阅读说明：本技术 针对低温应用优化的具有唇的密封部 (Seal with lip optimized for low temperature applications ) 是由 丹尼尔·J·利维 蒂莫西·帕特森 罗伯特·D·佩凯克 于 2020-09-14 设计创作，主要内容包括：一种密封部包括环形密封主体和密封突起,环形密封主体由弹性体材料形成并且具有相对的第一周向表面和第二周向表面,密封突起从第一周向表面径向地延伸。突起具有截头圆锥形主密封表面,截头圆锥形主密封表面具有第一轴向端部和第二轴向端部以及在第一端部与第二端部之间的轴向长度。当密封主体与内构件联接时,突起能够与外构件的内表面密封地接合,使得主密封表面的基本上整个轴向长度抵靠外构件的内表面布置。作为另一种选择,当密封主体与外构件联接时,突起能够与内构件的外表面密封地接合,使得主密封表面的基本上整个轴向长度抵靠内构件的外表面布置。(A seal includes an annular seal body formed of an elastomeric material and having first and second opposing circumferential surfaces, and a sealing protrusion extending radially from the first circumferential surface. The projection has a frustoconical primary sealing surface having first and second axial ends and an axial length between the first and second ends. When the seal body is coupled with the inner member, the protrusion is configured to sealingly engage with the inner surface of the outer member such that substantially an entire axial length of the primary sealing surface is disposed against the inner surface of the outer member. Alternatively, the protrusion is sealingly engageable with the outer surface of the inner member when the seal body is coupled with the outer member such that substantially an entire axial length of the primary sealing surface is disposed against the outer surface of the inner member.)

1. A seal for sealing an annular space between an inner member and an outer member, the inner member having an outer peripheral surface and the outer member having an inner peripheral surface, the annular space being defined between the inner and outer peripheral surfaces, one of the inner and outer members being displaceable along a central axis through a stroke length, the seal comprising:

an annular seal body formed of an elastomeric material, coupled with the inner member or coupled with the outer member, and having a first circumferential surface, an opposing second circumferential surface; and a sealing protrusion extending radially from the first circumferential surface, the protrusion having a generally frustoconical primary sealing surface having a first axial end, a second axial end, and an axial length between the first and second ends, wherein one of:

when the seal body is coupled with the inner member, the protrusion is sealingly engageable with an inner surface of the outer member such that substantially an entire axial length of the primary sealing surface is disposed against the inner surface of the outer member; and

the protrusion is configured to sealingly engage with an outer surface of the inner member when the seal body is coupled with the outer member such that substantially an entire axial length of the primary sealing surface is disposed against the outer surface of the inner member.

2. The seal of claim 1, wherein one of the following is satisfied:

the outer member has an axial end and the projection is formed as a cantilever extending radially inwardly from the inner surface of the body and axially beyond the axial end of the outer member; and

the inner member has an axial end, and the projection is formed as a cantilever extending radially outward from the outer peripheral surface of the seal body and axially beyond the axial end of the inner member.

3. The seal of claim 1, wherein the axial length of the primary sealing surface has a value of at least the stroke length.

4. The seal of claim 1, wherein the tapered sealing surface defines an angle with the central axis or a line parallel to the central axis when the seal is not engaged with the inner member or the outer member, the angle having a value less than 7.5 degrees.

5. The seal of claim 4, wherein the angle has a value of less than 5 degrees.

6. The seal of claim 1, wherein the primary sealing surface has a diameter about the central axis that varies at least substantially linearly between a first axial end of the sealing surface and a second axial end of the sealing surface.

7. The seal of claim 1, wherein the sealing protrusion has a secondary sealing surface extending radially and axially between the first circumferential surface and the primary sealing surface, a portion of the secondary sealing surface being disposed against one of the outer surface of the inner member or the inner surface of the outer member when the annular space has a radial length less than a predetermined value.

8. The seal of claim 1, wherein the annular body includes a body axial portion providing the first and second circumferential surfaces and a body radial portion extending from one of the first and second circumferential surfaces and integrally connected with the axial portion such that a joint is formed, the sealing protrusion extending from the first circumferential surface adjacent the joint.

