Rotating union with pressure sleeve

Abstract

The rotary union includes a non-rotating component defining a bore and a non-rotating seal carrier slidably disposed within the bore. A pressure sleeve is slidably disposed within the bore between the non-rotating component and the non-rotating seal carrier. A non-rotating seal member is disposed on the non-rotating seal carrier, the rotating seal carrier having the rotating seal member disposed thereon. The rotating seal member is disposed in opposing relationship to the non-rotating seal member such that a sliding mechanical face seal is formed between the non-rotating seal member and the rotating seal member when the non-rotating seal carrier slides toward the rotating seal carrier in the presence of fluid pressure.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This patent application claims the benefit of U.S. Provisional Patent Application No. 63 / 303,434, filed January 26, 2022, and incorporated by reference.

[0002] FIELD OF THEINVENTION FIELD OF THE DISCLOSURE This disclosure relates to rotating unions, and more particularly, to rotating unions having multiple flow passages. [Background technology]

[0003] Rotary unions having multiple passages are known to provide sealed or sealable fluid passages between rotating and non-rotating machine components. Due to their typical complexity, multi-passage rotary unions are often prone to leaking due to wear or, in some cases, faulty or incorrect device assembly. Furthermore, the complex assembly or disassembly processes associated with repairing such unions result in time-consuming and costly operations.

[0004] A typical rotating union includes a non-rotating seal carrier having a seal between the media channel of the union and a housing or bore, the non-rotating seal carrier being slidably and sealably disposed within the housing or bore. An example of a rotating union can be found in U.S. Pat. No. 7,815,224 to Ford et al. (hereinafter "Ford"). As described in Ford, rotating unions typically have a balance ratio, which is defined algebraically as the ratio of the average loads exerted by the sealed internal pressure on the seal faces between the rotating and non-rotating seals, B=P f / P, where P f is the sealing pressure on the sealing faces of the primary seal assembly, i.e., the sealing pressure acting along the interface between the rotating and non-rotating seal members, and P is the sealing pressure present in the media channel of the union.

[0005] In the Ford device, the seal used to slidably seal the non-rotating seal carrier as it moves between seal engaged and seal disengaged positions is shown as a U-cup seal, which proves effective in providing an effective seal when pressure is applied to the concave surface of the seal. However, such a seal is not effective when pressure is applied to both sides of the seal, i.e., when the rotating union is operating under internal as well as external pressurization. Summary of the Invention

[0006] The present disclosure relates to a rotary union used as a stand-alone device or as part of a multi-passage rotary union, such as the union described in co-pending U.S. Patent Application No. 16 / 152,749, filed October 5, 2019, which is incorporated herein by reference in its entirety. In the rotary union according to the present disclosure, the housing forms a generally straight bore that allows the union to be a modular assembly. This is an improvement over known rotary union configurations. The rotary union components include one or more sliding seal carriers that are configured not to rotate relative to the housing and include an intermediate collar disposed between at least one non-rotating seal carrier and the housing. A pair of seals are disposed on either side of the intermediate collar. The collars and seals are involved in defining opening and closing hydraulic or opening and closing pneumatic surfaces that correspondingly open and close mechanical face seals formed between a non-rotating seal member or seal ring disposed on the non-rotating seal carrier and a corresponding rotating seal carrier or seal ring disposed on the rotating seal carrier. The intermediate ring moves axially between the pair of seals to provide at least an additional closing force that tends to push the seal rings together under certain circumstances. A rotating union according to the present disclosure is advantageously configured or arranged to operate under an internal or external application of fluid pressure.

[0007] In one aspect, the disclosure describes a rotary union including a non-rotating component defining a bore and a non-rotating seal carrier slidably disposed within the bore. A pressure sleeve is slidably disposed within the bore between the non-rotating component and the non-rotating seal carrier. A non-rotating seal member is disposed on the non-rotating seal carrier, which has a rotating seal member disposed on the rotating seal carrier. The rotating seal member is disposed in opposing relationship to the non-rotating seal member such that a sliding mechanical face seal is formed between the non-rotating seal member and the rotating seal member when the non-rotating seal carrier slides toward the rotating seal carrier in the presence of fluid pressure.

