Cartridge seals used in extreme environments

Abstract

A sealing assembly includes an annular housing disposed within and coupled to a rotatable external member for angular displacement about an axis. An annular flexible seal is disposed within and coupled to the housing to be angularly displaced about the axis as the external member rotates about the axis. The flexible seal has an elastomeric sealing lip capable of engaging the outer circumferential surface of a shaft or a sleeve disposed around the shaft. An annular inner rigid seal is disposed within the housing and has an inner radial end coupled to the shaft or sleeve; the flexible seal is radially displaceable relative to the inner rigid seal. An annular outer rigid seal is disposed around the inner rigid seal and has an inner end capable of sealing with the inner rigid seal. A biasing member forces the outer rigid seal to bias toward the inner rigid seal.

Description

Technical Field

[0001] This invention relates to sealing assemblies, and more particularly to radial lip seal assemblies (or radial lip seal assemblies) used in harsh or extreme environments. Background Technology

[0002] Radial lip seal assemblies are known, typically comprising at least one elastomeric member having one or more sealing lips that are inwardly engageable with a shaft or outwardly engageable with a housing, hub, or other component mounted around the shaft. When used in harsh or extreme environments (e.g., in the roller system of a metal casting machine), the seal may be required to prevent potentially hazardous substances such as vapors or metal scale from contacting other mechanical components (e.g., bearings). In such applications, these radial lip seals may be used in combination with rigid seals such as thermoplastic scrapers to provide initial protection or a barrier against such hazardous substances. Summary of the Invention

[0003] On one hand, the present invention is a seal assembly for sealing between a central rotating shaft and an external member disposed around the rotating shaft, the external member being rotatable about an axis passing through the rotating shaft. The seal assembly includes an annular housing located within and connected to the external member to allow angular displacement about the axis. An annular flexible seal is disposed within the housing and connected to the latter to allow angular displacement about the axis as the external member rotates about the axis. The flexible seal has at least one elastomeric sealing lip capable of engaging the outer circumferential surface of the rotating shaft or a sleeve disposed around the rotating shaft. An annular inner rigid seal is at least partially located within the housing, having an inner radial end spaced axially from the sealing lip and connected to the rotating shaft or a sleeve disposed around the rotating shaft. The outer radial end of the inner rigid seal slides against the flexible seal so that the flexible seal can be radially displaced relative to the rigid seal when the external member undergoes axial displacement relative to the rotating shaft. Furthermore, an annular outer rigid seal is disposed around an inner rigid seal and connected to the housing, thereby enabling angular displacement about a central axis, and has an inner end capable of sealingly engaging with the inner rigid seal. A biasing member is configured to force the outer rigid seal to apply a bias to the inner rigid seal, thereby sealingly engaging the outer and inner rigid seals.

[0004] In another aspect, the present invention also relates to a sealing assembly as described above, wherein the housing has: a cylindrical portion having first and second axial ends; a first radial flange extending inwardly from the first axial end of the cylindrical portion; and a second radial flange extending inwardly from the second axial end of the cylindrical portion. Furthermore, the flexible seal is a first flexible seal, and the sealing assembly further includes a second flexible seal. The second flexible seal is located within the housing and connected to the housing so as to allow angular displacement about a central axis when the external member rotates about an axis. The second flexible seal is axially spaced from the first flexible seal and has at least one elastomeric sealing lip capable of engaging with the outer circumferential surface of a shaft or a sleeve disposed around a shaft. Furthermore, the biasing member is either axially disposed between the first radial flange of the housing and the outer rigid seal, or disposed around the cylindrical portion of the outer rigid seal. Attached Figure Description

[0005] The above summary and detailed description of preferred embodiments of the invention will be better understood by reading in conjunction with the accompanying drawings. For the purpose of illustrating the invention, the drawings show illustrative embodiments that currently appear preferable. However, it should be understood that the invention is not limited to the specific structures and means shown in the drawings. In the following drawings:

[0006] Figure 1 This is an axial sectional view of the sealing assembly of the present invention, showing a seal and, in a preferred case, a sleeve between the central rotating shaft and the external component;

[0007] Figure 2 for Figure 1 Partial cross-sectional perspective view of the sealing assembly;

[0008] Figure 3 for Figure 1 A magnified cross-sectional view of a portion of the structure;

[0009] Figure 4 for Figure 1 A magnified cross-sectional view of another part of the structure;

[0010] Figure 5 The enlarged cross-sectional view of the sealing assembly shows another candidate structure for the outer rigid seal.

[0011] Figure 6 This is an axial cross-sectional view of the housing of the sealing assembly;

[0012] Figure 7 This is an axial cross-sectional view of the sleeve of the sealing assembly;

[0013] Figure 8This is an axial cross-sectional view of the inner rigid seal.

[0014] Figure 9 This is an axial cross-sectional view of the outer rigid seal.

