Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B1/00—Layered products having a non-planar shape
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/34—Layered products comprising a layer of synthetic resin comprising polyamides
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J15/00—Sealings
  • F16J15/16—Sealings between relatively-moving surfaces
  • F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
  • F16J15/3268—Mounting of sealing rings
  • F16J15/3272—Mounting of sealing rings the rings having a break or opening, e.g. to enable mounting on a shaft otherwise than from a shaft end
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16J—PISTONS; CYLINDERS; SEALINGS
  • F16J9/00—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction
  • F16J9/12—Details
  • F16J9/14—Joint-closures
  • F16J9/16—Joint-closures obtained by stacking of rings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/54—Yield strength; Tensile strength

Definitions

• the present invention relates to a multi-layered seal ring or other geometric configuration that minimizes, controls or essentially eliminates fluid leakage over a wide range of temperatures.
• Sealing rings are used for creating a seal between a shaft or rod and the walls of a bore or cylinder in many types of mechanical devices such as, for example, compressors, pumps, automatic transmissions and power steering devices.
• a seal ring generally has an open annular shape and is mounted in the circumferential groove of a shaft or rod (e.g., a piston) that is situated within a cylindrical housing.
• the normal function of the seal ring is to prevent or control the leakage of fluid across the ring structure from one side to the other, while also allowing the shaft or rod upon which it is disposed to rotate, pulsate or reciprocate within the cylindrical housing.
• seal ring designs having a joint are described in the industry, wherein the joint allows the seal ring to expand or contract in response to the thermal expansion and/or contraction of the cylindrical member, rod or shaft upon which they are mounted.
• the joints of these seal rings have a variety of geometric configurations such as, for example, step joints, scarf joints and butt joints.
• thermal expansion and exposure to other forces exerted upon the seal rings during their use causes seal rings using these types of joints have gaps in their structure. These gaps are disadvantageous in that they allow for the excessive leakage of fluid across their structure. Varying degrees of leakage occur over a range of temperatures, a factor that needs to be taken into account in fluid systems (e.g. automatic transmissions) for proper operation.
• the rate of leakage across known joints such as, for example, a micro-cut, step gap or butt gap (and others) is reduced by sizing the seal ring to have a smaller gap at cold temperatures.
• this is problematic because as the ring thermally expands in response to its operating temperature, a completely closed gap may result in the ring binding in the groove or even buckle.
• the binding or buckling results in premature wear and/or causes the ring to improperly seal, wherein the rate of leakage actually increases, especially with the lower viscosities of higher temperature oil. Therefore, there is a need within the industry to develop a seal ring that eliminates leakage or only allows for minimal yet controlled amounts of leakage across its structure over a wide range of temperatures.
• the present invention provides just such a seal ring.
• the present invention relates to an expandable multi-layered seal ring design or other geometric configuration allowing for its installation onto a shaft, rod or other cylindrical member, wherein the present invention essentially eliminates or allows for only minimal yet controlled leakage over a wide range of operating temperatures.
• An embodiment of the present invention relates to a multi-layered seal ring or other geometric configuration comprising: a.) a first annular or non-annular form having a gap or fracture therein; and b.) a second annular or non-annular form having a gap or fracture therein, wherein the second annular form is contiguous with or adjoining to the first annular form; and wherein the at least first and second annular forms are affixed to one another at an affixation zone with an affixing agent.
• the present invention also relates to a process for forming a multi- layered seal ring or other geometric configuration comprising: (i) affixing at least a first annular or non-annular form and second annular or non-annular form to one another at an affixation zone with an affixing agent, wherein the at least first annular or non- annular form is contiguous with (or adjoining to) the second annular or non-annular form.
• Figure 1 depicts a side view of an embodiment of the multi-layered seal ring according to the present invention.
• Figure 2 depicts an exploded side view of an embodiment of the multi- layered seal ring according to the present invention.
• Figure 3 depicts a side view of an embodiment of the multi-layered seal ring positioned on a rod or shaft.
• Figure 4 depicts a side view of an embodiment of the multi-layered seal ring having a fracture therein.
• the multi-layered seal rings are used in applications where fluids in the form of a liquid or gas are isolated, such that the fluid exerts pressure against the seal ring thereby creating a sealed surface.
• the present invention relates to an expandable multi-layered seal ring design or other geometric configuration thereby allowing its installation onto a shaft, rod or other cylindrical member, and then once in position, provide a seal as though it were a continuous solid ring.
• the present invention provides for a multi-layered seal ring that essentially eliminates or allows for only minimal yet controlled leakage over a wide range of operating temperatures. More specifically, as shown in FIGS.
