KR20070015501A - Multi-layered seal structure - Google Patents

Abstract

The present invention relates to a multi- layered seal ring capable of expanding for installation onto a shaft, rod or other cylindrical member, and then once in position, provides a seal as though it were a continuous solid ring allowing for only a minimal amount of leakage over a wide temperature range. More specifically, the present invention relates to first and second annular or non-annular forms having gaps or fractures in their structure, wherein the first and second annular or non-annular forms are affixed to one another. ® KIPO & WIPO 2007

Description

 Multilayer Seal Structures {MULTI-LAYERED SEAL STRUCTURE}

The present invention is directed to a multilayer seal ring or other geometry that minimizes, controls or essentially eliminates fluid leakage over a wide range of temperatures.

Sealing rings are used to form a seal between a shaft or rod and a wall of a bore or cylinder in various types of mechanical devices, for example compressors, pumps, automatic transmissions, power steering devices.

The seal ring generally has an open annular shape and is mounted in the circumferential groove of the shaft or rod (eg piston) located in the cylindrical housing. The general function of the seal ring is to prevent or control fluid from leaking from one side to the other across the ring structure while allowing the shaft or rod on which it is placed to rotate, oscillate or reciprocate within the cylindrical housing.

Several seal ring structures with joints have been described in the industry, which allow the seal ring to expand or contract in response to thermal expansion and / or contraction of the cylindrical member, rod or shaft on which the seal ring is mounted. . Joints of such seal rings have various geometric configurations, such as, for example, step joints, scarf joints, and butt joints. However, thermal expansion and exposure to other forces exerted on the seal ring during use cause the seal ring using this type of joint to have a gap in its structure. Such gaps are undesirable in that they allow excessive leakage of fluid through the structure.

Various degrees of leakage occur depending on the range of temperatures that is a factor that needs to be considered in the fluid system (eg automatic transmission) for proper operation. A wide range of temperatures is observed from the initial inception over the top of the operating temperature range of the mechanical process. For example, a fluid, such as oil, will change in viscosity in response to temperature changes, thereby increasing the leak rate as the viscosity decreases, resulting in a larger leak rate. Moreover, for example, due to thermal expansion, the size of a particular material, such as a metal shaft or rod, changes with temperature, with increasing temperature generally increasing the size of the joint gap of the seal ring known in the art, and The result is a greater leak.

The industry has been trying to minimize or eliminate leaks through the seal ring, but these attempts have been found to fail. As an example, the leak rate through known joints, such as micro-cut, step clearance or butt clearance (and others), is reduced by resizing the seal ring to have a smaller clearance at cold temperatures. However, this is problematic in that as the ring thermally expands in response to the operating temperature, a fully closed gap may cause or even twist the ring joint into the groove. The joining or twisting causes premature wear and / or causes the ring to seal improperly, and the leak rate actually increases with the low viscosity of the hot oil.

Thus, there is a need in the industry to develop seal rings that eliminate leaks or only allow a minimum controlled amount of leak through the structure over a wide range of temperatures. The present invention provides such a seal ring.

FIELD OF THE INVENTION The present invention relates to an inflatable multi-layer seal ring structure or other geometry that can be installed over a shaft, rod or other cylindrical member, and the present invention allows or essentially eliminates only minimal controlled leakage over a wide range of operating temperatures. .

Embodiments of the present invention include a) a first annular or acyclic portion having a gap or fracture portion therein;

b) a second annular or acyclic part having a gap or breakage therein,

The second annular portion is adjacent to or in contact with the first annular portion,

At least the first and second annular portions relate to a multilayer seal ring or other geometry that is attached to each other at an attachment area with an adhesive.

The present invention includes the step of attaching at least a first annular or acyclic portion and a second annular or acyclic portion to each other in an attachment region with an adhesive, wherein at least the first annular or acyclic portion is in contact with the second annular or acyclic portion, or A method of forming adjacent multilayer seal rings or other geometries.

Other alternatives, modifications, or equivalents of the present invention will be apparent to those skilled in the art upon reviewing the following detailed description. Such additional alternatives, modifications, and equivalents are included within the scope of this description and the present invention.

1 is a side view of an embodiment of a multilayer seal ring according to the present invention.

