阅读说明：本技术 用于密封组件的套筒 (Sleeve for sealing assembly ) 是由 约翰·M·多明格斯 马修·W·施威格 于 2021-05-06 设计创作，主要内容包括：一种用于唇密封组件的套筒包括刚性部,所述刚性部具有管状段和径向凸缘,所述管状段具有限定用于接纳轴的孔内表面和提供密封接合表面的外表面,所述径向凸缘从所述管状段的轴向端部延伸。附接到所述刚性部的弹性部具有管状段和唇,所述管状段布置在所述刚性部的孔内,所述唇从所述管状段的一个轴向端部在轴向上向外延伸以布置在所述刚性部的孔的外部,并且具有可与所述轴的外表面接合的密封表面,并且所述弹性部可以具有从相对的轴向端部在轴向上延伸的另一个唇。轴向唇使得安装力减小,在运输、处理、安装和拆卸测试轴和插塞以及最后的轴组装的过程中将润滑剂保持在套筒孔内,并且空气侧的唇防止了组装润滑剂的泄漏。(A sleeve for a lip seal assembly includes a rigid portion having a tubular section with an inner surface defining a bore for receiving a shaft and an outer surface providing a seal engagement surface, and a radial flange extending from an axial end of the tubular section. The resilient portion attached to the rigid portion has a tubular section disposed within the bore of the rigid portion and a lip extending axially outward from one axial end of the tubular section to be disposed outside the bore of the rigid portion and having a sealing surface engageable with the outer surface of the shaft, and may have another lip extending axially from an opposite axial end. The axial lip reduces installation forces, retains lubricant within the sleeve bore during shipping, handling, installation and removal of the test shaft and plug and final shaft assembly, and the air side lip prevents leakage of assembly lubricant.)

1. A sleeve for a unitized radial lip seal assembly for sealing an annular space between a shaft and a seat, the shaft having a circumferential outer surface, and the seal assembly including an annular primary seal lip, the sleeve comprising:

a rigid portion including a tubular section having first and second opposite axial ends, a circumferential inner surface defining a bore for receiving the shaft, and a circumferential outer surface providing an engagement surface for the primary seal lip, and a radial flange extending from the first axial end of the tubular section of the rigid portion; and

a resilient portion attached to the rigid portion and including a tubular section disposed within the bore of the rigid portion and having a circumferential inner surface disposable about the outer surface of the shaft and first and second opposing axial ends, and a lip extending axially outward from the first axial end of the tubular section of the resilient portion so as to be disposed substantially outside the bore of the rigid portion and having a circumferential inner sealing surface sealingly engageable with the outer surface of the shaft.

2. The sleeve of claim 1 configured to be positioned on the shaft such that the lip of the resilient portion is on an air side of the seal assembly and to prevent fluid between the sleeve and the shaft from a fluid side of the seal assembly from flowing to the air side.

3. The sleeve of claim 1 wherein said lip has: an inner end portion integrally formed with a first axial end of the tubular section of the resilient portion; and an opposite free axially outer end spaced axially outwardly from the first axial end of the tubular section of the resilient portion and providing a sealing surface for the lip.

4. The sleeve of claim 1 wherein said lip includes a cantilevered annular body having: an inner end portion integrally formed with a first axial end of the tubular section of the resilient portion; and a free axial end portion providing a sealing surface of the lip.

5. A sleeve as claimed in claim 4, wherein the sealing surface of the lip is formed on or includes an annular projection proximate the free end of the lip and providing the sealing surface.

6. The sleeve of claim 1 wherein a sealing surface of the lip has an inner diameter sized to be smaller than an outer diameter of an outer surface of the shaft when the sleeve is separated from the shaft such that the lip is in tension when the sleeve is disposed about the shaft.

7. The sleeve of claim 1 wherein the tubular section of the resilient portion has a centerline and at least one of:

at least one annular sealing boss extending inwardly from an inner surface of the tubular section of the elastomeric portion and circumferentially about the centerline, the sealing boss being sealingly engageable with an outer surface of the shaft; and

at least one axial rib extending radially inward from an inner surface of the tubular section of the resilient portion and axially along the centerline and configured to prevent relative angular displacement between the sleeve and the shaft.

