Rotary seal assembly

Abstract

A composite seal for a rotary seal assembly includes an elastomeric seal ring bonded to at least one extrusion ring. The elastomeric seal ring includes an outer side annular valley formed along an outer diameter that separates a first outer side seal annular interface from a second outer side seal annular interface. The first outer side seal annular interface is disposed adjacent a first axial side and the second outer side seal annular interface is disposed adjacent the at least one extrusion ring. The elastomeric seal ring includes an inner side annular valley formed along an inner diameter that separates a first inner side seal annular interface from a second inner side seal annular interface. The first inner side seal annular interface is disposed adjacent the first axial side and the second inner side seal annular interface is disposed adjacent the at least one extrusion ring.

Description

[0001] Cross Reference to Related Applications

[0002] This international application claims priority to U.S. Utility Application 17 / 445,881, filed August 25, 2021, and U.S. Provisional Application 63 / 071,452, filed August 28, 2020, the entire contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0003] The present invention relates generally to rotary seal assemblies. More particularly, the present invention relates to a composite seal for a rotary seal assembly having a novel elastomeric ring bonded to at least one crush resistant ring. BACKGROUND

[0004] As is known in the art (such as U.S. Patent 10,619,774), rotary joints are commonly used in the oilfield industry to establish rigid, but dynamically configurable, flow lines between various equipment. For example, in an oilfield pumping stimulation operation or a fracturing operation, a rotary joint is commonly used to connect a plurality of high pressure pumping units to a manifold, and to connect the manifold to an injection wellhead.

[0005] These types of rotary joints generally include a tubular male member that is rotatably connected to a tubular female member. The male member includes a male race and the female member includes a female race that is configured to receive the male race. When the male race is positioned in the female race, each of a plurality of outer annular grooves on the male race is aligned with a corresponding inner annular groove on the female race to thereby form a plurality of bearing races within which a plurality of bearing balls are housed to rotatably connect the male member to the female member.

[0006] When the male member and the female member are connected together, an annular space is formed between the male race and the female race that is in fluid communication with a flow bore defined by the rotary joint. In order to contain fluid within the flow bore while still allowing the male member and the female member to rotate relative to one another, the rotary joint generally includes a dynamic primary seal located between a nose of the male race and an inner end of the female race.

[0007] However, if the primary seal fails, the pressurized fracturing fluid flow through the annular space rapidly erodes the male nose and / or the female inner end, resulting in failure of the rotary joint. In addition, the pressurized fluid will enter the annular space and create a hydrostatic end load between the male race and the female race that can cause the bearing races to fail. As a result, it is common practice to include a secondary seal to prevent the entire assembly from failing in the event of a primary seal breach. However, it would be desirable to have a better seal design. In addition, it would be desirable for such an improved seal to be able to eliminate the need for a secondary seal, thereby enabling a reduction in assembly cost and complexity.

[0008] Accordingly, there is a need for an improved seal. The present invention fulfills these needs and provides other related advantages. SUMMARY

[0009] With reference now to the drawing, and in particular Figure 7 and Figure 8 exemplary embodiments of a rotary seal assembly provided in accordance with the present invention are described. The rotary seal assembly can be configured for axial sealing and, when installed, abuts against a metal surface and covers a pre-existing crush gap between mating hardware. The rotary seal assembly includes an elastomeric seal body coupled with an anti-crush device configured to reduce crushing of the seal body into the crush gap when pressure is applied to the seal body. The rotary seal assembly can be used, for example, in systems where oil and high pressure gas are present, such as in hydraulic fracturing applications. The rotary seal assembly can be installed and operated without the need for temporary adjustments or lubrication.

[0010] As shown, the seal body can be in the shape of a torus and formed of a suitable elastomer, such as rubber or other types of elastomeric polymers. As best shown in the cross-sectional view, the seal body can 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 outer diameter of the seal body can vary between 85.8 mm and 86.0 mm, and the inner diameter of the seal body can be 73.74 mm, thus giving a maximum thickness of the seal body of about 6.2 mm. It should be understood that these values can vary depending on the size of the gland in which the seal body is installed.

