Split Polymer Labyrinth Seal Assembly

Abstract

A split labyrinth seal assembly having split stationary and rotating sealing elements and a split clamping mechanism. The clamping mechanism is configured to secure the rotating element to a rotating shaft. The rotating element may also include an integrally formed valve element that moves between contacting and non-contacting positions in response to rotation of the shaft. The rotating element and the clamping mechanism may have associated therewith surface features that facilitate nesting of the components.

Description

[Technical Field]

[0001] Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 223,426, filed July 19, 2021, entitled "Split Polymer Labyrinth Seal Assembly," the contents of which are incorporated herein by reference. [Background technology]

[0002] The present invention relates to a seal assembly for sealing a shaft or rod to a stationary housing component. The present invention relates generally to rotary shaft seals. More particularly, the present invention relates to labyrinth seals that seal fluids within a housing and help prevent contaminants from entering the housing.

[0003] Polymer and rubber mechanical seal assemblies are used in a wide variety of environments and settings, such as within machinery, to provide fluid-tight seals. Typically, these sealing assemblies are mounted within and disposed around a rotating shaft or rod that protrudes from a stationary machine housing. Rotary seals are generally constructed and designed to prevent unwanted particles from entering the machine housing and contaminating the fluid contained therein; however, the seal must also retain fluids, such as oil, process fluids, or barrier fluids, that are typically present in fluid reservoirs within the housing. Therefore, as reliability demands and penalties for failure continue to increase, while extending the operational life of machinery is important, there is also a need to minimize leakage.

[0004] Those of ordinary skill in the art will readily recognize that maintaining rotating equipment is generally difficult due to the equipment's extreme duty cycles, reduced service rates, specialized seal designs, and the lack of spare rotating equipment in many process plants. In the art of the present invention, various types of conventional shaft sealing devices have been utilized, such as lip seals, labyrinth seals, and magnetic seals, to attempt to protect the integrity of the sealing environment.

[0005] A conventional lip seal includes a sealing element with a lip that contacts a rotating shaft to help prevent fluid leakage from a housing. A drawback of conventional lip seals is that they wear quickly and can fail over time, and they are also known to allow excessive amounts of moisture and other contaminants to undesirably migrate into the housing's fluid reservoir.

[0006] Labyrinth seals are typically frictionless seals, typically without friction, because there is no sealing contact between stationary and rotating components during use. Labyrinth seals can create a seal and prevent contaminants from reaching the fluid within a housing by creating a complex path (i.e., a labyrinth) for liquids and contaminants to pass through. Therefore, contaminants have difficulty passing through or traversing the labyrinth, making it difficult for them to overcome the barrier created by the seal. This type of seal is used in a variety of applications and can be used with rotating or otherwise moving objects. In fact, depending on the design, movement, such as the rotation of a shaft, can further enhance the effectiveness of labyrinth seals by generating centrifugal forces that serve to further trap contaminants and fluids within the seal. Labyrinth seals are typically not designed to handle pressure differentials, but they can be used in many other types of critical environments.

[0007] Disadvantages of conventional labyrinth seals include their high cost and complex design, which typically requires tight tolerances. If the seal components move from their predetermined positions during operation, fluid leakage increases and the seal's ability to prevent contaminants from entering the machine housing is reduced. Furthermore, conventional labyrinth seals typically have a solid, continuous structure, requiring disassembly of the rotating equipment to install them. Summary of the Invention

[0008] It is therefore an object of the present invention to provide a labyrinth seal that uses rotating and stationary seal ring components that can be easily positioned relative to one another to improve fluid tightness and debris containment, and more importantly, the components are separate and can be easily installed into a device without disassembly.

[0009] One object of the present invention is to provide a labyrinth seal that uses a valve element as part of a seal assembly that is selectively movable between a non-contacting position and a contacting sealing position, the valve closing when the rotating shaft is stopped to prevent contaminants (e.g., moisture) from entering a fluid reservoir.

[0010] The labyrinth seal assembly of the present invention relates to a split seal having split stationary and rotating sealing elements and a split clamping mechanism configured to secure the rotating element to a rotating shaft, and may further include an integrally formed valve element that moves between contacting and non-contacting positions in response to rotation of the shaft.

[0011] The present invention relates to a labyrinth seal assembly for forming a seal between a shaft and a stationary equipment housing. The split labyrinth seal assembly includes a stationary element, a rotating element, and a clamp assembly. The stationary element is configured to couple to the stationary equipment housing and has an annular shape defining a space through which the shaft extends. The stationary element is divided into a first stationary element segment and a second stationary element segment, each of the first and second stationary element segments having associated therewith first and second non-flat end surfaces. The rotating element is disposed within the space between the stationary element and the shaft and is coupled to the shaft for rotation therewith. The rotating element is divided into a first rotating element segment and a second rotating element segment, each of the rotating element segments having associated therewith first and second non-flat end surfaces. The rotating element further has an outer surface integrally formed with a valve element extending axially outward. The clamp assembly is disposed around the rotating element to secure the rotating element to the shaft. When assembled, the valve element is disposed between the stationary element and the rotating element, the valve element being positioned against a portion of the stationary element to selectively form a seal, the valve element being movable between a contacting position and a non-contacting position in response to rotation of the shaft, the valve element being adapted to contact the stationary element in the contacting position to form the seal when the shaft stops rotating, and being positioned in the non-contacting position when the shaft rotates.

