RU65158U1 - COMPOSITE, HIGH TEMPERATURE DYNAMIC SEAL (OPTIONS) - Google Patents

Abstract

Composite dynamic seals suitable for use in high-temperature environments and a method for its manufacture are proposed. A dynamic seal includes an elastic, substantially annular, seal body having a first layer formed from a first elastic sealing material and a second layer formed from their second elastic sealing material. The first and second layers are preferably formed simultaneously and vulcanized with each other and chemically crosslinked with each other. The first elastic sealing material is selected in accordance with its dynamic properties of wear resistance, and the second elastic sealing material is selected in accordance with its properties of resistance to permanent deformation under compression. The first resilient sealing material is preferably a copolymer of tetrafluoroethylene and propylene, and the second resilient sealing material is preferably fluorocarbon rubber. The first and second resilient sealing materials have compatible vulcanization systems, preferably peroxide vulcanization systems.

Description

The technical field to which the utility model relates.

This utility model relates to sealing elements for sealing between moving relative to each other mechanical components, and, in particular, to rotating sealing elements for use in high temperature applications.

State of the art

but. Parker Hannifin Corporation manufactures a series of well-known two-piece O-ring seals under the registered trademark “POLYPAK.” As indicated in its catalog No. 5205B-1 with the name “LC Profile Seal” . The POLYPAK seal consists of an O-ring and a lip seal housing. The O-ring is used as an expansion ring, which is compressed during installation to load the cuffs. The o-ring often consists of a material different from the lip seal material, with each material being selected based on its performance. In dynamic use, the o-ring is often prone to bias, causing leaks, as disclosed in Parker Hannifin Corporation catalog No. 5205B-1. Displacement of the o-ring can also lead to the absorption of dirt and accelerated wear of the seal.

b. Spring-reinforced lip seals according to the prior art

Many firms manufacture two-part spring-reinforced lip seals for dynamic applications, where the spring presses the dynamic lip onto the moving surface of the machine component. Some types of springs used include cantilever springs, hold-down springs, and tapered coil springs. When such seals are used to eliminate highly contaminated environments, the springs are displaced, causing leakage, contamination, and accelerated seal wear. Such seals are not suitable for applications in which differential pressures in both directions can occur. Such seals can withstand pressure only when the differential pressure acts from the side of the seal where the springs are located, so that the pressure acts inside the dynamic cuff to press the dynamic cuff tighter

relative to a moving surface. When a pressure difference occurs in the opposite direction, the pressure lifts the seal from a relatively moving surface, allowing fluid to break through the seal.

from. Hydrodynamic rotary seals according to prior art Kalsi Engineering, Inc. manufactures a number of well-known patented dynamic seals under the registered trademark "KALSI SEALS". These seals, which are one-piece hydraulically lubricated seals, are widely used in oil drilling and other rotating equipment. These seals use the principles of hydrodynamic lubrication and the elimination of contamination specified in US patent No. 4610319, 5230520, 5678829, 5738358, 6109618, 6120036, 6315302 and 6382634. The full contents of these patents are included in this description. The basic principles of hydrodynamic lubrication and the elimination of contamination of a number of KALSI SEALS seals are shown in US Pat. No. 4,610,319. US Pat. No. 5,230,520 discloses a static cuff that provides reduced seal distortion, improved seal stability, and improved abrasive particle exclusion. US Pat. No. 5,678,829 discloses a circumferential groove that can be used to reduce contact pressure between surfaces to provide improved lubrication and higher speeds. US Pat. No. 5,738,358 discloses a dual modular construction that can be used to reduce contact pressure between surfaces to provide improved lubrication, higher speeds, and higher pressure differences. US Pat. No. 6,109,618 discloses an aggressive hydrodynamic geometry that provides better lubrication under adverse conditions. US Pat. No. 6120036 discloses a beveled cuff design that can be used to control contact pressure between surfaces, which in turn increases resistance to damage by extrusion. US Pat. No. 6,315,302 discloses axially-limited geometry that provides improved exclusion of abrasive particles in applications having a small or zero pressure difference, or low levels of reverse pressure difference. US Pat. No. 6,382,634 discloses a geometry that provides additional consumables to compensate for abrasive wear.

The rotary seals offered by Kalsi Engineering are installed radially (i.e. compression) and are sealed by blocking the creepage distance. Service life is determined by the ability of the seal to remain resilient and maintain adequate contact pressure between the surfaces.

(i.e., maintain sufficient contact force with the mating opposite shaft surface). Loss of elasticity is called permanent compression deformation. Permanent compression deformation is a measure of the departure after a given period of time, and is usually expressed as a percentage of the initial compression. As in all types of elastomer fracture, the permanent deformation from compression deteriorates at high temperatures and is influenced by media compatibility.

Consisting of a single material, homogeneous rotating seals made in accordance with FIGS. 1, 2, 2A and 5 of US Pat. No. 5,230,520 are usually made of a highly saturated nitrile elastomer, also known as HSN or HNBR, but can also be made of FKM ( fluorocarbon rubber) or TFE / P (a copolymer of tetrafluoroethylene and propylene). Tests have shown that when such seals are made of HSN, they are only suitable for temperatures around 300 ° F (150 ° C). Above this temperature, solidification and permanent compression deformation will limit service life. Such seals are widely used in oil well drilling equipment. As the wells get deeper and deeper, the need for cost-effective rotating seals that can withstand temperatures in the range of 300 to 400 ° F (150-200 ° C) has become critical. Increasing rotational speeds are also used for drilling oil wells, which leads to an increase in the actual seal temperature. Conventional FKM elastomers have good compressive strength and chemical resistance at high temperatures, but are not suitable for use in the rotary seal for the petroleum industry of type 1, 2, 2A and 5 of US Pat. No. 5,230,520, due to the strong cracking of the dynamic interface, which occurs already at a temperature of 300 ° F (150 ° C), and since FKM usually has poor abrasion resistance characteristics, which makes it unsuitable for sealing high pressure differences. FKM is often called "VITON", which is a trademark for DuPont's high performance elastomers. The TFE / P elastomer (commonly referred to as the AFLAS trademark of Asahi Glass Co., Ltd.) is a fluoroplastic that has good high temperature dynamic properties and good chemical resistance, but is not suitable for use as a single bore rotary seal material shown in figures 1, 2, 2A and 5 of US patent No. 5230520 type, due to the extremely poor characteristics of resistance to permanent deformation under compression. Compared to FKM, TFE / P has significantly lower high temperature resistance to permanent deformation

in compression (i.e. TFE / P has a higher residual deformation in compression than FKM in high temperature conditions).