[0011] With reference now Figure 7, the outer diameter surface and the inner diameter surface can be mirror images of each other. The outer diameter surface and the inner diameter surface can each have a first sealing interface formed adjacent to an exposed axial face of the seal body and a second sealing interface formed adjacent to the crush resistant device. The seal body can have a non-linear variable thickness portion between the exposed axial face and the first sealing interface, where the thickness of the seal body varies in an axial direction from the exposed axial face to the first sealing interface. A third sealing interface between the crush resistant device and the second sealing interface extends from the elastomeric body to the mating face and provides enhanced sealing capabilities. The thickness of the seal body can vary in a non-linear manner in the non-linear variable thickness portion to provide a radiused profile for the outer diameter surface and the inner diameter surface in the non-linear variable thickness portion. A pair of linear variable thickness portions can be disposed between the non-linear variable thickness portion and the second sealing interface. The linear variable thickness portions represent portions where the thickness of the seal body varies linearly in the axial direction toward a minimum thickness region. The minimum thickness region includes a radiused valley where the thickness of the seal body is at a minimum, which enables compressibility and increases sealing capabilities over a range of axial groove widths. On the other hand, the first sealing interface and the second sealing interface can represent regions where the thickness of the seal body is at a maximum, thereby sealing against the gland when installed.

[0012] To reduce the risk of the seal body being crushed into the crush gap, the crush resistant device can include a pair of support rings that are bonded to the seal body and can abut against the sealing interfaces. The support rings can be formed of a material that is more rigid than the seal body, including but not limited to a metal, such as stainless steel, and / or a rigid polymer, such as polyether ether ketone (PEEK). In some embodiments, the support rings include the same material, but it should be understood that the support rings can be formed of different materials.

[0013] Each support ring can abut against a radiused axial extension of the seal body, such that the support rings sandwich the axial extension. The axial extension can define, for example, an axial length that is greater than its thickness. The axial length of the axial extension can be slightly greater than a respective axial length of each support ring, such that the axial extension has a portion that extends farther axially than the exposed axial faces of the two support rings. In this regard, the support rings can define a gap therebetween that is substantially filled by the axial extension of the seal body, with a portion of the axial extension extending out of the gap. In this regard, the portion of the axial extension that extends out of the gap can also contact a portion of the gland provided with the rotary seal assembly. As shown, the exposed axial faces of the seal body and the support rings can extend substantially parallel.

[0014] The radiused axial extension of the seal body will be compressed during assembly of the male tubular member and the female tubular member. Upon installation, the radiused axial extension of the seal will conform with the support rings, such that all of the axial faces of the seal will be in full contact with the mating groove surfaces, eliminating any potential gaps.

[0015] The overall axial length of the rotary seal assembly can be between 9.93 mm and 10.13 mm, with the face-to-face axial length of the seal body being about 6.1 mm and the axial length of the backup ring being about 3.7 mm. In some embodiments, the axial length of the backup ring can be a portion of the overall length of the seal, such as one-third to one-half of the overall length of the seal. A portion of the axial extension extending through the backup ring can have an axial length of about 0.1 mm to 0.3 mm. The rotary seal assembly can define an overall thickness of between 6.0 mm and 6.2 mm. It should be understood that these dimensions are exemplary only, and that these dimensions can vary depending on the application and gland size.

[0016] Reference is now made to Figure 8 which shows another exemplary embodiment of a rotary seal assembly provided in accordance with the present application. Similar to the foregoing rotary seal assembly, Figure 8 The rotary seal assembly of

[0017] Unlike the foregoing seal body shown in Figure 7 Figure 8 ​The inner diameter surface and the outer diameter surface of the seal body of the illustrated rotating seal assembly are not mirror images of each other with multiple variable thickness portions. The seal body can include an exposed axial face with a linear variable thickness. The seal body can have a first portion of variable thickness adjacent to the exposed axial face. In the first portion of variable thickness, the inner diameter surface defines a relatively flat surface, while the outer diameter surface defines a surface with a radiused profile. In a second portion of variable thickness adjacent to the first portion of variable thickness, the outer diameter surface can have a radiused profile that extends to the first seal interface and a linear tapered profile, while the inner diameter surface has a linear tapered profile throughout the second portion of variable thickness. In a third portion of variable thickness, the outer diameter surface can have a linear tapered profile, while the inner diameter surface can have a radiused profile that includes a plateau defining a region where the maximum inner diameter of the seal body is located. In a fourth portion of variable thickness, the outer diameter surface can have a radiused profile that includes a valley defining a region where the minimum outer diameter of the seal body is located, and the inner diameter surface can have a radiused profile that enables compressibility and increases sealing capability over a range of axial groove widths. It will be appreciated that the valley of the outer diameter surface and the plateau of the inner diameter surface can be radially offset from each other. In a fifth portion of variable thickness, both the outer diameter surface and the inner diameter surface can have a linear tapered profile that terminates in a constant thickness portion adjacent to where the seal body is joined to the crush resistant device.