[0008] In another aspect, the disclosure describes a multimedia rotary union including a housing having a cylindrical bore extending through a body, the cylindrical bore being substantially linear, and a shaft rotatably supported within the cylindrical bore of the housing. A carriage defines the bore and a radial flow passage and is disposed in sealed relationship within the cylindrical bore of the housing. A non-rotating seal carrier is slidably disposed within the bore. A pressure sleeve is slidably disposed within the bore between the carriage and the non-rotating seal carrier. A non-rotating seal member is disposed on the non-rotating seal carrier, and a rotating seal carrier having a rotating seal member is disposed on the non-rotating seal carrier to define an additional radial flow passage. The non-rotating seal carrier is engaged to rotate with the shaft. The rotating seal member is disposed in opposing relationship to the non-rotating seal member such that a sliding mechanical face seal is formed between the non-rotating seal member and the rotating seal member when the non-rotating seal carrier slides toward the rotating seal carrier in the presence of fluid pressure, providing a sealed fluid passageway extending between the radial flow path and the additional radial flow path. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a front schematic view of a multi-channel rotary union in accordance with the present disclosure; [Diagram 2]FIG. 2 is a rear schematic view of a multi-channel rotary union in accordance with the present disclosure; [Diagram 3] FIG. 3 is a cross-sectional view of the multi-channel rotary union shown in FIGS. 1 and 2. [Figure 4] 4A and 4B are enlarged detailed views of the cross sections of FIG. 3, respectively. [Diagram 5] 4A and 4B are enlarged detailed views of the cross sections of FIG. 3, respectively. Detailed Description of the Drawings

[0010] In an exemplary embodiment described herein, the multi-channel rotary union includes a housing having a cylindrical bore extending through the body, the cylindrical bore being substantially linear. The rotary union further includes a shaft rotatably mounted within the cylindrical bore, the shaft having a longitudinal axis extending along a centerline of the bore. A plurality of annular plates are mounted on the shaft, the plurality of annular plates being spaced apart from one another at regular intervals along the longitudinal axis, each of the plurality of annular plates extending a radial distance within the bore from the shaft and having a radial flow passage extending therethrough, the plurality of annular plates being rotatably and sealably engaged for rotation with the shaft. A plurality of spools are disposed alternately between the plurality of annular plates. The plurality of spools sealably engage the cylindrical bore and are axially constrained by the housing against rotation with the shaft. Each of the plurality of spools is disposed between two adjacent annular plates from the plurality of annular plates and includes a corresponding sliding seal carrier that moves axially in one direction or the other along the centerline of the bore to engage and disengage a corresponding mechanical seal surface between a seal ring carried by the sliding seal carrier and one side of the adjacent annular plate facing the seal carrier.

[0011] Schematic views of the rotary union 100 from the front and rear are shown in Figures 1 and 2, respectively. An enlarged cross-sectional view of a portion of the interior of the union 100 is shown in Figure 3. The rotary union 100 in the illustrated embodiment includes eight fluid passages, however, it should be understood that the modular construction is suitable for rotary unions having fewer or more than eight fluid passages, such as unions having a single fluid passage. It should be understood that in the multi-passage union 100 shown here, each fluid passage extending through the union (if multiple fluid passages are present) has a corresponding mechanical face seal arrangement, as described in the following paragraphs.

[0012] As shown in the exemplary embodiment depicted in the figures, the rotary union 100 includes a housing 102 that encloses a rotor shaft 104, which can be seen partially in cross section in the cross section of FIG. 3 so as not to obscure the remaining structure depicted. Generally speaking, the rotor shaft 104 and any associated structure coupled to the shaft are configured to rotate relative to the housing 102 and structures associated with or generally coupled to the housing. The fluid passages extending through the rotor shaft 104 and the housing 102 are connected to respective rotating and non-rotating machine components such that the union 100 can provide a sealed or sealable fluid passage for fluid therethrough. In a known manner, a seal arrangement operating within the union 100 provides a sealable connection to some of the fluid passages whether rotating or not. In the illustrated embodiment, the rotor shaft 104 is connected at one end to a flange 108 ( FIG. 1 ), which provides a fluid interface to the various fluid passages extending through the rotary union 100. The housing 102 also provides fluid interfaces, i.e., fluid ports 120, 152, or 160. The fluid interfaces on the shaft are connectable to the fluid interfaces on the housing to communicate a fluid connection therebetween during operation. The formation of seals between the rotating and non-rotating portions of the fluid passages within the union is configured to occur automatically when a fluid under pressure is introduced into either the rotating or non-rotating portions of the flow passages. These fluid passages are fluidically isolated from each other and from the environment through the use of sliding mechanical face seals formed along the sliding interfaces of components attached between the rotatable rotor shaft 104 and the housing 102 that extend through the union, as described in more detail below.

