Self-adjusting seal ring

Abstract

A seal assembly (108) for forming a seal between a casing (106) and a rotor (104) includes a seal member (110) arranged to surround a rotor seal surface. The seal member includes a ring seal surface that cooperates with the rotor seal surface to define the seal, a high- pressure land (210) positioned on a high-pressure side of the seal member, and a low-pressure land (212) positioned on a low-pressure side of the seal member. A slider (112) sealingly engages the casing to define an outer surface and an inner surface sized to provide a net biasing force toward the seal member during operation. The slider sealingly engages the high-pressure land to apply the net biasing force to the seal member and to sealingly engage the low-pressure land and the casing to axially position the seal member.

Description

Docket No. 2024PF00209SELF-ADJUSTING SEAL RINGBACKGROUND

[0001] Shaft seals or seal assemblies are often positioned adjacent rotating components to form a seal between the rotating component and the stationary casing in which the rotating component is positioned. These seal assemblies generally include non-contact seals that reduce any leakage past the seals. However, the clearance must be large enough to inhibit contact between the rotating component and the seals during operation. It is desirable to minimize this clearance for efficiency improvements without increasing the potential contact during operation.SUMMARY

[0002] In one aspect, a seal assembly for forming a seal between a casing and a rotor includes a seal member arranged to surround a rotor seal surface. The seal member includes a ring seal surface that cooperates with the rotor seal surface to define the seal, a high-pressure land positioned on a high-pressure side of the seal member, and a low-pressure land positioned on a low-pressure side of the seal member. A slider sealingly engages the casing to define an outer surface and an inner surface sized to provide a net biasing force toward the seal member during operation. The slider sealingly engages the high-pressure land to apply the net biasing force to the seal member and to sealingly engage the low-pressure land and the casing to axially position the seal member.

[0003] In another aspect, a method of axially and radially positioning a seal member to form a seal between a casing and a rotor includes abutting a seal member against a casing wall that partially defines a seal member space formed as part of the casing to fix an axial position of the seal member. The method also includes connecting a slider to the casing, the slider sealablyDocket No. 2024PF00209 engaged with the casing to define an outer surface and an inner surface, and exposing the outer surface to a high-pressure fluid and the inner surface to the high-pressure fluid to generate a net biasing force. The method further includes engaging the slider with the seal member, and transmitting the net biasing force to the seal member to produce a friction force between the casing and the seal member sufficient to support the seal member in a desired radial position.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0005] FIG. 1 is a sectional view of a rotor including a compressor positioned adjacent a casing with a seal assembly therebetween.

[0006] FIG. 2 is an enlarged cross-sectional view of the seal assembly of FIG. 1.

[0007] FIG. 3 is a perspective view of a seal member of the seal assembly of FIG. 1.

[0008] FIG. 4 is an enlarged perspective view of a joint for the seal member of FIG. 3.

[0009] FIG. 5 is an enlarged perspective view of an anti-rotation pin for the seal member of FIG. 3.

[0010] FIG. 6 is a cross-sectional schematic of the seal assembly illustrating the various forces applied during operation.DETAILED DESCRIPTION

[0011] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in this description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out inDocket No. 2024PF00209 various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0012] Various technologies that pertain to systems and methods will now be described with reference to the drawings, where like reference numerals represent like elements throughout. The drawings discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged apparatus. It is to be understood that functionality that is described as being carried out by certain system elements may be performed by multiple elements. Similarly, for instance, an element may be configured to perform functionality that is described as being carried out by multiple elements. The numerous innovative teachings of the present application will be described with reference to exemplary non-limiting embodiments.

[0013] It should be understood that the words or phrases used herein should be construed broadly, unless expressly limited in some examples. For example, the terms “including,” “having,” and “comprising,” as well as derivatives thereof, mean inclusion without limitation. The singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, the term “and / or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. The term “or” is inclusive, meaning and / or, unless the context clearly indicates otherwise. The phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like. Furthermore, while multiple embodiments or constructions may be described herein, any features, methods, steps, components, etc. described with regard to one embodiment are equally applicable to other embodiments absent a specific statement to the contrary.