[0018] The crush resistant device is provided in the form of a backup ring that is joined to the axial face of the seal body. As shown, the axial face of the backup ring can be joined to the axial face of the seal body such that the backup ring and the seal body are in face-to-face contact. The thickness of the backup ring can be constant and can be equal to the thickness of the seal body in the constant thickness portion. Similar to the crush resistant devices previously described, the backup ring can include a material that is more rigid than the elastomeric material of the seal body, including but not limited to metals, such as stainless steel and / or rigid polymers, such as PEEK. The backup ring can be joined to the seal body in any suitable manner that holds 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 face that is opposite the axial face that contacts the seal body, the exposed axial face extending generally perpendicular to the inner diameter surface and the outer diameter surface of the backup ring. Due to the variable thickness of the exposed axial face of the seal body, the exposed axial face of the seal body can extend at an angle relative to the exposed axial face of the backup ring, i.e., not parallel thereto.

[0019] The rotating seal assembly can define a total axial length between 9.91 mm and 10.16 mm, with an axial length of the seal body of 6.48 mm and an axial length of the backup ring of 3.56 mm. The backup ring can define a constant thickness between 5.97 mm and 6.22 mm, with the seal body having a variable thickness at different portions of the variable thickness, as previously described. It will be appreciated that the dimensions described previously are merely exemplary and can be adjusted according to the application and size of the gland in which the rotating seal assembly is installed.

[0020] With reference to Figures 1 to 8 The composite seal (30) of the present invention is configured for use in a rotating seal assembly (10) having a first portion (11) rotatable about a longitudinal axis (12) relative to a second portion (13), wherein the first portion and the second portion collectively form an inner annular recess (15) disposed between the first portion and the second portion, the inner annular recess being cylindrical and aligned about the longitudinal axis; wherein a gap (20) between the first portion and the second portion is connected to the inner annular recess; wherein the composite seal is configured to be disposed within the inner annular recess to seal the gap; wherein the composite seal is configured to be aligned about the longitudinal axis and defined by an inner diameter (31) opposite an outer diameter (32) connected by a first axial side (33) opposite a second axial side (34); wherein the composite seal comprises: an elastomeric seal ring (34) bonded to at least one crush resistant ring (36), wherein the at least one crush resistant ring is disposed at the second axial side configured to be placed adjacent to the gap when the composite seal is disposed within the inner annular recess; wherein the elastomeric seal ring extends longitudinally along the inner diameter and the outer diameter from the first axial side until reaching the at least one crush resistant ring; wherein the elastomeric seal ring includes an outer annular valley (37) formed along the outer diameter, the outer annular valley separating a first outer seal annular interface (38) disposed adjacent to the first axial side from a second outer seal annular interface (39) disposed adjacent to the at least one crush resistant ring; and wherein the elastomeric seal ring includes an inner annular valley (40) formed along the inner diameter, the inner annular valley separating a first inner seal annular interface (41) disposed adjacent to the first axial side from a second inner seal annular interface (42) disposed adjacent to the at least one crush resistant ring.

[0021] In other exemplary embodiments, the transition portion (43) between the first axial side and the first outer sealing annular interface may be rounded. The first outer sealing annular interface may be an annular edge (38) formed at the intersection of the rounded transition portion and the outer annular valley portion. The second outer sealing annular interface may be cylindrical and may be aligned with the outer diameter.

[0022] The transition portion between the first axial side and the first inner sealing annular interface ( Figure 4 44) can be rounded. The first inner sealing annular interface can be an annular edge formed at the intersection of the rounded transition and the inner annular valley. Figure 4 41).

[0023] The second inner sealing ring interface can be cylindrical and aligned with the inner diameter.

[0024] First inner sealing ring interface ( Figure 6 41) can be cylindrical and can have a diameter greater than the inner diameter.

[0025] At least one anti-compression ring may include an outer anti-compression ring separated from an extension (37E) of an elastomeric sealing ring. Figure 4 36a) and inner anti-extrusion ring ( Figure 4 36b), wherein the outer anti-extrusion ring is configured to be placed adjacent to the gap when the composite seal is located in the inner annular groove.

