-8, a composite seal (30) of the present invention is configured for use in a swivel seal assembly (10) having a first member (11) rotatable about a longitudinal axis (12) relative to a second member (13), the first member and the second member cooperating to define an inner annular groove (15) disposed between the first member and the second member, the inner annular groove being cylindrically shaped and extending about the longitudinal axis. The composite seal is configured to be centered about the longitudinal axis and is defined by an outer diameter (32) and an opposite inner diameter (31) connected by a first axial side (33) opposite a second axial side (34), and the composite seal is configured to be centered about the longitudinal axis and is defined by an outer diameter (32) and an opposite inner diameter (31) connected by a first axial side (33) opposite a second axial side (34), and the composite seal is defined by an elastomeric seal ring ( 35), the elastomeric sealing ring coupled to at least one anti-extrusion ring (36), the at least one anti-extrusion ring disposed on a second axial side configured to be disposed adjacent the gap when the composite seal is disposed within the inner annular groove, the elastomeric sealing ring extending longitudinally from the first axial side to the at least one anti-extrusion ring along the inner and outer diameters, the elastomeric sealing ring including an outer annular recess (37) formed along the outer diameter, the outer annular recess forming a first outer sealing annular interface (38) with the second outer annular recess (39). The elastomeric seal ring is separated from an outer sealing annular interface (39), the first outer sealing annular interface being disposed adjacent to the first axial side surface and the second outer sealing annular interface being disposed adjacent to the at least one anti-extrusion ring, and the elastomeric seal ring includes an inner annular recess (40) formed along its inner diameter, the inner annular recess separating the first inner sealing annular interface (41) from a second inner sealing annular interface (42), the first inner sealing annular interface being disposed adjacent to the first axial side surface and the second inner sealing annular interface being disposed adjacent to the at least one anti-extrusion ring.

[0020] In another exemplary embodiment, the transition (43) between the first axial side and the first outer sealing annular interface can be rounded. The first outer sealing annular interface can be an annular edge (38) formed at the intersection of the rounded transition and the outer annular recess. The second outer sealing annular interface can be cylindrical and aligned with the outer diameter.

[0021] The transition between the first axial side and the first inner sealing annular interface (44 in FIG. 4) may be rounded, and the first inner sealing annular interface may be an annular edge (41 in FIG. 4) formed at the intersection of the rounded transition and the inner annular recess.

[0022] The second inner sealing annular interface may be cylindrical and is aligned with the inner diameter.

[0023] The first inner sealing annular interface (41 in FIG. 6) may be cylindrical and may have a large diameter compared to the inner diameter.

[0024] At least one anti-extrusion ring is an extension (37) of the elastomeric sealing ring. E ), the outer anti-extrusion ring configured to be positioned adjacent the gap when the composite seal is positioned within the inner annular groove.

[0025] The extension of the elastomeric sealing ring may extend at least partially beyond the second axial side of the first and second anti-extrusion rings by a predetermined distance (45).

[0026] The elastomeric sealing ring and the at least one anti-extrusion ring may be formed from different materials. The at least one anti-extrusion ring may be formed from a material having a higher stiffness compared to the elastomeric sealing ring. The elastomeric sealing ring may have a lower modulus of elasticity compared to the at least one anti-extrusion ring.

[0027] The at least one anti-extrusion ring may be made from any of the following materials: metal, stainless steel, or polyetheretherketone (PEEK).

[0028] The first axial side may have an annular angle (46 in FIG. 6) with respect to the longitudinal axis, which forms the first axial side in the shape of a frusto-cone that is angled downwardly toward the outer diameter.