[0015] Figure 10 for Figure 8 Enlarged cross-sectional view of the upper part;

[0016] Figure 11 for Figure 9 Enlarged cross-sectional view of the upper part;

[0017] Figure 12 This is an axial cross-sectional view of the first flexible seal.

[0018] Figure 13 This is an axial cross-sectional view of the second flexible seal.

[0019] Figure 14 for Figure 12 Enlarged cross-sectional view of the upper part;

[0020] Figure 15 for Figure 13 Enlarged cross-sectional view of the upper part; and

[0021] Figure 16 The image shows another axial cross-sectional view of the sealing assembly, illustrating a technical solution where the seal is applied directly to the shaft instead of using a sleeve. Detailed Implementation

[0022] In the following description, certain terms are used for convenience only and not for limitation. The terms “inner,” “inward,” and “outer,” “outward,” respectively refer to directions pointing towards or away from the specified centerline or geometric center of the described component, their specific meanings being self-evident from the context. Furthermore, as stated herein, the terms “connected” and “linked” each have both a direct connection between two components without the intervention of any other components, and an indirect connection between two components with the intervention of one or more other components. The terminology includes the specific words mentioned above, their derivatives, and words with similar meanings.

[0023] Now see the accompanying drawings, in which similar reference numerals are used throughout to indicate similar parts. Figures 1-16The image shows a sealing assembly 10 used to seal the annular space between the central shaft 1 and the external components 2 arranged around the shaft 1. The function of the sealing assembly 10 is to prevent fluids such as hot water and steam, and / or solids such as metal scale particles, from entering the interior side (IS) of the sealing assembly 10 from the exterior side (ES), thereby protecting the bearing 4 that connects the external components 2 and the shaft 1. Figure 1 The outer component 2 is an inner part 3, such as an inner part 3. In a preferred application, the outer component 2 is a roller (not shown) in a metal casting roll line, rotatable about an axis Ac passing through the shaft 1, but may also be any other suitable component rotatably assembled around the shaft 1. The sealing assembly 10 essentially includes an outer case (hereinafter referred to as "outer case") 12, at least one annular flexible seal 14 coupled to the outer case 12, an annular inner "scraper" or rigid seal 16 coupled to the shaft 1 or to a sleeve 18 disposed around the shaft 1, an outer rigid seal / scraper 28 disposed around the inner rigid seal 16, and a biasing member 48 configured to force the outer rigid seal 28 to apply a bias to the inner rigid seal 16. The sealing assembly 10 also preferably includes the sleeve 18.

[0024] Specifically, the housing 12 is disposed within and connected to the outer member 2 so as to be angularly displaced (i.e., rotated) about the central axis Ac. A flexible seal 14 is disposed within and connected to the housing 12 so as to be angularly displaced about the central axis Ac when the outer member 2 rotates about the axis Ac. The flexible seal 14 has at least one elastomeric sealing lip 15 capable of engaging with the outer circumferential surface 1a of the rotating shaft 1, such as... Figure 16 As shown, or in a preferred embodiment, it can engage with the outer circumferential surface 19A of the sleeve 18 disposed around the pivot 1. Furthermore, the inner rigid seal 16 is at least partially disposed within the housing 12 and has an inner radial end 16a and an outer radial end 16b.

[0025] Specifically, the inner radial end 16a of the inner rigid seal 16 is axially spaced from the sealing lip 15 and is connected to the rotating shaft 1. Figure 16Alternatively, it can be connected to sleeve 18 in a preferred manner to securely connect or link seal 16 to shaft 1. The outer radial end 16b of the seal can slide against flexible seal 14, such that when outer member 2 undergoes radial displacement relative to shaft 1, flexible seal 14 can radially displace relative to rigid member 16, and when seal 14 revolves around axis A... C During angular displacement, the flexible seal 14 slides against the rigid seal 16. This displacement of the flexible seal 14 relative to the rigid seal 16 typically occurs when the outer member 2 is eccentrically mounted about the axis of rotation 1, i.e., on the axis A of the outer member. C Offset from the center line of the rotation axis L C In the case of (the structure is not shown).

[0026] Furthermore, the outer rigid seal 28 is coupled to the housing 12, allowing for angular displacement about the centerline Ac, and has an inner end 28a that preferably seals with the inner rigid seal 16 via a sealing lip 40 (described below). When the outer member 2 rotates about the centerline Ac, the inner end 28a / lip 40 of the outer rigid seal 28 slides on the inner rigid seal 16 while maintaining a sealing engagement. Additionally, the outer rigid seal 28 is radially spaced from the inner rigid seal 16, defining a gap space Sc, as described later, to allow radial displacement of the outer rigid seal 28 relative to the inner rigid seal 16 when the outer member 2 rotates eccentrically about the centerline Ac. Moreover, the biasing member 48 is either axially positioned between the first radial flange 22 of the housing 12 and the outer rigid seal 28, or disposed around the cylindrical portion 34 of the outer rigid seal 28, as described in detail below. The function of the offset member 48 is to maintain the sealing engagement between the inner end 28a (preferably the sealing lip 40) of the outer rigid seal and the inner rigid seal 16, especially during the process of the outer member 2 undergoing angular displacement around the central axis Ac.