8. A sleeve as claimed in claim 7, wherein the at least one annular sealing boss has an inner diameter that is smaller than an outer diameter of an outer surface of the shaft when the sleeve is separated from the shaft, such that the boss sealingly engages the shaft when the sleeve is mounted on the shaft.

9. A sleeve as claimed in claim 7, wherein any portion of the tubular segments of the at least one sealing lug and the resilient portion disposed between the rigid portion and the at least one annular lug and any portion of the tubular segments of the at least one axial rib and the resilient portion disposed between the rigid portion and the at least one axial rib are compressed when the sleeve is mounted on the shaft.

10. The sleeve of claim 1 wherein said lip is a first lip and said elastomeric portion further includes a second sealing lip extending axially outwardly from a second axial end of the tubular section of said elastomeric portion so as to be disposed outside of the bore of said rigid portion, said second sealing lip having a circumferential inner sealing surface sealingly engageable with the outer surface of said shaft.

11. The sleeve of claim 1 wherein said resilient portion further comprises a radial segment having: an inner end portion integrally formed with a first axial end of the tubular section of the resilient portion; an opposite radially outer end; and a radial end surface attached to the flange of the rigid portion.

12. The sleeve of claim 11 wherein said elastomeric portion further comprises at least one dust exclusion lip extending from a radial segment of said elastomeric portion and having a free end engageable with or disposed proximate to a housing of said seal assembly.

13. The sleeve of claim 1 wherein said rigid portion is formed of a metallic material and said resilient portion is bonded to said rigid portion.

14. A composite radial lip seal assembly for sealing an annular space between a shaft and a seat, the shaft having a circumferential outer surface and the seat having a circumferential inner surface defining a bore, the seal assembly comprising:

a housing having an annular outer portion coupleable with the seat and a flange portion extending radially inward;

a primary seal lip coupled with the flange portion of the housing; and

an inner sleeve disposable about the shaft and comprising:

a rigid portion including a tubular section having opposite first and second axial ends, a circumferential inner surface defining a bore, and a circumferential outer surface providing an engagement surface for the primary seal lip, and a radial flange extending from the first axial end of the tubular section of the rigid portion; and

a resilient portion attached to the rigid portion and including a tubular section and a lip, the tubular section of the resilient portion disposed within the bore of the rigid portion and having a circumferential inner surface disposable about the outer surface of the shaft and opposing first and second axial ends, the lip extending axially outward from the first axial end of the tubular section of the resilient portion so as to be disposed substantially outside the bore of the rigid portion and having a circumferential inner sealing surface sealingly engageable with the outer surface of the shaft.

15. The composite radial lip seal assembly of claim 14, wherein said sleeve is configured to be positioned on said shaft such that a lip of said elastomeric portion is on an air side of said seal assembly and prevents fluid between said sleeve and said shaft from a fluid side of said seal assembly from flowing to said air side.

16. The composite radial lip seal assembly of claim 14, wherein said lip includes a cantilevered annular body having: an inner end portion integrally formed with a first axial end of the tubular section of the resilient portion; and a free axial end portion providing a sealing surface of the lip.

17. The composite radial lip seal assembly of claim 16, wherein said lip's sealing surface is formed on a free end of said lip, or said lip includes an annular projection proximate said lip's free end and providing said sealing surface.

18. The composite radial lip seal assembly of claim 14, wherein a sealing surface of said lip has an inner diameter sized to be smaller than an outer diameter of an outer surface of said shaft when said sleeve is separated from said shaft, such that said lip is in tension when said sleeve is disposed about said shaft.

19. The combined radial lip seal assembly of claim 14, wherein the tubular segment of the elastomeric portion has a centerline and at least one of:

at least one annular sealing boss extending inwardly from an inner surface of the tubular section of the elastomeric portion and circumferentially about the centerline, the sealing boss being sealingly engageable with an outer surface of the shaft; and

at least one axial rib extending radially inward from an inner surface of the tubular section of the resilient portion and axially along the centerline and configured to prevent relative angular displacement between the sleeve and the shaft.