[0026] The extension of the elastomeric sealing ring may extend at least partially beyond the second axial side of the first and second anti-compression rings by a distance (45).

[0027] The elastomeric sealing ring and at least one anti-compression ring may be formed of different materials. The at least one anti-compression ring may be formed of a material with greater rigidity than the elastomeric sealing ring. The elastic modulus of the elastomeric sealing ring may be lower than that of the at least one anti-compression ring.

[0028] At least one anti-compression ring may be formed from any of the following materials: metal, stainless steel or polyether ether ketone (PEEK).

[0029] The first axial side may include an annular angle relative to the longitudinal axis. Figure 6 46), the annular angle forms a first axial side, which is a truncated cone that slopes downward toward the outer radial direction.

[0030] In another exemplary embodiment, such as Figure 4 The best shown is the composite seal ( Figure 430a) is configured for a rotary seal assembly (10) having a first part (11) rotatable about a longitudinal axis (12) relative to a second part (13), wherein the first part and the second part jointly form an inner annular groove (15) disposed between the first part and the second part, the inner annular groove being cylindrical and aligned about the longitudinal axis; wherein a gap (20) between the first part and the second part is connected to the inner annular groove; wherein a composite seal is configured to be disposed within the inner annular groove to seal the gap; wherein the composite seal is configured to be aligned about the longitudinal axis and defined by an inner diameter (31) opposite an outer diameter (32), the outer diameter connected by a first axial side (33) opposite a second axial side (34); wherein the composite seal comprises: an elastomeric seal ring (34) bonded to at least one crush ring (36), wherein the at least one crush ring is disposed at the second axial side configured to be placed adjacent to the gap when the composite seal is disposed within the inner annular groove; wherein the elastomeric seal ring extends longitudinally along the inner diameter and the outer diameter from the first axial side until reaching the at least one crush ring; wherein the elastomeric seal ring comprises an outer annular valley (37) formed along the outer diameter, the outer annular valley separating a first outer seal annular interface (38) disposed adjacent to the first axial side from a second outer seal annular interface (39) disposed adjacent to the at least one crush ring; wherein the elastomeric seal ring comprises an inner annular valley (40) formed along the inner diameter, the inner annular valley separating a first inner seal annular interface (41) disposed adjacent to the first axial side from a second inner seal annular interface (42) disposed adjacent to the at least one crush ring; wherein an outer transition (43) between the first axial side and the first outer seal annular interface is rounded; wherein the first outer seal annular interface is an annular edge (44) formed at an intersection of the rounded transition and the outer annular valley; wherein the second outer seal annular interface is cylindrical and aligned with the outer diameter; wherein an inner transition (45) between the first axial side and the first inner seal annular interface is rounded; wherein the first inner seal annular interface is an annular edge (46) formed at an intersection of the rounded transition and the inner annular valley. Figure 4 Figure 4 Figure 4 Figure 4 ​​​the annular edge is formed at the intersection of the rounded transition and the inner annular valley; wherein the second inner seal annular interface is cylindrical and aligned with the inner diameter; wherein the at least one crush ring comprises an outer crush ring (36a) and an inner crush ring (36b) separated by an extension (37E) of the elastomeric seal ring, wherein the outer crush ring is configured to be placed adjacent to the gap when the composite seal is disposed within the inner annular groove; and wherein the elastomeric seal ring and the at least one crush ring are formed of different materials.

[0031] In other example embodiments, the extension of the elastomeric seal ring can extend at least partially beyond the first crush ring and the second crush ring a distance (45) on the second axial side.

[0032] The at least one crush ring can be formed of a material that is more rigid than the elastomeric seal ring.