[0014] Also, terms such as “first”, “second”, “third” and so forth may be used herein to refer to various elements, information, functions, or acts, but should not be considered as limiting in any way. Rather these numeral adjectives are used to distinguish different elements, information, functions or acts from each other. For example, a first element, information,Docket No. 2024PF00209 function, or act could be termed a second element, information, function, or act, and, similarly, a second element, information, function, or act could be termed a first element, information, function, or act, without departing from the scope of the present disclosure.

[0015] In addition, the term “adjacent to” may mean that an element is relatively near to but not in contact with a further element or that the element is in contact with the further portion unless the context clearly indicates otherwise. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Terms “about” or “substantially” or like terms are intended to cover variations in a value that are within normal industry manufacturing tolerances for that dimension. If no industry standard is available, a variation of twenty percent would fall within the meaning of these terms unless otherwise stated.

[0016] FIG. 1 illustrates an arrangement of a rotor 102 disposed within or partially disposed within a casing 106. In the arrangement of FIG. 1, the rotor 102 includes a centrifugal compressor impeller 104 that rotates about a rotational axis 116 adjacent the stationary casing 106 to compress a gas (e.g., air, carbon dioxide, hydrogen, etc.).

[0017] Before proceeding, it is important to note that the terms “high-pressure” and “low- pressure” as used herein simply refer to relative pressures between the two. Thus, “high- pressure” simply means a higher pressure than “low-pressure”. The terms are not intended to convey any particular pressure level or value, nor are they intended to convey an actual value of the difference in pressure between the two terms. Any pressure difference that might induce a flow therebetween would include a “high-pressure” region or fluid and a “low-pressure” region or fluid as these terms are used herein.

[0018] To operate efficiently, a seal is formed between the casing 106 and the rotor 102 to inhibit the leakage of compressed high-pressure gas backward to a region that contains low- pressure gas. With reference to FIG. 1, a seal assembly 108 is connected to the casing 106 such that it is adjacent the rotating compressor impeller 104 and is operable to form the desired seal therebetween.

[0019] The seal assembly 108 includes a seal member 110, a slider 112, and an anti-rotation pin 114 slidingly engaged with the seal member 110 and mounted in the casing 106 to inhibit unwanted rotation of the seal assembly 108 about the rotational axis 116.Docket No. 2024PF00209

[0020] While the construction illustrated herein includes a seal formed at an eye of a centrifugal compressor impeller, the same or similar sealing arrangement can be used on other equipment and at other locations.

[0021] Turning to FIG. 2, the components of the seal assembly 108 and their relationships to the compressor impeller 104 and the casing 106 are better illustrated.

[0022] The casing 106 includes a slot 202 that extends around the circumference of the casing 106 and that is sized to receive the seal assembly 108 while providing some axial (along the rotational axis 116) and radial (normal to the rotational axis 116) clearance for the seal assembly 108. A high-pressure port 230, in the form of one or more apertures extends between the region containing a high-pressure fluid 236 and the slot 202 to provide for the flow of high- pressure fluid 236 into the slot 202. The seal assembly 108 is positioned at least partially within the slot 202 between a region that contains the high-pressure fluid 236 and a region that contains a low-pressure fluid 238 to inhibit the unwanted flow of fluid therebetween.

[0023] As discussed, the seal assembly 108 includes a seal member 110 that is positioned at least partially within the slot 202. The illustrated seal member 110 includes a seal ring 204 that is connected to a backing ring 206 that is positioned radially outward of the seal ring 204. An engagement fit 234 is provided between the seal ring 204 and the backing ring 206 to provide the desired connection therebetween. The engagement fit 234 may be a simple rabbet fit as illustrated in FIG. 6 or could include more complex arrangements as may be required for the particular application. Additionally, it is possible to form the seal member 110 as a single component if desired.

[0024] The seal ring 204 includes a plurality of teeth 208, a high-pressure land 210, a low- pressure land 212, and a seal ring port 226 that extends between the high-pressure land 210 and the low-pressure land 212. The plurality of teeth 208 is arranged to include teeth that are positioned in close proximity to a rotating seal surface of the compressor impeller 104. For example, clearances between the tooth tips and the rotor seal surface may be between 0.2 mm and 1.6 mm with smaller and larger clearances being possible depending on the fluid being compressed and the operating parameters of the compressor impeller 104. In the illustrated construction, each tooth has the same tooth tip diameter and a slight forward lean. However,Docket No. 2024PF00209 any arrangement of teeth can be employed with the present arrangement with the illustrated construction being just one example of an arrangement of the plurality of teeth 208.