[0013] In the illustrated embodiment, the flange 108 includes one or more rotational fluid ports configured about the axis of rotation 110 on the rear face 112 of the flange 108. The configuration may be symmetrical or asymmetrical. The shape of the flange 108 is shown as a flat plate having a circular shape configured for connection to a rotating machine component (not shown). The flange 108 provides flexibility or opportunity to include various other flow passages and fluid ports disposed in locations that facilitate connection of the union 100 to various machines. For example, each of the rotational fluid ports on the flange 108 may be internally connected to a housing having an axially extending port 116 disposed radially outwardly relative to the rotational fluid ports, and / or to a radially facing fluid port 120 disposed along the outer periphery of the flange 108. These and other configurations allow for flexible and convenient connection of fluid passages of rotating machine components to the union 100.

[0014] For example, a seal groove 122 for receiving a radial seal (not shown) or any other type of seal or gasket may be incorporated in a flat surface of flange 108 at the rear of union 100, as well as mounting holes 124 for mounting the flange, and therefore union 100, to a rotating machine component (not shown). Housing 102 is made up of segments 142 stacked into a hollow cylinder. Rotating ports in flange 108 are fluidly connectable to corresponding non-rotating fluid ports 152 formed in housing 102.

[0015] 3, it can be seen that the shaft 104 extends through the housing 102 (a portion of which is shown). The housing 102 may include a generally hollow cylindrical outer shell, or housing 202, that defines a bore 204 within which components are mounted. As shown, contained within the shell 202 is a carriage 206 that is non-rotatably engaged with the shell 202. The carriage 206 includes a circumferentially extending channel 208 and one or more radially extending channels 210. The one or more radially extending channels 210 fluidly connect an annularly extending media channel 212 within the carriage 206 with the interior of the bore 204, thereby allowing fluid to be transferred through, for example, ports 152, 120, or 160 within the housing 102. Seals, such as radial seals (not shown), may be disposed within the circumferentially extending channels 208 to seal fluid present in the media channel 212 from fluid that may be present in adjacent channels in the same or adjacent carriages 206. When the union 100 is fully assembled, more than one fluid path may be created through the union 100 by assembling the carriages 206 in a stacked order.

[0016] Each carriage includes one or more seal channels 214 along an inner portion thereof. As shown, a first seal channel 214 (not numbered) accommodates a seal 216 therein. The second seal channel 214 is configured to accommodate a second seal 216 therein for a second rotary union arrangement (not shown) housed within the same carriage 206. The seal channels 214 are disposed on either side of the media channel 212. Each seal channel 214 includes a radial seal 216 axially flanked by annular seal retainers 218. The seal retainers 218 ensure proper compression of the seals 216, which in the illustrated embodiment are O-rings, to reduce deformation of the seals 216 under motion or pressure conditions during operation of the union 100.

[0017] The outer radial seal 216 is disposed to seal against the pressure sleeve 220 and, in the illustrated embodiment, has a generally hollow cylindrical shape including a cylindrical portion 222 and a flange portion or shoulder 224. The shoulder 224 acts in one direction as a mechanical stop against an inner stop surface 226 formed on a portion of the carriage 206. The cylindrical portion has a thickness t (see FIG. 4) in a radial direction perpendicular to the centerline 110. The pressure sleeve 220 is slidably disposed within the bore formed by the cartridge 206 and is sealably disposed when sliding through contact between the outer periphery and cylindrical surface of the cylindrical portion 222 and the outer radial seal 216.

[0018] The non-rotating seal carrier 228 is slidably and sealably disposed within the inner circumference and cylindrical surface of the cylindrical portion 222. The non-rotating seal carrier 228 includes a circumferentially extending channel that houses an inner non-rotating radial seal 230 that is flanged by two annular seal retainers 232. Similar to the outer non-rotating radial seal 216, the inner non-rotating radial seal 230 is prevented from excessive deformation due to sliding movement or application of pressure by the retainers 232. The non-rotating seal carrier 228 includes an internal bore 234 that forms a portion of the media channel 212 and is fluidly open to the media channel 212. The non-rotating seal carrier 228 further includes one or more radially extending keys 236 disposed within a pocket 238 formed in the carriage 206 to prevent the non-rotating seal carrier 228 from rotating relative to the carriage 206, and thus relative to the outer shell 202 and the housing 102 as a whole.