[0033] In another example embodiment, as Figure 6 Best shown, the composite seal (10) includes an elastomeric seal ring (12) disposed within an inner annular groove (14) of a seal carrier (16) and a first crush ring (18) disposed on a first axial side of the elastomeric seal ring (12) and a second crush ring (20) disposed on a second axial side of the elastomeric seal ring (12), wherein the first crush ring (18) and the second crush ring (20) are separated by an extension (22) of the elastomeric seal ring (12). Figure 630b) is configured for a rotary seal assembly (10) having a first part (11) rotatable about a longitudinal axis (12) relative to a second part (13), wherein the first part and the second part together form an inner annular groove (15) between the first part and the second part, the inner annular groove being cylindrical and aligned about the longitudinal axis; wherein a gap (20) between the first part and the second part is connected to the inner annular groove; wherein a composite seal is configured to be disposed within the inner annular groove to seal the gap; wherein the composite seal is configured to be aligned about the longitudinal axis and defined by an inner diameter (31) opposite an outer diameter (32), the inner diameter connected by a first axial side (33) opposite a second axial side (34); wherein the composite seal comprises: an elastomeric seal ring (34) bonded to at least one crush ring (36), wherein the at least one crush ring is disposed at the second axial side configured to be placed adjacent the gap when the composite seal is disposed within the inner annular groove; wherein the elastomeric seal ring extends longitudinally along the inner diameter and the outer diameter from the first axial side until reaching the at least one crush ring; wherein the elastomeric seal ring comprises an outer annular valley (37) formed along the outer diameter, the outer annular valley separating a first outer seal annular interface (38) disposed adjacent the first axial side from a second outer seal annular interface (39) disposed adjacent the at least one crush ring; wherein the elastomeric seal ring comprises an inner annular valley (40) formed along the inner diameter, the inner annular valley separating a first inner seal annular interface (41) disposed adjacent the first axial side from a second inner seal annular interface (42) disposed adjacent the at least one crush ring; wherein a transition (43) between the first axial side and the first outer seal annular interface is rounded; wherein the first outer seal annular interface is an annular edge (44) formed at an intersection of the rounded transition and the outer annular valley; wherein the second outer seal annular interface is cylindrical and aligned with the outer diameter; wherein the second inner seal annular interface is cylindrical and aligned with the inner diameter; wherein the first inner seal annular interface (41) is cylindrical and has a diameter greater than the inner diameter; wherein the elastomeric seal ring and the at least one crush ring are formed of different materials; and wherein the first axial side comprises an annular angle (46) relative to the longitudinal axis that forms the first axial side that is tapered downwardly toward the outer diameter. Figure 6 Figure 6 Figure 6 Figure 6

[0034] In other example embodiments, the at least one crush ring can be formed of a material that is more rigid than the elastomeric seal ring.​​​​

[0035] While the application has been described with respect to at least one embodiment, the application can be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or modifications of the application using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this application pertains. Other features and advantages of the application will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the application. BRIEF DESCRIPTION OF DRAWINGS

[0036] The accompanying drawings illustrate the application. In such drawings:

[0037] Figure 1 is a cross-sectional view taken through a simplified, schematic rotary seal assembly;

[0038] Figure 2 is an enlarged view of the structure of Figure 1 taken along line 2-2;

[0039] Figure 3 is an elevational view of a first embodiment of a composite seal of the present application;

[0040] Figure 4 is an enlarged cross-sectional view of the structure of Figure 3 taken along line 4-4;

[0041] Figure 5 is an elevational view of a second embodiment of a composite seal of the present application;

[0042] Figure 6 is an enlarged cross-sectional view of the structure of Figure 5 taken along line 5-5;

[0043] Figure 7 is a cross-sectional view of the composite seal of Figure 2 installed within the structure of Figure 4 ; and

[0044] Figure 8 is a cross-sectional view of the composite seal of Figure 2 installed within the structure of Figure 6 . DETAILED DESCRIPTION

[0045] Figure 1is a cross-sectional view taken through a simplified schematic rotary seal assembly 10 with the seal itself removed. While actual rotary seal assemblies can be much more complex in design, the embodiment shown here is simplified to help the reader focus on the important aspects of the present invention. The rotary seal assembly has a first portion 11 that is rotatable about a longitudinal axis 12 compared to a second portion 13. A plurality of ball bearings 14 facilitate smooth rotation between the first and second portions. Depending on the needs of any particular design, the ball bearings can be provided in one, two, three, or any number of races. Those skilled in the art of rotary joints and seals will appreciate that there are many variations of such rotary seal assemblies and thus further discussion is not required here.

[0046] Figure 2 is an enlarged view of the structure taken along line 2-2 Figure 1 where the first and second portions can be seen better to collectively form an inner annular groove 15 (i.e., gland) located between the first and second portions. The inner annular groove is cylindrical and aligned about the longitudinal axis. The inner annular groove has a first axial face 16 formed in the first portion 11 that is connected by an optional radius 17 to a vertically disposed inner cylindrical surface 18. A second axial face 19 facing the first axial face 16 is formed in the second portion 13. A gap 20 can be seen between the first and second portions. This gap 20 must be sealed by a seal so that any fluid within the first and second portions does not escape outwardly.

