radial shaft seal ring

Abstract

A radial shaft seal ring (10) is designed to electrically connect a shaft (3) with a component (7) stationary relative to the shaft (3). The radial shaft seal ring (10) has a carrier body (2) and a sealing element (1) attached to the carrier body, the sealing element having a sealing portion (11) in contact with the shaft. The material composition of the sealing element (1) and / or of a protective lip (16) comprises at least one base material made of at least one polymer and one or more fillers having at least one electrically conductive filler provided therein.

Description

Technical Field

[0001] The present invention relates to a radial shaft seal ring, wherein the radial shaft seal ring is designed to electrically connect a shaft to a component stationary relative to the shaft, the radial shaft seal ring having a support body and a sealing element attached to the support body, the sealing element having a sealing portion in contact with the shaft. Background Technology

[0002] Radial shaft seals are commonly known for sealing the interface between a rotating shaft and a fixed component, such as a housing. Various designs capable of fluid and / or dirt discharge functions are known in the prior art. Such radial shaft seals are also used to seal the rotor shaft in electric motors or generators. Seals are required on electric drives when using fluids (such as transmission oil) to cool and / or lubricate the interior of the electric motor housing.

[0003] This seal provides a seal relative to other spaces or the atmosphere.

[0004] In some cases, the rotor in an electric motor can become electrostatically charged, creating a potential between the rotor shaft and the housing components, and possibly relative to the stator of the electric motor. This potential can discharge suddenly. Such a discharge can damage not only electronic equipment but also the bearings supporting the rotor shaft. Therefore, to prevent this discharge, electrical contact must be provided between the rotor shaft and the stationary parts of the electric motor or generator (e.g., the housing) to reduce static electricity or prevent its accumulation.

[0005] DE 10 2013 000 982 A1 discloses a sealing ring made of a conductive rubber elastic material that enables electrical contact with a sealed rotor shaft.

[0006] DE 10 2014 010 269 B4 discloses a sealing ring that has a so-called buffer seal in addition to a non-conductive shaft seal.

[0007] The shaft seal here serves a sealing function, while the buffer seal is conductive and makes electrical contact with the rotor shaft. Therefore, the shaft seal and the buffer seal are optimized for different functions. Summary of the Invention

[0008] The purpose of this invention is to provide a radial shaft sealing ring that can achieve good sealing function and sufficient electrical contact with the shaft, while having a long service life.

[0009] To achieve the objectives of this invention, a radial shaft sealing ring is proposed. Further preferred embodiments are possible. According to the invention, the material composition of the sealing element comprises at least one substrate made of at least one polymer, particularly homopolymers and / or copolymers, and one or more fillers wherein at least one conductive filler is provided.

[0010] To achieve the objectives of this invention, a radial shaft sealing ring is proposed as an alternative. Therefore, the radial shaft sealing ring has a protective lip connected to a support body and in contact with the shaft. The material composition of the protective lip includes at least one substrate made of at least one polymer and one or more fillers provided with at least one conductive filler.

[0011] It is feasible to have only the (main) sealing element conduct electricity, only the (auxiliary) protective lip conduct electricity, or both the main sealing element and the protective lip conduct electricity.

[0012] When conductive fillers are discussed below, the term refers to the filler of the sealing element and / or the filler of the protective lip. When substrates are discussed below, the term refers to the substrate of the seal and / or the substrate of the protective lip.

[0013] The substrate is, or preferably includes, at least one fluoropolymer (e.g., PTFE, FKM), elastomer, fluorinated thermoplastic, or PTFE-based polymer, or a corresponding copolymer. Polytetrafluoroethylene (PTFE) is a plastic with good sliding properties and high mechanical and chemical resistance. The weight percentage of the substrate is preferably 50% to 99%, more preferably 70% to 90%, and even more preferably 80% to 85%. For example, the sealing element can also contain several different PTFE compounds. This can be pure PTFE (homopolymer) or modified PTFE, wherein another monomer is polymerized in addition to TFE (polymer).

[0014] To enable the conductivity of the sealing element to be set as needed, the conductive filler preferably has metal, metallized and / or metal-coated particles, microspheres, microtubes and / or fibers. The weight percentage of one or more conductive fillers or all conductive fillers is preferably 1% to 25%, more preferably 5% to 20%, and even more preferably 10% to 15%.

[0015] In an advantageous embodiment, the conductive filler is silver, i.e., the conductive filler preferably comprises silver, silver-plated and / or silver-coated particles, microspheres, microtubes and / or fibers. It is also proposed that the metallization of the particles, fibers, etc., primarily comprises silver (Ag), i.e., silver is used as the metal for metallization at a weight ratio of at least 50%.