20. The combined radial lip seal assembly of claim 14, wherein at least one of:

the lip of the resilient portion is a first lip, and the resilient portion further includes a second sealing lip extending axially outward from a second axial end of the tubular section of the resilient portion so as to be disposed outside the bore of the rigid portion, the second sealing lip having a circumferential inner sealing surface sealingly engageable with an outer surface of the shaft;

the resilient portion further includes a radial segment having: an inner end portion integrally formed with a first axial end of the tubular section of the resilient portion; an opposite radially outer end; and a radial end surface attached to the flange of the rigid portion; and

the rigid portion is formed of a metal material, and the elastic portion is bonded to the rigid portion.

Technical Field

The present invention relates to seal assemblies, and more particularly to a sleeve (/ bushing) (sleeve) for a radial lip seal assembly.

Background

Radial lip seals are well known and typically comprise a housing (/ outer case) (outer case) and an annular resilient seal member (/ annular elastomeric seal member) having a circumferential lip sealingly engageable with a shaft or seat (/ bearing seat) (housing). In certain "combined/unitized" configurations, the sealing assembly further includes an inner sleeve rotatably coupleable with the shaft and providing an engagement surface for the sealing member. The sleeve can enable the seal assembly to be provided as an encapsulated (enclosed) unit that protects the seal member during shipping and assembly and better prevents contaminants from entering the sealing interface.

Disclosure of Invention

In one aspect, the present invention is a sleeve for a combined radial lip seal assembly (assembled radial lip seal assembly/unitized radial lip seal assembly) for sealing an annular space between a shaft having a circumferential outer surface and a seat (bearing seat/housing) (housing), the seal assembly including an annular primary seal lip. The sleeve includes a rigid portion including a tubular section (tubular section) having opposite first and second axial ends, a circumferential inner surface defining a bore (bore) for receiving the shaft, and a circumferential outer surface providing an engagement surface for the primary seal lip, and a radial flange extending from the first axial end of the tubular section. An elastomeric portion (elastomeric portion) is attached to the rigid portion and includes a tubular section disposed within the bore of the rigid portion and having a circumferential inner surface disposable about the outer surface of the shaft and opposing first and second axial ends. A lip extends axially outwardly from a first axial end of the tubular section of the resilient portion to be disposed substantially (/ substantially) (substantally) outside of the bore of the rigid portion and has a circumferential inner sealing surface (/ inner circumferential sealing surface) sealingly engageable with an outer surface of the shaft.

In another aspect, the present invention is a composite radial lip seal assembly for sealing an annular space between a shaft and a seat, the shaft having a circumferential outer surface and the seat having a circumferential inner surface defining a bore. The seal assembly includes a housing (/ outer case) having an annular outer portion coupleable with the seat and a radially inwardly extending flange portion. A primary seal lip is coupled with the flange portion of the shell. An inner sleeve may be disposed about the shaft and include a rigid portion including a tubular section having opposite first and second axial ends, a circumferential inner surface defining a bore, and a circumferential outer surface providing an engagement surface for the primary seal lip, and a radial flange extending from the first axial end of the tubular section. A resilient portion is attached to the rigid portion and includes a tubular section disposed within the bore of the rigid portion and having a circumferential inner surface disposable about the outer surface of the shaft and opposing first and second axial ends. Further, a lip extends axially outwardly from a first axial end of the tubular section of the resilient portion to be disposed substantially outside the bore of the rigid portion and has a circumferential inner sealing surface sealingly engageable with an outer surface of the shaft.

Drawings

The foregoing summary, as well as the detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings exemplary embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:

FIG. 1 is a cut-away axial cross-sectional view of a sleeve in a first configuration, the sleeve shown incorporated (incorporated) in a seal assembly and mounted on a shaft and within a seat;

FIG. 2 is a cut-away axial cross-sectional view of the sleeve and seal assembly of FIG. 1;

FIG. 3 is a cutaway axial cross-sectional perspective view of the sleeve in a first configuration;

FIG. 4 is a sectioned axial section of the sleeve in a first configuration;

FIG. 5 is a cut-away axial cross-sectional perspective view of the sleeve in a second configuration;

FIG. 6 is a sectioned axial section of the sleeve in a second configuration;

FIG. 7 is a cutaway axial cross-sectional perspective view of the sleeve in a third configuration;

FIG. 8 is a sectioned axial section of the sleeve in a third configuration;

FIG. 9 is an enlarged cut-away portion of a scraping lip (wiper lip) of the sleeve in a first configuration;

FIG. 10 is an enlarged cut-away portion of the scraping lip of the sleeve in a second configuration; and

FIG. 11 is an enlarged cut-away portion of the scraping lip of the sleeve of the third configuration.