[0012] According to the present invention, the rotating element includes a body having an inner surface, an opposing outer surface, an upper surface having associated surface features, and an outboard portion extending axially outward from the upper surface. The clamping assembly has a body with a bottom surface having associated surface features complementary in shape to the surface features of the upper surface of the rotating element, the surface features of the bottom surface of the clamping assembly being disposed in engaging contact with the surface features of the upper surface of the rotating element. In one embodiment, the surface feature of the upper surface of the rotating element is a channel, and the surface feature of the clamping assembly includes a protrusion sized and dimensioned to be received in the channel. According to another embodiment, the outboard portion of the rotating element can optionally include an outer surface having one or more surface features associated therewith. The inner surface of the body of the clamping assembly has associated therewith one or more surface features complementary in shape to the surface features of the outboard portion of the rotating element. According to one embodiment, the surface features of the outer surface of the outboard portion of the rotating element include one or more channels, and the surface features associated with the inner surface of the body of the clamping assembly include one or more protrusions sized and dimensioned to be at least partially received in the channels of the outboard portion.

[0013] The non-planar end surface of the first stationary element segment can be configured to include a notch, and the non-planar end surface of the second stationary element segment can include a protrusion complementary in shape to the notch. When assembled together, the notch and the protrusion prevent axial movement of the first and second stationary element segments relative to one another. Similarly, the non-planar end surface of the first rotating element segment can include a notch, and the non-planar end surface of the second rotating element segment can include a protrusion complementary in shape to the notch, and when engaged together, the notch and the protrusion prevent axial movement of the first and second rotating element segments relative to one another. When engaged together, the divisions forming the non-planar end surfaces of the first and second stationary element segments and the rotating element segments can have an arrow or chevron profile shape.

[0014] According to the present disclosure, the surface feature on the upper surface of the rotating element is a protrusion extending axially outward, and the surface feature on the bottom surface of the body of the clamping assembly includes a channel, with the axially outwardly extending protrusion being disposed in engaging contact with the channel formed in the bottom surface of the clamping assembly. The surface feature on the outer surface of the outboard portion of the rotating element can include one or more channels, and the surface feature associated with the inner surface of the body of the clamping assembly can include one or more protrusions sized and dimensioned to be at least partially received in the channel of the outboard portion. The non-planar end surface of the first stationary element segment can include a notch, and the non-planar end surface of the second stationary element segment includes a protrusion complementary in shape to the notch. When engaged with each other, the notch and the protrusion prevent axial movement of the first and second stationary element segments relative to each other.

[0015] The clamping assembly of the present invention can include an annular body having first and second end portions, the first end portion including a first retention feature and the second end portion including a second retention feature, and a fastening assembly. The fastening assembly can include first and second barrel nuts and a fastener. The first barrel nut can be sized and dimensioned to be received within the first retention feature of the first end portion, and the second barrel nut can be sized and dimensioned to be received within the second retention feature of the second end portion, with openings formed in each of the first and second barrel nuts. The fastener element can be sized and dimensioned to be received within the openings in the first and second barrel nuts.

[0016] The first and second retention mechanisms may optionally include first and second loop elements. The first barrel nut is sized and dimensioned to be received within the first and second loop elements of the first retention mechanism, and the second barrel nut is sized and dimensioned to be received within the first and second loop elements of the second retention mechanism. The rotating element has a body with an inner surface, an opposing outer surface, and an outboard portion extending axially outward from an upper surface. The outer surface of the outboard portion defines a channel sized and dimensioned to receive the annular body of the clamping mechanism. The fastener element, when installed within the first and second barrel nuts and tightened, couples the rotating element to the shaft. [Brief explanation of the drawings]