[0029] In another exemplary embodiment, best shown in FIG. 4, a composite seal (30a in FIG. 4) is configured for a swivel seal assembly (10) having a first member (11) rotatable about a longitudinal axis (12) relative to a second member (13), the first member and second member cooperating to define an inner annular groove (15) disposed between the first and second members, the inner annular groove being cylindrically shaped and having a longitudinal axis (16). The composite seal is configured to be centered about the longitudinal axis and has an inner annular groove connecting a gap (20) between the first member and the second member, and a composite seal is configured to be disposed within the inner annular groove to seal the gap, the composite seal is configured to be centered about the longitudinal axis and is defined by an outer diameter (32) and an opposite inner diameter (31) connected by a first axial side (33) opposite a second axial side (34), and the composite seal is configured to be centered about the longitudinal axis and has an elastomeric seal ring ( 35), the elastomeric sealing ring coupled to at least one anti-extrusion ring (36), the at least one anti-extrusion ring disposed on a second axial side configured to be disposed adjacent the gap when the composite seal is disposed within the inner annular groove, the elastomeric sealing ring extending longitudinally from the first axial side along the inner and outer diameters to the at least one anti-extrusion ring, The elastomeric seal ring includes an outer annular recess (37) formed along its outer diameter, the outer annular recess separating a first outer sealing annular interface surface (38) from a second outer sealing annular interface surface (39), the first outer sealing annular interface surface being disposed adjacent to the first axial side surface and the second outer sealing annular interface surface being disposed adjacent to the at least one anti-extrusion ring; the elastomeric seal ring includes an inner annular recess (40) formed along its inner diameter, the inner annular recess separating a first inner annular interface surface (38) from a second outer sealing annular interface surface (39), the first outer sealing annular interface surface being disposed adjacent to the first axial side surface and the second outer sealing annular interface surface being disposed adjacent to the at least one anti-extrusion ring; The first inner sealing annular boundary surface (41) is disposed adjacent to the first axial side surface, and the second inner sealing annular boundary surface is disposed adjacent to the at least one anti-extrusion ring. The outer transition (43 in FIG. 4) between the first axial side surface and the first outer sealing annular boundary surface is rounded. The first outer sealing annular boundary surface has an annular edge formed at the intersection of the rounded transition and the outer annular recess. the second outer sealing annular interface is cylindrical and aligned with the outer diameter, the inner transition (44, FIG. 4) between the first axial side and the first inner sealing annular interface is rounded, the first inner sealing annular interface is an annular edge (41, FIG. 4) formed at the intersection of the rounded transition and the inner annular recess, the second inner sealing annular interface is cylindrical and aligned with the inner diameter, and the at least one anti-extrusion ring is an elastomeric seal ring extension (37, FIG. 4). EThe composite seal includes an outer anti-extrusion ring (36a) and an inner anti-extrusion ring (36b) separated by a gap (36b), the outer anti-extrusion ring configured to be positioned adjacent the gap when the composite seal is positioned within the inner annular groove, and the elastomeric seal ring and the at least one anti-extrusion ring are formed from different materials.

[0030] In another exemplary embodiment, the extension of the elastomeric sealing ring may extend at least partially beyond the second axial side of the first and second anti-extrusion rings a predetermined distance (45).

[0031] The at least one anti-extrusion ring may be formed from a material that has a higher stiffness compared to the elastomeric sealing ring.

[0032] In another exemplary embodiment, best shown in FIG. 6, a composite seal (30b in FIG. 6) is configured for a swivel seal assembly (10) having a first member (11) rotatable about a longitudinal axis (12) relative to a second member (13), the first member and second member cooperating to define an inner annular groove (15) disposed between the first and second members, the inner annular groove being cylindrically shaped and having a longitudinal axis (16). The composite seal is configured to be centered about the longitudinal axis and has an inner annular groove connecting a gap (20) between the first member and the second member, and a composite seal is configured to be disposed within the inner annular groove to seal the gap, the composite seal is configured to be centered about the longitudinal axis and is defined by an outer diameter (32) and an opposite inner diameter (31) connected by a first axial side (33) opposite a second axial side (34), and the composite seal is configured to be centered about the longitudinal axis and has an elastomeric seal ring ( 35), the elastomeric sealing ring coupled to at least one anti-extrusion ring (36), the at least one anti-extrusion ring disposed on a second axial side configured to be disposed adjacent the gap when the composite seal is disposed within the inner annular groove, the elastomeric sealing ring extending longitudinally from the first axial side along the inner and outer diameters to the at least one anti-extrusion ring, and the elastomeric sealing ring extending longitudinally along the outer diameter from the first axial side to the at least one anti-extrusion ring. The elastomeric seal ring includes an outer annular recess (37) formed along an inner diameter thereof, the outer annular recess separating a first outer sealing annular interface surface (38) from a second outer sealing annular interface surface (39), the first outer sealing annular interface surface being disposed adjacent the first axial side and the second outer sealing annular interface surface being disposed adjacent the at least one anti-extrusion ring, and the elastomeric seal ring includes an inner annular recess (40) formed along an inner diameter thereof, the inner annular recess separating a first inner sealing annular interface surface (41) from a second outer sealing annular interface surface (39), the first outer sealing annular interface surface being disposed adjacent the first axial side and the second outer sealing annular interface surface being disposed adjacent the at least one anti-extrusion ring. the first inner sealing annular boundary surface is disposed adjacent to the first axial side surface, the second inner sealing annular boundary surface is disposed adjacent to the at least one anti-extrusion ring, the transition (43 in FIG. 6) between the first axial side surface and the first outer sealing annular boundary surface is a rounded annular edge (38 in FIG. 6) formed at the intersection of the rounded transition portion and the outer annular recess, and the second outer sealing annular boundary surface is the first inner sealing annular interface (41 in FIG. 6) is cylindrical and aligned with the outer diameter, the second inner sealing annular interface is cylindrical and aligned with the inner diameter, the first inner sealing annular interface (41 in FIG. 6) is cylindrical and has a large diameter compared to the inner diameter, the elastomeric sealing ring and the at least one anti-extrusion ring are formed from different materials, and the first axial side has an annular angle (46 in FIG. 6) with respect to the longitudinal axis, the annular angle forming the first axial side in the shape of a frusto-cone tilted downwardly toward the outer diameter.