2 is an exploded side view of an embodiment of a multilayer seal ring in accordance with the present invention.

3 is a side view of an embodiment of a multilayer seal ring located on a rod or shaft.

4 is a side view of an embodiment of a multilayer seal ring having breaks therein.

Where a numerical range is cited herein, unless stated otherwise, the range is deemed to include the endpoint and all integers and fractions within that range. The protection scope of the present invention is not limited to the specific values recited when defining the numerical range. Moreover, all ranges described herein include the specific ranges specifically described and any combination of values therein, including the minimum and maximum values recited.

The multilayer seal ring according to the invention can be used in a variety of products, including static, reciprocating or rotating products that perform a sealing function. Multilayer seal rings are used in articles where the fluid in the form of a liquid or gas is isolated so that the fluid presses against the seal ring to create a sealed surface.

The present invention relates to an expandable multilayer seal ring structure or other geometry that can be installed on a shaft, rod, or other cylindrical member and, when in place, provides a seal such as a continuous solid ring. In addition, the present invention provides a multilayer seal ring that permits or essentially eliminates only minimal controlled leakage over a wide range of operating temperatures. More specifically, as shown in Figures 1-3, embodiments of the present invention comprise a) a first annular portion 2 having a gap 4 therein and b) a gap 4 therein. And a second annular portion (3), wherein the second annular portion is adjacent to or abuts the first annular portion, and at least the first and second annular portions are attached to the adhesive (6) in the attachment region (5). A multilayer seal ring 1 is attached to each other.

The structure of the present invention contemplates the use of several annular or acyclic parts, wherein at least two separate annular or acyclic parts are formed and connected to one another. For ease of description, embodiments using two annular portions are described herein. Preferably, each single annular portion has a thickness that is half of the conventional corresponding seal ring thickness when only two annular portions are used.

At least the first and second annular portions of the multilayer seal ring according to the invention generally have a wide range of diameters and can provide their particular advantages.

At least the first and second annular parts 2, 3 according to the invention are of various materials, for example cast iron, flexible, which can provide the necessary sealing function withstanding the forces or temperatures generated in the environment in which they are used. It can be composed of metals such as elastomers and various polymers. Preferably, at least the first and second annular parts 2, 3 are made of a polymeric material, and the first and second annular parts 2, 3 may be made of the same polymer or different polymers.

Preferred embodiments of the multilayer seal ring 1 include high performance polymers. More preferably, the present invention includes synthetic high performance polymers that are temperature resistant, have a high melting point, have a high compressive strength, do not easily break, and have a low coefficient of thermal expansion and a low coefficient of friction.

For example, other physical properties such as tensile strength, modulus, elongation are also important in the seal ring. Metal seal rings tend to have better tensile strength and modulus, but elongation is higher in the polymer. In the ring of the present invention, the tensile strength should be in the range of about 9000 to 18000 psi (62.1 × 10 ³ to 124.1 × 10 ³ kPa), the stretching should be in the range of about 2.5% to 10%, and the tensile modulus is about 310,000 to about 750,000 psi (2.14 × 10 ⁶ to 5.17 × 10 kPa). Those skilled in the art will understand that this is only a preferred range and not a limitation. A wide variety of polymers are suitable for use in the multilayer seal ring 1 of the present invention. Particularly suitable are polyimide, polyamide, polyester, polyether ether ketone (PEEK), polyamide imide (PAI), polyether imide, polyether ketone ketone (PEKK), polyether ketone (PEK), polyphenyl Lene sulfide, polybenzimidazloe, thermoplastic polyimide (TPI), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP).

If the polymer is polyimide, it is preferably prepared from at least one diamine and at least one anhydride. Preferred diamines include M-phenylene diamine (MPD), p-phenylene diamine (PPD), oxydianiline (ODA), methylene dianiline (MDA), toluene diamine (TDA). Preferred anhydrides are benzophenone tetracarboxylic dianhydride (BTDA), biphenyl dianhydride (BPDA), trimellitic anhydride (TMA), pyromellitic dianhydride (PMDA), maleic anhydride (MA) and nadic anhydride ( NA).

