SWIVEL SEAL ASSEMBLY

Abstract

A composite seal for a swivel seal assembly includes an elastomeric seal ring bonded to at least one anti-extrusion ring. The elastomeric seal ring includes an outside annular valley formed along an outside diameter, the outside annular valley separating a first outside sealing annular interface apart from a second outside sealing annular interface. The first outside sealing annular interface is disposed adjacent to a first axial side and the second outside sealing annular interface is disposed adjacent to the at least one anti-extrusion ring. The elastomeric seal ring includes an inside annular valley formed along an inside diameter, the inside annular valley separating a first inside sealing annular interface apart from a second inside sealing annular interface. The first inside sealing annular interface is disposed adjacent to the first axial side and the second inside sealing annular interface is disposed adjacent to the at least one anti-extrusion ring.

Claims

1) A composite seal configured for a swivel seal assembly, the swivel seal assembly having a first part rotatable about a longitudinal axis in comparison to a second part, wherein the first and second parts cooperatively form an inside annular groove disposed between the first and second parts, the inside annular groove being cylindrically-shaped and aligned about the longitudinal axis, wherein a gap between the first and second parts is connected to the inside annular groove, wherein the composite seal is configured to be disposed within the inside annular groove to seal the gap, wherein the composite seal is configured to be aligned about the longitudinal axis and is delimited by an inside diameter opposite an outside 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 anti-extrusion ring, wherein the at least one anti-extrusion ring is disposed at the second axial side configured to be placed adjacent to the gap when the composite seal is disposed within the inside annular groove; wherein the elastomeric seal ring starts from the first axial side and extends longitudinally along the inside and outside diameters until it reaches the at least one anti-extrusion ring; wherein the elastomeric seal ring includes an outside annular valley formed along the outside diameter, the outside annular valley separating a first outside sealing annular interface apart from a second outside sealing annular interface, the first outside sealing annular interface disposed adjacent to the first axial side and the second outside sealing annular interface disposed adjacent to the at least one anti-extrusion ring; and wherein the elastomeric seal ring includes an inside annular valley formed along the inside diameter, the inside annular valley separating a first inside sealing annular interface apart from a second inside sealing annular interface, the first inside sealing annular interface disposed adjacent to the first axial side and the second inside sealing annular interface disposed adjacent to the at least one anti-extrusion ring.

2) The composite seal of claim 1, wherein a transition between the first axial side and the first outside sealing annular interface is rounded.

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

4) The composite seal of claim 1, wherein the second outside sealing annular interface is cylindrical and aligns with the outside diameter.

5) The composite seal of claim 1, wherein a transition between the first axial side and the first inside sealing annular interface is rounded.

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

7) The composite seal of claim 1, wherein the second inside sealing annular interface is cylindrical and aligns with the inside diameter.

8) The composite seal of claim 1, wherein the first inside sealing annular interface is cylindrical and has a larger diameter in comparison to the inside diameter.

9) 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 seal ring, wherein the outer anti-extrusion ring is configured to be placed adjacent to the gap when the composite seal is disposed within the inside annular groove.

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

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

12) The composite seal of claim 1, wherein the at least one anti-extrusion ring is formed of a material having a greater rigidity in comparison to the elastomeric seal ring.

13) The composite seal of claim 1, wherein the elastomeric seal ring has a lower modulus of elasticity in comparison 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 any of the following materials: metal, stainless steel or polyether ether ketone (PEEK).

15) The composite seal of claim 1, wherein the first axial side comprises an annular angle with respect to the longitudinal axis, the annular angle forming the first axial side that is frustoconical in shape that is sloped downwards towards the outside diameter.