[0016] Metallized particles and fibers are particles or fibers with a metallic coating on their surface. Therefore, metallized particles and fibers possess metallic properties in their outer shell, making them conductive when bonded together. On the other hand, other properties such as strength and / or density are primarily determined by the internal materials of the particles and fibers.

[0017] Introducing conductive fillers into the substrate of the sealing element allows for sufficient conductivity without significantly reducing the substrate's properties in terms of friction, temperature resistance, and mechanical properties (such as strength). This results in excellent sealing performance and a long service life. Due to the conductivity of the sealing element, no additional buffer seal is required, which simplifies design, reduces costs, and lowers overall frictional losses in the seal.

[0018] For example, conductive carbon in powder or pigment form has proven to be a preferred filler. The weight percentage of conductive carbon is preferably 1% to 15%, and / or preferably at least 4%, more preferably at least 7%, and even more preferably at least 10%. Conductive carbon is inexpensive and allows for simple and precise setting of the desired conductivity of the sealing element. Additionally or alternatively, conductive carbon fiber can be considered as a filler.

[0019] Preferred fillers are composed of fibers, particularly glass fibers, to reduce wear. The weight percentage of glass fibers is preferably 5% to 20%, more preferably 6% to 15%, more preferably 7% to 12%, and for example 8% to 10%. The weight percentage of at least one or all fiber fillers is preferably 1% to 30%, more preferably 5% to 20%, and even more preferably 7.5% to 15%, for example 10%. Fiber fillers are primarily used for mechanically reinforcing sealing elements.

[0020] In some embodiments of the invention, at least one filler comprises a metal oxide or a mixture of metal oxides. Fillers made of tin oxide (IV), indium tin oxide, or mixtures thereof have proven particularly suitable. The weight percentage of one or more metal oxide-containing fillers, or all fillers, is preferably 0.5% to 10%, more preferably 1% to 5%. Another preferred filler is dendritic silver. The weight percentage of dendritic silver filler is preferably 1% to 10%, more preferably 1% to 5%.

[0021] The filler can be composed of silver-plated glass fibers. Silver-plated glass fibers give the sealing element good tribological properties. Fillers made of silver-plated glass fibers can have a silver content of 8 to 20% by weight. For example, the silver content in a filler made of silver-plated glass fibers can be 12% by weight. Such a silver content allows for a good trade-off between conductivity and cost. The average fiber length of the silver-plated glass fibers in the filler is 100 to 160 µm. For example, the average fiber length can be 130 µm. The short fiber length allows for the use of various standard manufacturing methods. Meanwhile, satisfactory surface quality can be obtained within the recommended average fiber length range.

[0022] The filler can consist of silver-plated, preferably solid glass spheres. In possible alternative embodiments, hollow glass spheres can also be used.

[0023] Using silver-plated glass spheres as filler allows for the manufacture of radial shaft seals using standard manufacturing methods without major adjustments. Filler made from silver-plated glass spheres can contain 4 to 20% by weight, preferably 4 to 12% by weight, of silver. For example, the silver content can be 12% by weight. By using silver-plated glass spheres, the utilization rate of silver relative to the filler volume can be utilized particularly effectively. The average diameter of the silver-plated glass spheres can be 10 to 45 μm, preferably 10 to 30 μm. For example, the average diameter of the glass spheres can be 14 μm. These diameters are particularly suitable for keeping peak mechanical stress in the material at a low level and preventing crack formation under alternating loads.

[0024] The filler can be composed of silver-plated copper particles. The combination of highly conductive copper particles and a silver coating with equally high conductivity significantly improves the conductivity of the filler. In this way, the conductivity of the radial shaft seal ring, and therefore its effect in eliminating static voltage, can be increased. The silver-plated copper particles can have a dendritic structure to achieve high conductivity between the individual silver-plated copper particles in the filler, because the dendritic structure achieves a high degree of branching in the sealing element. The filler made of silver-plated copper particles can have a silver content of 9 to 19% by weight. This allows for a largely integral coating, especially of dendritic copper particles. The average diameter of the silver-plated copper particles in the filler is 30 to 55 μm. Therefore, a good trade-off can be achieved between the quality of individual copper particles and the quality of the silver coating and the conductivity in the sealing element.