(VESPEL) 열가소성 재료와 같은 상업적으로 제공되는 폴리이미드를 포함한다.Preferred polyimides are BTDA-MPD, MA-MDA, BTDA-MDA-NA, TMA-MPD and TMA-ODA, BPDA-ODA, BPDA-MPD, BPDA-PPD, BTDA-4, Prepared from 4'-diaminobenzophenone, BTDA-bis (P-phenoxy) -p, p'-biphenyl. Essentially satisfactory polyimides useful in the seal rings of the present invention are those prepared from pyromethylritic dianhydrides and 4,4'-oxydianiline (PMDA-ODA). More preferably, the multilayer seal ring is, for example, E. I. Wilmington, Delaware. Vespel commercially provided by EI du Pont de Nemours and Company

(VESPEL) commercially available polyimides such as thermoplastic materials.

The polyimide composition comprises at least one polyimide and at least one other polymer that is melt processable at temperatures up to about 400 ° C. and is selected from polyamides and polyester resins and may be present at a concentration from about 45 to 79.9 weight percent. Contains blends. Melt processing is used in the conventional sense, and the polymer can be processed in the injection apparatus at the indicated temperature without substantial degradation of the polymer.

Various polyamides and / or polyesters can be used in the present invention and / or mixed with polyimides. For example, polyamide can be used, which includes nylon 6, nylon 6,6, nylon 610 and nylon 612. Polyester can be used, which includes polybutylene terepthalate and polyethylene terepthalate.

Soluble or melt processible polyamides or polyesters may additionally be in the form of liquid crystal polymers (LCPs). The liquid crystal polymer is generally polyester and includes, but is not limited to, polyesteramide and polyesterimide. Liquid crystal polymers are described, for example, in US Pat. Nos. 4,169,933, 4,242,496, 4,238,600 and "Liquid Crystal Polymers: V-I Liquid Substrate of Alternative Hydroquinone" by Jackson et al.

The polymer of the multilayer seal ring 1 of the present invention may further comprise other additives, fillers and dry lubricants, which will not degrade the overall characteristics of the finished seal ring, as will be apparent to those skilled in the art. For example, incorporation of graphite into the composition can extend its use as a wear resistant material. Another beneficial additive is carbon fiber to reduce the coefficient of thermal expansion. Various inorganic fillers are known to reduce the coefficient of friction and improve wear resistance. The filler used in the present invention should not prevent fracture of the seal ring.

Alternatively, as mentioned above, the multilayer seal ring 1 according to the invention can be composed of various combinations of polymers, each individual annular portion comprising a different polymer. For example, the polymer may be selected based on performance and use in various products, wherein the wear side of the two layers of ring may comprise a first polymer that provides high wear and low friction properties, while The annulus adjacent to includes a softer polymer that provides better sealing against static surfaces. Preference is given to using polymers having similar thermal expansion rates when a combination of polymers is used, preferably within 10% of each other.

Since the rotary installation is often concluded with a substantially circular passageway, the invention preferably relates to the multilayer seal ring 1. However, various other multilayer geometries may be used in more specialized products, including but not limited to multilayer elliptical sealing structures.

Preferably, the individual annular parts according to the invention have a square or square cross-sectional configuration, but other cross-sectional configurations can be used, for example chamfered corners. The chamfers can be angled or have an inner radius.

At least the first and second annular parts 2, 3 of the invention have a gap 4 in their structure, which allows adjacent rings to slide relative to one another. Thus, the gap 4 acts as a "joint" or expansion point during installation of the invention for installation. The gap 4 formed in the several annular portions of the present invention is preferably a gap formed directly. As shown in Figs. 1 to 3, each individual annular portion has a gap penetrating the entire thickness, and thus a pair of ends having opposing surfaces 4a and 4b having substantially smooth and parallel surfaces to each other. To form. In addition, the opposing surfaces 4a, 4b of the gap are preferably substantially perpendicular to the major axis or plane of the particular individual annulus.

Alternatively, instead of a gap, the present invention utilizes a broken individual form as shown in FIG. Each individual annulus completely breaks through the entire thickness (12) thereby forming a pair of ends having opposing surfaces 11a, 11b substantially parallel to each other. The opposing surfaces 11a, 11b or breaking lines of the break are preferably substantially perpendicular to the major axis or plane of the particular individual annulus. In general, the opposite ends of the break are rough and can mesh together when the surfaces are forced to contact and help prevent leakage.