• an embodiment of the present invention relates to a multi-layered seal ring (1) comprising: a.) a first annular form (2) having a gap (4) therein; and b.) a second annular form (3) having a gap(4) therein, wherein the second annular form is contiguous with or adjoining to the first annular form; wherein the at least first and second annular forms are affixed to one another at an affixation zone (5) with an affixing agent (6).
• the design of the present invention contemplates the use of multiple annular or non-annular forms, wherein at least two individual annular or non- annular forms are connected to one another. For ease of description, an embodiment utilizing two annular forms is set forth herein.
• each singular annular form has a thickness that is about one-half as thick as a typical equivalent seal ring.
• the at least first and second annular forms of the multi-layered seal ring according to the present invention may generally have a wide range of diameters and still confer its particular advantages.
• the at least first (2) and second (3) annular forms according to the present invention may be comprised of any material capable of providing the necessary sealing function while being able to withstand the forces and temperatures generated in the environment in which it is used, for example, metals such as cast iron, flexible elastomers and various polymers.
• the at least first (2) and second (3) annular forms are comprised of polymeric materials, where the first (2) and second (3) annular forms may comprise either the same polymer or different polymers.
• a preferred embodiment of the multi-layered seal ring (1) comprises a high performance polymer. More preferably, the present invention comprises a synthetic high performance polymer that is temperature resistant, has a high melting point, has high compressive strength, is not brittle, has a low coefficient of thermal expansion and a low coefficient of friction. Other physical properties are also important in a seal ring such as, for example, tensile strength, modulus and elongation. Although metal seal rings tend to have better tensile strength and modulus, elongation is higher in polymers.
• tensile strength should be in the range of about 9000 to about 18000 psi (62.1 x 10 3 to 124.1 x 10 3 kPa), elongation in the range of about 2.5% to about 10%, and tensile modulus in the range of about 310,000 to about 750,000 psi (2.14 x 10 6 to 5.17 x 10 kPa).
• tensile modulus in the range of about 310,000 to about 750,000 psi (2.14 x 10 6 to 5.17 x 10 kPa).
• polymers are suitable for use in the multi-layered seal rings (1) in the present invention.
• polyimide polyamide, polyester, polyether ether ketone (PEEK), polyamide imide (PAI), polyether imide, polyether ketone ketone (PEKK), polyether ketone (PEK), polyphenylene sulfide, polybenzimidazole, and thermoplastic polyimide (TPI), polytetrafluoroethylene (PTFE), and liquid crystal polymer (LCP).
• PEEK polyether ether ketone
• PAI polyamide imide
• PEKK polyether ketone ketone
• PEK polyphenylene sulfide
• TPI thermoplastic polyimide
• PTFE polytetrafluoroethylene
• LCP liquid crystal polymer
• Preferred diamines include m- phenylene diamine (MPD), p-phenylene diamine (PPD), oxydianiline (ODA), methylene dianiline (MDA), and toluene diamine (TDA).
• Preferred anhydrides include benzophenone tetracarboxylic dianhydride (BTDA), biphenyl dianhydride (BPDA), trimellitic anhydride (TMA), pyromellitic dianhydride (PMDA), maleic anhydride (MA), and nadic anhydride (NA).
• Preferred polyimides include those prepared from the following combinations of anhydride and diamine: BTDA-MPD, MA-MDA, BTDA-MDA- NA, TMA-MPD & TMA-ODA, BPDA-ODA, BPDA-MPD, BPDA-PPD, BTDA-4, 4'-diaminobenzophenone, and BTDA-bis(P-phenoxy)-p, p'-biphenyl.
• An especially satisfactory polyimide useful in the seal ring of present invention is that prepared from pyrometillitic dianhydride and 4,4'-oxydianiline (PMDA- ODA).
• the multi-layered seal ring comprises a commercially available polyimide such as, for example, VESPEL® Thermoplastic material (available from E.I. du Pont de Nemours and Company, Wilmington, DE).
• the polyimide compositions can also contain a blend of at least one polyimide with at least one other polymer which is melt processible at a temperature of less than about 400°C and is selected from polyamide and polyester resin and may be present in a concentration of from about 45 to 79.9 weight percent. Melt processible is used in its conventional sense, that the polymer can be processed in an extrusion apparatus at the indicated temperatures without substantial degradation of the polymer.
• polyamides and/or polyesters can be used in the present invention and/or can be blended with polyimides.
• polyamides which can be used, include nylon 6, nylon 6,6, nylon 610 and nylon 612.
• Polyesters which can be used, include polybutylene terepthalate and polyethylene terepthalate.
• a fusible or melt processible polyamide or polyester can additionally be, in the form of a liquid crystal polymer (LCP).
• LCP's are generally polyesters, including, but not limited to polyesteramides and polyesterimdes. LCP's are described by Jackson et al., for example, in US Pat. Nos.