9. A seal for sealing an annular space between an inner member and an outer member, the inner member having an outer peripheral surface and the outer member having an inner peripheral surface and an axial end, the annular space being defined between the inner and outer peripheral surfaces, one of the inner and outer members being linearly displaceable along a central axis through a stroke length, the seal comprising:

an annular seal body formed of an elastomeric material and having an inner peripheral surface and an opposing outer peripheral surface, the outer peripheral surface disposed on an inner surface of the outer member; and a generally cantilevered sealing projection extending radially inwardly from the inner peripheral surface and axially beyond the axial end of the outer member, the projection having a generally frustoconical primary sealing surface having a first axial end, a second axial end, and an axial length between the first and second ends, the projection being sealingly engageable with the outer surface of the inner member such that substantially the entire axial length of the primary sealing surface is disposed against the outer peripheral surface of the inner member.

10. The seal of claim 9, wherein the axial length of the primary sealing surface has a value of at least the stroke length.

11. The seal of claim 10, wherein the tapered sealing surface defines an angle with the central axis when the seal is not engaged with the inner member, the angle having a value less than 7.5 degrees.

12. The seal of claim 11, wherein the angle has a value of less than 5 degrees.

13. The seal of claim 9, wherein the sealing surface has a diameter about the central axis that varies at least substantially linearly between a first axial end of the sealing surface and a second axial end of the sealing surface.

14. The seal of claim 9, wherein the sealing protrusion has a secondary sealing surface extending radially and axially between the inner peripheral surface of the seal body and the primary sealing surface, a portion of the secondary sealing surface being disposed against the outer surface of the inner member when the annular space has a radial length less than a predetermined value.

15. A seal for sealing an annular space between an inner member and an outer member, the inner member having an outer peripheral surface and an axial end and the outer member having an inner peripheral surface, the annular space being defined between the inner and outer peripheral surfaces, one of the inner and outer members being linearly displaceable along a central axis through a stroke length, the seal comprising:

an annular seal body formed of an elastomeric material and having an inner peripheral surface and an opposing outer peripheral surface, the inner peripheral surface disposed on the outer surface of the inner member; and a generally cantilevered sealing protrusion extending radially outwardly from the outer peripheral surface of the seal body and axially beyond the axial end of the inner member, the protrusion having a generally frustoconical primary sealing surface having a first axial end, a second axial end, and an axial length between the first and second ends, the protrusion being sealingly engageable with the inner surface of the outer member such that substantially the entire axial length of the primary sealing surface is disposed against the inner peripheral surface of the outer member.

16. The seal of claim 15, wherein the axial length of the sealing surface has a value of at least the stroke length.

17. The seal of claim 16, wherein the tapered sealing surface defines an angle with the central axis when the seal is not engaged with the outer member, the angle having a value less than 7.5 degrees.

18. The seal of claim 17, wherein the angle has a value of less than 5 degrees.

19. The seal of claim 15, wherein the sealing surface has a diameter about the central axis that varies at least substantially linearly between a first axial end of the sealing surface and a second axial end of the sealing surface.

20. The seal of claim 15, wherein the sealing protrusion has a secondary sealing surface extending radially and axially between the outer peripheral surface of the seal body and the primary sealing surface, a portion of the secondary sealing surface being disposed against the inner surface of the outer member when the annular space has a radial length less than a predetermined value.

Technical Field

The present invention relates to seals, and more particularly to lip seals (lip seals) that operate at least partially at relatively low temperatures.

Background

Conventional lip seals include an annular elastomer having a generally semi-circular lip that engages inwardly against a shaft or outwardly against a bore surface. During initial start-up of a machine containing a seal, the seal may experience rigidity (inflexibility) when the initial temperature is below the glass transition temperature (glass transition temperature) of a particular elastomer. Thus, the sealing lip may allow leakage past the seal until the temperature rises above the glass transition temperature.