[0017] These and other features and advantages of the present invention will be more fully understood by reference to the following detailed description and the accompanying drawings, in which like reference characters indicate like parts throughout the several different views, which illustrate the principles of the invention and which show relative dimensions, although not to scale. [Figure 1] FIG. 1 is a perspective view of a first embodiment of a labyrinth seal assembly mounted about a shaft and disposed within a stationary equipment housing in accordance with the teachings of the present invention. [Figure 2] FIG. 2 is a partial cross-sectional perspective view of the labyrinth seal assembly of FIG. 1 in accordance with the teachings of the present invention. [Figure 3] FIG. 3 is a partial cross-sectional view of a labyrinth seal assembly in accordance with the teachings of the present invention. [Figure 4] 4 is a side view of an assembled split labyrinth seal assembly of the present invention prior to installation around a shaft and in a stationary device, also showing the linear and V-shaped interlocking splits of at least the stationary elements. [Figure 5] FIG. 5 is a side view of an assembled labyrinth assembly of the present invention showing another embodiment of a combined straight and V-shaped split in the stationary elements. [Figure 6]FIG. 6 is a perspective view of an assembled labyrinth assembly of the present invention showing the linear and V-shaped interlocking divisions in the rotating elements. [Figure 7] FIG. 7 is a perspective view of the assembled clamping mechanism of the labyrinth seal assembly of the present invention. [Figure 8] FIG. 8 is an end view of a section of a clamping mechanism of a labyrinth seal assembly according to the present invention. [Figure 9] FIG. 9 is a partial cross-sectional perspective view of a labyrinth seal assembly illustrating another embodiment of a stationary element without a static sealing element in accordance with the teachings of the present invention. [Figure 10] FIG. 10 is a partial cross-sectional view of a second embodiment of a labyrinth seal assembly in accordance with the teachings of the present invention. [Figure 11] FIG. 11 is a partial cross-sectional perspective view of a second embodiment of the labyrinth seal assembly of FIG. 10 in accordance with the teachings of the present invention. [Figure 12] FIG. 12 is a partial cross-sectional view of a clamping mechanism of the labyrinth seal assembly of FIG. 10 in accordance with the teachings of the present invention. [Figure 13] FIG. 13 is a perspective view of another embodiment of a labyrinth seal assembly in accordance with the teachings of the present invention. [Figure 14] FIG. 14 is a partial cross-sectional perspective view of the labyrinth seal assembly of FIG. 13 in accordance with the teachings of the present invention. [Figure 15] FIG. 15 is a partial cross-sectional view of the labyrinth seal assembly of FIG. 13 in accordance with the teachings of the present invention. [Figure 16] FIG. 16 is a partial cross-sectional view of the rotating elements of the labyrinth seal assembly of FIG. 13 in accordance with the teachings of the present invention. [Figure 17] 17 is a perspective view of a clamping mechanism without a fastening assembly of the labyrinth seal assembly of FIG. 13 in accordance with the teachings of the present invention. [Figure 18] FIG. 18 is a perspective view of a clamping mechanism of the labyrinth seal assembly of FIG. 13 in accordance with the teachings of the present invention. [Figure 19] FIG. 19 is a partial perspective view of a clamping mechanism of the labyrinth seal assembly of FIG. 13 in accordance with the teachings of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

[0018] The present invention provides a split polymer labyrinth seal assembly for providing a seal on a rotating shaft or other suitable device. The labyrinth seal assembly also helps reduce the amount of particles or fluids that enter or exit a machine housing by creating a labyrinth, or tortuous path. The present invention is described below in connection with the illustrated embodiments. Those skilled in the art will readily appreciate that the present invention may be implemented in multiple different applications and embodiments and is not limited in its application to the specific embodiments described and disclosed herein. The split polymer labyrinth seal assembly of the present invention provides a method and system for installing a seal without disassembling the equipment as a solid, continuous piece.

[0019] As used herein, the terms "mechanical seal," "seal assembly," and "sealing assembly" are intended to include various types of mechanical seals or sealing assemblies, including, for example, labyrinth seals, single seals, split seals, concentric seals, and other types of known seal and sealing assemblies and components. As used herein, the terms "labyrinth seal assembly," "labyrinth seal assembly," and "labyrinth seal" are used interchangeably to refer to the labyrinth seals shown in the accompanying drawings.

[0020] The term "shaft" is intended to refer to any suitable rotating device in a mechanical system that can be fitted with a seal and that is housed within a stationary device, including axles, rods, and other known devices.

[0021] As used herein, the terms "axial" and "axially" refer to directions generally parallel to the axis of any shaft. As used herein, the terms "radial" and "radially" refer to directions generally perpendicular to the axis of any shaft. The terms "fluid" and "fluids" refer to liquids, gases, and combinations thereof.

[0022] As used herein, the term "axially inner" refers to the portion of the stationary equipment and seal assembly located adjacent to the mechanical system in which the seal assembly is used. Conversely, as used herein, the term "axially outer" refers to the portion of the stationary equipment and seal assembly distal to the mechanical system.

[0023] As used herein, the term "radially inner" refers to the portion of the seal assembly that is proximal to any shaft. Conversely, as used herein, the term "radially outer" refers to the portion of the seal assembly that is distal from that shaft.

[0024] As used herein, the terms "machine housing," "stationary device," "stationary device housing," and / or "stationary surface" are intended to include any suitable stationary mechanical structure that houses a shaft or rod to which a seal assembly is fixed or coupled.

[0025] Labyrinth seals are typically made of multiple components. One component, known as the stator or stationary element, is attached to the stationary device housing and remains stationary. The other component, called the rotor or rotating element, is attached to the shaft and rotates therewith. The stationary and rotating sealing components typically cooperate in a frictionless, non-contact manner to effectively seal out most contaminants while retaining the lubricant or process fluid inside. Labyrinth seals are non-contacting, meaning that the two opposing axial and radial faces of the sealing element typically do not come into contact with each other during use. Because the rotating and stationary elements are separated by a small gap that defines the labyrinth path, the sealing components are also considered frictionless. Any contaminants attempting to enter the bearing housing must typically traverse a maze of bends and corners that form the labyrinth path and are formed by the stationary and rotating elements when assembled to reach the axially inner region of the seal assembly and stationary device or housing. In their labyrinth path through all these bends, particles are constantly subjected to centrifugal forces due to the rotational movement of the shaft, and ultimately only a very small number of particles make it through the entire length of the seal, which is the primary sealing function of the labyrinth seal assembly.