[0025] The filler can be composed of silver-plated nickel particles. Similar to silver-plated copper particles, silver-plated nickel particles can generate high conductivity in the sealing element. Furthermore, the silver-plated nickel particles can be magnetically aligned during manufacturing, for example, to align the mechanical properties of the sealing element in a preferred direction. The filler made from silver-plated nickel particles can have a silver content of 8 to 40% by weight. The silver content can be, for example, 8% by weight or, for example, 18% by weight. The silver-plated nickel particles can have an average diameter of 8 to 32 μm. For example, the average particle diameter can be 31 μm. Therefore, a good trade-off can be achieved between the quality of individual nickel particles and the quality of the silver coating, as well as the conductivity in the sealing element.

[0026] The filler can be composed of silver-plated glass powder. As a result, an exceptionally fine distribution of conductive filler can be achieved. Therefore, conventional manufacturing methods can be used without significant adjustments. Simultaneously, due to the particularly small particle size of the silver-plated glass powder, mechanical stress peaks at the interface between the sealing element material and the filler are avoided. The filler made from silver-plated glass powder can have a silver content of 3 to 8% by weight. In addition to silver, the coating can have a zinc content of 3 to 11% by weight. This allows for a cost-effective reduction in silver usage. The glass powder particles can have an average diameter of 3 μm. This results in the aforementioned advantages while maintaining practical manageability due to the small particle size of the filler.

[0027] The sealing element can have a mixture of fillers made of silver-plated glass fiber and fillers made of silver-plated glass spheres.

[0028] In advantageous embodiments, the sealing element and / or protective lip are attached to the support and / or contact ring (if present) by an adhesive. In some embodiments, the adhesive is conductive. For example, this can be achieved by using conductive particles or fibers in the adhesive substrate. If a conductive adhesive is provided between the sealing element or protective lip and the support element, a contact ring is not required. The adhesive between the sealing element or protective lip and the support can also be non-conductive; in this case, a conductive contact ring (see below) is advantageously used to achieve electrical connection with the fixing component. The adhesive can be a vulcanizable rubber compound, used as a non-vulcanized strip and cross-link during compression and under temperature action. Other adhesives, such as epoxy-based adhesives, are conceivable. Additionally or alternatively, other types of attachment are feasible. For example, the sealing element and / or protective lip can be secured to the support by metal rivets.

[0029] In a preferred embodiment, the radial shaft sealing ring includes a preferably conductive, in particular metallic, contact ring for electrical contact with the sealing element and / or protective lip. The contact ring contacts the sealing element or protective lip, thereby ensuring electrical connection between the sealing element or protective lip and the mounting component, especially where any adhesive used between the sealing element / protective lip and the support body is insufficiently conductive. To improve electrical contact, the contact ring preferably has at least one conductive penetrating element that penetrates into the sealing element and / or protective lip in the installed state. If the sealing element or protective lip is attached to the contact ring in a conductive manner, a conductive adhesive is not required. In this case, the sealing element or protective lip is electrically connected to the outer flange of the support element and / or the mounting component / housing via the contact ring.

[0030] Additionally or alternatively, the support body may have at least one conductive, protruding penetrating portion that, in the installed state, penetrates into the sealing element and / or protective lip. In a further embodiment, the support body has at least one conductive extension in its inner circumferential direction that contacts the sealing element and / or protective lip in the installed state, particularly in the transition portion between the attachment and contact portions of the sealing element and / or in the protective lip. This also improves the electrical contact between the sealing element / protective lip and the support body. Another method for improving contact is to metallize the surface of the PTFE compound by electroplating or metal (vapor / atom) deposition processes.

[0031] For applications with particularly high requirements for sealing performance, additional sealing lips made of conventional materials (e.g., non-conductive materials) can be provided in possible embodiments.

[0032] In another advantageous embodiment, in addition to or as a substitute for the preferred conductivity of the body of the sealing element and / or protective lip, the sealing element and / or protective lip have a corresponding conductive surface coating. In this way, a significant improvement in the conductivity of the radial shaft sealing ring can be achieved.

[0033] This can preferably be a metallic coating, such as one based on copper, silver, gold, tin, aluminum, or other metals or alloys. Multiple metal layers can also be combined. Furthermore, metals or semiconductors can be combined with conductive non-metallic components.

[0034] The coatings can be based on non-metallic conductive materials such as graphene, graphite, carbon nanoparticles, carbon fibers, conductive carbon black, or conductive polymers (e.g., polyaniline or its derivatives), especially those without a sticky matrix. Furthermore, metals can also be incorporated into these layers, such as metallized graphite.