Disclosure of Invention

In one aspect, the invention is a seal for sealing an annular space between an inner member and an outer member, the inner member having an outer peripheral surface and the outer member having an inner peripheral surface. An annular space is defined between the inner and outer peripheral surfaces, and one of the inner and outer members is displaceable through a stroke length along the central axis. The sealing portion includes: an annular seal body formed of an elastomeric material, coupled with the inner member or coupled with the outer member, and having a first circumferential surface, an opposing second circumferential surface; and a sealing protrusion extending radially from the first circumferential surface, the protrusion having a generally frustoconical primary sealing surface with a first axial end, a second axial end, and an axial length between the first and second ends. Further, when the seal body is coupled with the inner member, the protrusion is configured to sealingly engage with the inner surface of the outer member such that substantially an entire axial length of the primary sealing surface is disposed against the inner surface of the outer member. Alternatively, the protrusion is sealingly engageable with the outer surface of the inner member when the seal body is coupled with the outer member such that substantially an entire axial length of the primary sealing surface is disposed against the outer surface of the inner member.

In another aspect, the invention continues to a seal for sealing an annular space between an inner member and an outer member, the inner member having an outer peripheral surface and the outer member having an inner peripheral surface and an axial end. An annular space is defined between the inner and outer peripheral surfaces, one of the inner and outer members being linearly displaceable through a stroke length along the central axis. The sealing portion includes: an annular seal body formed of an elastomeric material and having an inner peripheral surface and an opposing outer peripheral surface, the outer peripheral surface disposed on an inner surface of the outer member; and a substantially cantilever-like sealing protrusion extending radially inward from the inner peripheral surface and axially beyond an axial end of the outer member. The projection has a generally frustoconical primary sealing surface having a first axial end, a second axial end, and an axial length between the first and second ends. The protrusion is sealingly engageable with an outer surface of the inner member such that substantially an entire axial length of the primary sealing surface is disposed against the outer peripheral surface of the inner member.

In yet another aspect, the invention continues to a seal for sealing an annular space between an inner member and an outer member, the inner member having an outer peripheral surface and an axial end, and the outer member having an inner peripheral surface. An annular space is defined between the inner and outer peripheral surfaces, one of the inner and outer members being linearly displaceable through a stroke length along the central axis. The sealing portion includes: an annular seal body formed of an elastomeric material and having an inner peripheral surface and an opposing outer peripheral surface, the inner peripheral surface disposed on the outer surface of the inner member; and a generally cantilevered sealing projection extending radially outwardly from the outer peripheral surface of the seal body and axially beyond the axial end of the inner member. The projection has a generally frustoconical primary sealing surface having a first axial end, a second axial end, and an axial length between the first and second ends. The protrusion is sealingly engageable with an inner surface of the outer member such that substantially an entire axial length of the primary sealing surface is disposed against the inner peripheral surface of the outer member.

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, which are diagrammatic, embodiments that 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 an axial cross-sectional view of a seal according to the present invention, showing an inward seal configuration mounted on an outer member and sealing against an inner member;

FIG. 2 is an axial cross-sectional view of the seal portion of FIG. 1, shown in an uninstalled or "free" condition;

FIG. 3 is an enlarged fragmentary view of a portion of FIG. 2;

FIG. 4 is a more enlarged, fragmentary view of a portion of FIG. 3;

FIG. 5 is an axial cross-sectional view of the seal according to the present invention, showing an outward seal configuration mounted on and sealing against the inner member;

FIG. 6 is an enlarged fragmentary view of a portion of the seal of FIG. 1, showing the seal formed at a larger end of the tolerance range;

FIG. 7 is an enlarged fragmentary view of a portion of the seal of FIG. 1, showing the seal formed at the smaller end of the tolerance range;

FIG. 8 illustrates a comparison of a current seal with a previously known seal having a standard semi-circular lip; and

fig. 9 shows a comparison of the current seal with a previously known seal having significantly increased lip interference.

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 the particular meaning being apparent from the context of the description. Further, as used herein, the terms "connected" and "coupled" are intended to include both direct connection between two members (without any other members interposed therebetween) and indirect connection between two members (with one or more other members interposed therebetween). The terminology includes the words above specifically mentioned, derivatives thereof and words of similar import.