16) A composite seal configured for a swivel seal assembly, the swivel seal assembly having a first part rotatable about a longitudinal axis in comparison to a second part, wherein the first and second parts cooperatively form an inside annular groove disposed between the first and second parts, the inside annular groove being cylindrically-shaped and aligned about the longitudinal axis, wherein a gap between the first and second parts is connected to the inside annular groove, wherein the composite seal is configured to be disposed within the inside annular groove to seal the gap, wherein the composite seal is configured to be aligned about the longitudinal axis and is delimited by an inside diameter opposite an outside 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 anti-extrusion ring, wherein the at least one anti-extrusion ring is disposed at the second axial side configured to be placed adjacent to the gap when the composite seal is disposed within the inside annular groove; wherein the elastomeric seal ring starts from the first axial side and extends longitudinally along the inside and outside diameters until it reaches the at least one anti-extrusion ring; wherein the elastomeric seal ring includes an outside annular valley formed along the outside diameter, the outside annular valley separating a first outside sealing annular interface apart from a second outside sealing annular interface, the first outside sealing annular interface disposed adjacent to the first axial side and the second outside sealing annular interface disposed adjacent to the at least one anti-extrusion ring; wherein the elastomeric seal ring includes an inside annular valley formed along the inside diameter, the inside annular valley separating a first inside sealing annular interface apart from a second inside sealing annular interface, the first inside sealing annular interface disposed adjacent to the first axial side and the second inside sealing annular interface disposed adjacent to the at least one anti-extrusion ring; wherein an outside transition between the first axial side and the first outside sealing annular interface is rounded; wherein the first outside sealing annular interface is an annular edge formed at an intersection of the rounded transition and the outside annular valley; wherein the second outside sealing annular interface is cylindrical and aligns with the outside diameter; wherein an inside transition between the first axial side and the first inside sealing annular interface is rounded; wherein the first inside sealing annular interface is an annular edge formed at an intersection of the rounded transition and the inside annular valley; wherein the second inside sealing annular interface is cylindrical and aligns with the inside diameter; 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 seal ring, wherein the outer anti-extrusion ring is configured to be placed adjacent to the gap when the composite seal is disposed within the inside annular groove; and wherein the elastomeric seal ring and the at least one anti-extrusion ring are formed of different materials.

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

18) The composite seal of claim 16, wherein the at least one anti-extrusion ring is formed of a material having a greater rigidity in comparison to the elastomeric seal ring.

19) A composite seal configured for a swivel seal assembly, the swivel seal assembly having a first part rotatable about a longitudinal axis in comparison to a second part, wherein the first and second parts cooperatively form an inside annular groove disposed between the first and second parts, the inside annular groove being cylindrically-shaped and aligned about the longitudinal axis, wherein a gap between the first and second parts is connected to the inside annular groove, wherein the composite seal is configured to be disposed within the inside annular groove to seal the gap, wherein the composite seal is configured to be aligned about the longitudinal axis and is delimited by an inside diameter opposite an outside 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 anti-extrusion ring, wherein the at least one anti-extrusion ring is disposed at the second axial side configured to be placed adjacent to the gap when the composite seal is disposed within the inside annular groove; wherein the elastomeric seal ring starts from the first axial side and extends longitudinally along the inside and outside diameters until it reaches the at least one anti-extrusion ring; wherein the elastomeric seal ring includes an outside annular valley formed along the outside diameter, the outside annular valley separating a first outside sealing annular interface apart from a second outside sealing annular interface, the first outside sealing annular interface disposed adjacent to the first axial side and the second outside sealing annular interface disposed adjacent to the at least one anti-extrusion ring; wherein the elastomeric seal ring includes an inside annular valley formed along the inside diameter, the inside annular valley separating a first inside sealing annular interface apart from a second inside sealing annular interface, the first inside sealing annular interface disposed adjacent to the first axial side and the second inside sealing annular interface disposed adjacent to the at least one anti-extrusion ring; wherein a transition between the first axial side and the first outside sealing annular interface is rounded; wherein the first outside sealing annular interface is an annular edge formed at an intersection of the rounded transition and the outside annular valley; wherein the second outside sealing annular interface is cylindrical and aligns with the outside diameter; wherein the second inside sealing annular interface is cylindrical and aligns with the inside diameter; wherein the first inside sealing annular interface is cylindrical and has a larger diameter in comparison to the inside diameter; wherein the elastomeric seal ring and the at least one anti-extrusion ring are formed of different materials; and wherein the first axial side comprises an annular angle with respect to the longitudinal axis, the annular angle forming the first axial side that is frustoconical in shape that is sloped downwards towards the outside diameter.