[0047] Figure 3 is an enlarged view of the structure taken along line 2-2 Figure 4 where the first and second portions can be seen better to collectively form an inner annular groove 15 (i.e., gland) located between the first and second portions. The inner annular groove is cylindrical and aligned about the longitudinal axis. The inner annular groove has a first axial face 16 formed in the first portion 11 that is connected by an optional radius 17 to a vertically disposed inner cylindrical surface 18. A second axial face 19 facing the first axial face 16 is formed in the second portion 13. A gap 20 can be seen between the first and second portions. This gap 20 must be sealed by a seal so that any fluid within the first and second portions does not escape outwardly. Figure 3 is an enlarged view of the structure taken along line 2-2 Figure 7 is a cross-sectional view of the composite seal Figure 2 installed within the structure of Figure 4 The composite seal 30a is configured to be disposed within the inner annular groove 15 to seal the gap 20 as best shown in the later Figure 7 The composite seal 30a is configured to be aligned about the longitudinal axis 12 and is defined by an inner diameter 31 opposite an outer diameter 32 connected by a first axial side 33 opposite a second axial side 34.

[0048] This embodiment shows an elastomeric seal ring 35 bonded to at least one crush ring 36. The at least one crush ring 36 is disposed at the second axial side that is configured to be placed adjacent to the gap 20 when the composite seal is disposed within the inner annular groove 15 as best shown in the later Figure 7

[0049] ​In this embodiment, the at least one crush ring 36 includes an outer crush ring 36a and an inner crush ring 36b separated by an extension 37E of the elastomeric seal ring. Note that the outer crush ring 36a is configured to be placed adjacent to the gap 20 when the composite seal is disposed within the inner annular groove.

[0050] The elastomeric seal ring 35 extends longitudinally along the inner diameter and the outer diameter from the first axial side 33 until it reaches the at least one crush ring 36. The elastomeric seal ring 35 includes an outer annular valley 37 formed along the outer diameter 32. The outer annular valley 37 separates a first outer annular interface 38 from a second outer annular interface 39. The first outer annular interface is disposed adjacent to the first axial side. The second outer annular interface is disposed adjacent to the at least one crush ring.

[0051] The elastomeric seal ring also includes an inner annular valley 40 formed along the inner diameter. The inner annular valley separates a first inner annular interface 41 from a second inner annular interface 42. The first inner annular interface is disposed adjacent to the first axial side. The second inner annular interface is disposed adjacent to the at least one crush ring.

[0052] As Figure 4 It can be seen that a transition 43 is located between the first axial side and the first outer annular interface. This transition is rounded. The rounded transition 43 intersects with the left portion of the outer annular valley 37 to form an annular edge 38. Thus, the first outer annular interface 38 is an annular edge formed at the intersection of the rounded transition 43 and the outer annular valley. The second outer annular interface 39 is cylindrical and is aligned with the outer diameter 32. The outer diameter 32 of the second outer annular interface 39 is the same as the outer diameter of the outer crush ring 36a.

[0053] Likewise, a transition 44 is located between the first axial side and the first inner annular interface. This transition is also rounded. The rounded transition 44 intersects with the left portion of the inner annular valley 40 to form an annular edge 41. Thus, the first inner annular interface 41 is an annular edge formed at the intersection of the rounded transition 44 and the inner annular valley. The second inner annular interface 42 is cylindrical and is aligned with the inner diameter 31. The inner diameter 31 of the second inner annular interface 42 is the same as the inner diameter of the inner crush ring 36b. Finally, the extension 37E of the elastomeric seal ring extends at least partially beyond the second axial side 34 of the first and second crush rings. This extension distance is indicated by the numeral 45.

[0054] As Figure 4As shown, both the outer crush ring 36a and the inner crush ring 36b are bonded to the extension 37E of the elastomeric seal ring. To facilitate good bonding and increase reliability, each annular corner of the extension 37E has an annular radius 47a and 47b.

