TW202023837A - Seals, vacuum systems with such seals and a method of manufacture of such seals - Google Patents

Abstract

A longitudinal seal having a cross section comprising a wall around an inner section; wherein the wall is formed of a material which is configured such that a physical characteristic of the material varies by at least 10% along at least one of a length and the cross section of the seal, the variation in the physical characteristic causing a variation in at least one of a deformability and a resilience of a corresponding portion of the seal.

Description

Seals, vacuum systems with these seals, and methods for manufacturing these seals

The field of the present invention relates to seals, vacuum systems with such seals, and a method of manufacturing seals.

Systems that operate under pressure differences, such as vacuum systems, require effective seals at the junctions between different components in order to operate effectively.

An effective seal is a seal that is resilient and deformable to fill a gap. Generally, resilient and deformable elastomeric materials have been used to manufacture seals.

Some vacuum systems operate at high temperatures and/or handle aggressive materials. Elastomer seals may not be sufficient to resist high temperatures or aggressive materials as effective seals in these systems.

Materials with higher resistance to these environments include metals. Metal seals are known. One of the disadvantages of metal seals is that they are effectively sealed, which require both a high clamping force and a fine luminosity on the surface to be sealed. Higher clamping force can cause distortion of the clamped components and may require special clamping components and tools to loosen and clamp the clamped components. The finer luminosity of the surface is expensive.

It would be desirable to provide a seal that resists higher temperature operation and/or at least some aggressive materials and forms an effective seal with relatively low clamping forces.

A first aspect provides a longitudinal seal having a cross-section that includes a wall surrounding an inner section; wherein the wall is formed of a material that is configured such that a physical property of the material is along the seal At least one of a length of the member and the cross section changes by at least 10%, and the change in the physical property causes a change in at least one of a deformability and a resilience of a corresponding part of the sealing member.

The degree of deformation and resilience of a seal affect its sealing properties. The inventor of the present invention recognizes that both resilience and deformability depend on the physical properties of the material forming the seal and changing these properties at different parts of the seal allows the seal to be more effective run. The physical properties include the density and width of the wall of the seal.

Changing the physical properties along the length or cross section of the seal changes its sealing properties and these can be selected to improve the sealing effectiveness of the seal. For example, the deformability of a section configured to mate with a surface to be sealed can be increased and the resilience of this section can be correspondingly decreased. However, the total resilience of the seal can be maintained by increasing the resilience of another part of the seal, where deformability may be less important. In this way, the characteristics of a seal formed from a material that is not as resilient or deformable as an elastomer can be tuned to increase the effectiveness of the seal. This allows an effective seal to be made of a material with lower elasticity, which may have increased resistance to higher temperatures and aggressive chemicals.

A longitudinal seal is an elongated seal that is longer than its width. The length is the distance along the wall of the seal and the width is the distance across the cross section. The seal can be a ring, wherein the length is the circumference of the ring. The sealing surface is on the outer circumference of the wall.

In some embodiments, the at least one physical property includes a thickness of the wall.

Changing the thickness of the wall (which is the size of the wall in the cross section of the seal) changes the resilience and deformability of the seal; a thicker wall provides higher resilience and a thinner wall provides More deformability. The knowledge of the effect of the thickness change of the wall on the properties allows the seal to be designed and configured to have increased deformability where appropriate. This is used to increase the return at other points where deformability is not so important. Flexible compensation.

In some embodiments, the thickness of the wall varies along a length of the seal.

The thickness of the wall can vary along the length of the seal and in some embodiments and in some locations is reduced to 0.01 mm down the seal and increased to higher values in other embodiments (possibly as high as 0.5 mm). In any case, the change along the length will be at least 10% and in some embodiments at least 50% and in other embodiments at least 100%.

In some embodiments, the seal is configured to seal a surface in a vacuum system and the wall is configured to move away from the edge of the clamping element used to clamp the seal between the surfaces The length of the sealing element is thinner, so that the resilience of one of the sealing elements away from the clamping elements is reduced.

Varying the thickness of the wall along the length of the seal allows the seal to be configured so that it has greater resilience at the point where it will clamp the seal when in use. At these clamping points, there is a greater force on the seal and, therefore, the greater resilience at these points allows the seal to maintain a more uniform cross-section along the length of the seal and a more uniform seal effect. In fact, it allows the resilience of the sealing member far away from the clamping elements to be reduced and allows the clamping force to be reduced and more effective sealing.