The two-module HSN seals made in accordance with FIG. 9 of US Pat. No. 5,738,358 provide a lower cuff load than seals according to US Pat. No. 5,230,520, and therefore provide lower temperature operation at higher rotational speeds. The two-module design is also more resistant to damage caused by extrusion of lubricant pressure. Under conditions of a low pressure difference or a low level of a reversing pressure difference, the contact pressure distribution of such two-module seals is not suitable for eliminating abrasive particles if a bevel seal design is not used, according to US Pat. No. 6120036. Under conditions of high pressure differences, flattening of the structure with a beveled cuff caused by the pressure of the lubricant may worsen the exclusion of abrasive particles. Used in this case, the concept of "module" or "elastic modulus" of the elastomer can be evaluated in accordance with figure 1 of ASTM D 1415-83 (standard for a method of testing the properties of rubber - international hardness).

Two-module HSN seals made in accordance with FIG. 9 of US Pat. No. 5,738,358 are very expensive to manufacture, which limits their widespread use. The most productive way is a multi-stage method that requires a lot of labor. The interior with a higher modulus, which is called the "insert", is made first and is partially hardened (ie partially cured), then cooled, cleaned and checked. After stripping, several labor-intensive special processes are used to ensure efficient bonding with a reinforcing material with a lower modulus. During final molding, the partially vulcanized insert is manually inserted into the hot mold cavity to ensure proper synchronization between the waveform of the mold and the waveform of the insert. Only then can a material with a lower modulus be introduced into the mold cavity for final molding and vulcanization. After this, the finished part must be cooled again, cleaned and checked. Various types of defects can occur at almost every stage of manufacture, due to which the reject rate is often high. The manufacturing process is considered undesirable for use with very thin inserts.

Several attempts have been made to produce two-module seals using two different HSN materials with peroxide vulcanization in a single-stage molding process when two unvulcanized materials

simultaneously form together in one cavity of the mold. Non-vulcanized material with a higher modulus does not always remain in place and is displaced and / or distorted due to the molding pressure and movement of the non-vulcanized material with a low modulus during the molding process. Even worse, a high modulus material does not bond well with a low modulus material and can be detached in practical use. Indeed, the connection can be so poor that two layers can sometimes be separated manually. In any case, the connection is weaker than either of the two HSN materials.

It is desirable to have a rotating seal suitable for sealing between two elements that are movable relative to each other, for use in high-temperature environments, including temperatures above 300 ° F (150 ° C). It is also desirable for the rotary seal to separate one fluid on one side of the seal from the second fluid on the second side of the seal. It is desirable that the rotary seal remain resilient and maintain adequate contact inter-surface pressure with the conjugate opposite surface of the rotatable element.

Utility Model Disclosure

This utility model relates to a composite rotary seal suitable for use in high temperature environments, including temperatures above 300 ° F. (150 ° C.). The composite rotary seal is suitable for sealing between two elements configured to move relative to each other. The composite rotary seal is preferably a dynamic seal to separate one fluid from another fluid. The composite rotary seal remains resilient and maintains adequate inter-surface contact pressure with the associated opposite surface of the rotatable member.

A preferred embodiment of this utility model includes an elastic, substantially annular, sealing body having a first layer formed from a first elastic sealing material and a second layer formed from their second elastic sealing material. The first layer defines at least one part of the dynamic sealing surface having a dynamic sealing cuff, and the second layer defines at least a part of the static sealing surface. The first and second layers are connected to each other as a single unit and are preferably formed simultaneously and vulcanized with each other.

The first resilient sealing material is preferably selected based on its dynamic wear resistance properties and has a predetermined modulus of elasticity. The second elastic sealing material is preferably selected based on its compressive strength and has an elastic modulus that is approximately equal to or less than the elastic modulus of the first elastic sealing material. The first layer is preferably relatively thin compared to the thickness of the second layer. In a preferred embodiment, the first elastic sealing material is a copolymer of tetrafluoroethylene and propylene, and the second elastic sealing material is fluorocarbon rubber.

Brief Description of the Drawings

For a better understanding of the ways to achieve the above characteristics, advantages and goals of this utility model, the following is a more detailed description of the utility model with reference to the accompanying drawings. However, it should be noted that the accompanying drawings only illustrate typical embodiments of this utility model, and therefore should not be construed as limiting its scope, since the utility model allows for other equally effective embodiments.