[0026] According to one embodiment of the present invention, a split polymer labyrinth seal assembly 10 is provided that is formed between a shaft 12 and an associated stationary device 14. As shown, for example, in Figures 1-3, the labyrinth seal assembly 10 of the first embodiment of the present invention employs a stationary element 20 housed within the stationary device 14, a rotating element 60 coupled to the rotatable shaft 12, a valve element coupled to or integrally formed with the rotating element 60 that is configured to operatively interact with the stationary element 20 to form a seal therebetween, and a split clamping mechanism or assembly 90 that serves to couple, clamp, or secure the rotating element 60 to the shaft 12.

[0027] The illustrated stationary element 20 has a segmented annular shape and is configured to couple to the stationary device 14 and define a space within which the shaft 12 extends. The stationary element 20 is preferably segmented into corresponding stationary element sections (e.g., sealing sections). The stationary element 20 has a body 22 with an outer, generally axially extending surface and an opposing, inner, generally axially extending surface. The outer surface can include multiple distinct surfaces. For example, the outer surface can include a radially outermost outer surface 24 and a radially inward, stepped, axially extending outer surface 26. The outer surfaces 24 and 26 can be joined to one another by a radially extending, stepped wall surface 25. The stepped wall surface 25 is configured to abut and be received against a corresponding radially extending wall 14A of the stationary device 14. The radially innermost outer surface 26 of the body 22 can be relatively flat or, optionally, can include or form one or more static sealing surface elements or features, such as, for example, boss elements 26A. The boss element 26A can be received in a corresponding groove formed along the inner surface of the stationary device 14 to form a fluid-tight seal. Alternatively, the inner surface of the stationary device can be free of grooves, and the sealing boss 26A can form a fluid-tight seal by contacting an opposing axially extending surface. An example of an outer surface 26 without the boss element 26A is shown, for example, in FIG. 9 . Those of ordinary skill in the art will readily recognize that the outer surface 26 can include any selected number or type of static sealing surface features, and that these surface features can have any selected shape or size. Furthermore, the outer surface 26 can have any suitable shape or design, such as a plurality of stepped surfaces. The body 22 of the stationary element 20 can include an axially innermost end wall 28 configured to abut and be received against the radially extending end wall 14B of the stationary device 14.

[0028] The stationary element includes an inwardly extending surface. The inwardly extending surface may be formed by a plurality of different axially extending surfaces. For example, the stationary element 20 may include an axially outermost or outboard end 30 having a first generally axially extending inner surface formed by inner axially extending surfaces 32A and 32B connected to one another by a radially extending stepped wall 34. Additionally, the body 22 includes a radially extending sealing surface 36 for forming a sealing surface with the valve element 120 of the rotating element 60. The stationary element 20 further includes a radially innermost axially extending second inner surface 38 terminating in a flange portion 40. The flange portion 40 may include a pair of radially inwardly extending flange or rib elements 40A, 40B spaced apart to define a channel 42 therebetween. The flange elements 40A, 40B extend radially inward toward the shaft 12. Those of ordinary skill in the art will readily recognize that the inner surface of the stationary element 20 can be of any suitable shape and design and can include any selected number and type of surface features. The second inner surface 38 can also include, or be formed into, one or more channels or grooves positioned and configured to cooperate with one or more surface features formed on the rotating element 60 to aid in the formation of a labyrinth pathway. According to one embodiment, the inner surface 38 can include channels 44A and 44B for receiving corresponding surface features on the rotating element 60. Furthermore, the shape and design of the surface features on the rotating element 60 can help concentrate localized sealing forces against the stationary equipment surface, forming a static seal. Furthermore, the surface features can help secure these stator and rotor components in place relative to the equipment bore and shaft, respectively. A labyrinth seal can form a complex labyrinth pathway through which liquids and contaminants pass, thereby forming a seal and preventing contaminants from reaching the fluid within the housing. Contaminants therefore have difficulty passing through or traversing the labyrinth and therefore overcoming the barrier formed by the seal. The labyrinth path can include a space formed between a rotating element and a stationary element.

[0029] The illustrated rotating element 60, when attached to the stationary device 14, is positioned within the space defined by the stationary element 20 and can be coupled to the shaft 12 by a clamping mechanism 90 for rotation therewith. The rotating element 60 has a body 62 with an axially extending inner surface 64 for contacting the outer surface of the shaft. The rotating element 60 also includes an upper surface 66 and a generally axially extending outer surface. The upper surface 66 can have any selected type of surface features formed thereon. For example, the surface features can include one or more grooves, channels, or depressions, or any selected type of protrusion, such as one or more ribs or extensions. The outer surfaces include a first axially extending outer surface 68 and a second axially extending outer surface 70 that is stepped radially inward. The outer surfaces 68 and 70 are coupled to one another via a radially extending stepped wall 72. A valve element 120 is integrally formed on the second outer surface 70 to provide a supplemental seal between the stationary element 20 and the rotating element 60. Specifically, the valve element 120 includes an annular body having a flange element 122 formed at its radially outermost end. The flange element 22 may have any suitable shape and design. In use, the valve element 120 functions as a secondary or supplemental sealing mechanism to further help prevent contaminants from entering the housing. The valve element 120 is movable between a contacting position in which the flange element 122 contacts the stationary sealing surface 36 and a non-contacting position in which the flange element is positioned away from the sealing surface. The valve element 120 is movable between these two positions by rotation of the shaft 12.