[0027] See Figure 1 , 26. The housing 12 preferably includes a cylindrical portion 20 and first and second radial flanges 22 and 24, respectively, wherein the cylindrical portion has inner and outer circumferential surfaces 21A and 21B and first and second axial ends 20a and 20b opposite to each other. Each radial flange 22 and 24 extends inward from an independent axial end 20a or 20b of the cylindrical portion 20. The outer circumferential surface 21B is frictionally engaged with the inner circumferential surface 2a of the outer member ( / outer member) 2 to connect the sealing assembly 10 to the outer member 2. The first flange 22 is preferably a single continuous portion of the housing 12, while the second flange 24 is preferably formed by a plurality of (e.g., six) flange portions 24a. The flange portions 24a are initially formed as flat and extend axially from the second axial end 20b of the cylindrical portion 20, such as Figure 6 As shown. With this second flange structure, various components of the sealing assembly 10 can pass through the opening Oc defined at the second axial end 20b position of the outer casing cylindrical portion 20. Figure 6 The component is inserted into the housing 12, and then the second flange 24 is bent inward to hold the component in the housing 12, as discussed later.

[0028] like Figure 1 and 4 As shown, the housing 12 preferably includes at least one, and preferably multiple, spacer portions 25 integrally formed therewith. Each of the spacer portions 25 extends axially from the second axial end 20b of the housing cylindrical portion 20 and has an outer end 25a that can contact a member 3, such as a bearing 4, which is axially spaced from the sealing assembly 10. The function of the spacer portions 25 is to transfer axial loads between the member 3 and the housing 12 of the sealing assembly 10, especially due to the thermal expansion of the member 3. In a preferred embodiment, the spacer portions 25 are generally curved and formed to be at least generally similar to the flange portion 24a, except that they are not bent inwards, but they may also be formed to be different from the flange portion 24a in size or shape. In addition, the housing 12 preferably also includes a molded annular elastomer portion 13 in the inwardly offset portion 20c of its cylindrical portion 20 near the first axial end 20a for sealing between the housing 12 and the outer member 2.

[0029] See Figure 1 , 2 As described above, the sealing assembly 10 preferably includes a tubular sleeve 18. The sleeve 18 is disposed around the rotating shaft 1 and includes an outer circumferential surface 19A and an inner circumferential surface 19B opposite to the outer circumferential surface 19A. The inner circumferential surface 19B defines a central hole B that receives a portion of the rotating shaft 1. S ( Figure 7In the preferred embodiment of sleeve 18, the sealing lip 15 of the flexible seal 14 seals against the outer circumferential surface 19A, and the sealing lip 17 located at the radially inner end 16a of the rigid seal 16 is frictionally connected to sleeve 18. Furthermore, sleeve 18 preferably has at least one, and preferably multiple, annular grooves 23 extending radially outward from the inner circumferential surface 19B, and a corresponding number of annular seals (preferably O-rings) 25 each located in an independent groove 23. In this manner, the seals 25 prevent fluid flow between sleeve 18 and shaft 1.

[0030] See now Figures 1-3 5, 8, and 10, the inner rigid seal 16 preferably comprises a cylindrical portion 30 and a radial flange portion 32, and is preferably formed of a rigid polymeric material (preferably polyetheretherketone (PEEK)), but may also be formed of other suitable rigid polymers, metals, etc. The cylindrical portion 30 at least partially surrounds the sealing lip 15 of the flexible seal 14, and has a first axial end 30a abutting against the flexible seal 14, a second axial end 30b in the opposite direction to the first axial end 30a, and inner and outer circumferential surfaces 31A and 31B facing each other. Preferably, the cylindrical portion 30 has an outwardly extending annular shoulder 30c formed near its first axial end 30a to increase the surface area in contact with the flexible seal 14. The radial flange portion 32 has an outer radial end 32a integrally formed with the second axial end 30b of the cylindrical portion 30, and inner and outer radial surfaces 33A and 33B facing each other.