[0019] The non-rotating seal carrier 228 further supports a non-rotating seal member 240, which includes a seal body portion 242 having a generally rectangular cross-section and defines a ridge 244 extending circumferentially around an outer surface of the seal member 240. In this regard, the outer surface of the seal member is the surface of the body portion that faces outwardly in the direction of axial movement of the carrier 228 within the carriage 206 and away from the seal carrier 228. In the illustrated embodiment, the non-rotating seal member 240 is configured to abut a rotating seal member 246 disposed on the rotating seal carrier 248 when the non-rotating seal carrier 228 is in the extended position (towards the right in the orientation shown in FIG. 3).

[0020] The abutting contact between the rotating seal member 246 and the non-rotating seal member 240 forms a sliding mechanical face seal between the ridges 244 and the exposed surface of the rotating seal member 246 to seal against fluids present within and / or outside of the mechanical face seal. Similar to the carriage 206, the non-rotating seal carrier 248 may be configured to include a radially extending flow passage 250 and support two or more rotating seal members 246 on opposing faces, as shown, within two axially opposed seal ring channels 252. The rotating seal carrier 248 is engaged on the shaft 104 and configured to rotate therewith. A fluid passageway (not shown) formed in the shaft is fluidly connected to the flow passageway 250 to pass fluid between a sealed chamber formed within the housing 202 and the engaged mechanical face seal formed between the non-rotating seal member 240 and the rotating seal member 246 in the presence of a pressurized medium during operation.

[0021] Schematic views of the rotating seal member and the non-rotating seal member in two operating states and positions are shown in FIGS. 4 and 5. In these figures, the same or similar structures and features as the corresponding structures and features described above are indicated by the same reference numerals for simplicity and explanation. In the operating state shown in FIG. 4, the pressurized fluid or medium is provided outside the mechanical face seal, that is, inside the housing 202 (FIG. 2), but outside the medium channel 212. In this operating state, an opening and closing hydraulic surface or an opening and closing pneumatic surface (depending on the nature of the fluid, which is a liquid or a gas) acts on the surfaces of the non-rotating seal carrier 228, the carriage 206, and the pressure sleeve 220. More specifically, the pressure distribution 300 acts in the opening direction (to the left as shown in FIG. 4) along an annular surface that exists along the interface 302 of sliding contact between the non-rotating seal member 244 and the rotating seal member 246 (shown by the dashed outlines in FIGS. 3 and 4) for explanation. As shown in FIG. 4, the pressure at the radially outer edge of the distribution 300 is maximum and equal to the pressure P of the fluid applied from the outside. Then, the pressure decreases along the interface 302 from the maximum value P to the internal pressure value p, and the internal pressure value p can be the atmospheric pressure or another pressure lower than P (p < P). The shape of the distribution 300 is shown as linear applied to a liquid, but for other types of fluids such as gases or liquids having high viscosity, it can take other shapes such as logarithmic or polynomial.

[0022] The net opening hydraulic surface area 304 can be defined as the total surface area of the pressure imbalance surfaces of all existing structures to which a net pressure is applied that acts to push the non-rotating seal carrier 228 in the opening direction (towards the left in FIG. 4). Similarly, the net closing hydraulic surface area 306 can be defined as the total surface area of the pressure imbalance surfaces of all existing structures to which a net pressure is applied that acts to push the non-rotating seal carrier 228 in the closing direction (towards the right in FIG. 4).

[0023] 4, net closed area 306 is smaller than net open area 304, but has a greater pressure acting on it (i.e., there is a pressure distribution profile with pressure P acting across the entire closed area). This means that when there is an external pressure P greater than internal pressure p, in the presence of external pressure P, the net closing force on non-rotating seal carrier 228 and pressure sleeve 220 will tend to push them in the closing direction (to the left in the orientation of FIG. 4) such that non-rotating seal member 244 and rotating seal member 246 engage to form mechanical face seal 302.