As is commonly known to those skilled in the art, the multilayer seal ring 1 is heated during the rotational or reciprocating motion of the shaft, rod or other cylindrical member and causes the multilayer seal ring to thermally expand when the multilayer seal ring is in operation. . For this reason, the opposing end surfaces 4a, 4b or 11a, 11b are not necessarily in contact until they reach operating conditions. The gap 4 or break 12 is preferably opened at cold and closed at the highest operating temperature, to minimize leakage by the first ring.

The width of the gap 4 is not critical, but its size should not be so large that there is no overlap of at least the first and second annular or acyclic portions 2, 3 when the multilayer seal ring 1 is formed. Preferably, the gap width is only a small part of the overall circumferential dimension of the particular annular portion. In addition, the gap width is generally linear with respect to the diameter of the particular annulus, so if the diameter of the individual annulus is twice, the width of the gap is likewise doubled.

Along with temperature, fluid pressure is another operating condition, which affects the ability to perform the sealing function of a multilayer seal ring. When the operating pressure is achieved on the pressurized side of the multilayer seal ring 1 and the operating temperature is achieved, the opposing surfaces 4a, 4b and 11a, 11b meet and thus the gap created for the installation of the seal ring ( 4) or the break 12 is sealed and the gap or break 12 does not become a leak point. Thus, a single multilayer seal ring is all that is required to perform the sealing function.

As can be expected, the undesirable leakage of fluid through the multilayer seal ring 1 is evidence that it is not functioning properly. As mentioned above, in some instances complete removal of the leak is not possible, and in practice only a minimal amount of controlled leakage of fluid is desired. For example, controlled leaks can be used for lubrication or heat removal for bearings or bushings that are not pressurized, such as in a transmission. When the multilayer seal ring is installed and pressed onto a shaft or rod used in a bore or cylinder, a suitably functioning multilayer seal ring will prevent or at least minimize leakage of fluid. Having the pressurized side upstream of the multilayer seal ring installed in the cylinder and the non-pressurized side downstream of the seal ring serves to isolate the pressurized side from the non-pressurized side.

Moreover, the passage of any leaking fluid is typically through the gap 4 or the fracture 12 in the first annulus 2, and then the gap 4 or the fracture 12 in the second annulus 3. Cross the interface between adjacent annulus until The length of these passages between the gaps 4 or breaks 12 of adjacent annular portions is important in reducing leakage. Thus, the longer the passage, the more the fluid leakage is correspondingly reduced. Thus, as long as the gaps 4 or breaks 12 are not aligned with each other when the multilayer seal ring is formed, these gaps 4 or breaks 12 can be located anywhere along the individual annulus. The gaps 4 or breaks 12 in the multilayer seal ring can be placed in close proximity to each other for ease of assembly to the shaft, rod or other cylindrical member 7, thereby reducing the leak passage, but increasing the leak volume. Done. The gaps 4 or breaks 12 are preferably substantially opposite to each other, more preferably about 180 degrees apart to eliminate or minimize the amount of leakage.

The advantage provided by the gaps or breaks 12 in the multilayer seal ring 1 of the present invention is that the individual annular portions rotate relative to each other, such that the gaps 4 or breaks on the shaft, rod or other cylindrical member 7. It disappears when (12) results in an ordered result. Thus, at least the first and second annular portions 2, 3 are attached to each other in the attachment region 5 using an adhesive to prevent rotation relative to one another, as shown in FIGS. 2 to 4.

The adhesive 6 may, for example, be adhesive, pinning using a dowel, one annular portion having a protrusion while the adjacent annular portion receives the protrusion, for example a male / male configuration. It may be any manner known in the art, such as shaped or manufactured annular parts with recesses that can. Attaching the individual forms of the multilayer seal ring 1 allows them to retain the ability to slide against each other for the purpose of expansion for the installation of the multilayer ring while they do not rotate relative to each other.