[0035] The coating can be made conductive by incorporating metallic components into the matrix, such as conductive paints with metallic fillers like copper, silver, gold, tin, or other metals or alloys thereof. The coating can also be made conductive by incorporating non-metallic conductive components into the matrix, such as conductive paints with non-metallic fillers like graphene, carbon nanoparticles, carbon fibers, or conductive carbon black. Conductive polymers (such as polyaniline or its derivatives) can be used as the matrix for the aforementioned fillers; non-conductive polymers or resins can also be used.

[0036] The coating can include a combination of metallic and non-metallic conductive components, such as copper and graphene or copper and polyaniline, which also advantageously serve as protection against copper corrosion.

[0037] Conductive particles are preferably deposited or applied to the body of the sealing element and / or protective lip by chemical, electroplating, or physical methods (e.g., PVD, CVD, ultrasonic, spraying, etc.). The surfaces of the sealing element and / or protective lip can be completely or partially coated with a conductive coating, especially on one side, both sides, or in partial areas of one or both surfaces.

[0038] Depending on the metal used for the coating, the metal can be transferred from the surface of the sealing element and / or the protective lip to the metal surface of the mating surface of the shaft, which can reduce the transition resistance under dynamic conditions with low radial forces. The thickness of the conductive layer is preferably one atomic layer to a maximum of 0.3 mm. Attached Figure Description

[0039] The present invention will now be explained with reference to the accompanying drawings, based on preferred embodiments, wherein:

[0040] Figure 1-6 This is a cross-sectional view of the radial shaft sealing ring installed in different embodiments;

[0041] Figure 7 It is based on Figure 6 A schematic diagram of the support body for the radial shaft seal ring; and

[0042] Figure 8-12 This is a cross-sectional view of the radial shaft sealing ring installed in a further embodiment. Detailed Implementation

[0043] The radial shaft seal ring 10 includes a support body 2 and a sealing element 1 fixed or attached to the support body 2. For example, the support body 2, made of metal, can be inserted into a cylindrical bore 12 of a component 7 (e.g., the housing of an electric motor) that is stationary relative to the rotor shaft 3, and for this purpose has a cylindrical flange 13 in its outer circumferential direction, the outer diameter of which corresponds to the inner diameter of the cylindrical bore 12. Furthermore, the radial shaft seal ring 10 has a static seal 14 in its outer circumferential direction, which is larger in size relative to the inner circumferential direction 12 of the stationary component 7, and thus seals the mounted radial shaft seal ring 10 to the component 7. As shown here, the static seal 14 can be integrally formed with the sealing element 1 or can be a separate component made of the same or different material as the sealing element 1. The support body 2 also has a radial support portion 15 that extends radially inward from the cylindrical flange 13 and serves to hold the sealing element attached thereto.

[0044] In its uninstalled state, the sealing element 1 has, for example, the shape of an annular disc. The sealing element 1 has an external radial attachment portion 17 through which it is planarly and electrically connected to the support body 2 or to the support portion 15. The sealing element also has an internal cylindrical contact portion 11, such as that which can be accessed from... Figure 1 As can be seen, in the installed state, the internal cylindrical contact portion preferably lies flat on the shaft 3 and has an axial length L, thus preferably contacting the shaft plane. Planar contact is not absolutely necessary; it is essentially sufficient for the sealing element 1 to rest against the shaft 3 with only one edge. Figure 1 As shown, in the installed operating state, the sealing element 1 with the contact portion 11 is preferably bent inward relative to the internal space 20. Alternatively, the sealing element 1 can be bent outward. The (main) sealing element 1 can also be referred to as a sealing lip.

[0045] The sealing element 1 is conductive. Due to the conductive contact between the conductive sealing element 1 and the shaft 3, the electrical attachment between the seal 1 and the metal support 2, and the conductive contact between the support 2 and, for example, the metal component 7, there is a continuous conductive connection between the shaft 3 and the component 7. In this way, the radial shaft sealing ring 10 establishes an equipotential connection between the shaft 3 and the component 7 in every operating state of the electric motor.

[0046] In the installed state, the radial shaft sealing ring 10 seals the internal space 18 of component 7 with the external space 19 by means of sealing element 1 (sealing relative to shaft 3) and static seal 14 (sealing relative to component 7). On the side facing shaft 3, sealing element 1 can have a structure in the form of one or more grooves 20, such as helical grooves or annular grooves, for returning particles from the outside to the inside (towards the internal space 18).