[0030] The outer surface of the rotating element 60 further includes a third outer surface 74 extending generally axially. The outer surface 74 can have one or more surface features associated therewith that are aligned with and complementary in shape to surface features associated with the inner surface 38 of the stationary element 20. For example, the outer surface 74 of the rotating element can include surface features such as ribs 76A and 76B that align with, and optionally at least partially nest within, grooves 44A and 44B formed in the inner surface 38 of the stationary element 20. These surface features of the rotating element 60 can have any selected size and shape. According to alternative embodiments, the outer surface 74 of the rotating element 60 can include one or more grooves or channels, and the inner surface 38 of the stationary element 20 can include one or more raised surface features. Furthermore, the outer surface 74 can have any suitable shape or design, for example, a plurality of stepped surfaces. The ribs 76A and 76B and grooves 44A and 44B form part of a labyrinth path.

[0031] The top surface 66 of the rotating element 60 has surface features associated therewith, which may be complementary in shape to surface features associated with the bottom surface of the clamping assembly 90. Additionally, the illustrated rotating element 60 may include an outboard portion 80 extending axially outward from the top surface 66 and configured to engage the clamping assembly 90. Specifically, the outboard portion 80 may include an outer surface 82 having one or more surface features associated therewith, which may be complementary in shape to surface features formed along the inner surface of the clamping assembly 90. According to one embodiment, the top surface 66 includes a channel 78 formed therein for receiving a portion of the clamping mechanism, and the surface features formed on the outer surface 82 of the outboard portion 80 include a plurality of channels 84 for receiving the surface features of the clamping mechanism 90.

[0032] The clamp assembly 90 is shown in detail in FIGS. 7 and 8 . The clamp assembly 90 may include an annular body 92 divided in any selected manner and configuration to form a pair of clamping sections 92A, 92B. Each of these sections may be formed at opposite ends with a fastener-receiving opening 94 formed in an end face and appropriate notches formed in the body for receiving a fastener 110. The fastener 110 secures the clamping sections 92A, 92B to one another. The body 92 may include a generally axially extending outer surface including a first outer surface 96 and a second outer surface 98 joined via a radially inwardly stepped wall surface 100. The body 92 also has a generally axially extending inner surface 102. According to one embodiment, the inner surface 102 may include one or more surface features 104 for interacting with surface features formed on the outer surface 82 of the outboard section 80. The surface features may include one or more protruding elements, such as ribs 104, configured to at least partially fit within surface features, such as channels 84, formed in the outer surface 82 of the outboard portion 80 of the rotating element 60 to enable engagement and nesting of the clamping mechanism 90 and the rotating element 60. The clamping sections 92A, 92B may be secured to one another via fasteners 110, which, when tightened, secure the rotating element 60 to the shaft 12. A person of ordinary skill in the art will readily recognize that the surface features 104 may be of any type, size, or shape. Furthermore, any selected number of surface features may be provided on or associated with the inner surface 102. The axially inboard portion of the clamping assembly 90, formed by the lower regions of the outer surface 98 and the inner surface 102, defines a protrusion 106 (e.g., a surface feature) extending from the bottom surface (e.g., stepped wall 100) of the clamping assembly and configured to fit within the channel 78 formed in the upper surface 66 of the rotating element 60. In this manner, the protrusions 106 and the channels 78 may have complementary shapes that allow these surface features to engage and nest together, thus providing an additional mechanism for securing the clamp assembly 90 and the rotating element 60 together.

[0033] The rotating element 60 and the stationary element 20 can be formed as a pair of segments, each having an end surface. For example, the end surfaces of the rotating seal element, the stationary seal element, and / or the clamping segment can be configured with non-planar surface features that allow the aligned end surfaces of the opposing segments to engage with each other and prevent axial movement relative to each other. The non-planar surface features thus form an interlocking mechanism. The interlocking mechanism can have any selected profile shape, such as a V-shape, a chevron shape, etc.