Dowels used in the present invention should be made of a rigid material that can be formed into pins of small cross section. The dowells should be sufficiently rigid so as to withstand the insertion into each hole in the individual annulus and withstand the pressure, force and thermal conditions of the fluid system while not degrading the retention of the individual annulus of the multilayer seal ring 1. Moreover, the dowell should be made of inert material or those that are chemically compatible with both the fluid system and the annulus in which it is used. Dowels suitable for use in the present invention include those made from small gauge wires, fiber glass, carbon fiber, stainless steel, copper, aluminum, glass, polymers, and the like. Preferably, the dowel diameter is 50% or less of the wall thickness of the individual annular portion, more preferably 20% or less of the wall thickness.

Dowels are typically sized to retain their position when pressed in place, but holding them in place can be supplemented by the use of adhesives such as those described below for attaching annular portions to each other. Moreover, grooves such as ring grooves, for example found in some shafts, rods or other cylindrical members in which the annulus is used, help to prevent the dowel from working out of position. In positioning the dowell, the dowels need to be sufficiently penetrated into each annulus to keep them in contact with each other and to prevent rotation of the annulus relative to each other, but not adjacent to the annulus perpendicular to the end surface of the dowell. It should not extend beyond the flat surface.

The adhesive used in the present invention should not weaken, for example chemically degrade, the annulus, and such adhesive can be applied by hand or use a variety of methods known in the art of these products. The portion of the multilayer seal ring 1 to which the individual annular portions are attached to each other is the attachment area 5, which is generally a small area for the entire circumference of the multilayer seal ring. Typically, the use of an adhesive allows the size of the attachment area (or where the individual annular or non-annular portions can be attached to each other, while being kept close to the intermediate point in the circumferential direction of the annular portion between the gap 4 or the break 12. Width) is kept as small as possible. No applied adhesive should be extruded from between the adjacent annular portions, so care must be taken in the application amount. Excessive application of the adhesive can interfere with the sealing ability of the multilayer structure, cause sudden failure and contaminate other fluid systems.

In general, when determining the positioning of the attachment area, it is located at the midpoint of the centerline between the gap 4 or the break 12. Preferably, when the gap 4 or break 12 is spaced 180 degrees, the attachment area is located 90 degrees from the position of this gap 4 or break.

(Loctite)와 같이 상업적으로 제공된다.Adhesives suitable for use in the present invention are well known to those skilled in the art and are typically chemically inert and have a temperature rating suitable for the particular products used. Suitable adhesives are, for example, Loctite from Henkel Loctite, Rocky Hill, Connecticut.

Commercially available as (Loctite).

The individual annulus according to the invention can be produced by various methods known in the art, for example injection molding, extrusion molding, compression molding and the like.

Methods of making individual at least first and second annular parts 2, 3 with breaks 12 according to the present invention are well known in the art and are known in the art, including attorney Docket No. AD7059 (E.I. DuPont). Although it includes what was described by de Nemours company, it is not limited to this.

The present invention relates to a method for forming a multilayer seal ring according to the present invention, which method comprises at least a first annular portion having a gap or breakage therein and a second annular portion having a gap or breakage therein as an adhesive. Attaching to each other at the attachment region, wherein at least the first annular portion is adjacent or abuts with the second annular portion. The method described above can be used to attach the acyclic portions to form a multilayer seal structure.

Claims (32)