[0047] The radial shaft seal ring 10 may have a dust lip 16, particularly facing the external space 19, which contacts the shaft, or as Figures 2 to 6 As shown, it does not contact the shaft, but this is not always the case. The dust lip 16 can be manufactured integrally or as a single piece with the static seal 14 and / or the sealing element 1, using the same material and / or the same process steps. The dust lip 16 can also be referred to as a second lip protection lip or a dust protection lip.

[0048] The material of sealing element 1 comprises a substrate having the largest weight proportion and one or more fillers having a smaller weight proportion, wherein at least one of the fillers is a conductive filler distributed in the substrate. The substrate is advantageously PTFE (polytetrafluoroethylene) or another fluoropolymer such as FKM (fluororubber), a simple elastomer such as ACM, AEM, HNBR or NBR, or a fluorinated thermoplastic. At least one conductive filler preferably comprises metal, metallized and / or metal-coated particles, fibers and / or hollow spheres, conductive carbon black, nanotubes, especially hollow fibers or carbon nanotubes, and / or conductive fibers, such as carbon fibers.

[0049] In the first embodiment, the sealing element 1 is made of 75% to 90% PTFE as its base material, 1% to 10% (e.g., 5%) of conductive carbon by weight, and 5% to 20% of fiber filler (especially carbon fiber and / or glass fiber) by weight. Additionally, it is possible to provide another polymer filler (e.g., PEEK and / or PI) at a weight ratio of 1% to 10% (e.g., 5%).

[0050] In the second embodiment, the material of the sealing element 1 comprises 75% to 90%, preferably 80% to 85%, of PTFE as its base material, 5% to 10% (e.g., 7%) of conductive carbon material, and 5% to 15% (e.g., 10%) of fiber filler (especially carbon fiber and / or glass fiber, such as glass fiber) by weight. Furthermore, 1% to 5% (e.g., 2%) of metallized, especially silver-plated filler, such as dendritic silver, tin oxide (IV), or indium tin oxide or mixtures thereof, may be provided, along with / or 1% to 5% (e.g., 2%) of another polymer filler, such as PEEK and / or PI.

[0051] In the third embodiment, the material of the sealing element 1 has 65% to 85%, preferably 70% to 80% (e.g. 75%) of PTFE as its base material and 15% to 35%, preferably 20% to 30% (e.g. 25%) of metallized, especially silver-plated fillers, such as silver-plated copper particles, silver-plated glass fibers, silver-plated microglass spheres and / or silver-plated amorphous glass powder.

[0052] There are multiple solutions for the conductive connection between the sealing element 1 and the support 2.

[0053] According to Figure 2 In one embodiment, the sealing element 1 is attached to the support 2 by a conductive adhesive 21, which is preferably applied planarly between the support portion 15 and the attachment portion 17. The adhesive 21 can be, for example, a conductive elastomer mixture or a conductive tape. Conductive epoxy resin or thermosetting adhesive 21 is also conceivable, as with any known and suitable adhesive. In other embodiments, the adhesive 21 between the support portion 15 and the attachment portion 17 can also be additionally provided.

[0054] In some embodiments, an adhesive (not shown) (e.g., made of steel) can be provided on the support 2 for bonding to, for example, an elastic sealing element 1. In this case, the adhesive is preferably also conductive. Additionally or alternatively, for example if the adhesive is not sufficiently conductive, the contact area 22, i.e., the area without adhesive, can be exposed on the surface of the support.

[0055] exist Figure 3 and 4 In this embodiment, the radial shaft sealing ring 10 has a contact ring 26 designed to clamp and secure the sealing element 1 to the support body 2. The contact ring 26 advantageously has a cylindrical outer portion 27, a cylindrical inner portion 28, and a radial connecting portion 29 connecting the cylindrical outer portion 27 to the cylindrical inner portion 28. The outer diameter of the outer portion 27 advantageously corresponds to the inner diameter of the cylindrical flange 13, allowing the contact ring 26 to be clamped and secured in the support body 2. The contact ring 26, particularly the cylindrical inner portion 28, in the installed state, presses the sealing element 1, particularly the attachment portion 17, against the support body 2, particularly against the support portion 15. The sealing element 1 is clamped to the support body 2 in this manner. Additional bonding can be performed using an adhesive 21.

[0056] The contact ring 26 is advantageously conductive, for example, made of metal, to facilitate electrical connection between the sealing element 1 and the support 2. To increase conductivity between the sealing element 1 and the support 2, the contact ring 26 preferably has at least one conductive penetrating element 30, particularly on the cylindrical inner portion 28. The penetrating element 30 can consist of, for example, a plurality of teeth arranged circumferentially around the contact ring 26. Alternatively, the penetrating element 30 can be designed to be circumferentially continuous around the contact ring 26.