[0033] In another exemplary embodiment, the at least one anti-extrusion ring may be formed from a material that has a higher stiffness compared to the elastomeric sealing ring.

[0034] While the invention has been described with respect to at least one embodiment, the invention may be further modified within the spirit and scope of this disclosure. Accordingly, this application is intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the disclosure as come within known or customary practice in the art to which this invention pertains. Further features and advantages of the invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. [Brief explanation of the drawings]

[0035] The invention is illustrated in the accompanying drawings. [Figure 1] FIG. 1 is a simplified cross-sectional view of a swivel seal assembly. [Figure 2] FIG. 2 is an enlarged view of the structure of FIG. 1 taken along line 2-2. [Figure 3] FIG. 1 is a front view of a first embodiment of a composite seal of the present invention. [Figure 4] FIG. 4 is an enlarged cross-sectional view of the structure of FIG. 3 taken along line 4-4. [Figure 5] FIG. 2 is a front view of a second embodiment of the composite seal of the present invention. [Figure 6] FIG. 5 is an enlarged cross-sectional view of the structure of FIG. 5 taken along line 5-5. [Figure 7] 5 is a cross-sectional view of the composite seal of FIG. 4 assembled within the structure of FIG. 2. [Figure 8] 7 is a cross-sectional view of the composite seal of FIG. 6 assembled within the structure of FIG. 2.

[0036] Detailed Description of the Preferred Embodiments FIG. 1 is a simplified cross-sectional view of a swivel seal assembly 10, with the seal itself removed. While actual swivel seal assemblies can be of significantly more complex design, the embodiment shown in FIG. 1 is simplified to help the reader focus on the key aspects of the invention. The swivel seal assembly includes a first member 11, which is rotatable about a longitudinal axis 12 relative to a second member 13. Smooth rotation between the first and second members is facilitated by a plurality of ball bearings 14. These ball bearings may be arranged with one, two, three, or any number of races as required by any particular design. Numerous variations of such swivel seal assemblies will be apparent to those skilled in the art of swivel joints and seals, and therefore further description is unnecessary herein.

[0037] FIG. 2 is an enlarged view of the structure of FIG. 1 taken along line 2-2. To better appreciate this view, the first and second members cooperate to define an inner annular groove 15 (i.e., gland) disposed between the first and second members. The inner annular groove is cylindrically shaped and centered about the longitudinal axis. The inner annular groove has a first axial surface 16 formed on the first member 11. The first axial surface 16 is connected by an optional radius 17 to a perpendicularly disposed inner cylindrical surface 18. Opposite the first axial surface 16, the second member 13 defines a second axial surface 19. A gap 20 can be seen between the first and second members. It is this gap 20 that must be sealed by a seal to prevent any fluid inside the first and second members from escaping outward.

[0038] Figure 3 is a front view of a first embodiment of a composite seal 30a of the present invention, and Figure 4 is an enlarged cross-sectional view of the structure of Figure 3 taken along line 4-4. Figure 7 is a cross-sectional view of the composite seal of Figure 4 assembled within the structure of Figure 2. As best shown in Figure 7 below, composite seal 30a is configured to be disposed within inner annular groove 15 to seal gap 20. Composite seal 30a is configured to be centered about longitudinal axis 12 and is defined by an outer diameter 32 and an opposing inner diameter 31 connected by a first axial side 33 opposite second axial side 34.

[0039] This embodiment shows an elastomeric sealing ring 35 coupled to at least one anti-extrusion ring 36. As best shown in FIG. 7, the at least one anti-extrusion ring 36 is disposed on a second axial side configured to be disposed adjacent gap 20 when the composite seal is disposed within inner annular groove 15.