In some embodiments, the thickness of the wall varies around the cross-section of the seal.

Alternatively and/or in addition, the thickness of the wall may vary around the cross-section of the seal. For example, it may be lower at and near one of the sealing surfaces of the seal. In this regard, the sealing member is configured to have a peripheral surface having a sealing surface thereon. These parts of the outer surface are the parts used to provide the seal. It is advantageous for these sealing surfaces to have a high deformability and, therefore, it may be advantageous to limit the thickness of the wall at these points. Having a higher thickness at other points provides a more resilient and stable seal while allowing it to deform at those points where it seals.

In some embodiments, the at least one physical property includes a density of the material forming the wall.

Another physical property that affects the resilience and deformability of a seal is the density of the material forming the wall of the seal. This change in density allows the properties of the seal to change and therefore allows the seal to be tuned to its specific use.

In some embodiments, the density of the material at a sealed portion of an outer periphery of the seal is lower than a density of the material at an inner edge of the seal.

A lower density material at the sealing outer surface of the seal allows the seal to be more deformable and provides a more effective seal. The increased density away from this part provides a more resilient seal.

In some embodiments, the sealing portion and a portion of the wall adjacent thereto includes a porous or cellular portion. In some embodiments, this may be an additional protrusion extending from the outer wall. This protrusion can also be used to help position the seal in a desired position.

One way to reduce the density of the material and provide a more deformable surface is to change the structure at and adjacent to the sealing surface so that it will collapse and conform to the mating surface. A porous or cellular structure will provide these properties.

In some embodiments, the density of the material forming the wall varies along a length of the seal.

As an alternative and/or in addition to the density of the material that changes around the cross-section, the density of the material that forms the wall can also vary along a length of the seal. In the case where the wall is formed of a porous or cellular material, this density change can be achieved by changing the porosity along the length of the wall.

In some embodiments, the density of the material forming the wall is lower at a part of the seal away from the clamping element used to clamp the seal between the surfaces, so that it is away from the The resilience of one of the seals of the holding element is reduced.

In particular, it may be advantageous to have a high-density material at a portion of the seal that is adjacent to the clamping element in use and a lower-density portion of the material away from these areas. This provides that one of the seals away from the clamping elements reduces resilience and one adjacent to them increases resilience. Adjacent to the clamping element, the clamping force will be higher and therefore the seal will be under greater compression. A more uniform compression cross section of one of the seals can be achieved by varying the density in this way and reducing the required clamping force.

In some embodiments, the wall surrounding the inner portion includes a portion having a substantially uniform cross-section and a portion having a spring-like configuration.

One way to provide the difference in the properties of the seal around the cross-section is to have a portion having a uniform cross-section and a portion having a spring-like configuration. The spring-like configuration will provide elasticity and resilience, while the uniform portion will provide an effective sealing surface.

In some embodiments, the portion having a spring-like configuration includes connecting portions that are angled with the portions having a uniform cross-section and connect the portions, with gaps between the connecting portions.

In some embodiments, the configuration of the spring-like portion can be changed along the length of the seal, so that the gap between the connecting portions or the thickness of the connecting portions can be changed to vary the seal along its length The resilience.

Although the seal can have several shapes, in some embodiments, the wall and inner portion have a circular cross-section.

Although the wall may only extend around a portion of the inner portion for at least some length of the seal, in some embodiments, the wall encloses the inner portion.

In some embodiments, the wall extends in a longitudinal direction and has a tubular shape.

In some embodiments, the wall extends longitudinally to form a loop.

In some embodiments, the material forming the wall of the seal is a non-elastomeric material.

A seal configured to provide varying resilience and deformability allows an effective seal to be formed of a material that is not an elastomer. Elastomers are highly elastic and usually form good seals but may not be resilient to high temperatures or aggressive chemicals. Therefore, forming a seal that is not a material of an elastomer allows the selection of a material with suitable properties for higher temperature and aggressive chemicals, and in the case of the configuration according to an embodiment, the seal can still Provide effective sealing.

In some embodiments, the material includes a metallic material.

In some embodiments, the metal material includes at least one of aluminum, aluminum alloy, nickel, nickel alloy, precious metal, steel, stainless steel, and copper.

In other embodiments, the material includes a polymer material, and the polymer material includes one or more thermoplastic materials.

In some embodiments, the polymer material includes at least one of fluoropolymer, polyether ether ketone (PEEK), and polyphenylene sulfide (PPS).