[0034] As shown in Figures 4-6, the stationary and rotating elements (e.g., seal ring elements) and clamping segments can be split into multiple segments to form non-planar mating end surfaces. Conventional split seal ring segments have relatively smooth, flat, axially exposed end surfaces. Because these axial surfaces are flat, they easily move axially and radially relative to one another. This often makes it difficult to align the seal ring segments with one another during installation. In accordance with the present invention, at least the stationary and rotating elements each include a pair of split seal ring segments having axially extending, non-planar end surfaces that mate with corresponding seal ring surfaces of the opposing seal ring segment. As used herein, the term "non-planar" is intended to encompass ring end surfaces that have more than a minor amount or degree of surface features, independent of any features that may be formed on the split surfaces as a result of the grain structure of the seal ring material. An axial end surface is considered non-planar if, when viewed axially from the axially outermost to the axially innermost surface of the axial end surface and radially from the radially outermost to the radially innermost surface of the end surface, surface features other than natural material grain variations are present on the axial end surface. For example, an end face is considered to have a non-planar end face if it incorporates or includes a surface feature having an inclined, downwardly sloping, V-shaped, zigzag (in cross section), curved or non-linear shape, chevron cuts, arrow-shaped cuts, channels or grooves, protrusions, or any other suitable non-planar shape. The present invention also contemplates forming multiple surface features on the end face above or below (or both) the axial end face surface. The opposing axial end faces of opposing seal ring segments preferably have complementary shapes when positioned in a face-to-face relationship. The seal ring segments interlock and are therefore self-aligning. This non-planar nature of the axial seal ring end faces of the seal ring segments interferes with each other in a manner that promotes engagement between the segments while simultaneously reducing or preventing sliding of the segments relative to each other, particularly in the axial direction. Figure 4 shows a stationary element 20 having divisions 46 formed therein to form seal ring segments 20A and 20B.The divisions 46 form stationary seal ring segments 20A, 20B, each having a pair of non-planar end faces. The non-planar end faces preferably include non-planar surface features, i.e., any surface features other than a straight, flat cross section forming the end faces. The non-planar surface features can be of any selected shape or configuration. The illustrated non-planar surface features formed on the non-planar end faces generally form an arrow shape. Thus, one of the segments 20A includes a notch formed in its end face, while the other segment's end face includes a complementary angled protrusion. As another example, as shown in FIG. 5, the non-planar divisions 46A formed along the end faces of the seal ring segments 20A, 20B have a chevron shape. FIG. 6 is a perspective view of the labyrinth seal assembly 10 illustrating that the rotating element 60 can also include non-planar divisions 86 to form the seal ring segments 60A, 60B. The seal segments 60A, 60B each include a non-planar end face, similar to the end faces of the rotating element segments 20A, 20B.

[0035] The stationary and rotating elements may be formed from any suitable material, and are preferably formed from an elastomeric material such as rubber, polyurethane, a silicone-based material, a polymeric material, a fluorocarbon material, a plastic material (e.g., polyurethane, nylon, acetal, polytetrafluoroethylene (PTFE)), or a metallic material.

[0036] A second embodiment of the labyrinth seal assembly 10 of the present invention is shown, for example, in FIGS. 10-12. Like reference numerals refer to like parts throughout the various views. The illustrated labyrinth seal assembly 10 includes a rotating element 60' coupled to a shaft 12 by a clamping mechanism 90'. The stationary element 20 is mounted within the stationary device 14 and is disposed around the rotating element 60'. The illustrated rotating element 60' is similar in structure to the rotating element 60, except for the configuration of the upper surface 66. The surface features of the upper surface 66 have been replaced with differently shaped surface features, namely, axially extending protrusions 130. The illustrated clamping mechanism 90' is similar in configuration to the clamping mechanism 90, except that the bottom portion or protrusion 106 extending from the bottom surface has been replaced with a channel 108 formed in the axially inner lower end 109 (e.g., bottom surface). The protrusions 130 of the rotating element 60' are sized and shaped to fit within and engage channels 108 formed in the lower end 109 of the clamping mechanism 90'. The surface features nest within one another in the assembled state. One skilled in the art will readily recognize that the protrusions 130 and corresponding channels 108 can have any selected size and shape.

[0037] 13-19 illustrate another embodiment of the labyrinth seal assembly 10 of the present invention. Like reference numerals refer to like parts throughout the various views. The illustrated labyrinth seal assembly 10 forms a seal between a shaft 12 and any associated stationary device 14. For example, as shown in FIGS. 13-16 , the illustrated labyrinth seal assembly 10 employs a stationary element 20 housed within a stationary device 14, a rotating element 60″ coupled to a rotatable shaft 12, a valve element 120 integrally formed with the rotating element 60″ and configured to operatively interact with the stationary element 20 to form a seal therebetween, and a clamping mechanism 160 that serves to clamp the rotating element 60″ to the shaft 12. The stationary element 20 is coupled to and housed within the stationary device 14. The rotating element 60″ is coupled to the rotatable shaft 12 by the clamping mechanism 160. The rotating element 60″ is similar in structure to the rotating element 60 of FIG. 3 , except that the outboard portion 140 has a different configuration. Specifically, an outer surface 142 of the outboard portion 140 defines a channel 144 that accommodates the body of the clamping mechanism 160 when attached. As such, the channel 144 is configured to accommodate the width of the clamping mechanism 160.

[0038] The clamping mechanism 160 is shown in more detail in FIGS. 17-19. The illustrated clamping mechanism includes a body 162 having a circular or annular shape and is therefore generally configured as a band clamp. The body 162 has a pair of end portions or terminal sections 164A, 164B disposed adjacent to one another. Each end portion includes a retention feature. In the illustrated embodiment, the retention features may include a pair of loop elements 166. Those of ordinary skill in the art will readily recognize that the retention features may be of any selected type and shape. The loop elements are configured to engage at least a portion of a securing assembly 170. The securing assembly may include, for example, a pair of barrel nuts 172 and a fastener element 174. The barrel nuts 172 include fastener-receiving openings sized and configured to accommodate the fastener element 174. The fastener 174 can be tightened to move the clamping mechanism's end portions 164A, 164B toward one another. Movement of terminal ends 164A, 164B toward one another serves to secure rotating element 60" to shaft 12.