[0040] In this embodiment, at least one anti-extrusion ring 36 is an extension 37 of the elastomeric sealing ring. E The composite seal includes an outer anti-extrusion ring 36a and an inner anti-extrusion ring 36b separated by a gap 20. Additionally, the outer anti-extrusion ring 36a is configured to be positioned adjacent to the gap 20 when the composite seal is positioned within the inner annular groove.

[0041] Elastomeric sealing ring 35 begins at first axial side 33 and extends longitudinally along inner and outer diameters to at least one anti-extrusion ring 36. Elastomeric sealing ring 35 includes an outer annular recess 37 formed along outer diameter 32. Outer annular recess 37 separates a first outer sealing annular interface 38 from a second outer sealing annular interface 39. The first outer sealing annular interface is disposed adjacent to the first axial side. The second outer sealing annular interface is disposed adjacent to the at least one anti-extrusion ring.

[0042] The elastomeric sealing ring also includes an inner annular recess 40 formed along its inner diameter. The inner annular recess separates a first inner sealing annular interface 41 from a second inner sealing annular interface 42. The first inner sealing annular interface is disposed adjacent to the first axial side. The second inner sealing annular interface is disposed adjacent to the at least one anti-extrusion ring.

[0043] As can be seen in FIG. 4 , there is a transition 43 between the first axial side and the first outer sealing annular interface. This transition is rounded. The rounded transition 43 and the left portion of the outer annular recess 37 join to form an annular edge 38. Thus, the first outer sealing annular interface 38 is the annular edge formed at the intersection of the rounded transition 43 and the outer annular recess. The second outer sealing annular interface 39 is cylindrical and aligned with the outer diameter 32. The outer diameter 32 of the second outer sealing annular interface 39 is equal to the outer diameter of the outer anti-extrusion ring 36a.

[0044] There is also a transition 44 between the first axial side surface and the first inner sealing annular interface. This transition is also rounded. The rounded transition 44 and the left portion of the inner annular recess 40 join to form an annular edge 41. Thus, the first inner sealing annular interface 41 is the annular edge formed at the intersection of the rounded transition 44 and the inner annular recess. The second inner sealing annular interface 42 is cylindrical and aligned with the inner diameter 31. The inner diameter 31 of the second inner sealing annular interface 42 is equal to the inner diameter of the inner anti-extrusion ring 36b. Finally, the elastomeric seal ring extension 37 E extends at least partially beyond the second axial side 34 of the first and second anti-extrusion rings. This extension is designated as 45.

[0045] As shown in FIG. 4, both the outer anti-extrusion ring 36a and the inner anti-extrusion ring 36b have elastomer sealing ring extensions 37. E To facilitate a good connection and increase reliability, extension 37 E The annular corners have annular rounded portions 47a and 47b, respectively.

[0046] Figure 5 is a front view of a second embodiment of a composite seal 30b of the present invention, and Figure 6 is an enlarged cross-sectional view of the structure of Figure 5 taken along line 6-6. Figure 8 is a cross-sectional view of the composite seal of Figure 6 assembled within the structure of Figure 2. The structure shown in Figures 5 and 6 is very similar to Figures 3 and 4, but differs in structure as described below.

[0047] First, at least one anti-extrusion ring 36 is of unitary construction. Second, the inner diameter profile of the elastomeric sealing ring IS is different. In this embodiment, the first inner sealing annular interface 41 is cylindrical. Furthermore, the first inner sealing annular interface 41 has a larger diameter compared to the inner diameter 31. As will be apparent to those skilled in the art, the first inner sealing annular interface 41 may have a similar diameter (not shown) compared to the inner diameter 31, or even a smaller diameter (not shown) compared to the inner diameter 31.

[0048] 6, the first axial side 33 is inclined. Thus, the first axial side has an annular angle 46 with respect to the longitudinal axis 12. This annular angle creates a first axial side that is frustoconical in shape and angled downward toward the outer diameter 32. As will be apparent to one skilled in the art, the first axial side 33 may also be perpendicular (not shown) to the longitudinal axis.

[0049] In these embodiments, the elastomeric sealing ring and the at least one anti-extrusion ring are formed from different materials. Furthermore, the at least one anti-extrusion ring may be formed from a material having a higher stiffness than the elastomeric sealing ring. In other words, the elastomeric sealing ring may have a lower modulus of elasticity than the at least one anti-extrusion ring. Alternatively, the elastomeric sealing ring and the at least one anti-extrusion ring may be formed from the same material.