The drawings show:

figure 1 is a partial section of a composite dynamic seal, according to one preferred embodiment of this utility model, the composite dynamic seal has a dynamic layer of sealing material and a static layer of sealing material, the composite dynamic seal is shown in a compressed state inside the sealing groove and with the formation of a hydrodynamic sealing contact with a relatively rotatable surface in the absence of a difference in fluid pressure;

Figa and 1B are partial sections of the first and second embodiments of the composite dynamic seal shown in figure 1, while the composite dynamic seal is shown in an uncompressed state and is intended for radial sealing;

Figs. 1C and 1D are partial cross-sections of the first and second embodiments of the composite dynamic seal shown in Fig. 1, wherein the composite dynamic seals are shown in an uncompressed state and are intended for axial sealing;

FIG. 2 is a partial sectional view of a composite dynamic seal according to another preferred embodiment of the present invention, wherein the composite dynamic seal has an inner dynamic layer of sealing material and an outer static layer of sealing material, wherein the composite dynamic seal is shown in an uncompressed state and is intended for radial sealing;

figa is a partial section of a composite dynamic seal similar to the seal according to figure 2, but not having a static sealing collar, and the seal is shown in an uncompressed state;

FIG. 3 is a partial sectional view of a mold for molding a composite dynamic seal according to a preferred embodiment of the present invention; FIG. and

4 is a partial sectional view of a composite dynamic seal according to another preferred embodiment of this utility model, wherein the composite dynamic seal has an inner dynamic layer of sealing material and an outer static layer of sealing material, the composite dynamic seal being shown in an uncompressed state and intended for radial sealing .

Utility Model Implementation

The composite dynamic seal, according to the preferred embodiments of this utility model, is indicated in the drawings as a whole by 2. The drawings illustrate various embodiments of the composite dynamic seal 2 for axial sealing and for radial sealing, as will be described below. On figa and 1B shows the configuration in section in an unstated state of the preferred embodiments of the composite dynamic seal 2, made for radial sealing. On figs and 1D shows the configuration in section in an unstated state of the preferred embodiments of the composite dynamic seal 2, made for axial sealing. The features indicated in this description by the same positions have the same basic function. For orientation purposes, it should be understood that in the sections shown in figa-1D and other figures, the corresponding plane of the section pass through the longitudinal axis of the shown element or elements.

In a partial cross-section in FIG. 1, a composite dynamic seal 2, according to a preferred embodiment, is preferably located and

positioned using an annular sealing groove 4 defined by the first component 6 of the machine (such as the housing), and is compressed between the opposite surface 8 of the annular sealing groove 4 and relatively rotatable surface 10 of the second component 12 of the machine. Compression initiates a static sealing relationship between the opposite groove surface 8 and the relatively rotatable surface 10 in the same manner as compression of a conventional interference type seal, such as a ring with a circular cross section. The opposing groove surface 8 and the relatively rotatable surface 10 are located substantially opposite each other. The first machine component 6 and the second machine component 12 typically define at least a portion of the lubrication chamber 14 to accommodate the first fluid 16.

The circumferential sealing groove 4 preferably includes a first groove wall 20 and a second groove wall 22, which are substantially opposite each other. In the hydrodynamic seal industry, the first groove wall 20 is often referred to as the “oil seal wall”, and the second groove wall 22 is often referred to as the “oil seal wall on the surround side”. Although the first groove wall 20 and the second groove wall 22 are shown in a fixed, constant relation to each other, this should not limit the scope of the invention, since the utility model allows for other equally suitable shapes. For example, the first groove wall 20 and / or the second groove wall 22 may be removable from the first component 6 of the machine for ease of maintenance and repair, and then assembled into a more or less fixed position to accommodate the dynamic seal 2.

The compressed configuration of the dynamic seal 2 shown in FIG. 2 is in its shape when the pressure of the first fluid 16 is substantially the same as the pressure of the second fluid 18. If the pressure of the first fluid 16 is significantly higher than the pressure of the second fluid 18, then the resulting pressure difference presses the dynamic the device 2 to the second wall 22 of the grooves. If the pressure of the second fluid 18 is significantly higher than the pressure of the first fluid 16, then the resulting pressure difference presses the dynamic device 2 against the first wall 20 of the groove.

The dynamic seal 2, which has a generally annular configuration, is used to separate the first fluid 16 from the second fluid 18 and to prevent the second fluid 18 from entering the first fluid 16. The first fluid 16 is preferably used in the present invention to lubricate a dynamic sealant the interface between the dynamic seal 2 and the relatively rotatable surface 10, and

it is preferably a liquid lubricant, such as synthetic or natural oil, although other fluids are also suitable for dynamic seal lubrication, including greases, water, and other process fluids. The second fluid 18 may be any other desired type of fluid, such as a lubricant, process fluid, environment, drilling fluid, etc. The relatively rotatable surface 10 may take the form of an outward or inwardly oriented substantially cylindrical surface, wherein the dynamic seal 2 is compressed radially between the opposite groove surface 8 and the relatively rotatable surface 10. Alternatively, the relatively rotatable surface 10 can take the form of a substantially flat surface, while the dynamic seal 2 is compressed in the axial direction between the opposite surface 8 of the grooves and the relative but the rotatable surface 10 is essentially flat in shape. Illustrations of a preferred embodiment for radial compression are shown in FIGS. 1A and 1B. Illustrations of a preferred embodiment for axial compression are shown in FIGS. 1C and 1D.

The dynamic seal 2 preferably includes a dynamic seal 24 and a static seal 26, which are generally circular in shape and arranged substantially opposite each other, as shown in FIGS. 1A-1D, to minimize the possibility of twisting the seal inside the packing box, according to ideas US patent No. 5230520.

The dynamic seal 2 defines a dynamic sealing surface 28 that is opposite from the rotatable surface 10. The width of the dynamic sealing surface 28 preferably varies around the circumference of the seal, as shown in FIG. 1A. The dynamic seal 2 preferably also defines a hydrodynamic inlet curvature 30 opposite to the rotatable surface 10. The hydrodynamic inlet curvature 30 preferably changes the circumferential position of the dynamic seal 2.

The non-circular, wavy change in position of the hydrodynamic input curvature 30 may take any shape that is skewed relative to the direction of relative rotation, and may take the form of one or more repeating or non-repeating gyrus / waves of any shape, including a sine, jagged or square wave, or several straight or curved segments forming a toothed pattern, or one or more parabolic curves, cycloid curves, Witch / Versier curves, elliptic curves, etc., or

combinations, including, but not limited to, any configurations shown in US patent No. 4610319 and 6109618.