Although the seal can be formed entirely of a metal or entirely of a polymer material, in some embodiments, it can be formed by a combination of either of these materials.

In some embodiments, the inner portion includes a void.

In other embodiments, the inner part includes a substance for increasing the resilience of a seal.

The inventor of the present invention recognizes that an outer periphery with increased deformability but reduced resilience can be used for a seal, wherein an internal structure is provided in the outer periphery to improve the resilience. In this way, for example, the wall thickness can be reduced, thereby making it more deformable and providing a better sealing surface. In these circumstances, thicknesses as low as 0.01 mm may be acceptable.

In some embodiments, the substance includes a continuous solid structure attached to the wall.

In some embodiments, the continuous solid structure is uneven along a length of the seal, so that the resilience of one of the seals changes along the length.

In order to provide a change in the resilience of the seal along the length of the seal (as mentioned earlier, this may be desired), the structure in the seal can be made uneven along the length of the seal of.

Although the continuous solid structure can have several forms, in some embodiments it includes at least one inner wall extending across the inner section.

In some embodiments, the at least one inner wall extends across a diameter of the inner portion.

In other embodiments, the substance includes a porous or cellular material.

A porous or cellular material (a material with voids) allows it to be compressed and still provides resilience.

In some embodiments, the seal is configured to mate with the surface to be sealed and away from the clamping element used to clamp the seal between the surfaces. The density of the porous material is reduced , So that the resilience of one of the seals away from the clamping elements is reduced.

The change in the density of the internal substance can be used to change the resilience of the seal. In the case where the sealing element is used in combination with a clamping element to hold the sealing element, it may be advantageous to increase resilience at points adjacent to the clamping elements and to have reduced resilience at other points.

A second aspect of the present invention provides a vacuum system including at least one sealing member according to the first aspect of the present invention.

In some embodiments, the vacuum system includes at least one seal configured with a reduced thickness through the wall and/or an internal structure with reduced resilience to reduce resilience, and the vacuum system has clamping The element holds at least one sealing element between two cooperating surfaces at the part of the sealing element with increased resilience.

A third aspect of the present invention provides a method of manufacturing a seal according to any of the foregoing technical solutions using additive manufacturing technology.

Traditionally, for example, a seal made of metal is formed into a metal tube or other contour and connected by welding. It is difficult to control the Young's modulus and other mechanical properties of sealing elements made by such traditional methods. The use of an additive manufacturing technique allows the mechanical properties to vary in the cross section of the seal and also around the periphery of a seal and along its length. This allows the seal to be designed with changes in these properties suitable for its environment, thereby allowing less elastic materials to provide an effective seal. This can allow the vacuum system to use lower clamping forces and still provide high seal integrity.

In some embodiments, the additive manufacturing technology is selected from three-dimensional lithography (SLA), fused deposition modeling (FDM), multi-jet molding (MJM), 3D printing, and selective laser sintering (SLS).

Further specific and better aspects are stated in the attached independent technical solution and subsidiary technical solution. The features of the subsidiary technical solution can be combined with the features of the independent technical solution as appropriate, and can be a combination other than explicitly stated in the technical solution.

Where a device feature is described as being operable to provide a function, it will be understood that this includes a device feature that provides the function or is adapted or configured to provide the function.

Before discussing the embodiments in more detail, an overview will first be provided.

The use of additive manufacturing technology to manufacture the seal allows flexible calibration changes in the manufacture of the seal, which allows the sealing force to be optimized for the effectiveness of the seal against the clamping force. In fact, the contour, shape, and material of the seal can be designed to provide the seal integrity with a reduced clamping force.

Due to this ability of the fine tuning seal design, it can be made of materials with reduced elastic properties, such as metals. These materials can have improved heat resistance and chemical resistance.

Features that allow this improved seal integrity with reduced clamping force include: One of the contour elements has variable thickness; A complex structure used to provide elasticity in the seal; One of the structure or density changes at the sealing surface, for example, to provide an open structure that will collapse and conform to the mating surface, such as a foam.

In some embodiments, additional features can be added to enhance the integrity of the seal, such as features that position or align the seal to the sealing surface and a coating on the sealing surface.

Figure 1 shows a cross-section of a seal according to an embodiment in which the outer wall 10 of the enclosed inner section has a variable wall thickness. Providing wall thickness variation allows the wall portion (thicker portion) to provide increased resilience, while the thinner portion has increased deformability. The part with increased deformability provides a more effective sealing surface because it is easier to deform. Therefore, the sealing area of the seal (which is the area that provides the outer surface of the sealing effect when the seal is installed in a vacuum system in use) is configured to be thinner than the other parts away from these seals One wall. In this way, the effective sealing part is relatively deformable, while the entire sealing element maintains its resilience due to the thicker part.