20) The composite seal of claim 19, wherein the at least one anti-extrusion ring is formed of a material having a greater rigidity in comparison to the elastomeric seal ring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings illustrate the invention. In such drawings:

[0036] FIG. 1 is a sectional view taken through a simplistic representation of a swivel seal assembly;

[0037] FIG. 2 is an enlarged view of the structure of FIG. 1 taken along lines 2-2;

[0038] FIG. 3 is a front view of a first embodiment of a composite seal of the present invention;

[0039] FIG. 4 is an enlarged sectional view of the structure of FIG. 3 taken along lines 4-4;

[0040] FIG. 5 is a front view of a second embodiment of a composite seal of the present invention;

[0041] FIG. 6 is an enlarged sectional view of the structure of FIG. 5 taken along lines 5-5;

[0042] FIG. 7 is a sectional view of the composite seal of FIG. 4 installed within the structure of FIG. 2; and

[0043] FIG. 8 is a sectional view of the composite seal of FIG. 6 installed within the structure of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] FIG. 1 is a sectional view taken through a simplistic representation of a swivel seal assembly 10, where the seal itself has been removed. Actual swivel seal assemblies may be much more complicated in design, but the embodiment shown herein was simplified to help focus the reader on the important aspects of the present invention. The swivel seal assembly has a first part 11 that is rotatable about a longitudinal axis 12 in comparison to a second part 13. A plurality of ball bearings 14 facilitate the smooth rotation between the first and second parts. The ball bearings may be disposed with one, two, three or any number of races as needed by any specific design. Those skilled in the art of swivel joints and sealing will understand that a multitude of variations are possible for such swivel seal assemblies such that no further discussion is needed herein.

[0045] FIG. 2 is an enlarged view of the structure of FIG. 1 taken along lines 2-2 where one can better see that the first and second parts cooperatively form an inside annular groove 15 (i.e. gland) disposed between the first and second parts. The inside annular groove is cylindrically-shaped and aligned about the longitudinal axis. The inside annular groove has a first axial face 16 formed in the first part 11 that is connected by an optional radius 17 to a perpendicularly disposed inside cylindrical surface 18. A second axial face 19 is formed in the second part 13 that faces the first axial face 16. A gap 20 can be seen between the first and second parts. It is this gap 20 that must be sealed by the seal such that any fluid inside the first and second parts does not escape outwardly.

[0046] FIG. 3 is a front view of a first embodiment of a composite seal 30a of the present invention and FIG. 4 is an enlarged sectional view of the structure of FIG. 3 taken along lines 4-4. FIG. 7 is a sectional view of the composite seal of FIG. 4 installed within the structure of FIG. 2. The composite seal 30a is configured to be disposed within the inside annular groove 15 to seal the gap 20 as will be best shown later in FIG. 7. The composite seal 30a is configured to be aligned about the longitudinal axis 12 and is delimited by an inside diameter 31 opposite an outside diameter 32 connected by a first axial side 33 opposite a second axial side 34.

[0047] This embodiment shows an elastomeric seal ring 35 bonded to at least one anti-extrusion ring 36. The at least one anti-extrusion ring 36 is disposed at the second axial side configured to be placed adjacent to the gap 20 when the composite seal is disposed within the inside annular groove 15 as is best shown in FIG. 7.

[0048] In this embodiment, the at least one anti-extrusion ring 36 comprises an outer anti-extrusion ring 36a and an inner anti-extrusion ring 36b separated by an extension 37 of the elastomeric seal ring. It is noted that the outer anti-extrusion ring 36a is configured to be placed adjacent to the gap 20 when the composite seal is disposed within the inside annular groove.

[0049] The elastomeric seal ring 35 starts from the first axial side 33 and extends longitudinally along the inside and outside diameters until it reaches the at least one anti-extrusion ring 36. The elastomeric seal ring 35 includes an outside annular valley 37 formed along the outside diameter 32. The outside annular valley 37 separates a first outside sealing annular interface 38 apart from a second outside sealing annular interface 39. The first outside sealing annular interface is disposed adjacent to the first axial side. The second outside sealing annular interface is disposed adjacent to the at least one anti-extrusion ring.

[0050] The elastomeric seal ring also includes an inside annular valley 40 formed along the inside diameter. The inside annular valley separates a first inside sealing annular interface 41 apart from a second inside sealing annular interface 42. The first inside sealing annular interface is disposed adjacent to the first axial side. The second inside sealing annular interface is disposed adjacent to the at least one anti-extrusion ring.