[0025] The high-pressure land 210 extends axially beyond a first side 216 of the seal member 110. Similarly, the low-pressure land 212 extends axially beyond a second side 218 of the seal member 110. As will be discussed in greater detail, during operation, the low-pressure land 212 abuts a wall that defines the slot 202 and forms a seal therebetween. The seal ring port 226 extends from the low-pressure land 212 to the high-pressure land 210. A first end of the seal ring port 226 is open to the low-pressure fluid 238 and provides a flow path between the high- pressure land 210 and the low-pressure fluid 238. The seal ring port 226 may include any number of holes or other shaped apertures arranged as illustrated in FIG. 2 that cooperate to define the seal ring port 224.

[0026] The slider 112 is positioned on the high-pressure side of the seal member 110 such that one side of the slider 112 abuts and forms a seal with the high-pressure land 208. The slider 112 includes a first radial seal surface 218, a second radial seal surface 220, and a slider port 228. The first radial seal surface 220 and the second radial seal surface 222 slidingly engage the casing 106. The diameter of the first radial seal surface 220 and the second radial seal surface 222 are selected to achieve the desired surface area or size for various surfaces of the slider 112 as will be discussed in greater detail with regard to FIG. 6. In some constructions, each of the first radial seal surface 220 and the second radial seal surface 222 includes an Ciring 224 that operates to enhance the seal between the first radial seal surface 220, the second radial seal surface 222, and the casing 106.

[0027] The slider port 228 extends from the high-pressure land 210 to a space between the first radial seal surface 220 and the second radial seal surface 222 and cooperates with the seal ring port 226 to provide fluid communication between the region that contains the low-pressure fluid 238 and the space between the first radial seal surface 220 and the second radial seal surface 222. The seal ring port 226 may include one or more holes or other shaped apertures that cooperate to define the seal ring port 226.

[0028] The slider 112 engages the casing 106 and contacts the high-pressure land 210 and the seal member 110, and specifically the low-pressure land 212 contacts the casing 106 to sealably enclose the slot 202. The high-pressure port 230 extends through the casing 106 from theDocket No. 2024PF00209 region that contains the high-pressure fluid 236 to the slot 202 such that, during operation, the slot 202 is filled with high-pressure fluid 236. The space between the first radial seal surface 220 and the second radial seal surface 222 is in fluid communication with the low-pressure fluid 238 such that any high-pressure fluid 236 that leaks past the first radial seal surface 220 or the second radial seal surface 222 flow into the region that contains the low-pressure fluid 238.

[0029] In some constructions, a biasing member 232, and preferably an elastic force biasing member 232 is positioned within the slot 202 and engages the casing 106 and the seal member 110 to axially bias the seal member 110 to engage the low-pressure land 212 and the casing 106. The force generated by the biasing member 232 is sufficient to maintain the position of the seal member 110 during periods when there is no pressure differential (i.e., when the compressor impeller 104 is not operating) such that the seal member 110 maintains its operating position during these idle periods.

[0030] FIG. 3 illustrates one possible arrangement of the seal assembly 108 in which the seal member 110 includes an upper half 302 and a lower half 304 that are attached to one another to define the complete seal member 110. In the arrangement of FIG. 3, assembly hardware 306 in the form of nuts, bolts, studs, and the like are used to attach the upper half 302 to the lower half 304 at a mid or horizontal joint. Other constructions may position the joint differently or may include more than two portions. Still other constructions may use a single complete ring if it can be positioned in its operating position as a complete ring.

[0031] A single anti-rotation pin 114 is positioned at top dead center to inhibit rotation of the seal member 110 around the rotational axis 116 while still allowing vertical axial movement. It is important that only one pin (or one narrow region of the 108) be used to inhibit rotation. If additional pins are employed, radial movement in directions other than vertical may be undesirable restrained.