a) a first annular portion having a gap therein, b) a second annular portion having a gap therein, The second annular portion is adjacent to or in contact with the first polymerized annular portion, And the first and second annular portions are attached to each other at an attachment area with an adhesive. The multilayer seal ring of claim 1 wherein the first and second annular portions comprise a polymer, a metal or a flexible elastomer. The method of claim 2, wherein the polymer is polyimide, polyamide, polyester, polyether ether ketone, polyamide imide, polyether imide, polyether ketone ketone, polyether ketone, polyphenylene sulfide, polybenzimida. A multilayer seal ring that is a polybenzimidazloe, thermoplastic polyimide, polytetrafluoroethylene, or liquid crystal polymer. The multilayer seal ring of claim 3 wherein said polyimide is prepared from at least one diamine and at least one anhydride. The multilayer seal ring of claim 4 wherein the diamine is M-phenylene diamine, p-phenylene diamine, oxydianiline, methylene dianiline, toluene diamine and mixtures thereof. 6. The multilayer seal ring of claim 5 wherein said diamine is 4, 4'-oxydianiline. The multilayer seal ring according to claim 4, wherein the anhydride is benzophenone tetracarboxylic dianhydride, biphenyl dianhydride, trimellitic anhydride, pyromellitic dianhydride, maleic anhydride, nadic anhydride and mixtures thereof. 8. The multilayer seal ring of claim 7 wherein said anhydride is a pyromethyltic dianhydride. The polyimide of claim 4, wherein the polyimide is BTDA-MPD, MA-MDA, BTDA-MDA-NA, TMA-MPD and TMA-ODA, BPDA-ODA, BPDA-MPD, BPDA-PPD, BTDA-4, 4 ′. A multilayer seal ring which is diaminobenzophenone or BTDA-bis (P-phenoxy) -p, p'-biphenyl. The method of claim 1, wherein the first and second annular portions are melt processable at least one polyimide and at a temperature of about 400 ° C. or less and are selected from polyamide and polyester resin and are present at a concentration of about 45 to 79.9 weight percent. A multilayer seal ring comprising a polyimide composition comprising a mixture of at least one other polymer that may be present. 4. The multilayer seal ring of claim 3 wherein the polyamide is nylon 6, nylon 6,6, nylon 610 and nylon 612. 4. The multilayer seal ring of claim 3 wherein the polyester is polybutylene terephthalate and polyethylene terephthalate. The multilayer seal ring of claim 3, wherein the liquid crystal polymer comprises polyesteramide and polyesterimide. The multilayer seal ring of claim 1 wherein the first and second annular portions comprise the same polymer. The multilayer seal ring of claim 1 wherein the first and second annular portions comprise different polymers. The multilayer seal ring of claim 1 wherein the first and second annular portions have a tensile strength in the range of about 9000 to about 18000 psi. The multilayer seal ring of claim 1, wherein the first and second annular portions have an elongation in the range of about 2.5% to about 10%. The multilayer seal ring of claim 1, wherein the first and second annular portions have a tensile modulus in the range of about 310,000 to about 750,000 psi. 3. The multilayer seal ring of claim 2 wherein the polymer further comprises an additive, filler or dry lubricant. The multilayer seal ring of claim 1 wherein the gap between the first and second annular portions is about 180 degrees apart. 2. The multilayer seal ring of claim 1 wherein the adhesive is a dowel, an adhesive or a protrusion / recess structure formed in the first and second annular portions. The multilayer seal ring of claim 21 wherein the dowel comprises wire, fiber glass, carbon fiber, stainless steel, copper, aluminum, glass, or polymer. A compressor comprising the multilayer seal ring of claim 1. A power steering device comprising the multilayer seal ring of claim 1. An automatic transmission comprising the multilayer seal ring of claim 1. a) a first non-cyclic portion having a gap therein, b) a second acyclic portion having a gap therein, The second annular portion is in contact with the first polymerized annular portion, Wherein the first and second annular portions are attached to each other at an attachment region with an adhesive to form a multilayer seal ring. 27. The multilayer seal structure of claim 26, wherein the acyclic shape is elliptical. a) a first annular portion having a fracture portion therein, b) a second annular portion having a break therein, The second annular portion is in contact with or adjacent to the first polymerized annular portion, And the first and second annular portions are attached to each other at an attachment area with an adhesive. 29. The multilayer seal ring of claim 28 wherein the breaks of the first and second annular portions are spaced about 180 degrees apart. a) a first non-cyclic portion having a fracture portion therein, b) a second acyclic portion having a fracture therein, The second acyclic portion is in contact with or adjacent to the first polymeric acyclic portion, And the first and second acyclic portions are attached to each other at an attachment region with an adhesive. Attaching at least a first annular portion having a gap or break therein and a second annular portion having a gap or break therein in an attachment region with an adhesive, at least the first annular portion being in contact with the second annular portion Or adjacent multilayer seal ring formation methods. Attaching at least a first acyclic portion having a gap or break therein and a second acyclic portion having a gap or break therein with an adhesive in an attachment region, wherein at least the first acyclic portion has the second acyclic portion A method of forming a multilayer seal structure in contact with or adjacent to.

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