[0051] As can be seen in FIG. 4, a transition 43 is between the first axial side and the first outside sealing annular interface. This transition is rounded. The rounded transition 43 and the left part of the outside annular valley 37 meet to form an annular edge 38. Thus, the first outside sealing annular interface 38 is the annular edge formed at the intersection of the rounded transition 43 and the outside annular valley. The second outside sealing annular interface 39 is cylindrical and aligns with the outside diameter 32. The outside diameter 32 of the second outside sealing annular interface 39 is the same as the outside diameter of the outer anti-extrusion ring 36a.

[0052] Likewise, a transition 44 is between the first axial side and the first inside sealing annular interface. This transition is also rounded. The rounded transition 44 and the left part of the inside annular valley 40 meet to form an annular edge 41. Thus, the first inside sealing annular interface 41 is the annular edge formed at the intersection of the rounded transition 44 and the inside annular valley. The second inside sealing annular interface 42 is cylindrical and aligns with the inside diameter 31. The inside diameter 31 of the second inside sealing annular interface 42 is the same as the inside diameter of the inner anti-extrusion ring 36b. Finally, the extension 37 of the elastomeric seal ring at least partially extends beyond the second axial side 34 of the first and second anti-extrusion rings. This extension distance is noted as numeral 45.

[0053] As shown in FIG. 4, both the outer anti-extrusion ring 36a and the inner anti-extrusion ring 36b are bonded to the extension 37 of the elastomeric seal ring. To facilitate a good bonding and to increase reliability the annular corners of the extension 37 each have an annular radius 47a and 47b.

[0054] FIG. 5 is a front view of a second embodiment of a composite seal 30b of the present invention and FIG. 6 is an enlarged sectional view of the structure of FIG. 5 taken along lines 6-6. FIG. 8 is a sectional view of the composite seal of FIG. 6 installed within the structure of FIG. 2. The structure shown in FIGS. 5 and 6 is very similar to FIGS. 3 and 4, but differs in structure as now described.

[0055] First, the at least one anti-extrusion ring 36 is a single structure. Second, the contour of the inner diameter of the elastomeric seal ring IS different. Now, the first inside sealing annular interface 41 is cylindrical. Furthermore, the first inside sealing annular interface 41 has a larger diameter in comparison to the inside diameter 31. It will be understood by those skilled in the art that the first inside sealing annular interface 41 could also have a similar diameter (not shown) in comparison to the inside diameter 31 or even a smaller diameter (not shown) in comparison to the inside diameter 31.

[0056] As can be seen in FIG. 6, the first axial side 33 is angled. Therefore, the first axial side comprises an annular angle 46 with respect to the longitudinal axis 12. The annular angle forms the first axial side that is frustoconical in shape and that is sloped downwards towards the outside diameter 32. It will also be understood by those skilled in the art that the first axial side 33 may also be perpendicular (not shown) to the longitudinal axis.

[0057] In these embodiments, the elastomeric seal ring and the at least one anti-extrusion ring are formed of different materials. Additionally, the at least one anti-extrusion ring may be formed of a material having a greater rigidity in comparison to the elastomeric seal ring. In other words, the elastomeric seal ring may have a lower modulus of elasticity in comparison to the at least one anti-extrusion ring. Alternatively, the elastomeric seal ring and the at least one anti-extrusion ring may be formed of the same materials.

[0058] The inventors have disclosed two different embodiments that are improvements over the prior art. Prior art seal designs will experience hardware swelling due to the high pressures inside the various tubes and parts of the swivel seal assembly. The present invention allows the seal to maintain sufficient sealing force across the range of part rotations. Specifically, the present invention accommodates a larger tolerance range of gland (inside annular groove 15) width compared to prior art designs. In the present invention, the outer diameter and inner diameter of the elastomer allow for compression in the smallest groove width while also allowing sufficient sealing force at the widest groove width. For example, at the widest groove width, the contour of the inner diameter surface allows for the fluid to energize the seal for increased contact force between the seal and the hardware to offset the reduced squeeze force cause by the widest groove. Said differently, the region of minimal thickness located at the rounded valleys where the thickness of the seal body is a minimum, allows compressibility and increases the seal's ability across a range of axial groove widths. Additionally, bonding the elastomer and polymer backup ring(s) allows simpler installation and reduces the likelihood of leakage occurring between the elastomer and the backup ring. Finally, one of the major failure modes of previous failed designs was because of excessive wear. Therefore, the backup ring(s) material of the present invention will be comprised of low friction and robust material to withstand oscillatory vibrations that the swivel seal assembly produces.

[0059] Although 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.