[0031] Furthermore, the inner radial end 32b of the flange portion 32 is sized to allow for frictional engagement with the rotating shaft 1 or a sleeve 18 disposed around the rotating shaft 1. That is, the radial flange portion 32 has an inner diameter dimension ID. R ( Figure 8 The outer diameter of the shaft 1 (not shown) or the outer diameter OD of the sleeve 18 is smaller than that of the shaft 1. S ( Figure 7 The central opening O RI ( Figure 8This allows the rigid seal 16 to be connected to the shaft 1 via an interference fit, or, preferably, to the sleeve 18. In this way, the inner rigid seal 16 is typically stationary or non-rotating during the rotation of the outer component 2 and consequently, the rotation of components such as the flexible seal 14 and the outer rigid seal 28. However, the flexible seal 14 is allowed to slide axially along the shaft 1 or sleeve 18 to a certain extent when axial displacement occurs (e.g., due to thermal expansion). Furthermore, the radial flange 32 preferably has an inner angled section 35 extending substantially outward from the outer side ES of the sealing assembly 10 and providing a sealing lip 17. The orientation of the angled section 35 causes the fluid pressure acting on the rigid seal 16 to bias the sealing lip 17 radially inward, thereby promoting a seal.

[0032] See Figures 1-3 5, 9, and 11, the annular outer rigid seal 28 is preferably made of the same material as the inner rigid seal 16 (preferably the aforementioned PEEK material). In a preferred embodiment, the outer rigid seal 28 includes a cylindrical portion 34, an inwardly extending radial flange portion 36 for providing a sealing lip 40, and an outwardly extending radial flange portion or shoulder portion 38. Specifically, the cylindrical portion 34 of the outer rigid seal 28 preferably at least partially surrounds the cylindrical portion 30 of the inner rigid seal 16 and includes first and second axial ends 34a and 34b that are opposite to each other, and inner and outer circumferential surfaces 35A and 35B that are opposite to each other. Furthermore, the cylindrical portion 34 of the outer rigid seal 28 is also spaced radially outward from the cylindrical portion 30 of the inner rigid seal 16, such that an annular gap space S is defined between the inner rigid seal 16 and the outer rigid seal 28. C ( Figure 3 and 5 The gap space S C The outer rigid seal 28 may be radially displaced relative to the inner rigid seal 16, or vice versa.

[0033] Furthermore, the radial flange portion 36 extends inward from the cylindrical portion 34 and seals against the radial flange portion 32 of the inner rigid seal 16. More specifically, the flange portion 36 has an outer radial end 36a integrally formed with the second axial end 34b of the cylindrical portion 34, an inner radial end 36b providing the sealing lip 40, and inner and outer radial surfaces 37A and 37B that are opposite to each other. The inner radial end 36b of the flange defines the central hole O. RO ( Figure 9 The size is significantly larger than the central hole O of the inner rigid seal 16. RI ( Figure 8The inner radial end 36b is positioned such that it abuts against the middle of the outer radial surface 33B of the rigid seal 16. In a preferred embodiment, the radial flange 36 of the outer rigid seal 28 also has a tapered portion 43 near its inner radial end 36b. Figure 9 The tapered portion 43 extends axially inward toward the rigid seal 16, providing the sealing lip 40.

[0034] See now Figures 1-3 In some configurations, the cylindrical portion 34 of the outer rigid seal 28 is sized such that the first axial end 34a of the outer rigid seal 28 abuts against the flexible seal 14, and an annular biasing member 48 is disposed between the first radial flange 22 of the housing 12 and the outer rigid seal 28. In a preferred embodiment, the biasing member 48 is formed as a slotted disk spring 50 having a plurality of radially inwardly extending fingers 52, such as... Figure 2 As is most clearly shown, the disc spring biasing member 50 is configured to force the radial flange 36 of the outer rigid seal 28 against the radial flange 32 of the inner rigid seal 16, thereby maintaining the sealing engagement between the rigid seals 16 and 28, while simultaneously connecting the outer rigid seal 28 to the housing 12 and the flexible seal 14 by friction.

[0035] In other structures, especially referencing Figure 5 The cylindrical portion 34 of the outer rigid seal 28 is axially spaced from the flexible seal 14. The biasing member 48 preferably includes a tubular body 56 disposed around the cylindrical portion 34 of the outer rigid seal 28. The tubular body 56 has a first axial end 56a abutting against the housing flange 22 and a second axial end 56b abutting against a radial flange / shoulder 38 projecting outwardly from the outer rigid seal 28. The tubular biasing spring 56 is configured to force the radial flange 36 of the outer rigid seal 28 against the radial flange 32 of the inner rigid seal 16, and to connect the outer rigid seal 28 to the housing 12. Preferably, the tubular biasing member 56 is formed as a solid tube made of a compressible polymer material (preferably natural or synthetic rubber), but it can also be formed as a coil spring or any other suitable form that performs the general function described herein.