[0050] The inventors disclose two different embodiments that are improvements over the prior art. Prior art seal designs result in material part expansion due to high pressures inside the various tubes and components of the swivel seal assembly. The present invention allows the seal to maintain sufficient sealing force throughout the range of component rotation. In particular, the present invention provides a greater tolerance range for the gland width (inside the annular groove 15) compared to prior art designs. In the present invention, the outer and inner diameters of the elastomer allow compression at the minimum groove width, while also allowing sufficient sealing force at the maximum groove width. For example, at the maximum groove width, the contour of the inner diameter surface allows the fluid to impart energy to the seal to increase the contact force between the seal and the material part, compensating for the reduced crushing force caused by the widest groove. In other words, the area of ​​minimum thickness, located in the rounded recess where the seal body thickness is minimum, allows compressibility, enhancing the seal's capabilities across a range of axial groove widths. Additionally, combining the elastomer with a polymer backup ring allows for easier assembly and reduces the likelihood of leakage between the elastomer and the backup ring. Finally, one of the primary failure modes of previous designs resulting in failure was due to excessive wear. Therefore, the backup ring material of the present invention is constructed from a low-friction, robust material to withstand the vibrations generated by the swivel seal assembly.

[0051] While several embodiments have been described in detail for purposes of illustration, various modifications may be made to each without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited except as by the appended claims.

Claims

1. 1. A composite seal configured for use in a swivel seal assembly, the swivel seal assembly including a first member rotatable about a longitudinal axis relative to a second member, the first member and the second member cooperating to define an inner annular groove disposed between the first member and the second member, the inner annular groove being cylindrically shaped and centered about the longitudinal axis, a gap between the first member and the second member being connected to the inner annular groove, the composite seal being configured to be disposed within the inner annular groove to seal the gap, the composite seal being configured to be centered about the longitudinal axis and defined by an outer diameter and an opposite inner diameter connected by a first axial side opposite a second axial side; an elastomeric sealing ring coupled to at least one anti-extrusion ring disposed on the second axial side configured to be disposed adjacent the gap when the composite seal is disposed within the inner annular groove, an extension of the elastomeric sealing ring extending at least to the second axial side adjacent the at least one anti-extrusion ring; the elastomeric sealing ring extends longitudinally from the first axial side along the inner diameter and the outer diameter to the at least one anti-extrusion ring; the elastomeric sealing ring includes an outer annular recess formed along the outer diameter, the outer annular recess separating a first outer sealing annular interface from a second outer sealing annular interface, the first outer sealing annular interface being disposed adjacent the first axial side surface and the second outer sealing annular interface being disposed adjacent the at least one anti-extrusion ring; the elastomeric sealing ring includes an inner annular recess formed along the inner diameter, the inner annular recess separating a first inner sealing annular interface from a second inner sealing annular interface, the first inner sealing annular interface being disposed adjacent the first axial side surface and the second inner sealing annular interface being disposed adjacent the at least one anti-extrusion ring; Composite seal.

2. The composite seal of claim 1 , wherein a transition between said first axial side surface and said first outer sealing annular interface surface is radiused.

3. The composite seal of claim 2 , wherein the first outer sealing annular interface is an annular edge formed at the intersection of the radiused transition portion and the outer annular recess.

4. The composite seal of claim 1 , wherein said second outer sealing annular interface is cylindrical and aligned with said outer diameter.

5. The composite seal of claim 1 , wherein a transition between said first axial side surface and said first inner sealing annular interface surface is radiused.

6. The composite seal of claim 5 , wherein the first inner sealing annular interface is an annular edge formed at the intersection of the radiused transition portion and the inner annular recess.

7. The composite seal of claim 1 , wherein said second inner sealing annular interface is cylindrical and aligned with said inner diameter.

8. The composite seal of claim 1 , wherein the first inner sealing annular interface is cylindrical and has a large diameter compared to the inner diameter.

9. 2. The composite seal of claim 1, wherein the at least one anti-extrusion ring comprises an outer anti-extrusion ring and an inner anti-extrusion ring separated by an extension of the elastomeric sealing ring, the outer anti-extrusion ring configured to be positioned adjacent the gap when the composite seal is positioned within the inner annular groove.

10. 10. The composite seal of claim 9, wherein the extension of the elastomeric sealing ring extends at least partially beyond the second axial side of the outer anti-extrusion ring and the inner anti-extrusion ring a predetermined distance.

11. The composite seal of claim 1 , wherein the elastomeric sealing ring and the at least one anti-extrusion ring are formed from different materials.

12. The composite seal of claim 1 , wherein the at least one anti-extrusion ring is formed from a material having a higher stiffness compared to the elastomeric seal ring.

13. The composite seal of claim 1 , wherein the elastomeric sealing ring has a low modulus of elasticity compared to the at least one anti-extrusion ring.