Detailed Description

Certain terminology is used in the following description for convenience only and is not limiting. The words "inner", "inwardly" and "outer", "outwardly" refer to directions toward and away from, respectively, a designated centerline or geometric center of the described element, with particular meanings being apparent from the context of the description. Further, as used herein, the terms "connected" and "coupled" are each intended to include: a direct connection between two members without any other member interposed therebetween; and indirect connections between components, wherein one or more other components are interposed therebetween. The terminology includes the words above specifically mentioned, derivatives thereof and words of similar import.

Referring now in detail to the drawings, wherein like reference numerals are used to identify like elements throughout, there is shown in fig. 1-11 a sleeve (/ bushing) (sleeve)10 for a combined radial lip seal assembly (/ assembled radial lip seal assembly/unitized radial lip seal assembly)12, the combined radial lip seal assembly 12 being used to seal an annular space (not depicted) between a shaft 1 and a seat (/ bearing seat) (housing) 2. The shaft 1 being rotatable about a central axis A_CRotating and having a circumferential outer surface 1a, and the seat 2 has a circumferential inner surface 2a (figure 1) defining a hole 3. Further, the seal assembly 12 includes: a housing 14 couplable with the seat 2; an elastomeric primary seal member 16 coupled with the housing 14; and a sleeve 10 arranged within the housing 14 and mountable about the shaft 1.

The sleeve 10 mainly comprises an outer rigid portion 20 and an inner resilient portion 22, the inner resilient portion 22 being arranged partly within the rigid portion 20. The rigid portion 20 includes: a tubular section (tubular section)24 having a bore 21 for receiving the shaft 1; and a radial flange 26 extending outwardly from the tubular section 24. More specifically, the tubular segment 24 has opposite first and second axial ends 24a, 24B, a circumferential inner surface 25A defining the bore 21, and a circumferential outer surface 25B providing the primary seal lip 16 with the engagement surface 11, the engagement of the lip 16 with the surface 11 defining the primary sealing interface SI. Further, the radial flange 26 has a radially inner end 26a, a radially outer end 26B, the radially inner end 26a being integrally formed with the first axial end 24a of the tubular section 24, and opposite radial surfaces 27A, 27B, the radial surfaces 27A, 27B extending between the ends 26a, 26B.

Furthermore, the resilient portion 22 comprises a tubular section 30 and at least one axial sealing lip 32 connected to the tubular section 30, and preferably also a radial section 34 extending outwardly from the tubular section 30. The tubular section 30 is disposed within the bore 21 of the rigid portion and has a circumferential inner surface 31A disposable about the outer surface 1A of the shaft, a circumferential outer surface 31B attached to the inner surface 25A of the rigid tubular section 24, and opposite first and second axial ends 30a, 30B. The inner surface 31A of the resilient tubular section 30 is preferably frictionally engaged with the outer surface 1A of the shaft by one or more annular sealing beads 70 and/or axial ribs 72 as described below to rotatably couple the sleeve 10 with the shaft 1 (i.e., the sleeve 10 together with the shaft 1 about the axis a. a_CRotation). Furthermore, a sealing lip 32 extends axially outwards from the first axial end 30a of the tubular section 30, to be arranged substantially outside the bore 21 of the rigid portion. The lip 32 has an inner circumferential sealing surface 33, the inner circumferential sealing surface 33 being sealingly engageable with the outer surface 1a of the shaft to prevent fluid flow outwardly from the sleeve 10 (as discussed below).