[0055] Figure 5 is a front view of a second embodiment of the composite seal 30b of the present invention, Figure 6 is a cross-sectional view of the composite seal taken along line 6-6. Figure 5 is an enlarged cross-sectional view of the structure of Figure 8 is a cross-sectional view of the composite seal installed within the structure of Figure 2 Figure 6 Figure 5 and Figure 6 the structure shown in Figure 3 and Figure 4 is very similar to the structure shown in

[0056] First, the at least one crush ring 36 is a single structure. Second, the profile of the inner diameter of the elastomeric seal ring is different. Now, the first inner side seal annular interface 41 is cylindrical. In addition, the first inner side seal annular interface 41 has a larger diameter than the inner diameter 31. Those skilled in the art will understand that the first inner side seal annular interface 41 can also have a similar diameter as the inner diameter 31 (not shown), or even a smaller diameter than the inner diameter 31 (not shown).

[0057] As can be seen in Figure 6 the first axial side 33 is inclined. Thus, the first axial side includes an annular corner 46 with respect to the longitudinal axis 12. The annular corner forms the first axial side, which is frustoconical and inclined downwardly toward the outer diameter 32. Those skilled in the art will also understand that the first axial side 33 can also be perpendicular (not shown) to the longitudinal axis.

[0058] In these embodiments, the elastomeric seal ring and the at least one crush ring are formed of different materials. In addition, the at least one crush ring can be formed of a material that is more rigid than the elastomeric seal ring. In other words, the modulus of elasticity of the elastomeric seal ring can be lower than the modulus of elasticity of the at least one crush ring. Alternatively, the elastomeric seal ring and the at least one crush ring can be formed of the same material.

[0059] ​​The inventors have disclosed two different embodiments that are improvements over the prior art. The prior art seal designs experience hardware swelling due to the high pressures within the various tubes and parts of the rotating seal assembly. The present invention allows the seal to maintain sufficient sealing force over the range of component rotation. Specifically, the present invention accommodates a larger gland (inner annular groove 15) width tolerance range compared to the prior art designs. In the present invention, the outer and inner diameters of the elastomer allow for compression over the minimum groove width, while also allowing sufficient sealing force over the widest groove width. For example, at the widest groove width, the profile of the inner diameter surface allows for fluid to activate the seal for increased contact force between the seal and hardware to offset the reduced squeeze force caused by the widest groove. In other words, the region of minimum thickness at the rounded valley where the seal body thickness is the smallest enables compressibility and increases the sealing ability of the seal over the range of axial groove widths. Furthermore, the combination of the elastomer and polymer backup ring together enables a simpler installation and reduces the likelihood of a leak occurring between the elastomer and backup ring. Finally, one of the primary failure modes of previous failed designs was due to excessive wear. Therefore, the backup ring material of the present invention will be comprised of a low friction and robust material to withstand the oscillatory vibrations generated by the rotating seal assembly.

[0060] While several embodiments have been described in detail, various modifications to the embodiments can be made without departing from the scope and spirit of the application. Accordingly, the application is not limited except as by the appended claims.

Claims

1. A composite seal configured for use in a rotary seal assembly having a first portion rotatable about a longitudinal axis relative to a second portion, wherein, The first portion and the second portion collectively form an inner annular groove disposed between the first portion and the second portion, the inner annular groove being cylindrical and aligned about the longitudinal axis; wherein a gap between the first portion and the second portion is connected to the inner annular groove; wherein the composite seal is configured to be disposed within the inner annular groove to seal the gap; wherein the composite seal is configured to be aligned about the longitudinal axis and is defined by an inner diameter opposite an outer diameter, the outer diameter connected by a first axial side opposite a second axial side; wherein the composite seal comprises: an elastomeric seal ring bonded to at least one crush ring, wherein the at least one crush ring is disposed at the second axial side, the second axial side configured to be placed adjacent to the gap when the composite seal is disposed within the inner annular groove; wherein the elastomeric seal ring extends longitudinally along the inner diameter and the outer diameter from the first axial side until reaching the at least one crush ring; wherein the elastomeric seal ring comprises an outer annular valley formed along the outer diameter, the outer annular valley separating a first outer seal annular interface disposed adjacent to the first axial side from a second outer seal annular interface disposed adjacent to the at least one crush ring, wherein the first outer seal annular interface and the second outer seal annular interface are disposed at a same first diameter at the outer diameter; wherein the elastomeric seal ring comprises an inner annular valley formed along the inner diameter, the inner annular valley separating a first inner seal annular interface disposed adjacent to the first axial side from a second inner seal annular interface disposed adjacent to the at least one crush ring, wherein the first inner seal annular interface and the second inner seal annular interface are disposed at a same second diameter at the inner diameter; and wherein the at least one crush ring has an inner crush diameter that is cylindrical and disposed at the same second diameter at the inner diameter.