[0039] In operation, the labyrinth seal assembly 10 of the present invention is mounted within the housing of a stationary device 14. To do so, the stationary element 20 is mounted within the housing 14. The rotating element 60 is then mounted on the shaft 12 and positioned relative to the stationary element 20 to define a selected clearance between the stationary and rotating elements. Thus positioned, the stationary and rotating elements form a non-contacting, or frictionless, sealing arrangement. The stationary and rotating elements 20, 60 operate as a primary sealing mechanism. When assembled together, they form a tortuous path (i.e., a labyrinth path) extending between the ambient environment at the outboard end and the interior space of the machine housing, which typically contains one or more fluid reservoirs and associated process fluids. The tortuous labyrinth path helps trap particulates within it, minimizing their access to the interior space of the seal assembly and, therefore, the stationary device. Furthermore, the labyrinth seal assembly 10 helps retain fluids, such as process fluids, within the housing 14.

[0040] The valve element 120 is integrally formed on the second outer surface 70 of the rotating element 60. The flange element 122 of the valve element 120 is configured to selectively contact the sealing surface 36 of the stationary element 20. The valve element 120 is movable between a contact position, in which the flange element 122 of the valve element contacts the sealing surface when the shaft is not rotating, and a non-contact position, in which the flange element 122 does not contact (is spaced apart from) the sealing surface 36 when the shaft is rotating. Thus, the valve element is movable between these two positions by rotation of the shaft 12. The rotating element 60 is secured to the shaft 12 by a clamping mechanism 90. The clamping mechanism 90 may be formed with surface features configured to cooperate with or complementary in shape to surface features formed on or within the rotating element 60. The clamping mechanism 60 may be formed as a pair of clamping segments that may be secured together around the rotating element 60 using one or more fasteners. When tightened, the clamping mechanism serves to secure the rotating element to the shaft. Alternatively, the clamping mechanism 160 may be configured as a band clamp with a securing mechanism 170 for clamping and securing the rotating element 60 to the shaft 12 .

[0041] Prior to starting the mechanical device, and thus prior to rotation of the shaft 12, the valve element 120 is positioned in a contact position (i.e., shutoff position) in which the valve element contacts the stationary element 20. Specifically, the valve element 120 is positioned within the space defined between the stationary element and the rotating element and sealably contacts the sealing surface 36 of the stationary element 20. The sealing surface thus essentially functions as a valve seat for the valve element 120. The valve element 120 thus serves to form a secondary seal between the stationary element 20 and the rotating element 60, helping to prevent contaminants from the ambient environment from entering the stationary device 14 (e.g., into an oil / lubricant reservoir contained therein) while also helping to retain fluid therein. The stationary element 20 and the rotating element 60 of the labyrinth seal assembly 10 form a primary sealing mechanism that helps prevent contaminants from entering the housing and fluid from escaping due to the labyrinth (i.e., tortuous path) formed by the stationary and rotating sealing elements. When used as described above, the valve element acts as a secondary or supplemental sealing mechanism by further preventing fluid leakage and contaminants from entering the housing when the shaft is stationary based on the sealing engagement between the valve element and the stationary element.

[0042] As the shaft begins to rotate, the valve element 120 transitions from a contacting position to a non-contacting position, thus moving away from the sealing surface 36 to reduce resistance and prevent undesirable heat generation. As mentioned above, the valve element 120 has an asymmetric design, with the flange element 122 coupled to a relatively thin body. When the shaft is rotating, centrifugal forces generated by the shaft exert a moment force on the center of gravity of the valve element 120, causing the flange element 122 to lift away from the sealing surface 136 of the stationary element. The operating principles of the valve element are described in U.S. Pat. No. 9,366,340, the contents of which are incorporated herein by reference. When the valve element 120 is disposed in the non-contacting position, the labyrinth seal assembly 10 still prevents contaminants from entering the housing due to the maze, or labyrinth, of passages formed between the seal components. Furthermore, the rotational motion of the shaft 12 serves to trap contaminants and retain the fluid within the housing due to the centrifugal force applied to the fluid contacting the rotating element 60. The fluid is then forced to flow radially outward into channels formed in the stationary element 20. During operation of the device, the fluid is generally discharged downward towards the bottom and eventually back into the housing.

[0043] It will thus be seen that the present invention effectively attains the objects set forth above, among those made apparent from the foregoing description. Since certain changes can be made to the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense.

[0044] Furthermore, the following claims should be understood to encompass all general and specific features of the invention described herein, and all statements regarding the scope of the invention may also be said to fall within their scope.