The cross-sectional profile of the dynamic sealing surface 28 may be of any suitable shape, including straight or curved lines or combinations of lines. Between the hydrodynamic inlet curvature 30 and the dynamic sealing surface 28, there is preferably a transition point 32. The transition point 32 is shown by a dashed line in FIGS. 1A and 1C. The transition point 32 is preferably a contact point between the hydrodynamic inlet curvature 30 and the dynamic sealing surface 28.

The dynamic seal 2 preferably also defines a static sealing surface 34, which is mainly circular and is located mainly opposite the dynamic sealing surface 28.

A static exclusion intersection 36 is preferably provided at the intersection between the second end 38 of the seal and the static sealing surface 34 to exclude the second fluid 18. The static sealing surface 34 preferably defines an edge 40 on the lubricant side and preferably defines an edge on the surrounding side that is created by the static exclusion intersection 36 .

In an uncompressed state, the dynamic sealing surface 28 and / or the static sealing surface 34 may have, if desired, an inclined configuration at an angle to the respective mating surfaces of the first machine component 6 and the second machine component 12, according to the teachings of US Pat. No. 6,767,016. The inclination of the static sealing surface 34 and / or the dynamic sealing surface 28 increases the contact pressure between the dynamic sealing collar 24 and the relatively rotatable surface 10 near the dynamic exclusion intersection 46 for improved elimination of the second fluid 18.

The dynamic seal 2 defines an annular sealing body 42. As shown in FIG. 1, the dynamic seal 2 has a first seal end 44 facing the first fluid 16 and a second seal end 38 facing the second fluid 18. In the hydrodynamic seal industry, the first the end 44 of the seal is often referred to as the “end of the lubricant”, and the second end 38 of the seal is often called the “end of the environment”. The first end 44 of the seal is preferably located opposite the second end 38 of the seal. When installing the dynamic seal 2, the dynamic sealing collar 24 is pressed against a relatively rotatable surface 10 and creates a contour of the inter-surface contact mainly

circular in shape and having a width W, which preferably varies in size around the circumference of the dynamic seal 2. The dynamic sealing surface 28 in a preferred embodiment extends from the dynamic exclusive intersection 46 to the hydrodynamic input curvature 30. The geometry of the hydrodynamic input curvature 30 can take any suitable configuration that leads to a gradually narrowing non-circular geometry to facilitate hydrodynamic wedging without departing from the idea or scope MA of the invention, including any type of curve, such as, but not limited to, the radius of an ellipse, part of a sine wave part parabolic curve portion of a cycloid curve, a curve portion Vitchev / Versera or combinations thereof, etc.

As shown in FIG. 1, the dynamic seal 2 preferably defines a dynamic control surface 48 opposite to the rotatable surface 10, and preferably defines a static control surface 50 opposite to the opposite groove surface 8. The dynamic control surface 48 interacts with the relatively rotatable surface 10, and the static control surface 50 interacts with the opposite groove surface 8 to prevent unwanted twisting of the installed seal inside the circular sealing groove 4.

The dynamic seal 2 sets the depth D from the static sealing surface 34 to the dynamic sealing surface 28, and also sets the length 62 of the sealing body from the first end 44 of the seal to the second end 38 of the seal. The dynamic exclusion intersection 46 is preferably a sharp exclusion geometry adapted to act on the second fluid 18 to prevent the penetration of the second fluid 18 according to US Pat. No. 4,610319.

When there is no relative rotation, a fluid tight static sealing relationship is maintained on the interface between the dynamic sealing sleeve 24 and the relatively rotating surface 10, and between the static sealing sleeve 24 and the opposite groove surface 28. When the honey rotates relative to the circular sealing groove 4 and the relatively rotatable surface 10, the dynamic seal 2 preferably remains stationary relative to the opposite surface 8 of the groove and maintains a static sealing relationship with it, while the interface between the dynamic sealing collar 24 and the relatively rotatable surface 10 becomes a dynamic sealing interface so that the relatively rotatable surface 10 slides

relatively dynamic sealing cuff 24 with a given speed of rotation. The direction of relative rotation is normal (perpendicular) to the plane of the section shown in figure 1.

In the installed position, as shown in FIG. 1, the dynamic sealing collar 24 is deformed to form an inter-surface contact with a relatively rotatable surface 10. This contour has a width W, which preferably varies in size around the circumference of the dynamic seal 2 essentially synchronously with the change in the position of the hydrodynamic the input curvature 30. The first edge 52 of the intersurface contact contour is preferably not circular, i.e. wavy, due to a change in the position of the hydrodynamic input curvature 30, and in combination with the deformed shape of the dynamic sealing collar 24 creates a hydrodynamic wedging action in response to relative rotation between the dynamic seal 2 and the relatively rotating surface 10. This hydrodynamic wedging action wedges the film of lubricating fluid ( i.e., the first fluid 16) into the inter-surface contact circuit between the dynamic sealing collar 24 and relatively rotatable th surface 10 for the purpose of lubrication, which reduces wear, torque and heat.

The second edge 54 (sometimes referred to as the "surrounding edge") of the intersurface contact contour is preferably substantially circular and therefore does not produce a hydrodynamic wedging action in response to relative rotation between the dynamic seal 2 and the relatively rotating surface 10, which facilitates the exclusion of the second fluid 18.

At least a portion of the dynamic sealing collar 24 is made of a first layer 56 of elastic sealing material selected based on its wear resistance characteristics and having a predetermined elastic modulus. A second layer 58 of elastic sealing material is also provided, which has an elastic modulus that is approximately equal to or less than the elastic modulus of the material used to form the first layer 56 of elastic sealing material. The first layer 56 of resilient sealing material is relatively thin compared to the thickness of the second layer 58 of resilient sealing material.