[0057] According to Figure 4In this embodiment, a conductive, particularly metallic, contact ring 26 is also provided, having a protruding metallic penetrating portion 23 that penetrates into the sealing element 1, particularly into the attachment portion 17, when the radial shaft sealing ring 10 is in the installed state. The penetrating portion 23 can be, for example, a sharp edge or wing that curves upward from an area of ​​the contact ring 26 having one or more grooves. Advantageously, a plurality of penetrating portions 23 are distributed circumferentially on the contact ring 26.

[0058] In embodiments with contact ring 26, a contact element 24, preferably of metal, can also be provided, which electrically connects contact ring 26 to component 7. Contact element 24 can advantageously be integrally formed with contact ring 26. Advantageously, circumferential contact element 24 can have a cylindrical portion 25 for contacting component 7 in the region of cylindrical bore 12, and a radial portion 30 for connecting the remainder of contact ring 26 to cylindrical portion 25. In the case of conductive contact element 24, radial shaft sealing ring 10 can be provided with a seat 14 made entirely of non-conductive elastomer or rubber, without direct contact between support 2 and component 7.

[0059] According to Figure 5 In this embodiment, a metal, protruding penetrating portion 31 is also provided. However, in this embodiment, these are formed by a metal support 2, particularly the support portion 15, and therefore from the other side—relative to the embodiment according to Figure 3 and 4 In some embodiments, the penetration extends into the sealing element 1, particularly into the attachment portion 17. The penetration portion 31 can be, for example, a sharp edge portion or wing that curves upward from an area of ​​the support body 2, particularly the support portion 15, having one or more slots. Advantageously, a plurality of penetration portions 31 are distributed circumferentially on the support body 2.

[0060] According to Figure 5 In one embodiment, the sealing element 1 can be injected or attached from the peripheral side 19 through the penetration portion 31. Then, due to the manufacturing process, an elastomeric stop 32 can be formed on the peripheral side 19.

[0061] According to Figure 6 and Figure 7 In this embodiment, the metal extension 33 is disposed on the inner circumferential direction of the support body 2 or the support portion 15, particularly in the form of a tab, which supports the sealing element 1 in contact when the radial shaft sealing ring 10 is in the installed state, particularly in the curved transition portion 34 between the attachment portion 17 and the contact portion 11. In this embodiment, as referenced Figure 5 As described, a protruding through-hole 31 of metal can be additionally provided.

[0062] Such as combination Figure 2 As described, all the described embodiments can optionally have a conductive adhesive 21 between the sealing element 1 and the support 2.

[0063] According to Figure 8 In this embodiment, a plurality of metal rivets 35 are distributed circumferentially on the radial shaft sealing ring 10 and engage through corresponding holes 36 in the sealing element 1, particularly in the attachment portion 17, and corresponding holes 37 in the support body 2, particularly in the support portion 15, thereby establishing a conductive riveting connection between the sealing element 1 and the support body 2. In this way, the adhesive 21 or elastomer attachment is electrically bridged.

[0064] According to Figure 9 In this embodiment, a contact ring 26 is sequentially arranged, which is, for example, substantially U-shaped. A chamfered leg 38 is also provided between the cylindrical outer portion 27 and the radial connecting portion 29, but this is not strictly necessary. In this embodiment, the contact ring 26 serves, for example, as a clamping ring for pressing the sealing element 1, particularly the attachment portion 17, against the support element 2, particularly the support portion 15, thereby firmly holding it in place. An adhesive 39 can be provided between the contact ring 26 (particularly the radial portion 29) and the sealing element 1 (particularly the attachment portion 17). If there is an conductive connection between the sealing element 1 (particularly the attachment portion 17) and the support ring 2 (particularly the support portion 15), this can be a non-conductive adhesive.

[0065] Figure 10 Another advantageous embodiment is shown, wherein the sealing element 1 has at least one conductive coating 50 on the surface of its body 49. As already described above, especially with reference to Figures 1 to 9 The body 49 can correspond to the sealing element 1 without coating 50. The body 49 is preferably conductive, ensuring reliable grounding even in the event of wear of coating 50. The material and thickness of the conductive coating 50 are advantageously selected as described above.

[0066] The conductive coating 50 can be applied to both sides, namely, the side of the sealing element 1 facing the external space 19 and the side of the sealing element facing the internal space 18. The conductive coating 50 can also be applied to only one side, namely, only on the side facing the external space 21 or only on the side facing the internal space 20. The conductive coatings 50 on both sides of the sealing element 1 can differ from each other in terms of material, application pattern, and / or layer thickness.