[0036] See now Figures 1-35, 12, 14, and 16, the flexible seal 14 preferably includes a radially outer housing portion 60 connected to the housing 12 and a radially inner elastomeric seal portion 62 attached to the housing portion 60, providing at least one (preferably at least two) sealing lips 15. The seal housing portion 60 is preferably formed of a combination of metal and elastomeric materials, generally C-shaped, and includes an outer axial portion 64, an intermediate radial portion 66 extending inward from the outer axial portion 64, and an inner axial portion 68. The outer axial portion 64 has inner and outer circumferential surfaces 65A and 65B, the outer circumferential surface 65B being frictionally engaged with the inner circumferential surface 21A of the housing 12 to connect the seal 14 to the housing 12. The intermediate radial portion 66 has an outer radial end 66a integrally formed with the outer axial portion 64, an inner radial end 66b integrally formed with the inner axial portion 68, and first and second radial surfaces 67A and 67B. Figure 14 The outer radial end 16b of the rigid seal 16 slides against the first radial contact surface 67A of the seal housing portion 60 located on the intermediate radial portion 66, such that during the rotation of the outer member 2, the housing surface 67A slides relative to the rigid seal end 16b, and during the radial displacement of the outer member 2 relative to the axis of rotation 1 (e.g., due to eccentricity), the housing surface 67A also slides radially relative to the end 16b. Furthermore, the inner axial portion 68 extends axially from the inner end 66b of the radial portion 66, making it substantially parallel to the outer axial portion 64.

[0037] The elastomeric seal 62 is preferably formed on the housing portion 60 by compression molding, preferably connected to the elastomeric portion of the housing portion 60, and is configured such that one or more sealing lips can extend radially inward from the inner axial portion 68 of the housing portion. Specifically, the two sealing lips 15 preferably used are axially spaced apart, each annular, and include a radially outer end 15a integrally formed with the rest of the elastomeric portion and a radially inner free end 15b capable of sealingly engaging with the outer surface 1a of the shaft (or, in the preferred case, the outer surface 19A of the sleeve). Furthermore, each sealing lip 15 is preferably angled generally toward the high-pressure outer side ES of the sealing assembly 10 (and thus generally toward the side facing the rigid seal 16).

[0038] See now Figure 1 , 214, 13, 15, and 16, the flexible seal 14 is preferably a first flexible seal 14, and the sealing assembly 10 further includes a second flexible seal 70 formed substantially similarly to the first seal 14. The second flexible seal 70 is located within the housing 12 and axially spaced from the first flexible seal 14, such that the first flexible seal 14 is axially positioned between the rigid seal 16 and the second flexible seal 70. In this way, the second flexible seal 70 serves as a "backup" to the first flexible seal 14, preventing any fluid (or solid) from passing through it. The second flexible seal 70 has at least one, preferably three, elastomeric sealing lips 72 capable of engaging with the outer circumferential surface 1a of the shaft 1 (or, preferably, the outer circumferential surface 19A of the sleeve 18).

[0039] Specifically, the second flexible seal 70 preferably includes a C-shaped housing portion 74 connected to the housing 12 and an elastomeric sealing portion 76 attached to the housing portion 74 to provide a sealing lip 72. Figure 13 The sealing housing portion 74 includes an outer axial portion 78 that frictionally engages with the housing 12, an intermediate radial portion 80 extending inward from the outer axial portion 78, and an inner axial portion 82 extending from the intermediate radial portion 80 and parallel to the outer axial portion 78. The elastomeric sealing portion 76 is preferably formed on the housing portion 74 by molding, preferably integrally formed with the elastomeric portion of the housing portion 74, and is configured such that the sealing lip 72 extends radially inward from the inner axial portion 82 of the housing portion. Furthermore, the sealing lips 72 are axially spaced, each generally annular, and include a radially outer end 72a integrally formed with the remainder of the elastomeric portion 76 and a radially inner free end 72b that sealably engages with the outer surface 1a of the shaft (or, preferably, the outer surface 19A of the sleeve). Like the sealing lip 15 of the first flexible seal 14, each sealing lip 72 is preferably angled generally toward the high-pressure outer side ES of the sealing assembly 10 (and thus generally toward the side just toward the first flexible seal 14).

[0040] Still referencing Figure 1 , 2In cases where two flexible seals 14 and 70 are preferably provided, the sealing assembly 10 preferably also includes an annular spacer (hereinafter referred to as "spacer ring") 84 made of a rigid material such as a rigid polymer or metal and disposed between the two flexible seals 14 and 70. The spacer ring 84 has a first axial end 84a abutting against the first flexible seal 14 and a second axial end 84b abutting against the second flexible seal 70 in the opposite direction to the first axial end 84a. Preferably, the spacer ring 84 is sandwiched between the respective intermediate radial portions 66 and 80 of the seal housing portions 60 and 74 and is configured to transmit axial load between the first and second flexible seals 14 and 70. Furthermore, cavities 90 are formed between the two flexible seals 14 and 70, between the individual lips 15 or 72 of each seal 14 and 70, and between the first flexible seal 14 and the inner rigid seal 16. Figure 1 Each of them is preferably filled with a viscous lubricant (such as grease).