When the pressure difference acts on the dynamic seal 2, so that the pressure of the lubricant 16 exceeds the pressure of the second fluid 18, the second end 36 of the seal is pressed against the second wall 28 of the groove. Since the second end 38 of the seal preferably has the same flat shape as the groove wall 22, the wall 22 provides support against pressure at all points except for the extrusion gap,

existing between the relatively rotatable surface 10 and the lower edge of the groove wall 22. This displacement gap is preferably relatively small so that the seal material can overlap and resist pressure. It is known from the prior art that at high pressure, a small portion of the sealing collar tends to protrude or extrude into the displacement gap, and that pulsating pressure and beating can bend the displaced material, resulting in damage to the displaced part.

In a preferred embodiment of the present invention, the displacement resistance of the dynamic sealing collar 24 primarily depends on the elastic modulus of the first layer 56 of the elastic sealing material, and the inter-surface contact pressure between the dynamic sealing collar 24 and the relatively rotatable surface 10 largely depends on the elastic modulus of the second layer 58 elastic sealing material, since it is the thicker of the two layers. The material interface between the first layer 56 of resilient sealing material and the second layer 58 of resilient sealing material may be of any suitable shape.

It is generally accepted that the greater the elastic modulus of the sealing material, the more resistant the seal is to damage due to displacement under high pressure. In the seal shown in FIG. 1, as well as in the seals shown in other figures, a second layer 58 of elastic sealing material having a lower elastic modulus as compared to the material of the first layer 56 of elastic sealing material can be used. When the second layer 58 of elastic sealing material is made of a material that has a lower elastic modulus than the material of the second layer 58 of elastic sealing material, a small tearing moment and torque due to the reduced inter-surface contact pressure provided by the elastic modulus of the second layer 58 of elastic sealing material . A small torque minimizes the temperature of rotation, which reduces the temperature-induced destruction of the seal.

In the geometry of the prior art shown in FIG. 9 of US Pat. No. 5,738,358, the inter-surface contact pressure near the end of the seal environment may be small in applications with a small or zero pressure difference, resulting in poor exclusion of the environment. This can be corrected by skewing the exclusive edge according to US Pat. No. 6120036, or by implementing a conical dynamic surface and / or convex end according to US Pat. No. 6,767,016. With two-material seals,

According to the present invention, another way to combat low inter-surface contact pressure near the dynamic exclusion intersection 46 is to produce a second layer 58 of elastic sealing material from a material that has an elastic modulus that is approximately equal to the elastic modulus of the first layer 56 of elastic sealing material. This makes the inter-surface contact pressure equal to the pressure of the seal of a single material.

One of the primary goals of a two-material structure according to this invention is to provide a seal structure that is suitable for operation at high temperatures compared with the prior art. The composite seal 2 of two materials according to this invention is preferably formed from FKM and TFE / P elastomers having compatible compositions and compatible vulcanization systems that can be formed together in a single-stage process to create a dynamic seal 2 having a second layer 58 of elastic sealing material, made of FKM, and a first layer 56 of resilient sealing material made of TFE / P. The result is a seal that is primarily made of FKM but has a relatively thin TFE / P layer that forms at least part of the dynamic sealing surface 28. This allows the best characteristics of both materials to be used in seal 2, so that the strengths of one material compensate for the weaknesses of another material. The good dynamic characteristics of TFE / P compensate for the poor dynamic properties of the FKM by isolating or substantially isolating the FKM from the relatively rotatable surface 10. The good properties of the resistance to permanent compression deformation of the FKM-based second layer 58 of elastic sealing material compensate for the poor resistance properties of the compression resistance based on TFE / P of the first layer 56 of elastic sealing material.

As an alternative, silicone-type elastomers can be used to form a second layer 58 of resilient sealing material. Like FKM, silicone-type elastomers have excellent resistance to permanent compression deformation, but poor abrasion resistance.

The length 60 of the first layer is preferably less than the length 62 of the seal body, since the difference in lengths between the first layer 56 of elastic sealing material and the second layer 58 of elastic sealing material helps to hold the first layer 56 of elastic sealing material in place during the forming process. In addition, the connection that occurs between the first layer 56 of the elastic sealing material and the inner protrusion 64 of the second layer 58 of the elastic sealing material helps to ensure structural integrity

dynamic seal 2 by preventing separation between the first layer 56 of elastic sealing material and the second layer 58 of elastic sealing material.

In general, a preferred embodiment of this utility model is a dynamic seal, which has a first relatively thin part of a high-temperature material with good dynamic driving characteristics, homogeneously connected to a second, thicker part of a material having good resistance to permanent deformation under compression. This system allows the thicker second part to compensate for the potentially poor resistance to permanent deformation under compression, while the thin first part protects the second, thicker part from abrasive damage due to the good dynamic running properties of the first thin part.

Unlike spring-reinforced seals, according to the prior art, this utility model is preferably suitable for applications where pressure differences can occur in both directions. In contrast to seals reinforced with an O-ring, according to the prior art, this utility model preferably does not have a loose reinforcing means that can be displaced during operation.

As indicated above, this utility model is suitable for both radial compression systems and axial compression systems. In the case of a very large diameter of the seals, the dynamic sealing surface 28 and the dynamic control surface 48 can be easily manufactured as oriented mainly inwardly, while the dynamic sealing surface 28 is designed to seal against a rotating surface 10 defining an outwardly oriented cylindrical surface. The cross section of large diameter seals can be rotated 90 °, so that the dynamic sealing surface 28 becomes an axially oriented surface for sealing relatively substantially flat shape with respect to the rotated surface 10, or it can be rotated 180 ° so that the dynamic sealing surface 28 becomes an outward oriented surface for sealing against a rotatable surface 10 defining an inwardly oriented cyl -cylindrical surface.

On figa-1D shows that the basic concept of a preferred embodiment can be performed for dynamic sealing of a shaft, hole or end surface without departing from the idea and essence of the utility model.