FIG. 2 shows a longitudinal section through a second embodiment of a seal, which has a varying thickness of the outer wall 10 in a manner similar to the embodiment of FIG. 1. In this particular embodiment, the thickness change occurs along the length of the seal. It should be noted that changes can occur across the cross-section and/or around the periphery and/or along the length of the seal. In this case, the thicker part of the seal is configured to be positioned adjacent to the clamping element in a vacuum system, so that the clamping force 20 acts on the more resilient part of the seal and is away from the clamping element And the part of the seal that reduces the clamping force acting on it is formed to have a thinner wall and lower resilience but greater deformability. In this way, a seal that is adapted to its use and allows the sealing force to optimize or at least improve the effectiveness of the sealing against the clamping force is provided.

FIG. 3 shows an alternative embodiment in which the physical properties used to adapt the seal according to the force acting on it during use are the density of the material, and the density of the material forming the outer wall 10 changes. In this case, the density may change across the cross section of the seal and/or it may change along the length of the seal. Therefore, a reduced density portion with lower resilience is provided and an increased density portion with high resilience is provided. The reducing resilience part can be arranged towards the sealing surface around the periphery, and the increasing density part can be arranged away from these parts and corresponding to the clamping when the seal is installed in a vacuum assembly in use The longitudinal position of the location of the component.

Figure 4 shows a further embodiment in which the outer wall is provided with an additional zone 12 protruding from the wall and in which the material is porous and therefore has a certain low density. These are arranged at the sealing surface of the seal and will compress and conform to the mating surface. They can also be used to position the seal in a specific orientation within the vacuum system.

FIG. 5 shows a cross section of a further embodiment in which an internal structure is provided in the outer wall 10. In this embodiment, inner walls 22 are provided that span the inner section of the seal and provide resilience against deformation of the seal. The addition of this internal structure allows the outer wall to be made thinner than in the case where there is no internal structure. This has the advantage of providing an improved deformability of the external structure, which can provide an improved seal and allow the seal to provide an effective seal in a vacuum system with a less fine sealing surface luminosity.

Although in this embodiment, the internal structure is provided by an inner wall extending and attached to the outer wall 10, in other embodiments, the internal structure may be different and may be formed of, for example, a porous material. The porous material can have a different density across its cross section and can also have a different density along its length, thereby providing a calibration change in the resilience of the seal at different points. In a similar manner, the seal of FIG. 5 may have a width variation of the inner wall 22 along its length to provide a difference in resilience. In addition to the porosity of the internal substance and therefore the change in density, the wall can also be formed of a porous substance, and the porosity of the wall can also vary along its length.

Figure 6 shows a longitudinal section through a seal having a porous interior 24, where the density of the porous interior changes along the length of the seal, allowing the seal to be configured such that the area of increased density and increased resilience is close to The area where the clamping element has reduced density and reduced resilience is far away from these elements when installed in the vacuum assembly. This allows the use of reduced clamping force to hold the seal in place without unduly affecting the sealing properties of the seal.

FIG. 7 shows a side view of a further embodiment in which a part of the periphery of the seal is formed by a strip 30 of material forming the outer wall 10. This provides a spring-like structure and increases the resilience of the seal.

Figure 8 shows a cross section of this seal. It should be noted that the number, thickness, and gap between the strips can be varied along the length of the seal to increase or decrease the resilience of the seal at different parts as needed.

The seal is shown in cross section, longitudinal section or as a side view. They may have a tubular form and the tubular form may be a ring adapted to be sealed between, for example, the stators of a vacuum pump or around a connecting element in a vacuum system. Since elastomer materials are not used for the ability of these seals, they are especially effective when used in abatement systems where aggressive materials can be pumped and high temperatures are used.

The use of additive manufacturing techniques to manufacture seals allows them to be made of, for example, metal and still have properties that can vary along the length and/or around the periphery and/or across the cross section. This allows the seal to be adapted to a specific position and specific clamping force and improves the effectiveness of the seal.

Although the illustrative embodiments of the present invention have been disclosed in detail herein with reference to the accompanying drawings, it should be understood that the present invention is not limited to the precise embodiments, and without departing from the scope of the patent application for the appended invention and its equivalents. In the context of the scope of the present invention defined by things, various changes and modifications can be made by those familiar with the art.