Reference will now be made in detail to the accompanying drawings, in whichLike reference numerals are used to refer to like elements throughout, and in fig. 1-7 there is shown a seal 10, the seal 10 being for sealing an annular space AS between an inner member 1 and an outer member 2 to prevent fluid in a first chamber C containing a first fluid (e.g., oil)₁With a second chamber C containing a second fluid (e.g. air)₂And flow between them. As used herein, the terms "inner member" and "outer member" are used to indicate the relative positioning of any two members between which sealing of an annular space is desired, such that the outer member may be disposed within a third member or/and the inner member may be disposed about a different third member. For example, the inner member 1 may be a shaft 3 and the outer member 2 may be a central piston 4 (as shown in fig. 1) arranged around the shaft 3 and within a housing/drum (/ drum)5, or the inner member 1 may be the central piston 4 and the outer member 2 may be the housing/drum 5 (as depicted in fig. 5), or the inner member 1 and the outer member 2 may be any other suitable combination of the inner member 1 and the outer member 2 that requires sealing.

In any case, the inner member 1 has an outer peripheral surface 1a and the outer member 2 has an inner peripheral surface 2a, an annular space AS being defined between the inner and outer peripheral surfaces 1a, 2a, respectively. As best shown in fig. 1 and 5, one of the inner and outer members 1 and 2, respectively, is along the central axis a, respectively_CAt least linearly displaceable (D) through a stroke length L_S(i.e., in the first position P₁And a second position P₂In between) and may also be about axis a_CAngularly displaceable (i.e. also about axis a during linear displacement)_CTurning or rotating).

The seal portion 10 includes an annular seal body 12 and a sealing protrusion 18, the annular seal body 12 being formed of an elastomeric material and having a first circumferential surface 14 and an oppositely facing (/ opposing) second circumferential surface 16. Preferably, the second circumferential surface 16 of the sealing body 12 is arranged on the inner surface 2a of the outer member 2 or on the outer surface 1a of the inner member 1 to couple the sealing portion 10 with a specific member 1 or 2. Alternatively, the seal body 12 may be disposed in an annular groove (not shown) in either member 1, 2. Furthermore, the seal 10 may be coupled with a movable one of the members 1, 2 or with another non-movable or "stationary" member 2, 1, respectively.

Furthermore, when used in applications having a central member (such as the piston 4), the present seals 10 are preferably used in pairs, with one seal 10 sealing inwardly against the shaft 3 and the other seal 10 sealing outwardly against the housing 5 (structure not shown). However, to simplify the description of the details of the seal 10, the inward seal type and the outward seal type of the seal 10 are separately described and shown in combination with the standard seal 6 in fig. 1 and 5, respectively.

Further, a sealing protrusion 18 extends radially from the first circumferential surface 14 and has a main sealing surface 20 that is generally frustoconical. Preferably, the sealing projection 18 is substantially cantilevered and extends axially beyond the axial end 1b or 2b, respectively, to which the sealing body 12 of the particular component 1, 2 is coupled. I.e. axially beyond the axial end 2b when coupled with the outer member 2 (as shown in fig. 1), or axially beyond the axial end 1b when coupled with the inner member 1 (as depicted in fig. 5). Further, the primary sealing surface 20 has a first axial end 20a, a second axial end 20b, and an axial length L between the first and second ends 20a, 20b_AAs shown in fig. 3 and 4.

When the seal body 12 is coupled with the outer member 2, the protrusion 18 is in sealing engagement with the outer surface 1a of the inner member 1 (as shown in FIG. 1) such that substantially the entire axial length L of the primary sealing surface 20_AIs arranged against the inner member outer surface 1 a. Alternatively, when the body 12 is coupled with the inner member 1, the protrusion 18 is in sealing engagement with the inner surface 2a of the outer member 2 (as depicted in FIG. 5) such that substantially the entire axial length L of the primary sealing surface 20_AIs arranged against the outer member inner surface 2 a.