On figa shows a partial section of the dynamic seal 2 in an unsteady state, made with the possibility of compression in the radial direction in order to seal relative to the rotating surface oriented outwardly cylindrical in shape, such as the outer surface of the shaft. The dynamic sealing surface 28, the hydrodynamic inlet curvature 30, and the dynamic control surface 48 are mainly oriented inwardly, while the dynamic sealing surface 28 is intended to seal the outer cylinder.

On figv shows a partial section of the dynamic seal 2 in an unsteady state, made with the possibility of compression in the radial direction in order to seal relative to the rotating surface oriented inwardly cylindrical, such as the surface of the hole. The dynamic sealing surface 28, the hydrodynamic inlet curvature 30, and the dynamic control surface 48 are outwardly oriented surfaces, while the dynamic sealing surface 28 is designed to seal the hole.

On figs-1D shows partial sections of a dynamic seal 2 in an unsteady state, made with the possibility of compression in the axial direction in order to seal against a rotating surface of a substantially flat shape, and clearly show that this utility model can be used in sealing systems of end surfaces. The dynamic sealing surface 28, the hydrodynamic inlet curvature 30, and the dynamic control surface 48 are axially oriented surfaces, while the dynamic sealing surface 28 is designed to seal the end surface. 1C, the dynamic sealing surface 28, the hydrodynamic inlet curvature 30, and the dynamic exclusion intersection 46 are arranged so as to have a first fluid 16, i.e. lubricating fluid inside the seal, and in FIG. 1D they are positioned to have a first fluid outside the seal.

Figure 2 and 2A shows simplified variants of the preferred embodiments shown in figa-1D. In the embodiments shown in FIGS. 2 and 2A, the dynamic sealing surface 28 and the static sealing surface 34 are not conical. The first layer 56 of elastic sealing material is located inside the second layer 58 of elastic sealing material, and the dynamic seal 2 is designed to seal relative to the rotatable surface of the shaft.

As indicated above, a preferred embodiment of this utility model includes first and second layers 56 and 58 of elastic sealing material, namely made of TFE / P and FKM, respectively. The TFE / P and FKM elastomers preferably have compatible vulcanization systems, preferably chemically compatible vulcanization systems. Compatible TFE / P and FKM vulcanization systems are preferably peroxide vulcanization agents. Additionally, the composition of the TFE / P and FKM elastomers is preferably compatible.

A vulcanization agent is a chemical substance that causes chemical crosslinking of polymer chains of elastomer molecules when heated during the formation process. This vulcanization converts a non-vulcanized material from a sticky, soft state of thermoplastic into a strong elastic state. The terms “crosslinking”, “hardening” and “vulcanization” used here have the same meaning and are used interchangeably. Examples of elastomer cure systems are peroxide cure, sulfur cure, and biphenol cure.

Formulation of an elastomer means a “recipe” of various substances or ingredients for use in developing a rubber composition to create the desired mechanical properties of the finished product. Each recipe contains various ingredients that have each special function in the processing, vulcanization or end use of the product. In addition to basic elastomers (i.e. FKM, TFE / P, and EPDM), other substances in the mixture include fillers (i.e. carbon black, silicon dioxide and calcium carbonate), processing aids (i.e. various waxes, oils and plasticizers) ), antioxidants (i.e. antioxidants and antiozonants), vulcanization additives (i.e. various sulfur and peroxides and biphenol), accelerators (i.e. amines, guanides and thioureas) and activators (i.e. zinc oxides and stearic acid). It is understood that the action of the ingredients used is known to those skilled in the art of elastomer formulation engineering. Some substances in the mixture, such as plasticizers or oils, may prohibit crosslinking between two elastomers of different compositions. Thus, the addition of such a formulation compound to the composition of the elastomer results in incompatible formulations.

The first layer 56 of resilient sealing material preferably consists of a CDI TFE / P 904-80 compound having a nominal Shore scale hardness of about 80a. The second layer 58 of resilient sealing material preferably consists of a CDI compound FKM 901-80 or 901-75 having a nominal Shore scale hardness of about 80a or about 75a, respectively. Preferred materials have

compatible formulation and peroxide vulcanization substance, and also have approximately the same hardness. Preferred CDI materials are available from CDI Seals of Humble, Texas.

During the formation of the composite dynamic seal 2, non-vulcanized material for forming the first layer 56 of elastic sealing material and non-vulcanized material for forming the second layer 58 of elastic sealing material are preferably placed together in a mold and formed simultaneously. The bonding of preferred materials between the first layer 56 of resilient sealing material and the second layer 58 of resilient sealing material is excellent, even without the use of a binder. During tests for tearing one material from another, the connection between the two materials withstood the load, and the FKM material was torn. By using the FKM compound and the TFE / P compound with vulcanization systems that are compatible with both compounds, the crosslinking of the elastomer chains that exist in the two compounds is accelerated, so that the two compounds homogeneously connect to each other. It is believed that this is achieved due to the compatibility of TFE / P and FKM compounds, although this is not necessarily true for any elastomer mixtures having the same basic types of vulcanization systems.

As indicated above, this is significantly different from what happens when two HSN materials are formed with a peroxide vulcanization system using the same simultaneous formation technology. When the compression molding of two different peroxide vulcanized HSN materials was tested, the connection between the materials was weak and did not actually exist. When trying to tear two HSN materials from each other, they were separated clearly along the connection line without breaking the material, leaving smooth surfaces where the interface between the two materials passed. When tested under rotation conditions, the layers of such HSN materials were often separated.

We can assume that the reason for the homogeneous combination of FKM material with peroxide vulcanization and TFE / P material with peroxide vulcanization, as opposed to the combination of HSN material with peroxide vulcanization and HSN material with peroxide vulcanization, is the presence of fewer additives in the compound FKM and TFE / P, which may interfere with compound formation. Thus, in addition to the compatibility of vulcanization systems, FKM and TFE / P have a compatible formulation.