2. The composite seal of claim 1, wherein, A transition between the first axial side and the first outer seal annular interface is rounded.

3. The composite seal of claim 2, wherein, The first outer seal annular interface is an annular edge formed at an intersection of the rounded transition and the outer annular valley.

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

5. The composite seal of claim 1, wherein, A transition between the first axial side and the first inner seal annular interface is rounded.

6. The composite seal of claim 5, wherein, The first inner seal annular interface is an annular edge formed at an intersection of the rounded transition and the inner annular valley.

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

8. The composite seal of claim 1, wherein, The at least one crush ring includes an outer crush ring and an inner crush ring separated by an extension of the elastomeric seal ring, wherein the outer crush ring is configured to be placed adjacent to the gap when the composite seal is disposed within the inner annular groove.

9. The composite seal of claim 8, wherein, The extension of the elastomeric seal ring extends at least partially beyond the second axial side of the outer crush ring and the inner crush ring by a distance.

10. The composite seal of claim 1, wherein, The elastomeric seal ring and the at least one crush ring are formed of different materials.

11. The composite seal of claim 1, wherein, The at least one crush ring is formed of a material that is more rigid than the elastomeric seal ring.

12. The composite seal of claim 1, wherein, The elastomeric seal ring has a modulus of elasticity that is lower than a modulus of elasticity of the at least one crush ring.

13. The composite seal of claim 1, wherein, The at least one crush ring is formed of any one of the following materials: metal, stainless steel, or polyether ether ketone (PEEK).

14. A composite seal configured for use in a rotary seal assembly having a first portion rotatable about a longitudinal axis relative to a second portion, wherein, The first portion and the second portion collectively form an inner annular groove disposed between the first portion and the second portion, the inner annular groove being cylindrical and aligned about the longitudinal axis; wherein a gap between the first portion and the second portion is connected to the inner annular groove; wherein the composite seal is configured to be disposed within the inner annular groove to seal the gap; wherein the composite seal is configured to be aligned about the longitudinal axis and defined by an inner diameter opposite an outer diameter, the outer diameter connected by a first axial side opposite a second axial side; wherein the composite seal includes: an elastomeric seal ring joined to at least one crush ring, wherein the at least one crush ring is disposed at the second axial side, the second axial side configured to be placed adjacent to the gap when the composite seal is disposed within the inner annular groove; wherein the elastomeric seal ring extends longitudinally along the inner diameter and the outer diameter from the first axial side until reaching the at least one crush ring; wherein the elastomeric seal ring includes an outer annular valley formed along the outer diameter, the outer annular valley separating a first outer seal annular interface disposed adjacent to the first axial side from a second outer seal annular interface disposed adjacent to the at least one crush ring, wherein the first outer seal annular interface and the second outer seal annular interface are disposed at a same first diameter at the outer diameter; wherein the elastomeric seal ring includes an inner annular valley formed along the inner diameter, the inner annular valley separating a first inner seal annular interface disposed adjacent to the first axial side from a second inner seal annular interface disposed adjacent to the at least one crush ring, wherein the first inner seal annular interface and the second inner seal annular interface are disposed at a same second diameter at the inner diameter; wherein an outer transition between the first axial side and the first outer seal annular interface is rounded; wherein the first outer sealing annular interface is an annular edge formed at the intersection of a rounded transition and the outer annular valley; wherein the second outer sealing annular interface is cylindrical and aligned with the outer diameter; wherein an inner transition between the first axial side and the first inner sealing annular interface is rounded; wherein the first inner sealing annular interface is an annular edge formed at the intersection of a rounded transition and the inner annular valley; wherein the second inner sealing annular interface is cylindrical and aligned with the inner diameter; wherein the at least one crush ring comprises an outer crush ring and an inner crush ring separated by an extension of the elastomeric sealing ring, wherein the outer crush ring is configured to be placed adjacent to the gap when the composite seal is disposed within the inner annular groove; and wherein the elastomeric sealing ring and the at least one crush ring are formed of different materials.

15. The composite seal of claim 14, wherein, The extension of the elastomeric sealing ring extends at least partially beyond the second axial side of the outer crush ring and the inner crush ring by a distance.

16. The composite seal of claim 14, wherein, The at least one crush ring is formed of a material that is more rigid than the elastomeric sealing ring. The at least one crush ring is formed of a material that is more rigid than the elastomeric sealing ring.

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