With the above structure, the sleeve 10 is configured to be positioned on the shaft 1 such that the lip 32 of the resilient portion 22 is located on the air side AS of the seal assembly 12. Specifically, the primary seal member 16 engages a central region on the outer surface 25B of the rigid tubular segment 24 such that the first axial ends 24a, 30a of the sleeve tubular segments 24, 30 are located on the sealing air side AS of the seal assembly 12 and the second axial ends 24B, 30B of the tubular segments 24, 30 are located on the liquid or "oil" side OS of the seal assembly 12. With such orientation, the lip 32 prevents any fluid (e.g., oil, grease (grease), etc.) from the oil side OS from leaking to the air side AS between the resilient tubular section 30 of the sleeve 10 and the shaft 1. Furthermore, the lip 32, which is located outside the bore 21 of the rigid member, is designed to be in tension (as described below) when installed on the shaft 1, and therefore the lip 32 seals more effectively throughout the product life of the sleeve 10 than the "compressed" seal of the sleeve 10. Having described the basic structure and function above, these and other components of the sleeve 10 and seal assembly 12 of the present invention are described in more detail below.

Referring now to fig. 1 and 2, the housing 14 of the seal assembly 12 preferably includes an annular axial portion 40 and at least one inwardly extending or "inner" radial flange 42. The axial portion 40 has opposite axial ends 40a, 40B and a circumferential inner surface 41A and a circumferential outer surface 41B, the outer surface 41B being frictionally engageable with the inner surface 2a of the seat. An inner radial flange 42 has a radially outer end 42a integrally formed with one axial end 40b and a free radially inner end 42b for mounting the primary seal member 16 (described below). Preferably, the shell 14 also includes an outwardly extending or "outer" flange 44, the outer flange 44 having a radially inner end 44a and an opposite radially outer end 44b, the radially inner end 44a being integrally formed with the other axial end 40a of the axial portion 40 of the shell.

Preferably, the seal assembly 12 further includes a closure member 46, the closure member 46 being coupled with the outer flange 44 of the shell and configured to close the air side AS of the seal assembly 12. Specifically, the closing member 46 includes: an inner axial segment 48 having a circumferential inner surface 49A for engaging the dust lip (dust lip)36 (described below) of the sleeve 10; and an outer radial portion 50 having a hook-shaped section 52. The hook-shaped segment 52 may engage on the radially outer end 44b of the outer radial flange 44 of the shell to couple the closure member 46 with the shell 14.

Further, the sealing member 16 preferably includes: a circular plate-like base 54 coupled to and most preferably molded (mold) to inner end 42b of shell inner radial flange 42; and an annular cantilevered seal portion 56 extending axially from the base portion 54. The annular seal portion 56 has: a first end portion 56a integrally formed with the base portion 54; an opposite free end 56 b; and a wedge-shaped inner section 56c providing a circumferential inner sealing lip 58. The sealing portion 56 also has an outer circumferential groove 57, and a helical spring (/ garter spring)59 is disposed within the groove 57 to bias the sealing lip 58 radially inwardly and against the engagement surface 11 of the rigid member (bias). In addition, the seal member 16 preferably further includes a plurality of dust exclusion lips 60, the dust exclusion lips 60 extending from the base 54 and engaging or being located adjacent to sections of the rigid portion 20 of the sleeve.

Referring to fig. 1-8, the sleeve 10 has a centerline L_CEach of the tubular sections 24, 30 of the rigid portion 20 and the resilient portion 22 is preferably generally circular and is centered about the centerline L_CAre coaxially arranged. The rigid portion 20 of the sleeve 10 is preferably formed of a metallic material, such as aluminum, low carbon steel, or the like, and the resilient portion 22 is preferably formed of natural or synthetic rubber, and is preferably attached to the rigid portion 20 by molding or bonding (bonding). However, the rigid portion 20 and/or the resilient portion 22 may be formed of any suitable material (such as, for example, the rigid portion 20 is formed of a ceramic or rigid polymer material) and attached together by any suitable means (e.g., fasteners (friction fit), etc.).