[0024] As shown, the net closed area 306 is approximately 75% of the net open area 304. This biases the combination of the non-rotating seal carrier 228 and pressure sleeve 220 in a closing direction until approximately 25% of the open area 304 remains and the seal members abut, forming the mechanical face seal 302. In the configuration of the structure shown in FIG. 4, it can be seen that the net closed area 306 is formed primarily by the pressure sleeve 220, and more specifically, by the thickness t of the cylindrical portion 222 and the gap thickness between the outer surface of the cylindrical portion 222 and the inner bore surface of the carriage 206. The radial seals 216 and 230 can be externally pressurized on either side of the cylindrical portion 222 of the pressure sleeve 220 and deform against the inner (left) retainer 218 as shown. Advantageously, the movement of the non-rotating seal carrier 228 in the closing direction (right) as the mechanical face seal 302 is formed is divided between the non-rotating seal carrier 228 and the pressure sleeve 220, thereby reducing the overall sliding motion experienced by the radial seals 216 and 230, reducing wear and also reducing the tendency of the seal rings to rotate.

[0025] 5, pressurized fluid or medium is provided within the interior of the mechanical face seal, i.e., within the media channel 212 (FIG. 2) within the carriage 206 and the non-rotating seal carrier 228. In this operating condition, similar to the external pressure condition (FIG. 4), opening and closing hydraulic or pneumatic surfaces (depending on the nature of the fluid, liquid or gas) act on the surfaces of the non-rotating seal carrier 228, carriage 206, and pressure sleeve 220.

[0026] More specifically, the pressure distribution 300' acts in the opening direction (to the left as shown in FIG. 4) along the interface of the mechanical face seal 302. As shown in FIG. 5, the pressure at the radially inner edge of the distribution 300' is maximum and equal to the pressure P of the fluid applied from the outside. Then, the pressure decreases along the interface 302 from the maximum value P to the external pressure value p, and the external pressure value p can be the atmospheric pressure or another pressure lower than P (p < P). The shape of the distribution 300' is shown here as linear, which also applies to liquids, but for other types of fluids such as gases or even liquids with higher viscosities, it can take other shapes, for example, logarithmic or polynomial.

[0027] The net opening pressure face region 304' can be defined as the total area of the pressure imbalance faces of all existing structures to which a net pressure is applied that acts to push the non-rotating seal carrier 228 in the opening direction (towards the left in FIG. 5). Similarly, the net closing pressure face region 306' can be defined as the total area of the pressure imbalance faces of all existing structures to which a net pressure is applied that acts to push the non-rotating seal carrier 228 in the closing direction (towards the left in FIG. 4).

[0028] As can be seen in FIG. 5, the net opening region 304' is larger than the net closing region 306'. Similar to the state shown in FIG. 4, the total pressure acting on the closing region 306' is constant over its area, and thus the pressure distribution is constant over the net closing region 306' having a magnitude P. The pressure acting on the net opening region follows, for example, a distribution 300' having a triangular or another shaped profile. For example, if the distribution is triangular, the net force applied by the distribution is lower than or about 1 / 2 of the force for a constant application of pressure P. Even if the net closing region 306' is small, for example, 75% or another value of the net opening region 304', the net closing force acts on both the non-rotating seal carrier 228 and also on the pressure sleeve 220, pushing and extending the shoulder of the non-rotating seal carrier 228 and is overall larger than the net opening force.

[0029] In one example, the closed area is 75% of the open area, but assuming a pressure distribution (e.g., triangular) is applied to the open area, the open area would be 50% of its total if the pressure distribution was uniform across the open area, which means that overall there is a 25% force predominance in the closing direction. Thus, the net closing force acting on the non-rotating seal carrier 228 urges the non-rotating seal carrier 228 and pressure sleeve 220 in the closing direction, resulting in the non-rotating seal member 244 and rotating seal member 246 engaging to form the mechanical face seal 302.

[0030] 5, it can be seen that the net closed area 306' is formed primarily by the pressure sleeve 220, and more specifically, the thickness t of the cylindrical portion 222 exposed to pressure between the seals 216 and 230, and the gap thickness between the inner surface of the cylindrical portion 222 and the outer surface of the non-rotating seal carrier 228 around the seal 230. In this condition, the flange portion or shoulder 224 of the pressure sleeve 220 also pushes the non-rotating seal carrier 228 in the closing direction (to the right in the figure). The radial seals 216 and 230 are pressurized from the inside on both sides of the cylindrical portion 222 of the pressure sleeve 220 and may deform against the outer (right) retainer 218 as shown. Advantageously, the movement of the non-rotating seal carrier 228 in the closing direction (right) as the mechanical face seal 302 is formed is divided between the non-rotating seal carrier 228 and the pressure sleeve 220, thereby reducing the overall sliding motion experienced by the radial seals 216 and 230, reducing wear and also reducing the tendency of the seal rings to rotate.