[0041] In the case where the sealing assembly 10 preferably includes a second flexible seal 70 and a spacer ring 84, the second radial flange 24 of the housing 12 is arranged abutting against the second flexible seal 70, specifically against the radial surface 81 of the middle portion 80 of the seal housing portion. In this way, the outer rigid seal 28, the first flexible seal 14, the annular spacer ring 84, and the second flexible seal 70 are axially held between the first and second flanges 22, 24 of the housing 12, thereby connecting it to the housing 12 and the outer member 2. As a result, the entire sealing assembly 10, as a whole, can withstand relatively high axial loads, especially due to thermal expansion, and can be axially displaced relative to the shaft 1 by sliding directly on the outer surface 1a of the shaft or the outer surface 19A of the sleeve.

[0042] The sealing assembly 10 of the present invention has many advantages over previously known sealing assemblies for relatively harsh or extreme applications (e.g., those discussed above for metal casting roll lines). The structure of the inner and outer rigid seals or "scrapers" 16, 28 allows for radial relative displacement between the outer member 2 and the shaft 1, thus allowing for eccentricity, while preventing the seals 16, 18 from separating from each other during axial relative displacement. By forming rigid seals 16, 28 made of a rigid polymeric material such as PEEK, the seals 16, 28 provide a high-temperature barrier capable of blocking high-temperature substances such as steam, hot water, and metal scale particles. Furthermore, the flexible seals 14, 70 are also protected by the rigid seals 16, 28 from substances that could damage the elastomeric material of the sealing lips 15, 17. At the same time, since the elastomeric material has better ductility and flexibility than more rigid polymeric materials, graphite, metal materials, etc., it provides more effective sealing protection. Furthermore, the multiple sealing lips 15, 72 of the two flexible seals 14, 70 provide a significant barrier that prevents any fluid leakage into the inner side IS of the sealing assembly 10. Moreover, as described above, the "stacking" of the bias member 48, the outer rigid seal 28, the first flexible seal 14, the spacer ring 84, and the second flexible seal 70 between the two housing flanges 22, 24 provides a sealing assembly 10 that can be axially displaced as a whole (e.g., due to thermal expansion) and can absorb high axial loads without damaging the aforementioned components or causing sealing assembly failure.

[0043] The foregoing detailed description of representative, non-limiting embodiments of the present invention, taken in conjunction with the accompanying drawings, is intended only to teach those skilled in the art to implement the preferred aspects of the present teachings, and is not intended to limit the scope of protection of the invention.

[0044] Furthermore, the combination of features and steps disclosed in the above detailed description is not essential for carrying out the invention in a broad sense; its teachings are only used to specifically describe representative embodiments of the invention. Moreover, the various features of the above representative embodiments, as well as the various independent and dependent claims thereafter, can be combined in ways not specifically stated or expressly enumerated to provide additional useful implementations beyond the present teachings.

[0045] All features disclosed in the specification and / or claims are disclosed individually and independently for the purposes of the original written disclosure and to limit the scope of the claimed subject matter, without dependence on the feature composition of the embodiments and / or claims. Furthermore, all numerical ranges or representations of entity groups are disclosed for the purposes of the original written disclosure and to limit the scope of the claimed subject matter, for each possible intermediate value or intermediate entity. The invention is not limited to the specific embodiments described above and may be modified within the scope of the following claims.

Claims

1. A sealing assembly for sealing between a central rotating shaft and an external member disposed around the rotating shaft, the external member being rotatable about an axis extending through the rotating shaft, the sealing assembly comprising: An annular outer shell is housed within and connected to the outer component, enabling angular displacement about the central axis; An annular flexible seal is disposed within and connected to a housing, enabling angular displacement about a central axis when an external component rotates about an axis. The flexible seal has at least one elastomeric sealing lip capable of engaging with the outer circumferential surface of a shaft or a sleeve disposed about a shaft. An annular inner rigid seal, at least partially located within the housing, has an inner radial end and an outer radial end, the inner radial end being axially spaced from the sealing lip and connected to a shaft or a sleeve, the outer radial end being slidably arranged against a flexible seal such that when the external component undergoes radial displacement relative to the shaft, the flexible seal can be radially displaced relative to the rigid seal. An annular outer rigid seal, surrounding an inner rigid seal, is connected to the housing, allowing for angular displacement about a central axis, and has an inner end capable of sealingly engaging with the inner rigid seal; and The biasing member is configured to force the outer rigid seal to apply bias pressure to the inner rigid seal, such that the outer rigid seal seal seals sealably engages with the inner rigid seal seal.