[0032] FIG. 4 better illustrates an arrangement of the seal member 110 in which the upper half 302 is attached to the lower half 304 using assembly hardware 306 in the form of bolts. The upper half 302 includes a flange having an aperture that passes through the flange and that is sized to allow passage of the shaft of the bolt but not the head of the bolt. The lower half 304 includes a flange that includes a threaded aperture sized to threadably receive the bolt toDocket No. 2024PF00209 complete the attachment. To maintain alignment of the lower half 304 and the upper half 302, a tight fitting hollow locating bushing 402 is positioned at the interface joint between the upper half 302 and the lower half 304and received into close fitting bores concentric with the assembly hardware 306. Of course, other arrangement and other assembly hardware 306 could be employed without affecting the operation of the seal assembly 108.

[0033] FIG. 5 better illustrates one arrangement of the anti-rotation pin 114. In the illustrated construction, the anti-rotation pin 114 is fixedly attached to the casing 106 at or near top dead center. The upper half 302 of the seal member 110, and in particular the backing ring 206 includes a pocket 502 sized and oriented to receive the anti-rotation pin 114. With the antirotation pin 114 disposed within the pocket 502, the seal member 110 retains substantially free to move in the vertical direction 504 as well as the axial direction 506. However, the seal member 110 is inhibited from rotating about the rotational axis 116 as the pocket 502 cannot move circumferentially with respect to the anti-rotation pin 114. In other arrangements, the anti-rotation pin 114 is located at bottom dead center or some other location around the circumference of the seal member 110. In still other arrangements, the anti-rotation pin 114 is fixedly attached to the seal member 110 and the pocket 502 is formed as part of the casing 106. As one of ordinary skill in the art will understand, the function of the anti-rotation pin 114 can be performed by many different arrangements and the use of these different arrangements will not affect the operation of the seal assembly 108.

[0034] FIG. 6 schematically illustrates the arrangement of FIG. 2 illustrating the axial forces generated during operation. One of ordinary skill in the art will understand that each of the forces illustrated is generated by the product of the pressure of the fluid in that region and the normal or projected surface area normal to the axial direction. In this application, the fluid operates as either a high-pressure fluid 236 or a low-pressure fluid 238. While the fluid does transition through these two pressures, the surface area exposed to these transitions in the axial direction is negligible and is ignored in this description.

[0035] During operation, it is desirable to have a net biasing force 622 acting to push the low- pressure land 212 into contact with the casing 106 with sufficient force to produce a friction force 620 in opposition to gravity 618 that exceeds the weight of the 110 (the desired force), thereby holding the seal member 110 in an operating position. However, it is also preferred that this net biasing force 622 be close to the desired force (e.g., within twenty percent) withoutDocket No. 2024PF00209 being excessive to allow for movement of the seal member 110 should it contact the compressor impeller 104 during operation.

[0036] As illustrated in FIG. 6, there are five distinct surfaces that are exposed to high- pressure fluid 236 that results in a high-pressure (HP) force. The high-pressure forces are labelled as HP1 602, HP2 604, HP3 606, HP4 608, and HP5 610. HP1 602 results from the application of pressure from the high-pressure fluid 236 on the annular surface area defined by the plurality of teeth 208. This produces a force that biases the seal member 110 to the right (toward the low-pressure fluid 238) in FIG. 6. The level of the force HP1 602 can be adjusted through the selection of the height of the teeth as well as the diameter of the teeth.

[0037] The second high-pressure force, HP2 604 is a result of the application of pressure from the high-pressure fluid 236 on the projected or normal surface area of the slider 112 opposite the high-pressure land 210. This produces a force that biases the slider 112 and the seal member 110 to the right (toward the low-pressure fluid 238) in FIG. 6. The third high-pressure force, HP3 606 is generated via contact with a second surface of the slider with high-pressure fluid 236 that is admitted into the slot 202. HP3 606 biases the slider 112 to the left and thus cancels or counteracts a portion of the HP2 604 force. The size and position of the high- pressure land 210 as well as the diameters of the first radial seal surface 220 and the second radial seal surface 222 are selected to manipulate or adjust the value of HP2 604 and HP3 606.

[0038] The fourth high-pressure force, HP4 608 is produced through the application of pressure from the high-pressure fluid 236 within the slot 202 onto the surface of the seal member 110 that extends from the high-pressure land 210 to the outermost diameter 214. The level of this force can be adjusted by adjusting the position of the high-pressure land 210 as well as by selecting the outermost diameter 214. The force HP4 608 biases the seal member 110 to the right. However, the force HP5 610 is generated in opposition to the force HP4 608 by applying pressure from the high-pressure fluid 236 trapped in the slot 202 to the surface between the low-pressure land 212 and the outermost diameter 214. The force HP5 610 tends to bias the seal member 110 to the left.