10: Outer wall/outer wall of seal 12: Porous structure/extra area 20: Clamping element/holding force 22: inner wall 24: Cellular inner filling/porous inner 30: Spring-like strips/strips

The embodiments of the present invention will now be further described with reference to the accompanying drawings, in which: Figure 1 shows a cross section of a seal with a variable wall thickness according to a first embodiment; Figure 2 shows a longitudinal section of a seal with a variable wall thickness along a length of a seal according to a second embodiment; Fig. 3 schematically shows a cross section of a seal having a variable density across the cross section according to a third embodiment; Figure 4 schematically shows a cross section of a seal having a variable density across the cross section according to a further embodiment; Figure 5 shows a cross section of a seal with an internal structure to increase resilience; Figure 6 shows a longitudinal section of a seal with an internal structure having a variable density along a length of the seal; Figure 7 shows a longitudinal section of a seal having a spring-like configuration for a section of the outer wall; and Figure 8 shows a cross section of the seal of Figure 7;

10: Outer wall

Claims (20)

A longitudinal sealing member configured to seal a surface in a vacuum system, the sealing member having a cross section including a wall surrounding an inner section; wherein The wall is formed of a material that is configured such that a physical property of the material varies by at least 10% along at least one of a length of the seal and the cross-section, and the change in the physical property results in the seal A corresponding portion changes at least one of a deformability and a resilience. The seal of claim 1, wherein the at least one physical property includes a thickness of the wall, wherein the thickness of the wall varies along a length of the seal. The seal of claim 2, wherein the wall is configured to be away from the clamping element used to clamp the seal between the surfaces in use along the seal The length part is thinner, so that the resilience of one of the seals away from the clamping elements is reduced. The seal of claim 2 or 3, wherein the thickness of the wall varies around the cross section of the seal. The seal of claim 4, wherein the thickness of the wall is lower at a sealing surface of the seal. The seal of any preceding claim, wherein the at least one physical property includes a density of the material forming the wall, wherein the density of the material forming the wall varies along a length of the seal. The seal of claim 6, wherein the density of the material at a sealed portion of an outer periphery of the seal is lower than a density of the material at an inner edge of the seal. The seal of claim 6 or 7, wherein a density of the wall at a sealed portion of the seal is lower than a density of the wall at a point away from the sealed portion. The sealing member of claim 8, wherein the sealing part and a part of the wall adjacent thereto includes a porous or cellular part. The seal of any one of claims 6 to 9, wherein the density of the material forming the wall is configured to be away in use from a clamping element for clamping the seal between surfaces A part of the sealing element is lower, so that the resilience of one of the sealing elements away from the clamping elements is reduced. The seal of any of the preceding claims, wherein the wall surrounding the inner portion includes a portion having a substantially uniform cross-section and a portion having a spring-like configuration. For example, the seal of claim 11, wherein the part having a spring-like configuration includes connecting parts that are angled with the parts having a uniform cross section and connect the parts, and the connecting parts have gaps between them. The seal of any of the preceding claims, wherein the material forming the wall of the seal is a non-elastomeric material. Such as the seal of claim 13, wherein the material includes: A metal material, preferably at least one of aluminum, aluminum alloy, nickel, nickel alloy, precious metal, steel, stainless steel, and copper; and/or A polymer material includes one or more thermoplastic materials, preferably at least one of fluoropolymer, polyether ether ketone (PEEK) and polyphenylene sulfide (PPS). The seal of any of the preceding claims, wherein the inner part includes a gap. The seal according to any one of claims 1 to 14, wherein the inner part includes a substance for increasing the resilience of the seal. The seal of any of the preceding claims, wherein the wall includes at least one external protrusion formed of a porous or cellular material. A vacuum system including at least one seal as in any of the foregoing claims. Such as the vacuum system of claim 18, which includes at least one sealing element such as claim 3 or 10 and at least one clamping element for holding the at least one sealing element between two cooperating surfaces, and the sealing element is constructed Shape, so that the resilience of one of the sealing members is reduced at a portion away from the at least one clamping element. A method of using additive manufacturing technology to manufacture a seal as in any one of claims 1 to 17, preferably selected from the group consisting of stereo lithography (SLA), fused deposition modeling (FDM), multi-jet molding (MJM), 3D Printing and selective laser sintering (SLS) are an additive manufacturing technology.

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