• the polymers of the multi-layered seal ring (1) of the present invention can further include other additives, fillers and dry lubricants, which do not depreciate the overall characteristics of the finished seal rings, as would be evident to those skilled in the art.
• the incorporation of graphite into the composition can extend the range of its utility as a wear resistant material.
• Another beneficial additive is carbon fiber, for the purpose of reducing coefficient of thermal expansion.
• Various inorganic fillers are known to reduce the coefficient of friction and improve wear resistance.
• the multi-layered seal ring (1) according to the present invention may be comprised of various combinations of polymers, wherein each individual annular form comprises a different polymer.
• the polymers may be chosen based on their performance and use in varying applications, wherein the wear side of a two-layered ring may comprise a first polymer that provides high wear and low friction characteristics, while the adjoining annular form comprises a more ductile polymer providing for better sealing against a stationary surface.
• combinations of polymers it is preferred to use those polymers having similar thermal expansion rates, preferably within 10% of one another.
• the present invention preferably relates to a multi-layered seal ring (1) since rotating equipment frequently draws a substantially circular path.
• a variety of other multi-layered geometric configurations including, but not limited to, multi-layered elliptical sealing structures may be utilized in more specialized applications.
• the individual annular forms according to the present invention have a square or rectangular cross-sectional configuration, however other cross sectional configurations such as, for example, chamfered corners may be used.
• the chamfer may be an angle or have an inside radius.
• the at least first (2) and second (3) annular forms of the present invention have a gap (4) in their structures, which allows the adjoining rings to slide in relation to one another.
• each individual annular > form has a gap (4) through the entirety of its thickness thereby forming a pair of ends having opposing faces (4a, 4b) that are substantially parallel to one another and have smooth faces. Additionally, the gap's opposing faces (4a, 4b) are preferably substantially perpendicular to the major axis or plane of the particular individual annular form.
• the present invention utilizes individual forms that have been fractured as shown in Figure 4.
• Each individual annular form is completely fractured (12), through the entirety of its thickness thereby forming a pair of ends having opposing faces (11a, 11b) that are substantially parallel to one another.
• the fracture's opposing faces (11a, 11b) or the fracture line is preferably substantially perpendicular to the major axis or plane of the particular individual annular form.
• the fracture's opposing end faces are rough, and mesh together when the faces are forced into contact, which may further aid in the prevention of leakage.
• the multi- layered seal ring (1) becomes heated during the rotational or reciprocating movement of the shaft, rod or other cylindrical member, causing the multi- layered seal ring to thermally expand when the multi-layered seal ring is at operating conditions.
• the opposing end faces (4a, 4b or 11a, 11b) may not necessarily make contact until the operating conditions are reached.
• the gap (4) or fracture (12) is open at cold temperatures and closed at peak operating temperatures, which minimizes the leakage by the first ring.
• the width of the gap (4) is not critical, however its size should not be so large such that when a multi-layered seal ring (1) is formed there is no overlap of the at least first (2) and second (3) annular or non-annular forms.
• the gap width is only a small fraction of the overall circumference measurement of the particular annular form.
• the gap width is generally in linear relation to the diameter of the particular annular form, wherein if the diameter of the individual annular form is doubled, the width of the gap likewise doubles.
• fluid pressure is another operating condition, which affects the multi-layered seal rings' ability to perform the sealing function.
• the opposing faces (4a, 4b and 11a, 11b) come together, thereby closing the gap (4) or fracture (12) that was created for installation of the seal ring and whereby the gap or fracture (12) does not become a point of leakage, therefore a single multi-layered seal ring is all that is required to perform the sealing function.
• a cylinder having a pressurized side upstream of the installed multi-layered seal ring and a non-pressurized side downstream of the seal ring generally functions by isolating the pressurized side from the non-pressurized side.
• the path of any leaking fluids is typically through the gap (4) or fracture (12) in the first annular form (2), then by way of the interface between the adjoining annular forms until reaching the gap (4) or fracture (12) in the second annular form (3).
• the length of this pathway between the gaps (4) or fractures (12) of the adjoining annular forms is important in the reduction of the leakage. Therefore the longer the pathway, the better the corresponding reduction in fluid leakage.
• the gap (4) or fracture (12) may be positioned anywhere along the individual annular forms, as long as these gaps (4) or fractures (12) are not in alignment with one another when the multi- layered seal ring is formed.
• the gaps (4) or fractures (12) in the multi-layered seal ring may be positioned in close proximity with one another for ease of assembling on a shaft, rod or other cylindrical member (7), thereby shortening the leakage pathway; however there will be an increase in the leakage volume. It is preferred that the gaps (4) or fractures (12) are substantially opposite one another, more preferably about 180 degrees apart, thereby eliminating or minimizing the amount of leakage.