[0031] In one exemplary embodiment according to the present disclosure, the disclosure describes a rotary union including a non-rotating component defining a bore, a non-rotating seal carrier slidably disposed within the bore, a pressure sleeve slidably disposed within the bore between the non-rotating component and the non-rotating seal carrier, a non-rotating seal member disposed on the non-rotating seal carrier, and a rotating seal carrier having a rotating seal member disposed thereon, the rotating seal member disposed in opposing relationship to the non-rotating seal member such that a sliding mechanical face seal is formed between the non-rotating seal member and the rotating seal member when the non-rotating seal carrier slides toward the rotating seal carrier in the presence of fluid pressure.

[0032] As described, the rotary union includes a first radial seal disposed in a first channel formed along the bore and forming a sliding seal between the non-rotating component and the pressure sleeve, and a second radial seal disposed in a second channel formed along an outer surface of the non-rotating seal carrier and forming a sliding seal between the non-rotating seal carrier and the pressure sleeve. The rotary union may further include a seal retainer disposed in the first channel and the second channel adjacent to the first radial seal and the second radial seal.

[0033] In one embodiment, the rotary union further includes a housing having a cylindrical bore extending through the body, the cylindrical bore being substantially linear and the non-rotating component being a carriage disposed within the cylindrical bore of the housing, and a shaft rotatably supported within the cylindrical bore of the housing, the rotary seal carrier being an annular plate rotatably engaged for rotation with the shaft. The rotary union may further include a plurality of mechanical face seal arrangements in stacked relationship within the multi-media rotary union housing.

[0034] In one embodiment, the pressure sleeve includes a cylindrical portion disposed in a sliding sealing relationship between the bore and the non-rotating seal carrier and a shoulder disposed adjacent to the non-rotating seal member, the pressure sleeve being configured to slide under hydrodynamic or pneumatic forces such that the shoulder abuts a portion of the non-rotating seal carrier when a fluid pressure is present internal to the non-rotating seal carrier.

[0035] All references cited in this specification, including publications, patent applications, and patents, are herein incorporated by reference to the same extent as if each reference was individually and specifically indicated to be incorporated by reference and was set forth in its entirety herein.

[0036] Use of the terms "a," "an," "the," and "at least one," and similar referents in the context of describing the invention (particularly in the context of the claims below) should be construed to encompass both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Use of the term "at least one" followed by a list of one or more items (e.g., "at least one of A and B") should be construed to mean one item selected from the listed items (A or B), or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" should be construed as open-ended terms (i.e., meaning "including, but not limited to"), unless otherwise indicated herein or clearly contradicted by context. The recitation of ranges of values ​​herein is merely intended to serve as a shorthand method of referring individually to each individual value falling within the range, unless otherwise indicated herein, and each individual value is incorporated herein as if it were individually recited herein. All methods described herein may be performed in any suitable order, unless otherwise indicated herein or clearly contradicted by context. Any and all examples provided herein, or the use of exemplary language (e.g., "etc.") are intended merely to better illustrate the invention, and do not impose limitations on the scope of the invention unless otherwise claimed. No language in this specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0037] Preferred embodiments of the present invention are described herein, including the best mode for carrying out the invention known to the inventors. Variations of these preferred embodiments may become apparent to those of skill in the art upon reading the foregoing description. The inventors anticipate that those skilled in the art will employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, the present invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the present invention unless otherwise indicated herein or clearly contradicted by context.

Claims

1. a non-rotating component defining a bore; a non-rotating seal carrier slidably disposed within the bore; a pressure sleeve slidably disposed within the bore between the non-rotating component and the non-rotating seal carrier; a non-rotating seal member disposed on the non-rotating seal carrier; a rotating seal carrier; the rotary seal carrier having a rotary seal member disposed thereon; a rotating union, the rotating seal member disposed in opposing relationship to the non-rotating seal member such that a sliding mechanical face seal is formed between the non-rotating seal member and the rotating seal member when the non-rotating seal carrier slides toward the rotating seal carrier in the presence of fluid pressure.