2. The sealing assembly as claimed in claim 1, characterized in that, The outer casing has an inwardly extending radial flange; The inner rigid seal includes a cylindrical portion and a radial flange. The cylindrical portion has a first axial end arranged against a flexible seal and a second axial end in the opposite direction to the first axial end. The radial flange is integrally formed with the second axial end of the cylindrical portion and provides the inner end of the inner rigid seal. The outer rigid seal includes a cylindrical portion and a radial flange. The cylindrical portion has a first axial end abutting against a flexible seal and a second axial end in the opposite direction to the first axial end. The radial flange is integrally formed with the second axial end of the cylindrical portion and provides an inner end for the outer rigid seal. The biasing member is arranged between the radial flange of the housing and the outer rigid seal, and is configured to force the radial flange of the outer rigid seal to apply bias towards the radial flange of the inner rigid seal.

3. The sealing assembly as described in claim 2, characterized in that, The biasing member is a slotted disc spring with multiple radially extending fingers.

4. The sealing assembly as claimed in claim 1, characterized in that, The outer casing has an inwardly extending radial flange; The outer rigid seal includes a cylindrical portion and a radial flange. The cylindrical portion has a first axial end abutting against a flexible seal and a second axial end in the opposite direction to the first axial end. The radial flange is integrally formed with the second axial end of the cylindrical portion and provides an inner end for the outer rigid seal. The biasing member includes a tubular body disposed around a cylindrical portion of an outer rigid seal, the tubular body having a first axial end disposed against a radial flange of a housing and a second axial end disposed against an outwardly extending radial flange of the outer rigid seal, the biasing member being configured to force the inwardly extending radial flange of the outer rigid seal to apply bias pressure to the radial flange of the inner rigid seal.

5. The sealing assembly as described in claim 4, characterized in that, The tubular body of the biasing member is made of a compressible elastomeric material or a deflectable metallic material.

6. The sealing assembly as claimed in claim 1, characterized in that, The inner rigid seal includes a cylindrical portion and a radial flange portion. The cylindrical portion is at least partially disposed around the sealing lip of the flexible seal, and has a first axial end abutting against the flexible seal and a second axial end in the opposite direction to the first axial end. The radial flange portion has an outer radial end integrally formed with the second axial end of the cylindrical portion and an inner radial end whose dimensions are set to frictionally engage with a rotating shaft or a sleeve disposed around a rotating shaft. The outer rigid seal includes a cylindrical portion and a radial flange portion extending inward from the cylindrical portion, wherein the cylindrical portion is arranged at least partially around the cylindrical portion of the inner rigid seal, and the radial flange portion is sealingly engaged with the radial flange portion of the inner rigid seal. The cylindrical portion of the outer rigid seal is spaced apart from the cylindrical portion of the inner rigid seal from the radially outer side, thereby defining an annular gap space between the inner and outer rigid seals.

7. The sealing assembly as claimed in claim 1, characterized in that, The flexible seal includes a housing portion and an elastomeric sealing portion, the housing portion being connected to an outer shell, and the elastomeric sealing portion being attached to the housing portion and providing the at least one sealing lip.

8. The sealing assembly as claimed in claim 7, characterized in that, The housing portion of the flexible seal is generally C-shaped, including an outer axial portion, a radial portion, and an inner axial portion. The outer axial portion has an outer circumferential surface that frictionally engages with the inner circumferential surface of the housing to connect the flexible seal to the housing. The radial portion extends inward from the outer axial portion and provides a radial contact surface. The inner axial portion extends axially from the inner end of the radial portion. At least one sealing lip extends radially inward from the inner axial portion.

9. The sealing assembly as claimed in claim 7, characterized in that, The flexible seal's elastomeric sealing portion includes at least two axially spaced sealing lips, each capable of engaging with a shaft or sleeve.

10. The sealing assembly as claimed in claim 1, characterized in that, The flexible seal is a first flexible seal, and the sealing assembly further includes a second flexible seal. The second flexible seal is arranged inside the housing and spaced apart from the first flexible seal in the axial direction, such that the first flexible seal is arranged in the axial direction between the inner rigid seal and the second flexible seal. The second flexible seal also has at least one elastomeric sealing lip that can engage with the outer circumferential surface of the shaft or sleeve.

11. The sealing assembly as claimed in claim 10, characterized in that, Each of the first and second flexible seals includes a housing portion having a rigid radial portion; The sealing assembly further includes an annular spacer having a first axial end arranged abutting against a rigid radial portion of a first flexible seal and a second axial end arranged abutting against a rigid radial portion of a second flexible seal in the opposite direction to the first axial end, the spacer being configured to transmit axial load between the first and second flexible seals.

12. The sealing assembly as claimed in claim 11, characterized in that, The outer casing has: a cylindrical portion having a first axial end and a second axial end that are opposite to each other; and a first radial flange extending inward from the first axial end of the cylindrical portion. An offset member is disposed between the first radial flange of the housing and the outer rigid seal; and a second radial flange extends inward from the second axial end of the cylindrical portion and is configured to abut against the second flexible seal, such that the outer rigid seal, the first flexible seal, the annular spacer and the second flexible seal are axially held between the first radial flange and the second radial flange of the housing.