In either case, the axial length L of the primary sealing surface 20_AIs at least the stroke length L of the movable member 1 or 2_SValue of (i.e., L)_AIs equal to or greater than length L_S). Thus, during displacement of the movable member 1 or 2, the portion of the surface 1a or 2a against which the projection 18 sealsWill never be located in two chambers C₁And C₂In (1). In other words, any portion of the surface 1a or 2a to be joined will always be located in the first chamber C₁In, always in the second chamber C₂In the first chamber C for the part of the "stroke₁And otherwise engaged by the sealing projection 18, is located in the second chamber C for the part of the "stroke₂And is otherwise engaged by the sealing projection 18, or is always engaged by the projection 18. Thus, any fluid (such as oil) that may be disposed within a gap (e.g., void, cavity, etc.) in the surface 1a or 2a being sealed against is prevented from "leaking" through the seal 10.

The present seal 10 configuration is particularly beneficial for low temperature applications, particularly when operating at ambient temperatures below the glass transition temperature of the particular elastomer of the seal body 12 (typically experienced at the initial "start-up" of a machine comprising the two components 1 and 2). More specifically, the glass transition temperature is the temperature below which the sealing material becomes brittle and inflexible. In this way, the sealing material at or below the glass transition temperature cannot expand and fill such surface indentations or fill voids/spaces between the seal 10 and the surface 1a or 2a being sealed against, which are caused by relative misalignment or "cocking" of the members 1, 2. Thus, the sealing surface 20 is made to have a stroke length L equal to or greater than_SAxial length L of_AIt will be ensured that no fluid leakage through the seal 10 will occur even when the seal material is below the glass transition temperature.

In the case of previously known seals having a conventional semi-circular profile, the seal "band" (i.e., the axial length of the surface of the seal in contact with the surface) is typically too narrow and exposes the surface breach to both chambers C1 and C2. To increase the sealing band, some prior art seals have been operated under increased radial loads to cause greater interference (interference), which also significantly increases the friction between the seal and the surface, especially when the temperature of the machine increases during operation.

Referring to fig. 1 to 4, the seal portion 10 may be formed as an "inward seal" such that the seal body 12 is disposed on the outer member 2, the first circumferential surface 14 is an inner circumferential surface 15A, the second circumferential surface 16 is an outer circumferential surface 17A, and the seal projection 18 extends radially inward from the inner circumferential surface 15A. The frustoconical sealing surface 20 is an inner peripheral sealing surface 21A and sealingly engages the outer peripheral surface 1A of the inner member 1. Alternatively, as shown in fig. 5, the seal portion 10 may be formed as an "outward seal" such that the seal body 12 is disposed on the inner member 1, the first circumferential surface 14 is an outer circumferential surface 15B, the second circumferential surface 16 is an inner circumferential surface 17B, and the seal projection 18 extends radially outward from the outer circumferential surface 15B. The frustoconical sealing surface 20 is an outer peripheral sealing surface 21B and sealingly engages the inner peripheral surface 2a of the outer member 2.

With particular reference to FIG. 4, when the seal 10 is not engaged with the inner member 1 or is not engaged with the outer member 2, the generally frustoconical sealing surface 20 is aligned with the central axis A_COr parallel to the central axis A_CDefines an angle theta. In other words, when the seal 10 is in the "free state" and is not pressed (/ compressed) by engagement with one of the two members 1 or 2. The angle θ is substantially "shallow (/ minor) (show)" and has a value of less than 7.5 degrees (7.5 °), and preferably less than 5 degrees (5 °). The shallow angle θ in the free state facilitates assembly of the seal 10 into engagement with the inner member outer surface 1a or the outer member inner surface 2a, but when the seal 10 is installed with at least substantially the entire sealing surface 20 engaged with the outer surface 1a or the inner surface 2a, the shallow angle θ in the free state does not exist.

Furthermore, the primary sealing surface 20 is preferably substantially "flat", although frustoconical or axially tapered in the free or uninstalled condition. Specifically, the primary sealing surface 20 has a central axis A about which_CDiameter D of_S(FIG. 3), diameter D_SAt least substantially linearly between the first axial end 20a of the sealing surface 20 and the second axial end 20b of the sealing surface 20, such that the sealing surface 20 appears substantially linear in any axial cross-section of the seal 10. This "flatness" ensures that the seal 10 is secured when it is installedThe engagement of the entire sealing surface 20 when installed and operated upon.