[0067] The conductive coating 50 can be formed on the entire surface of the sealing element 1 or partially on one or both sides of the sealing element 1. In the case of partial coating 50, the body 49 of the sealing element 1 has uncoated areas and coated areas, the number, shape, and arrangement of which can be appropriately selected. Different coating types can be selected on both sides of the sealing element 1. It is also feasible to have a full-surface conductive coating 50 on one side and a partial conductive coating 50 on the opposite side. Another embodiment has different partial conductive coatings 50 on the same side of the sealing element 1. In another embodiment, the sealing element 1 has a multilayer conductive coating 50 with multiple stacked layers, one, multiple, or all of which are conductive.

[0068] In principle, all conceivable combinations of coatings 50, including full-surface, partial, one-sided, two-sided, multi-layer, similar and / or different coatings, are feasible.

[0069] Figure 11 Another advantageous embodiment is shown, having a conductive dustproof lip or dust protection lip 16 in contact with shaft 3. In this embodiment, the material composition of the dustproof lip 16 includes at least one substrate made of a polymer and at least one conductive filler. The statements above regarding the substrate and filler of the sealing element 1 apply similarly to the substrate and filler of the dustproof lip 16.

[0070] In this embodiment, the dust lip 16 preferably includes: a contact portion 11', which is similar to the sealing portion 11 of the sealing element 1, abutting against the shaft 3 in an axially contact manner; an attachment portion 17', which is similar to the attachment portion 17 of the sealing element 1; and a transition portion 34, which is similar to the transition portion 34 of the sealing element, elastically bending between the attachment portion 17' and the contact portion 11'. The attachment portion 17' and thus the dust lip 16 are electrically connected to the support 2. This can be advantageously performed in the same manner as described above with respect to the conductive connection between the sealing element 1 and the support 2, especially by vulcanization, using conductive adhesives 21, 39, contact rings 26, penetrating elements 23, 30, penetrating portions 31, conductive extensions 33 and / or metal rivets 35.

[0071] According to Figure 11 In the aforementioned embodiments, a conductive connection (grounding connection) is established between the shaft 3 and the component 7 via the dust lip 16 and the metal support 2. In this embodiment, the sealing element 1 can also be conductive to improve grounding, or it can be non-conductive if the conductivity of the dust lip 16 is sufficient.

[0072] Figure 12Another embodiment with a contact protective lip 16 is shown. In this embodiment, the dust lip 16 has a conductive coating 51, and correspondingly, the statements regarding the conductive coating 50 of the sealing element 1 apply to this conductive coating. Therefore, in this case, the body 49' of the dust lip 16 is preferably also conductive, so that reliable grounding is still ensured even if the coating 51 wears down.

Claims

1. A radial shaft sealing ring (10), wherein, The radial shaft sealing ring (10) is designed to electrically connect the shaft (3) to a component (7) stationary relative to the shaft (3). The radial shaft sealing ring (10) has a support (2) and a sealing element (1) attached to the support. The sealing element has a sealing portion (11) in contact with the shaft. The sealing element (1) is characterized in that its material composition includes at least one substrate made of at least one polymer and one or more fillers provided with at least one conductive filler. In addition to the first conductive body (49) of the sealing element (1), the sealing element (1) also has a first conductive surface coating (50).

2. The radial shaft sealing ring (10) according to claim 1, comprising a protective lip (16) in contact with the shaft, characterized in that, The material composition of the protective lip (16) includes at least one substrate made of at least one polymer and one or more fillers provided therein with at least one conductive filler.

3. The radial shaft sealing ring according to claim 1 or 2, characterized in that, The conductive filler has metal, metallized and / or metal-coated particles, microspheres, microtubes and / or fibers.

4. The radial shaft sealing ring according to claim 3, characterized in that, The conductive filler has silver, silver-plated and / or silver-coated particles, microspheres, microtubes and / or fibers.

5. The radial shaft sealing ring (10) according to claim 3, characterized in that, The conductive filler has a weight ratio of 1% to 25%.

6. The radial shaft sealing ring (10) according to claim 1 or 2, characterized in that, Provide at least one filler made of conductive carbon.

7. The radial shaft sealing ring (10) according to claim 6, characterized in that, The conductive carbon accounts for 1% to 15% of the total weight.

8. The radial shaft sealing ring according to claim 1 or 2, characterized in that, It is provided with at least one filler made of fiber.