• the advantages conferred by the gaps or fracture (12) in the multi- layered seal ring (1) of the present invention are negated when the individual annular forms rotate relative to one another, resulting in alignment of the gaps (4) or fracture (12) on the shaft, rod or other cylindrical member (7). Therefore, the at least first (2) and second annular (3) forms are affixed to one another at an affixation zone (5) using an affixing agent (6) to prevent the rotation relative to one another, as shown in FIGS. 2 and 4.
• the affixing agent (6) may be any method known in the art such as, for example, an adhesive; pinning using a dowel, or annular forms molded or manufactured where one annular form has a projection, while an adjoining annular form has a recess capable of accepting the projection (e.g. a male/female configuration).
• Affixing the individual forms of the multi-layered seal ring (1) allows them to retain the ability to slide relative to one another for the purpose of expansion for installation of the multi-layered ring, while not rotating relative to one another.
• Dowels used in the present invention must be made from a strong material capable of be formed into small cross sectional pins.
• the dowel must be of a size that it is stiff enough to withstand its insertion into the respective holes in the individual annular forms as well as being capable of withstanding the pressures, forces and thermal requirements of the fluid system, while not degrading the integrity of the individual annular forms of the multi-layered seal ring (1).
• the dowel must also be made from inert materials or those chemically compatible with both the annular forms and the fluid system in which it is to be used. Suitable dowels for use in the present invention include those made from small gauge wire, fiberglass, carbon fiber, stainless steel, copper, aluminum, glass, polymers etc.
• the dowel diameter is no more than 50% of the wall thickness of the individual annular forms, more preferably no more than 20% of the wall thickness.
• the dowels are of a size that when pressed into place they maintain their positioning, however, maintaining them in position may be supplemented by the use of adhesives, such as those described below for affixing the annular forms to one another.
• a groove such as, for example, a ring groove found in some shafts, rods or other cylindrical members with which the annular forms are utilized also assists in preventing the dowel from working its way out of position. In positioning the dowel there needs to be sufficient penetration into each annular form such that the dowel holds the annular forms in contact with one another and prevents the rotation of the annular forms relative to one another, but should not extend beyond the non-adjoining planar surface of the annular form perpendicular to the end surface of the dowel.
• Adhesives utilized in the present invention should not weaken (e.g. chemically degrade) the annular forms, and such adhesives may be applied manually or using any method known in the art for such applications.
• the portion of the multi-layered seal ring (1) where the individual annular forms are affixed to one another is the affixation zone (5), which is generally a small area in relation to the overall circumference of the multi-layered seal ring.
• the size (or width) of the affixation zone is kept as small as possible where it is kept as close to the circumferential mid-point of the annular forms between the gaps (4) or fractures (12), while still being able to affix the individual annular or non-annular forms to one another.
• any applied adhesive should not extrude from between the adjoining annular forms, so care must be taken in the amount applied. Over-application of an adhesive may interfere with the sealing capabilities of the multi-layered structure and could also break-off and become a contaminant to the rest of the fluid system.
• the affixation zone is located at the mid-point of the centerline between the gaps (4) or fractures (12).
• the affixation zone is located 90 degrees from the location of the gaps (4) or fractures, when such gaps (4) or fractures (12) are 180 degrees apart.
• Suitable adhesives 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 appropriate for the particular application in which they are to be utilized.
• Suitable adhesives are also commercially available such as, for example, Loctite®, available from the Henkel Loctite Corporation, Rocky Hill CT.
• the individual annular forms according to the present invention may be produced by various methods known in the art such, for example, injection molding, extrusion molding, compaction formed and the like.
• the methods for making the individual at least first (2) and second (3) annular forms having a fracture (12) according to the present invention are well known in the art, including but not limited to that set forth in Attorney Docket AD7059 (E.I. Dupont de Nemours and Company).
• the present invention also relates to a process for forming a multi- layered seal ring according to the present invention, the process comprising affixing at least a first annular form having a gap or fracture therein and second annular form having a gap or fracture therein to one another at an affixation zone with an affixing agent, wherein the at least first annular form is contiguous with (or adjoining to) the second annular form.
• the above-noted process may also be utilized for affixing non-annular forms to form multi- layered seal structures.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Sealing Devices (AREA)

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• 2004
  • 2004-12-16 US US11/013,902 patent/US20050189725A1/en not_active Abandoned
  • 2004-12-21 JP JP2006547275A patent/JP2007525625A/ja active Pending
  • 2004-12-21 WO PCT/US2004/042984 patent/WO2005064212A2/en not_active Ceased
  • 2004-12-21 EP EP04815101A patent/EP1697664A2/en not_active Withdrawn

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