14. The composite seal of claim 1 , wherein the at least one anti-extrusion ring is formed from one of the following materials: metal, stainless steel, or polyetheretherketone (PEEK).

15. 2. The composite seal of claim 1, wherein said first axial side has an annular angle with respect to said longitudinal axis, said annular angle forming said first axial side in the shape of a frustocone tilted downwardly toward said outer diameter.

16. 1. A composite seal configured for use in a swivel seal assembly, the swivel seal assembly including a first member rotatable about a longitudinal axis relative to a second member, the first member and the second member cooperating to define an inner annular groove disposed between the first member and the second member, the inner annular groove being cylindrically shaped and centered about the longitudinal axis, a gap between the first member and the second member being connected to the inner annular groove, the composite seal being configured to be disposed within the inner annular groove to seal the gap, the composite seal being configured to be centered about the longitudinal axis and defined by an outer diameter and an opposite inner diameter connected by a first axial side opposite a second axial side; an elastomeric sealing ring coupled to at least one anti-extrusion ring disposed on the second axial side configured to be disposed adjacent the gap when the composite seal is disposed within the inner annular groove; the elastomeric sealing ring extends longitudinally from the first axial side along the inner diameter and the outer diameter to the at least one anti-extrusion ring; the elastomeric sealing ring includes an outer annular recess formed along the outer diameter, the outer annular recess separating a first outer sealing annular interface from a second outer sealing annular interface, the first outer sealing annular interface being disposed adjacent the first axial side surface and the second outer sealing annular interface being disposed adjacent the at least one anti-extrusion ring; the elastomeric sealing ring includes an inner annular recess formed along the inner diameter, the inner annular recess separating a first inner sealing annular interface from a second inner sealing annular interface, the first inner sealing annular interface being disposed adjacent the first axial side surface and the second inner sealing annular interface being disposed adjacent the at least one anti-extrusion ring; an outer transition between the first axial side surface and the first outer sealing annular boundary surface is radiused; the first outer sealing annular boundary surface is an annular edge formed at an intersection of the radiused transition portion and the outer annular recess; the second outer sealing annular boundary surface is cylindrical and aligned with the outer diameter; an inner transition between the first axial side surface and the first inner sealing annular boundary surface is radiused; the first inner sealing annular boundary surface is an annular edge formed at an intersection of the radiused transition portion and the inner annular recess; the second inner sealing annular boundary surface is cylindrical and aligned with the inner diameter; the at least one anti-extrusion ring comprises an outer anti-extrusion ring and an inner anti-extrusion ring separated by an extension of the elastomeric seal ring, the outer anti-extrusion ring configured to be positioned adjacent the gap when the composite seal is positioned within the inner annular groove; the elastomeric sealing ring and the at least one anti-extrusion ring are formed from different materials. Composite seal.

17. 17. The composite seal of claim 16, wherein the extension of the elastomeric sealing ring extends at least partially beyond the second axial side of the outer anti-extrusion ring and the inner anti-extrusion ring a predetermined distance.

18. The composite seal of claim 16 , wherein the at least one anti-extrusion ring is formed from a material having a higher stiffness compared to the elastomeric seal ring.

19. 1. A composite seal configured for use in a swivel seal assembly, the swivel seal assembly including a first member rotatable about a longitudinal axis relative to a second member, the first member and the second member cooperating to define an inner annular groove disposed between the first member and the second member, the inner annular groove being cylindrically shaped and centered about the longitudinal axis, a gap between the first member and the second member being connected to the inner annular groove, the composite seal being configured to be disposed within the inner annular groove to seal the gap, the composite seal being configured to be centered about the longitudinal axis and defined by an outer diameter and an opposite inner diameter connected by a first axial side opposite a second axial side; an elastomeric sealing ring coupled to at least one anti-extrusion ring disposed on the second axial side configured to be disposed adjacent the gap when the composite seal is disposed within the inner annular groove; the elastomeric sealing ring extends longitudinally from the first axial side along the inner diameter and the outer diameter to the at least one anti-extrusion ring; the elastomeric sealing ring includes an outer annular recess formed along the outer diameter, the outer annular recess separating a first outer sealing annular interface from a second outer sealing annular interface, the first outer sealing annular interface being disposed adjacent the first axial side surface and the second outer sealing annular interface being disposed adjacent the at least one anti-extrusion ring; the elastomeric sealing ring includes an inner annular recess formed along the inner diameter, the inner annular recess separating a first inner sealing annular interface from a second inner sealing annular interface, the first inner sealing annular interface being disposed adjacent the first axial side surface and the second inner sealing annular interface being disposed adjacent the at least one anti-extrusion ring; a transition between the first axial side surface and the first outer sealing annular boundary surface is rounded; the first outer sealing annular boundary surface is an annular edge formed at an intersection of the radiused transition portion and the outer annular recess; the second outer sealing annular boundary surface is cylindrical and aligned with the outer diameter; the second inner sealing annular boundary surface is cylindrical and aligned with the inner diameter; the first inner sealing annular boundary surface is cylindrical and has a large diameter compared to the inner diameter; the elastomeric sealing ring and the at least one anti-extrusion ring are formed from different materials; the first axial side has an annular angle with respect to the longitudinal axis, the annular angle forming the first axial side in the shape of a frusto-cone that is inclined downwardly toward the outer diameter. Composite seal.