KALSI SEALS standard two-module seals manufactured in accordance with US Pat. No. 5,738,358 have poor exclusive contact

edge pressure if not using a beveled edge. Seals of two materials FKM and TFE / P, according to this utility model, can have substantially the same modulus of elasticity, and therefore eliminating the contact pressure of the lip is substantially the same as a seal of a single material. Tests have shown that the advantage of significant resistance to permanent deformation under compression is retained when the first layer 56 of the elastic sealing material based on TFE / P and the second layer 58 of the elastic sealing material based on FKM have approximately the same hardness.

It is clear that other simplifications of this utility model are also possible. For example, the seal may have a first layer 56 of elastic sealing material based on TFE / P and a second layer 58 of elastic sealing material based on FKM without including one or more static sealing lips 26, hydrodynamic inlet curvature 30, junction 32, a static intersection 36, variable width W, dynamic exclusion intersection 46, dynamic control surface 48 or static control surface 50. For example, FIG. 2 shows a seal that includes a static arch cuff 26, while in FIG. 2A there is no static cuff. It is also clear that the advantages provided by the construction with two materials according to this invention can preferably be used in the reciprocating motion, and the movement of rotation.

FIG. 3 shows a preferred molding process comprising three preferred mold components: a mold core 80, a mold collar 82, and a mold cover 84. Figure 3 shows a form intended for forming a dynamic seal 2, according to figure 2. The mold core 80 defines a cavity length 86 and includes a dynamic cuff cavity 124 for forming a dynamic sealing collar 24, a cavity end surface 138 for forming a second seal end 38, a sharp inner angle 146 for forming a dynamic exclusion intersection 46, and an internal curvature 130 for forming a hydrodynamic input curvature 30 of the dynamic seal 2, according to figure 2. The collar 82 of the mold includes a cavity 126 of the static cuff for forming a static sealing cuff 26.

The inner preform 156 and the outer preform 158, each having a generally circular shape, are placed in the mold. Preforms 156 and 158 are preferably each non-vulcanized elastomer. The length 92 of the inner preform is preferably less than the length 86 of the cavity, and the length 94 of the outer preform is preferably greater than the length 86 of the cavity and greater than the length 92 of the inner preform.

When the mold cover 84 is lowered, it comes into contact with the outer blank 158, which causes the outer blank 158 to expand radially and overhangs over the inner blank 156 while holding the inner blank 156 in place while pressing the cavity 80 of the mold against the end surface 138. With further lowering of the mold cover 84, the outer blank 158 continues to expand in the radial direction. This radial expansion presses the inner blank 156 into the cavity 124 of the dynamic cuff and presses the outer blank 158 into the cavity 126 of the static collar 126 of the collar 82 of the form.

This technology with a shorter inner billet 156 than the outer billet 158 can be used with various sealing materials. For example, inner billet 156 may be a TFE / P elastomer, and outer billet 158 may be an FKM elastomer. As another example, inner billet 156 may be polytetrafluoroethylene (PTFE) plastic, and outer billet 158 may be an elastomer such as HSN or FKM, or a silicone elastomer.

In the seals of FIGS. 1A-1D, a dynamic control surface 48 and a static control surface 50 of the annular seal body 42 are preferably provided in order to prevent unwanted twisting of an unsealed seal inside the seal groove. In Fig. 4, the dynamic control surface and the static control surface are eliminated to the dynamic sealing lip 24 as a simplification, leaving the first end 44 of the seal undulating, i.e. not circular. The system is particularly suitable in applications where the pressure of the second fluid is higher than the pressure of the first fluid. For better utilization of the seal, according to FIG. 4, the first groove can be made with a wavy non-circular shape in accordance with the wavy shape of the first end 44 of the seal. If the first wall of the groove is made wavy so that it mates and maintains the wavy shape of the first end 44 of the seal, then the forces acting on the first end 44 of the seal or on the second end 38 of the seal cannot completely flatten the hydrodynamic input curvature 30 on a relatively rotatable surface, which maintains an effective, smoothly converging relationship between the hydrodynamic input curvature 30 and the relatively rotatable surface to maintain an effective hydrodynamic lubricant dynamic plotnitelnoy surface 28. With increasing temperature an elastomer, its modulus decreases. Hydrodynamic lubrication makes the dynamic seal 2 rotate much colder during rotation than comparable non-hydrodynamic seals, so the first layer 56 of elastic sealant is good

retains its modulus of elasticity, which contributes to the displacement resistance. If the first wall of the groove is wavy so that it mates and maintains the wavy shape of the first end 44 of the seal, then the dynamic exclusion intersection 46 is maintained in the desired substantially circular configuration to effectively eliminate the environment, despite the forces acting on the second end 38 of the seal, which, according to the prior art, the performance of such exclusive intersections is impaired.

As in the preferred embodiment, in all seals shown in the figures, the depth dimension D can, if desired, change in time with a change in the position of the hydrodynamic input curvature (and a change in the width W of the inter-surface contact contour) to equalize the changes in the inter-surface contact pressure around the circumference of the seal.

From the above it follows that this utility model is well suited to achieve all the goals and features mentioned above, together with other goals and features that are inherent in the device disclosed here.

As is understood by those skilled in the art, this utility model can be easily implemented in other special forms without departing from its idea or essential characteristics. Therefore, this embodiment should be considered as having only an illustrative character, but not limiting the scope of the utility model, given by the utility model formula, and not by the previous description, and therefore all changes within the value and range of the utility model formula equivalent are covered by it.