9. The radial shaft sealing ring according to claim 8, characterized in that, The weight percentage of at least one fiber filler is 1% to 20%.

10. The radial shaft sealing ring according to claim 1 or 2, characterized in that, The facility is provided with at least one filler made of metal oxide or a mixture of metal oxides.

11. The radial shaft sealing ring according to claim 10, characterized in that, It is provided with at least one filler made of tin oxide and / or indium tin oxide.

12. The radial shaft sealing ring according to claim 10, characterized in that, The filler containing metal oxides accounts for 1% to 10% by weight.

13. The radial shaft sealing ring (10) according to claim 1 or 2, characterized in that, The substrate includes fluoropolymers, elastomers, fluorinated thermoplastics, PTFE-based polymers, or corresponding copolymers.

14. The radial shaft sealing ring (10) according to claim 1 or 2, characterized in that, The substrate comprises 50% to 99% by weight.

15. The radial shaft sealing ring according to claim 1 or 2, characterized in that, It is provided with at least one filler made of dendritic silver.

16. The radial shaft sealing ring according to claim 15, characterized in that, The filler made of the dendritic silver is 1% to 10% by weight.

17. The radial shaft sealing ring according to claim 1, characterized in that, The sealing element (1) is attached to the support (2) and / or the contact ring (26) by adhesives (21, 39).

18. The radial shaft sealing ring according to claim 1, characterized in that, The radial shaft sealing ring (10) includes a conductive contact ring (26) for electrical contact with the sealing element (1).

19. The radial shaft sealing ring according to claim 18, characterized in that, The contact ring (26) has at least one conductive penetrating element (23, 30) that penetrates into the sealing element (1) in the installed state.

20. The radial shaft sealing ring according to claim 18, characterized in that, A conductive contact element (24) is provided for establishing contact between the contact ring (26) and the component (7).

21. The radial shaft sealing ring according to claim 1, characterized in that, The support (2) has at least one conductive, protruding penetrating portion (31) that penetrates into the sealing element (1) in the installed state.

22. The radial shaft sealing ring according to claim 1, characterized in that, The support (2) has at least one conductive extension (33) on its inner circumference, which contacts the sealing element (1) in the installed state.

23. The radial shaft sealing ring according to claim 2, characterized in that, In addition to the second conductive body (49') of the protective lip (16), the protective lip (16) also has a second conductive surface coating (51).

24. The radial shaft sealing ring (10) according to claim 7, characterized in that, The conductive carbon accounts for 4% to 10% of the total weight.

25. The radial shaft sealing ring (10) according to claim 8, characterized in that, The at least one filler is made of glass fiber.

26. The radial shaft sealing ring according to claim 9, characterized in that, The weight percentage of the at least one fiber filler is 5% to 15%.

27. The radial shaft sealing ring according to claim 12, characterized in that, The filler containing metal oxides has a weight ratio of 1% to 5%.

28. The radial shaft sealing ring according to claim 13, characterized in that, The fluoropolymer is PTFE or FKM.

29. The radial shaft sealing ring according to claim 16, characterized in that, The filler made of the dendritic silver is 1% to 5% by weight.

30. The radial shaft sealing ring according to claim 22, characterized in that, The at least one conductive extension (33) contacts the sealing element (1) in the transition portion (34) between the attachment portion and the contact portion of the sealing element (1) in the installed state.

31. The radial shaft sealing ring according to claim 2, characterized in that, The protective lip (16) is attached to the support (2) and / or the contact ring (26) by adhesives (21, 39).

32. The radial shaft sealing ring according to claim 2, characterized in that, The radial shaft sealing ring (10) includes a conductive contact ring (26) for electrical contact with the protective lip (16).

33. The radial shaft sealing ring according to claim 2, characterized in that, The support (2) has at least one conductive, protruding penetrating portion (31) that penetrates into the protective lip (16) in the installed state.

34. The radial shaft sealing ring according to claim 2, characterized in that, The support (2) has at least one conductive extension (33) on its inner circumference, which contacts the protective lip (16) in the installed state.

35. The radial shaft sealing ring according to claim 34, characterized in that, The at least one conductive extension (33) contacts the protective lip (16) in the transition portion (34) between the attachment portion and the contact portion of the protective lip (16) in the installed state.

36. The radial shaft sealing ring according to claim 2, characterized in that, The radial shaft sealing ring (10) includes a conductive contact ring (26) for electrical contact with the sealing element (1), the contact ring (26) having at least one conductive penetrating element that penetrates into the protective lip (16) in the installed state.

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