20. The composite seal of claim 19 , wherein the at least one anti-extrusion ring is formed from a material having a higher stiffness compared to the elastomeric seal ring.

21. A composite seal configured for use in a swivel seal assembly, the swivel seal assembly having a first member rotatable about a longitudinal axis relative to a second member, the first member and the second member cooperating to form an inner annular groove disposed between the first member and the second member, the inner annular groove being cylindrically shaped and aligned about the longitudinal axis, a gap between the first member and the second member being connected to the inner annular groove, the composite seal being configured to be positioned within the inner annular groove to seal the gap, the composite seal being aligned about the longitudinal axis and defined by an outer diameter and an opposite inner diameter connected by a first axial side opposite a second axial side, an elastomeric sealing ring coupled to at least one anti-extrusion ring disposed on the second axial side configured to be disposed adjacent the gap when the composite seal is disposed within the inner annular groove; the elastomeric sealing ring extends longitudinally from the first axial side along the inner diameter and the outer diameter to the at least one anti-extrusion ring; the elastomeric sealing ring includes an outer annular recess formed along the outer diameter, the outer annular recess separating a first outer sealing annular interface from a second outer sealing annular interface, the first outer sealing annular interface being disposed adjacent the first axial side surface and the second outer sealing annular interface being disposed adjacent the at least one anti-extrusion ring; the elastomeric sealing ring includes an inner annular recess formed along the inner diameter, the inner annular recess separating a first inner sealing annular interface from a second inner sealing annular interface, the first inner sealing annular interface being disposed adjacent the first axial side surface and the second inner sealing annular interface being disposed adjacent the at least one anti-extrusion ring; A composite seal wherein a transition between said first axial side surface and said first outer sealing annular interface surface is radiused.

22. A composite seal configured for use in a swivel seal assembly, the swivel seal assembly having a first member rotatable about a longitudinal axis relative to a second member, the first member and the second member cooperating to form an inner annular groove disposed between the first member and the second member, the inner annular groove being cylindrically shaped and aligned about the longitudinal axis, a gap between the first member and the second member being connected to the inner annular groove, the composite seal being configured to be disposed within the inner annular groove to seal the gap, the composite seal being aligned about the longitudinal axis and defined by an outer diameter and an opposite inner diameter connected by a first axial side opposite a second axial side, an elastomeric sealing ring coupled to at least one anti-extrusion ring disposed on the second axial side configured to be disposed adjacent the gap when the composite seal is disposed within the inner annular groove; the elastomeric sealing ring extends longitudinally from the first axial side along the inner diameter and the outer diameter to the at least one anti-extrusion ring; the elastomeric sealing ring includes an outer annular recess formed along the outer diameter, the outer annular recess separating a first outer sealing annular interface from a second outer sealing annular interface, the first outer sealing annular interface being disposed adjacent the first axial side surface and the second outer sealing annular interface being disposed adjacent the at least one anti-extrusion ring; the elastomeric sealing ring includes an inner annular recess formed along the inner diameter, the inner annular recess separating a first inner sealing annular interface from a second inner sealing annular interface, the first inner sealing annular interface being disposed adjacent the first axial side surface and the second inner sealing annular interface being disposed adjacent the at least one anti-extrusion ring; A composite seal wherein a transition between said first axial side surface and said first inner sealing annular interface surface is radiused.