[0039] In addition to the five high-pressure forces, there are two low-pressure forces. LP1 612acts on the annular surface defined by the difference in diameter between the first radial seal surface 220 and the second radial seal surface 222. This area is exposed to the low-Docket No. 2024PF00209 pressure fluid 238 such that the force LP1 612 is the product of the surface area of this annular surface and the pressure of the low-pressure fluid 238 and tends to bias the slider 112 and the seal member 110 to the right.

[0040] The second low-pressure force, LP2 614 is a result of the application of pressure from the low-pressure fluid 238 on the back side of the plurality of teeth and tends to bias the seal member 110 to the left.

[0041] The only remaining significant axial force is any biasing force 616 produced by the biasing member 232. This force biases the seal member 110 to the right.

[0042] Thus, the net biasing force 622 can be calculated as follows: net biasing force 622 = HP1 602 + HP2 604 - HP3 606 + HP4 608 - HP5 610 + LP1 612 - LP2 614 + biasing force 616. The net biasing force 622 acts as the normal force to determine the frictional force between the low-pressure land 212 and the casing 106. It is desired that this net biasing force 622 be sufficient to produce a friction force 620 that is between 100 and 120 percent of the weight of the seal assembly 108.

[0043] In operation, the compressor impeller 104 is rotated about the rotational axis 116 to draw in a low-pressure fluid 238 and to discharge a high-pressure fluid 236. A seal assembly 108 is positioned between the low-pressure fluid 238 and the high-pressure fluid 236 to reduce any leakage therebetween. To improve the efficiency of the seal, it is desirable to provide the minimum possible clearance between the rotor 102, or compressor impeller 104 and the seal assembly 108. However, during operation, upsets, vibrations, or other changes can result in the compressor impeller 104 moving with respect to the seal assembly 108 such that contact between the compressor impeller 104 and the seal assembly 108 may occur. The arrangement described herein holds the radial position of the seal assembly 108 using only the friction force 620 with the various components selected to provide a normal force that results in a friction force 620 that is close to the weight (100-120 percent) of the seal assembly 108. With this force maintained at these levels, contact between the compressor impeller 104 and the seal assembly 108 results in movement of the seal assembly 108 away from the contact. Thus, the seal assembly 108 tends to “re-center” itself during operation, thereby adjusting to all major concentricity variation between the rotor 102 and the stationary casing 106, allowing for much smaller clearances at the seal teeth 208.Docket No. 2024PF00209

[0044] Additionally, because the seal assembly 108 simply moves in response to contact, softer materials can be selected for the plurality of teeth 208. For example, some constructions could use a rub tolerant PEEK material or a soft metal such as Ni-Resist to form the plurality of teeth 208 which in turn reduces any heating or damage that might occur during contact between the compressor impeller 104 and the seal assembly 108.

[0045] Although an exemplary embodiment of the present disclosure has been described in detail, those skilled in the art will understand that various changes, substitutions, variations, and improvements disclosed herein may be made without departing from the spirit and scope of the disclosure in its broadest form.

[0046] None of the description in the present application should be read as implying that any particular element, step, act, or function is an essential element, which must be included in the claim scope: the scope of patented subject matter is defined only by the allowed claims. Moreover, none of these claims are intended to invoke a means plus function claim construction unless the exact words "means for" are followed by a participle.

Claims

Docket No. 2024PF00209CLAIMSWhat is claimed is:

1. A seal assembly for forming a seal between a casing and a rotor, the seal assembly comprising: a seal member arranged to surround a rotor seal surface, the seal member including a ring seal surface that cooperates with the rotor seal surface to define the seal, a high-pressure land positioned on a high-pressure side of the seal member, and a low-pressure land positioned on a low-pressure side of the seal member; and a slider sealingly engaged with the casing to define an outer surface and an inner surface sized to provide a net biasing force toward the seal member during operation, the slider sealingly engaged with the high-pressure land to apply the net biasing force to the seal member and to sealingly engage the low-pressure land and the casing to axially position the seal member.