As best shown in fig. 9-11, the at least one sealing lip 32 of the sleeve 10 preferably includes a cantilevered-like annular body 62, the cantilevered annular body 62 having an inner end 62a and an opposite free axially outer end 62b, the inner end 62a being integrally formed with the first axial end 30a of the resilient tubular section 30. The cantilevered free end portion 62b is spaced axially outwardly from the first axial end 30a of the tubular section 30 and provides the lip sealing surface 33. As shown in fig. 9, in a first preferred configuration, the lip body 62 is generally wedge-shaped (wedge-shaped) and the sealing surface 33 is formed directly on the free end 62b of the lip. As depicted in fig. 10, in a second preferred construction, the lip 32 has a generally cylindrical inner surface 63 (i.e., non-tapered) and has a generally triangular annular bead (annular ring/annular microprotrusion/annular bead)64, the annular bead 64 being spaced inwardly from the free end 62b and providing the sealing surface 33. As shown in fig. 11, in a third preferred construction, the cantilevered body 62 is generally frustoconical and tapers radially inwardly from the axially inner end 62a to the free axially outer end 62b, wherein the sealing surface 33 is provided by a relatively narrow tip 65 of the free end 62 b.

In either case, the lip 32 of the sleeve is formed as: such that the sealing surface 33 of the lip has an outer diameter OD that is sized to be larger than the outer diameter of the outer surface 1a of the shaft when the sleeve 10 is separated from the shaft 1_S(FIG. 1) Small inner diameter ID_L(as shown in fig. 4, 6 and 8). As such, when the sleeve 10 is installed on the shaft 1, the resilient material of the lip 32 is stretched (/ stretched/tensioned) radially outward such that the lip 32 is in tension while the sleeve 10 remains disposed on the shaft 1 (i.e., during use of the seal assembly 12). As such, the lip 32 (can) maintain sealing efficiency as the effectiveness of other sections of the elastomeric portion 22 of the sleeve decreases, as described below.

Referring now to fig. 2 to 8, the tubular section 30 of the resilient portion 22 preferably further comprises at least one annular sealing bulge 70 and/or at least one and preferably a plurality of axial ribs 72. Each annular boss 70 extends inwardly from the inner surface 31A of the tubular section and about the centerline L_CExtends in the circumferential direction and provides a "primary" seal between the sleeve 10 and the shaft 1. Specifically, each annular boss 70 is formed as: inner diameter ID of annular projection 70 when sleeve 10 is separated from shaft 1_B(FIGS. 4 and 6) an outer diameter OD smaller than the outer surface 1a of the shaft_S(FIG. 1). As such, when the sleeve 10 is installed on the shaft 1, the one or more bosses 70 frictionally and sealingly engage the outer surface 1a of the shaft. However, due to the seal provided by the lip 32 of the sleeve, the amount of interference between each lug 70 and the shaft 1 or/and the total number of lugs 70 may be reduced, thereby reducing the need to install the sleeve10 required to be mounted on the shaft 1.

Alternatively, the elastic portion 22 may be formed without any annular sealing protrusion, but include a second sealing lip 66 (shown in fig. 7 and 8). The second seal lip 66 extends axially outwardly from the second axial end 30b of the resilient tubular section 30 to dispose the bore 21 of the rigid portion outside the oil side OS of the seal assembly 12. The second seal lip 66 has a circumferential inner seal surface 68 which is sealingly engageable with the outer surface 1a of the shaft, and serves to prevent fluid of the oil side OS from entering between the sleeve 10 and the shaft 1. Like the first seal lip 32, the second seal lip 66 is designed to be in tension when engaged with the shaft 1 to achieve the benefits discussed above and in more detail below.

Still referring to fig. 2-8, each axial rib 72 extends radially inward from the inner surface 31A of the resilient tubular segment 30 and along the centerline L_CExtends in an axial direction and may be substantially straight (/ linear/straight) (i.e. mainly along the centre line L)_CExtended) or curved to extend both axially and circumferentially. Preferably, the elastic tubular section 30 has a center line L around the center line_CA plurality of axial ribs 72 circumferentially and evenly spaced, but alternatively the (plurality of axial ribs) may be "clustered" (not evenly spaced around the circumference) in a set of spaced ribs 72, or the sleeve 10 may be provided with only two or even one rib 72. In all cases, the axial ribs 72 may frictionally engage the outer surface 1a of the shaft and serve to prevent relative angular displacement of the sleeve 10 relative to the shaft 1. In other words, the ribs 72 prevent sliding (/ slippage) between the resilient tubular section 30 and the outer surface 1a of the shaft when the shaft 1 rotates about the central axis AC.