23. A composite seal configured for use in a swivel seal assembly, the swivel seal assembly having a first member rotatable about a longitudinal axis relative to a second member, the first member and the second member cooperating to form an inner annular groove disposed between the first member and the second member, the inner annular groove being cylindrically shaped and aligned about the longitudinal axis, a gap between the first member and the second member being connected to the inner annular groove, the composite seal being configured to be positioned within the inner annular groove to seal the gap, the composite seal being aligned about the longitudinal axis and defined by an outer diameter and an opposite inner diameter connected by a first axial side opposite a second axial side, an elastomeric sealing ring coupled to at least one anti-extrusion ring disposed on the second axial side configured to be disposed adjacent the gap when the composite seal is disposed within the inner annular groove; the elastomeric sealing ring extends longitudinally from the first axial side along the inner diameter and the outer diameter to the at least one anti-extrusion ring; the elastomeric sealing ring includes an outer annular recess formed along the outer diameter, the outer annular recess separating a first outer sealing annular interface from a second outer sealing annular interface, the first outer sealing annular interface being disposed adjacent the first axial side surface and the second outer sealing annular interface being disposed adjacent the at least one anti-extrusion ring; the elastomeric sealing ring includes an inner annular recess formed along the inner diameter, the inner annular recess separating a first inner sealing annular interface from a second inner sealing annular interface, the first inner sealing annular interface being disposed adjacent the first axial side surface and the second inner sealing annular interface being disposed adjacent the at least one anti-extrusion ring; The composite seal wherein the first inner sealing annular interface is cylindrical and has a large diameter compared to the inner diameter.

24. A composite seal configured for use in a swivel seal assembly, the swivel seal assembly having a first member rotatable about a longitudinal axis relative to a second member, the first member and the second member cooperating to form an inner annular groove disposed between the first member and the second member, the inner annular groove being cylindrically shaped and aligned about the longitudinal axis, a gap between the first member and the second member being connected to the inner annular groove, the composite seal being configured to be disposed within the inner annular groove to seal the gap, the composite seal being aligned about the longitudinal axis and defined by an outer diameter and an opposite inner diameter connected by a first axial side opposite a second axial side, an elastomeric sealing ring coupled to at least one anti-extrusion ring disposed on the second axial side configured to be disposed adjacent the gap when the composite seal is disposed within the inner annular groove; the elastomeric sealing ring extends longitudinally from the first axial side along the inner diameter and the outer diameter to the at least one anti-extrusion ring; the elastomeric sealing ring includes an outer annular recess formed along the outer diameter, the outer annular recess separating a first outer sealing annular interface from a second outer sealing annular interface, the first outer sealing annular interface being disposed adjacent the first axial side surface and the second outer sealing annular interface being disposed adjacent the at least one anti-extrusion ring; the elastomeric sealing ring includes an inner annular recess formed along the inner diameter, the inner annular recess separating a first inner sealing annular interface from a second inner sealing annular interface, the first inner sealing annular interface being disposed adjacent the first axial side surface and the second inner sealing annular interface being disposed adjacent the at least one anti-extrusion ring; the at least one anti-extrusion ring comprises an outer anti-extrusion ring and an inner anti-extrusion ring separated by an extension of the elastomeric sealing ring, the outer anti-extrusion ring configured to be positioned adjacent the gap when the composite seal is positioned within the inner annular groove.

25. A composite seal configured for use in a swivel seal assembly, the swivel seal assembly having a first member rotatable about a longitudinal axis relative to a second member, the first member and the second member cooperating to form an inner annular groove disposed between the first member and the second member, the inner annular groove being cylindrically shaped and aligned about the longitudinal axis, a gap between the first member and the second member being connected to the inner annular groove, the composite seal being configured to be positioned within the inner annular groove to seal the gap, the composite seal being aligned about the longitudinal axis and defined by an outer diameter and an opposite inner diameter connected by a first axial side opposite a second axial side, an elastomeric sealing ring coupled to at least one anti-extrusion ring disposed on the second axial side configured to be disposed adjacent the gap when the composite seal is disposed within the inner annular groove; the elastomeric sealing ring extends longitudinally from the first axial side along the inner diameter and the outer diameter to the at least one anti-extrusion ring; the elastomeric sealing ring includes an outer annular recess formed along the outer diameter, the outer annular recess separating a first outer sealing annular interface from a second outer sealing annular interface, the first outer sealing annular interface being disposed adjacent the first axial side surface and the second outer sealing annular interface being disposed adjacent the at least one anti-extrusion ring; the elastomeric sealing ring includes an inner annular recess formed along the inner diameter, the inner annular recess separating a first inner sealing annular interface from a second inner sealing annular interface, the first inner sealing annular interface being disposed adjacent the first axial side surface and the second inner sealing annular interface being disposed adjacent the at least one anti-extrusion ring; the first axial side has an annular angle with respect to the longitudinal axis, the annular angle forming the first axial side in the shape of a frusto-cone that is inclined downwardly toward the outer diameter.

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