2. a first radial seal disposed within a first channel formed along the bore; a second radial seal disposed within a second channel formed along an outer surface of the non-rotating seal carrier; the first radial seal forms a sliding seal between the non-rotating component and the pressure sleeve; The rotating union of claim 1 , wherein the second radial seal forms a sliding seal between the non-rotating seal carrier and the pressure sleeve.

3. The rotary union of claim 2 further comprising a seal retainer disposed within said first channel and said second channel adjacent said first radial seal and said second radial seal.

4. a housing having a cylindrical bore; a shaft rotatably supported within the cylindrical bore of the housing, the cylindrical bore extends through a body of the housing and is substantially linear, the non-rotating component being a carriage disposed within the cylindrical bore of the housing; The rotary union of claim 1 , wherein the rotary seal carrier is an annular plate rotatably engaged for rotation with the shaft.

5. the non-rotating component, the non-rotating seal carrier, the pressure sleeve, the non-rotating seal member, and the rotating seal carrier together define a seal stage; The rotary union of claim 4 , wherein the housing further includes a plurality of seal stages in stacked relationship to define a multi-passage rotary union.

6. The pressure sleeve comprises: a cylindrical portion disposed in sliding sealing relationship between the bore and the non-rotating seal carrier; 2. The rotating union of claim 1, further comprising a shoulder disposed adjacent said non-rotating seal member.

7. 5. The rotating union of claim 4, wherein the pressure sleeve is configured to slide under hydrodynamic or pneumatic forces such that the shoulder abuts a portion of the non-rotating seal carrier when the fluid pressure is internal to the non-rotating seal carrier.

8. a housing having a cylindrical bore extending through a body of the housing and being substantially linear; a shaft rotatably supported within the cylindrical bore of the housing; a carriage defining a bore and a radial flow passage, said carriage being disposed in sealed relationship within said cylindrical bore of said housing; a non-rotating seal carrier slidably disposed within the bore; a pressure sleeve slidably disposed within the bore between the carriage and the non-rotating seal carrier; a non-rotating seal member disposed on the non-rotating seal carrier; a rotating seal carrier; The rotary seal carrier includes a rotary seal member disposed on the rotary seal carrier and an additional radial flow passage; the non-rotating seal carrier is engaged for rotation with the shaft; a rotating seal member disposed in opposing relationship to the non-rotating seal member such that a sliding mechanical face seal is formed between the non-rotating seal member and the rotating seal member when the non-rotating seal carrier slides toward the rotating seal carrier in the presence of fluid pressure, providing a sealed fluid passageway extending between the radial flow passage and the additional radial flow passage.

9. a first radial seal disposed within a first channel formed along the bore, the first radial seal forming a sliding seal between the carriage and the pressure sleeve; and 9. The multimedia rotary union of claim 8, further comprising a second radial seal disposed in a second channel formed along an outer surface of the non-rotating seal carrier, the second radial seal forming a sliding seal between the non-rotating seal carrier and the pressure sleeve.

10. 10. The multi-media rotary union of claim 9, further comprising a seal retainer disposed within said first channel and said second channel adjacent said first radial seal and said second radial seal.

11. 10. A multimedia rotary union as claimed in claim 9, wherein said rotary seal carrier is an annular plate rotatably engaged for rotation with said shaft.

12. The pressure sleeve comprises: a cylindrical portion disposed in sliding sealing relationship between said bore and said carriage; 9. A multimedia rotary union as claimed in claim 8, further comprising a shoulder disposed adjacent said non-rotating seal member.

13. 13. A multimedia rotary union as claimed in claim 12, wherein the pressure sleeve is configured to slide under hydrodynamic or pneumatic forces such that the shoulder abuts a portion of the non-rotating seal carrier when the fluid pressure is present in the radial flow passage.

14. a plurality of carriages and a plurality of non-rotating seal carriers disposed in an alternating manner along the cylindrical bore of the housing; 9. The multi-media rotary union of claim 8, wherein each of said plurality of carriages and said plurality of non-rotating seal carriers has a respective non-rotating seal member and a respective rotating seal member thereon defining a respective sliding mechanical face seal along said housing.

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