Due to the diametrical sizing of the annular projections 70 and the axial ribs 72, any portion of each annular projection 70 and each axial rib 72 and of the main resilient tubular section 30 arranged between the rigid tubular section 24 and each annular projection 70 or between the rigid tubular section 24 and each axial rib 72 is compressed when the sleeve 10 is mounted on the shaft 1. That is, the convexity(s) 70And the inner surface (not shown) of the rib(s) 72 are each positioned from the sleeve centerline L_CIs less than the outer diameter OD of the outer surface 1a of the shaft_SSuch that when the sleeve 10 is mounted on the shaft 1, the boss(s) 70 and rib(s) 72 are compressed between the outer surface 1a of the shaft and the inner surface 25A of the rigid tubular section 24. Because these sections of the resilient portion 22 are in a compressed state, the material may develop (/ appear) (develoop) "compression set" during use of the seal assembly 12, which may reduce the effectiveness of the sealing of the bosses 70 and ribs 72. However, because the sealing lip 32 is located outside of the aperture 21 of the rigid member and remains in tension, the lip 32 maintains a sealing effectiveness (sealing effect) for a very long period of use, thereby contributing to a longer product life of the seal assembly 12.

Referring now to fig. 1-8, as discussed above, the resilient portion 22 preferably further includes a radial segment 34, the radial segment 34 extending from the tubular segment 30 and being attached to the flange 26 of the rigid portion 20. The radial segment 34 has an inner end 34a, an opposite radial outer end 34B, and opposite inner and outer radial surfaces 35A, 35B, the inner end 34a being integrally formed with the first axial end 30a of the tubular segment 30. The inner radial surface 35A is attached to the surface 27A of the flange 26 of the adjacent rigid part 20, preferably bonded (bond) to the surface 27A of the flange 26 of the adjacent rigid part 20. Preferably, the resilient portion 22 further includes at least one and most preferably two dust exclusion lips 36 extending from the resilient radial segment 34, each dust exclusion lip 36 having a free end 36a, the free ends 36a being engageable with the seal housing 14 or disposed proximate to the seal housing 14.

More specifically, one dust exclusion lip 36 preferably has an inner end 36b integrally formed with the central region 34c of the resilient radial segment 34 and extends generally in the axial direction with the free end 36a engaging the circumferential inner surface 49A of the closure member 46. The other dust lip 36 has an inner end 36b integrally formed with the outer end 34b of the resilient radial section 34 and extends radially outwardly, wherein a free end 36a of the other dust lip 36 engages an inner surface 41A of the axial portion 40 of the housing. The two dust lips 36 serve to prevent any solid particles (e.g., dust) from entering between the housing 14 and the sleeve 10 and reaching the sealing interface SI. While the sleeve 10 preferably includes a radial portion 34 having at least one and preferably two dust exclusion lips 36, the resilient portion 22 may alternatively be formed with a radial portion 34 without dust exclusion lips or a radial portion 34 with three or more dust exclusion lips, or even be formed without any radial portion.

The present sleeve 10 has a number of advantages over previously known sleeves for use with seal assemblies. By providing an outer sealing lip 32 that functions in tension, the lip 32 is able to (create) a large interference with the shaft 1, is less sensitive to thermal expansion and does not create compression set. Further, by providing the lip 32, the sleeve 10 may be formed with only a single annular sealing boss 70 (or no annular sealing boss 70) operating under compression, and the amount of interference between the boss 70 and the shaft 1 may be reduced, which reduces the force required during installation of the seal assembly 12. Further, since the cantilevered lip 32 does not require grease, grease is allowed to be applied only to the oil side OS of the seal lip 32, thereby avoiding false indications of seal assembly leakage on the air side AS. Furthermore, any grease applied to the shaft 1 during testing or any grease from the shipping (/ sliding) plug (shifting plug) is scraped off during installation of the sleeve 10 onto the shaft 1 and remains only on the oil side OS, thereby reducing fouling (fouling) of the test shaft and false indication of leakage of the seal assembly 12.

It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as generally defined in the appended claims.