Referring again to fig. 1-7, the sealing protrusion 18 has a secondary sealing surface 22 extending radially and axially between the first circumferential surface 14 and the primary sealing surface 20. Due to the structure of the seal body 12 and the projection 18, when the annular space AS has a value less than the predetermined value V_PRadial length L of_R(fig. 7) a portion of the secondary sealing surface 22 is disposed against the inner member outer surface 1a or the outer member inner surface 2 a. Thus, the configuration of the sealing projection 18 enables the seal 10 to function as intended over a wide range of dimensional tolerances of the seal 10 without significant variation in friction between the seal 10 and the engagement surface 1a or 2 a.

In other words, when the seal 10 is formed to seal inward, the seal 10 formed on the larger diameter end of the tolerance range will engage the inner member 1 with only the primary sealing surface 20 (as shown in FIG. 6), while the seal 10 formed on the smaller diameter end of the tolerance range will engage the inner member 1 with both a portion of the secondary sealing surface (/ secondary sealing surface) 22 and the primary sealing surface 20 (as depicted in FIG. 7). Similarly, when the seal portion 10 is formed to seal outwardly, the seal portion 10 formed on the smaller diameter end of the tolerance range will engage the outer member 2 only with the primary sealing surface 20 (as shown in FIG. 5), while the seal portion 10 formed on the larger diameter end of the tolerance range will engage the outer member 2 with both a portion of the secondary sealing surface 22 and the primary sealing surface 20 (not shown).

Referring to fig. 3-7, in certain applications, the seal ring body 12 preferably includes a body axial portion 30 and a body radial portion 32, and may include additional axial and/or radial portions (neither shown). The body axial portion 30 provides first and second circumferential surfaces 14 and 16, and the body radial portion 32 extends from one of the first and second circumferential surfaces 14 or 16 and is integrally connected with the axial portion 30 to form a junction (connection) 34. Preferably, the sealing protrusion 18 extends from the first circumferential surface 14 adjacent the joint 34, but alternatively, the sealing protrusion 18 may be centered on the joint 34 or otherwise spaced from the joint 34 (structure not shown).

Further, the second circumferential surface 16 of the seal body 12 is preferably bonded to the outer member inner surface 2a or the inner member outer surface 1a, and when the seal body 12 includes the radial portion 32, the radial surface 36 of the portion 32 is bonded to a radial surface (not shown) of the member 1 or 2. However, the seal body 12 may be coupled with the member 1 or 2 by any suitable means (such as fasteners, friction, etc.). Further, as described above, the seal body 12 may alternatively be formed as a substantially annular ring (not shown) having no radial portion and sized to fit within a groove in the inner member 1 or a groove in the outer member 2 (neither configuration depicted).

The benefits of the present invention are readily apparent by comparison with previously known seal designs, as shown in fig. 8. First, comparison of the current seal 10 with previously known seals having standard semicircular lips:

here, please refer to fig. 8.

Clearly, the seal 10 has a significantly larger contact band over a range of fluid pressures, and in particular a much larger minimum contact band width over a range of manufacturing tolerances, than a standard lip operating under normal radial loads.

Next, comparison of the current seal with previously known seals with significantly increased lip interference:

here, please refer to fig. 9.

As shown in fig. 9, the present seal 10 has a larger minimum contact band and a narrower contact bandwidth over the range of manufacturing tolerances, thereby providing more consistent performance over the range of tolerances.

Representative, non-limiting examples of the present invention are described in detail above with reference to the accompanying drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention.

Furthermore, combinations of features and steps disclosed in the foregoing detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, the various features of the above-described representative examples, as well as the various independent and dependent claims appended hereto, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

For the purposes of original written disclosure, as well as for the purposes of limiting the claimed subject matter, all features disclosed in the specification and/or the claims are intended to be disclosed separately and independently of each other, irrespective of the combination of features in the embodiments and/or the claims. Further, for purposes of original written disclosure, as well as for purposes of limiting the claimed subject matter, all value ranges or representations of groups of entities are intended to disclose every possible intermediate value or intermediate entity. The invention is not limited to the above-described embodiments and may be varied within the scope of the appended claims.