13. The sealing assembly as claimed in claim 12, characterized in that, The housing includes at least one spacer integrally formed therewith, the spacer extending axially from the cylindrical portion of the housing and having an outer end capable of contacting a member spaced axially from the sealing assembly.

14. The sealing assembly as claimed in claim 10, characterized in that, Each of the first and second flexible seals includes at least two elastomeric sealing lips, each capable of engaging with a shaft or sleeve.

15. The sealing assembly as claimed in claim 1, characterized in that, The sealing assembly further includes a tubular sleeve disposed around the pivot and having an outer circumferential surface, wherein at least one sealing lip of the flexible seal engages with the outer circumferential surface of the sleeve, and the inner radial end of the rigid seal is frictionally connected to the sleeve.

16. A sealing assembly for sealing between a central pivot and an external member disposed around the pivot, the external member being rotatable about an axis extending through the pivot, the sealing assembly comprising: An annular housing is disposed within and connected to an external member, allowing for angular displacement about a central axis. The housing has: a cylindrical portion having a first axial end and a second axial end; and a first radial flange extending inwardly from the first axial end of the cylindrical portion. And a second radial flange, extending inward from the second axial end of the cylindrical portion; An annular first flexible seal is disposed within and connected to the housing, such that it is angularly displaced about the central axis when the external component rotates about the axis. The first flexible seal has at least one elastomeric sealing lip capable of engaging with the outer circumferential surface of a rotating shaft or a sleeve disposed about the rotating shaft. A second flexible seal is annular, disposed within and connected to the housing, such that it is angularly displaced about the central axis when the external component rotates about the axis. The second flexible seal is axially spaced from the first flexible seal and has at least one elastomeric sealing lip capable of engaging with the outer circumferential surface of a shaft or a sleeve disposed about the shaft. An annular inner rigid seal, at least partially located within a housing, having an inner radial end and an outer radial end, the inner radial end being axially spaced from a sealing lip and connected to a shaft or a sleeve, the outer radial end being slidably arranged against a flexible seal such that the flexible seal can be radially displaced relative to the inner rigid seal when the outer component is radially displaced relative to the shaft; An annular outer rigid seal, the outer rigid seal being disposed around an inner rigid seal, connected to the housing, allowing angular displacement about a central axis, and having an inner end capable of sealingly engaging with the inner rigid seal; and A biasing member configured to force an outer rigid seal to bias an inner rigid seal such that the outer rigid seal and the inner rigid seal are sealingly engaged. The biasing member is axially arranged between a first radial flange of the housing and the outer rigid seal, or is disposed around a cylindrical portion of the outer rigid seal.

17. The sealing assembly as claimed in claim 16, characterized in that, The inner rigid seal includes a cylindrical portion and a radial flange. The cylindrical portion has a first axial end arranged against a flexible seal and a second axial end in the opposite direction to the first axial end. The radial flange is integrally formed with the second axial end of the cylindrical portion and provides the inner end of the inner rigid seal. The outer rigid seal includes a cylindrical portion and a radial flange. The cylindrical portion has a first axial end abutting against a flexible seal and a second axial end in the opposite direction to the first axial end. The radial flange is integrally formed with the second axial end of the cylindrical portion and provides an inner end for the outer rigid seal. The biasing member is arranged between the radial flange of the housing and the outer rigid seal, and is configured to force the radial flange of the outer rigid seal to apply bias towards the radial flange of the inner rigid seal.

18. The sealing assembly as claimed in claim 16, characterized in that, The outer rigid seal includes a cylindrical portion and a radial flange. The cylindrical portion has a first axial end abutting against a flexible seal and a second axial end in the opposite direction to the first axial end. The radial flange is integrally formed with the second axial end of the cylindrical portion and provides an inner end for the outer rigid seal. The biasing member includes a tubular body disposed around a cylindrical portion of an outer rigid seal, the tubular body having a first axial end disposed against a radial flange of a housing and a second axial end disposed against an outwardly extending radial flange of the outer rigid seal, the biasing member being configured to force the inwardly extending radial flange of the outer rigid seal to apply bias pressure against the radial flange of the inner rigid seal.

19. The sealing assembly as claimed in claim 16, characterized in that, Each of the aforementioned flexible seals includes a housing portion and an elastomeric sealing portion, the housing portion being connected to an outer shell, and the elastomeric sealing portion being attached to the housing portion and providing the at least one sealing lip.

20. The sealing assembly as claimed in claim 16, characterized in that, Each of the first and second flexible seals includes a housing portion having a rigid radial portion; The sealing assembly further includes an annular spacer having a first axial end arranged abutting against a rigid radial portion of a first flexible seal and a second axial end arranged abutting against a rigid radial portion of a second flexible seal in the opposite direction to the first axial end, the spacer being configured to transmit axial load between the first and second flexible seals.

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