2. The seal assembly of claim 1, wherein the seal member includes a seal ring that includes a plurality of teeth that defines the ring seal surface, and a backing ring that engages the seal ring.

3. The seal assembly of claim 1, wherein the seal member includes a first side that extends from the high-pressure land to an outermost diameter of the seal member and a second side that extends from the low-pressure land to the outermost diameter, the second side being larger than the first side.

4. The seal assembly of claim 3, wherein the slider includes a first radial seal surface having a first diameter and a second radial seal surface having a second diameter, the first diameter and the second diameter sized to define a first surface area for the outer surface and a second surface area for the inner surface that is different from the first surface area.

5. The seal assembly of claim 4, wherein each of the first side, the second side, the first surface area, and the second surface area are exposed to a high-pressure fluid and the sizes of each of the first side, the second side, the first surface area, and the second surface area are selected to produce the net biasing force.Docket No. 2024PF002096. The seal assembly of claim 5, wherein the net biasing force is axial and produces a friction force between the seal member and the casing that is radial and wherein the friction force is between 100 and 120 percent of the weight of the seal member.

7. The seal assembly of claim 4, further comprising a seal ring port formed as part of the seal ring and having a first end at the high-pressure land and a second end in fluid communication with the low-pressure fluid, and a slider port formed as part of the slider and having a first end in fluid communication with the first end of the seal ring port and a second end positioned between the first radial seal surface and the second radial seal surface.

8. The seal assembly of claim 1, further comprising a biasing member positioned between the seal member and the casing and operable to provide an axial biasing force to the seal member.

9. The seal assembly of claim 1, further comprising a single anti-rotation pin coupled to the casing and the seal member to inhibit rotation of the seal member about a rotational axis.

10. A method of axially and radially positioning a seal member to form a seal between a casing and a rotor, the method comprising: abutting a seal member against a casing wall that partially defines a seal member space formed as part of the casing to fix an axial position of the seal member; connecting a slider to the casing, the slider sealably engaged with the casing to define an outer surface and an inner surface; exposing the outer surface to a high-pressure fluid and the inner surface to the high- pressure fluid to generate a net biasing force; engaging the slider with the seal member; and transmitting the net biasing force to the seal member to produce a friction force between the casing and the seal member sufficient to support the seal member in a desired radial position.

11. The method of claim 10, wherein the seal member includes a seal ring that includes a plurality of teeth that defines the ring seal surface, and a backing ring that engages the seal ring.Docket No. 2024PF0020912. The method of claim 10, further comprising positioning a high-pressure land on the seal member to define a first side that extends from the high-pressure land to an outermost diameter of the seal member, and positioning a low-pressure land on the seal member to define a second side that extends from the low-pressure land to the outermost diameter, the second side being larger than the first side.

13. The method of claim 12, further comprising positioning a first radial seal surface of the slider having a first diameter and a second radial seal surface of the slider having a second diameter into sealing engagement with the casing, the first diameter and the second diameter sized to define a first surface area for the outer surface and a second surface area for the inner surface that is different from the first surface area.

14. The method of claim 13, wherein the first radial seal surface includes a first Ciring and the second radial seal surface includes a second O-ring.

15. The method of claim 13, further comprising exposing each of the first side, the second side, the first surface area, and the second surface area to a high-pressure fluid, and selecting the sizes of each of the first side, the second side, the first surface area, and the second surface area to produce the net biasing force.

16. The method of claim 15, further comprising producing a friction force between the seal member and the casing that is radial in response to the net biasing force, and wherein the friction force is between 100 and 120 percent of the weight of the seal member.

17. The method of claim 13, further comprising forming a seal ring port as part of the seal ring, the seal ring port having a first end at the high-pressure land and a second end in fluid communication with the low-pressure fluid, and forming a slider port as part of the slider, the slider port having a first end in fluid communication with the first end of the seal ring port and a second end positioned between the first radial seal surface and the second radial seal surface.

18. The method of claim 10, further comprising biasing the seal member into engagement with the casing.

19. The method of claim 10, further comprising coupling a single anti-rotation pin to the casing and the seal member to inhibit rotation of the seal member about a rotational axis.Docket No. 2024PF0020920. The method of claim 10, contacting the rotor and the seal member during operation to position the seal member in a desired radial position.

Images