Claims

1. 1. A labyrinth seal assembly for forming a seal between a shaft and a stationary equipment housing, comprising: a stationary element configured to couple to the stationary device housing and having an annular shape defining a space through which the shaft extends, the stationary element being divided into a first stationary element segment and a second stationary element segment, each of the first and second stationary element segments having a first and second non-planar end surface associated therewith; a rotating element disposed within the space between the stationary element and the shaft and coupled to the shaft for rotation therewith, the rotating element being divided into a first rotating element segment and a second rotating element segment, each of the first and second rotating element segments having a first and second non-planar end surface associated therewith, the rotating element having an outer surface having an axially outwardly extending valve element integrally formed therewith; a clamp assembly disposed around the rotating element to secure the rotating element to the shaft; a valve element disposed between the stationary element and the rotating element when assembled, the valve element disposed against a portion of the stationary element to selectively form a seal, the valve element movable between a contacting position and a non-contacting position in response to rotation of the shaft, the valve element adapted to contact the stationary element in the contacting position to form the seal when the shaft stops rotating, and the valve element disposed in the non-contacting position when the shaft rotates.

2. The rotating element is a body having an inner surface, an opposing outer surface, an upper surface having associated surface features, and an outboard portion extending axially outward from the upper surface; 2. The labyrinth seal assembly of claim 1, wherein the clamp assembly has a body with a bottom surface having associated surface features complementary in shape to the surface features on the top surface of the rotating element, the surface features on the bottom surface of the clamp assembly being positioned in engaging contact with the surface features on the top surface of the rotating element.

3. 3. The labyrinth seal assembly of claim 2, wherein the surface feature on the upper surface of the rotating element is a channel and the surface feature on the clamp assembly includes a protrusion sized and dimensioned to be received in the channel.

4. 3. The labyrinth seal assembly of claim 2, wherein the outboard portion of the rotating element includes an outer surface having one or more surface features associated therewith, and wherein an inner surface of the body of the clamping assembly has associated therewith one or more surface features complementary in shape to the surface features of the outboard portion of the rotating element.

5. 5. The labyrinth seal assembly of claim 4, wherein the surface feature of the outer surface of the outboard portion of the rotating element includes one or more channels, and the surface feature associated with the inner surface of the body of the clamp assembly includes one or more protrusions sized and dimensioned to be at least partially received in the channels of the outboard portion.

6. 5. The labyrinth seal assembly of claim 4, wherein the first and second non-planar end faces of the first stationary element segment include cutouts and the first and second non-planar end faces of the second stationary element segment include protrusions complementary in shape to the cutouts, the notches and the protrusions preventing axial movement of the first and second stationary element segments relative to one another when assembled together.

7. 7. The labyrinth seal assembly of claim 6, wherein the first and second non-planar end faces of the first rotating element segment include cutouts and the first and second non-planar end faces of the second rotating element segment include protrusions complementary in shape to the cutouts, the notches and protrusions preventing axial movement of the first and second rotating element segments relative to one another when engaged with one another.

8. 5. The labyrinth seal assembly of claim 4, wherein the divisions forming the first and second non-planar end surfaces of the first and second stationary element segments and the first and second rotating element segments have an arrow or chevron profile shape when engaged with one another.

9. 5. The labyrinth seal assembly of claim 4, wherein the surface feature on the top surface of the rotating element is a protrusion extending axially outward, and the surface feature on the bottom surface of the body of the clamp assembly includes a channel, the protrusion extending axially outward being positioned in engaging contact with the channel formed in the bottom surface of the clamp assembly.

10. the surface features of the outer surface of the outboard portion of the rotating element include one or more channels; 10. The labyrinth seal assembly of claim 9, wherein the surface features associated with the inner surface of the body of the clamp assembly include one or more protrusions sized and dimensioned to be at least partially received in the channel of the outboard portion.

11. 11. The labyrinth seal assembly of claim 10, wherein the first and second non-planar end faces of the first stationary element segment include cutouts and the first and second non-planar end faces of the second stationary element segment include protrusions complementary in shape to the cutouts, the notches and protrusions, when engaged with one another, preventing axial movement of the first and second stationary element segments relative to one another.

12. The clamp assembly includes: an annular body having first and second end portions, the first end portion including a first retention feature and the second end portion including a second retention feature; 1. A fastening assembly comprising: a first barrel nut sized and dimensioned to be received within the first retention feature of the first end portion and a second barrel nut sized and dimensioned to be received within the second retention feature of the second end portion, each first and second barrel nut having an opening formed therein; and a fastener element sized and dimensioned to be received within the openings of the first and second barrel nuts.

13. 13. The labyrinth seal assembly of claim 12, wherein the first and second retention features each include a first and second loop element, the first barrel nut sized and dimensioned to be received within the first and second loop elements of the first retention feature, and the second barrel nut sized and dimensioned to be received within the first and second loop elements of the second retention feature.

14. 14. The labyrinth seal assembly of claim 13, wherein the rotating element has a body with an inner surface, an opposing outer surface, and an outboard portion extending axially outward from an upper surface, the outer surface of the outboard portion defining a channel sized and dimensioned to receive the annular body of the clamp assembly.

15. 15. The labyrinth seal assembly of claim 14, wherein the fastener element, when installed and tightened within the first and second barrel nuts, couples the rotating element to the shaft.

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