Claims (31)

1. A rotating dynamic seal for use in a high-temperature environment between the first element and the second element, configured to move relative to the first element and serving as a separator between the first fluid and the second fluid to prevent the second fluid from entering the first fluid containing basically an annular seal body, wherein the seal body comprises: a first layer formed from a first elastic sealing material, wound in accordance with its dynamic properties of wear resistance, wherein said first layer defines at least a portion of the dynamic sealing surface; and a second layer formed from a second elastic sealing material selected in accordance with its properties of resistance to permanent deformation under compression, while said second layer defines at least a portion of the static sealing surface, wherein said first and second layers are chemically cross-linked with a friend. 2. The seal according to claim 1, wherein said first elastic sealing material is a copolymer of tetrafluoroethylene and propylene, and said second elastic sealing material is fluorocarbon rubber. 3. The seal according to claim 1, wherein said first elastic sealing material is a copolymer of tetrafluoroethylene and propylene having a peroxide vulcanization system, and said second elastic sealing material is a fluorocarbon rubber having a peroxide vulcanization system. 4. The seal according to claim 1, wherein said first layer and said second layer are molded simultaneously and cured with each other. 5. The seal according to claim 1, wherein said first layer is thinner than said second layer. 6. The seal of claim 1, wherein said first layer has a length of a first layer and said seal body has a length of a seal body and said first layer length is shorter than said seal body length. 7. The seal according to claim 1, wherein said dynamic sealing surface is a generally oriented inwardly surface intended for sealing an outwardly oriented, generally cylindrical surface of a machine component. 8. The seal according to claim 1, wherein said dynamic sealing surface is a generally oriented outwardly surface intended for sealing an inwardly oriented, generally cylindrical surface of a machine component. 9. The seal according to claim 1, wherein said dynamic sealing surface is basically an axially oriented surface for sealing a substantially flat surface of a machine component. 10. The seal of claim 1, wherein said dynamic sealing surface has a width that varies. 11. The seal according to claim 1, in which the specified dynamic sealing surface has an inclined configuration. 12. The seal of claim 1, wherein said dynamic sealing surface is substantially cylindrical. 13. The seal according to claim 1, in which the specified static sealing surface has an inclined configuration. 14. The seal according to claim 1, in which the specified dynamic sealing surface is pressed against the component of the machine and creates a contour of the inter-surface contact is mainly circular in shape, having a width, the size of which varies, 15. The seal according to claim 1, in which the specified dynamic sealing surface is pressed against a component of the machine and creates a contour of the inter-surface contact having a first edge of the contour, which is wavy. 16. The seal of claim 15, wherein said inter-surface contact contour has a second contour edge that is substantially circular. 17. The seal according to claim 1, wherein said first elastic sealing material has a first elastic modulus, and said second elastic sealing material has a second elastic modulus, which is approximately equal to said first elastic modulus. 18. The seal according to claim 1, wherein said first elastic sealing material has a first elastic modulus, and said second elastic sealing material has a second elastic modulus that is less than said first elastic modulus. 19. The seal of claim 1, wherein said first layer defines a dynamic sealing lip defining a hydrodynamic inlet curvature and defining said dynamic sealing surface. 20. The seal of claim 19, wherein said dynamic sealing lip defines a dynamic exclusion intersection of a substantially circular configuration. 21. The seal of claim 19, wherein said second layer defines a static sealing collar of a substantially circular configuration and substantially opposite of said dynamic sealing collar. 22. A rotary seal for use in a high-temperature environment between a first component of a machine and a second component of a machine having a relative rotating surface that is movable relative to the first component of the machine, the rotary seal separating between the first fluid and the second fluid and preventing penetration the second fluid in the first fluid, while the rotating seal contains a seal body in the main ring the second configuration, wherein said seal body comprises: a first layer formed of an elastomer in the form of a tetrafluoroethylene-propylene copolymer, wherein said first layer defines at least a portion of the dynamic sealing surface to establish a compression dynamic sealing relationship and a dynamic sealing interface with relatively rotating surface; and a second layer formed from an elastomer in the form of fluorocarbon rubber, wherein said second layer defines at least a portion of the static sealing surface to establish a compression static sealing relationship and a static sealing interface with the first component of the machine, wherein the first and second layers are chemically stitched together. 23. The seal of claim 22, wherein said second layer is thinner than said first layer. 24. The seal according to item 22, in which the specified elastomer in the form of a copolymer of tetrafluoroethylene and polypropylene has a peroxide vulcanization system, and the specified elastomer in the form of fluorocarbon rubber has a peroxide vulcanization system. 25. The seal of claim 22, wherein said first layer and said second layer are simultaneously formed and vulcanized together. 26. The seal according to item 22, in which the specified dynamic sealing surface is designed to seal the movable first element. 27. The seal of claim 22, wherein said first layer includes a dynamic sealing cuff defining a hydrodynamic curvature of the inlet. 28. The seal according to item 22, in which the specified elastomer in the form of a copolymer of tetrafluoroethylene and propylene has a first modulus of elasticity, and the specified elastomer in the form of fluorocarbon rubber has a second modulus of elasticity, which is approximately equal to the specified first modulus of elasticity. 29. The seal according to item 22, in which the specified elastomer in the form of a copolymer of tetrafluoroethylene and propylene has a first modulus of elasticity, and the specified elastomer in the form of fluorocarbon rubber has a second modulus of elasticity that is less than the specified first modulus of elasticity. 30. A rotating seal of the interference type, intended for use in a high-temperature environment between the first element and the second element, configured to move relative to the first element, and the rotating seal serves as a separator between the first fluid and the second fluid and prevents the penetration of the second fluid into the first fluid medium, wherein the rotary seal comprises a seal body in a generally annular configuration, wherein said seal body I contain: a first layer formed from a first material and having a length of a first layer and a thickness of a first layer, wherein said first layer defines a hydrodynamic curvature of the inlet; a second layer formed of a second material and having a length of a second layer and a thickness of a second layer, wherein said length of a first layer is less than a specified length of a second layer, said thickness of a first layer is less than a specified thickness of a second layer, and said first and second layers are connected to each other. 31. The seal of claim 30, wherein said first layer defines at least a portion of the dynamic sealing surface.