Bearing ring

Abstract

The invention relates to a bearing ring (1) having a sandwich structure composed of at least three layers (2, 4, 6), at least part of the first layer (2) forming a raceway (8), the second layer (6) being arranged as an intermediate layer on the first layer (2) and at least part of the third layer (4) being arranged on the intermediate layer (6), the first layer (2) being made of a first material, the intermediate layer (6) being made of a second material, and the third layer (4) being made of a third material, the second material differing from the first and third materials, and the second material of the intermediate layer (6) comprising a material that fulfills an insulating, damping, and / or weight-reducing function.

Description

[0001] bearing ring

[0002] Technical area

[0003] The present invention relates to a bearing ring according to the preamble of claim 1.

[0004] Technical background

[0005] In rolling or plain bearings, it may be necessary to optimize one or more bearing components with regard to electrical insulation, weight, or similar. For electrical insulation, for example, it is known to manufacture one of the bearing components, e.g., a ring or a rolling element, from an insulating material. However, this can have the disadvantage that other requirements for the corresponding bearing component are not met, or at least not sufficiently met, such as load-bearing capacity, etc. The same applies to weight. If a bearing component is made from a lighter material, this can have a negative impact on load-bearing capacity. Alternatively, it is possible to apply coatings to the outer surfaces of a bearing ring.However, this can also impair the load-bearing capacity and / or the coating, which can serve as electrical insulation, for example, is damaged by the usual load on a bearing ring and can then no longer fulfil its function.

[0006] It is therefore an object of the present invention to provide a bearing ring which has sufficient load-bearing capacity while at the same time being able to provide additional functionalities reliably and permanently.

[0007] Summary of the invention

[0008] This object is achieved by a bearing ring according to patent claim 1.

[0009] A bearing ring usually has a running surface and a surface opposite the running surface. The running surface can be either the inner or outer surface, depending on whether the bearing ring is an outer ring or an inner ring. The bearing ring proposed here has a sandwich structure made up of at least three layers. The first layer at least partially forms the running surface, the second layer is arranged as an intermediate layer on the first layer, and the third layer is arranged at least partially on the intermediate layer. This sandwich structure makes it possible to use different materials for the various layers and in this way to meet the requirements for the running surface and the surface opposite the running surface, e.g. with regard to load-bearing capacity, using the first and third layers, and to add further functionalities to the bearing ring using the intermediate layer.

[0010] To ensure good load-bearing capacity of the running surface that comes into contact with rolling elements or a mating surface, as well as the surface opposite the running surface, which comes into contact with a housing, for example, the running surface can be made of a first material and the surface opposite the running surface can be made of a third material. The first and third materials can be identical or different from one another. However, to simultaneously achieve additional functionalities that cannot be provided by the first and third materials, the intermediate layer consists of a second material that is at least partially arranged between the first and third materials. The second material differs from the first and third materials.In this way, the intermediate layer can easily provide one or more additional functions without compromising the functionalities of the bearing ring itself, which are provided by the first and third materials. For example, the intermediate layer can serve for damping, electrical insulation, or to save bearing steel. The second material of the intermediate layer therefore comprises a material that fulfills an insulating, damping, and / or weight-reducing function.

[0011] As described, the intermediate layer can add additional functionality to the bearing ring. At the same time, the bearing ring itself remains unchanged. This means that the bearing ring corresponds to a conventional bearing ring in both its external dimensions and handling. It can therefore be easily integrated into existing systems or bearings, or even replaced with bearing rings used in those systems. Furthermore, the proposed bearing ring can provide reduced machining effort and / or reduced energy consumption compared to existing bearing types.

[0012] According to one embodiment, the bearing ring has an inner and an outer circumferential surface and a first and a second end face, wherein the intermediate layer extends from the first end face to the second end face (where the running surface is the inner or outer circumferential surface). The intermediate layer extends in particular circumferentially, preferably continuously circumferentially.

[0013] This means that the intermediate layer can extend completely throughout the bearing ring, thus providing the functionality provided by the third material across the entire bearing ring. This is advantageous, for example, when the third material provides damping or electrical insulation.

[0014] The intermediate layer can also run obliquely and, in cross-section, extend, for example, from the first to the second end face and also to the inner and / or outer surface. Alternatively, the intermediate layer can also extend from the inner to the outer surface and also to the first and / or second end face. This can be particularly advantageous for angular contact ball bearings or angular contact roller bearings, where an oblique load occurs on the surfaces and thus also on the intermediate layer.

[0015] As mentioned above, the first material and the third material can be identical. For example, the first and third materials can be hardened, e.g., hardened steel, to withstand the loads that occur due to contact with a housing, rolling elements, or a counter-surface.

[0016] Preferably, the first material and / or the third material can comprise metal (e.g. steel, non-ferrous metals such as aluminum, etc.), ceramic, and / or composite materials, in particular non-polymer-based composite materials. These materials are particularly robust in order to withstand the above-mentioned loads exerted on the running surface and the surface opposite the running surface. As explained above, the second material of the intermediate layer comprises a material that fulfills an insulating, damping and / or weight-reducing function. For example, the second material can be a plastic, in particular a polymer, duromer, thermoplastic, a plastic composite, and / or a ceramic plastic. Alternatively, the second material can also be a metal, such as aluminum, e.g. aluminum foam.

[0017] To increase the load-bearing capacity of the second material, it can be fiber-reinforced, e.g., with carbon fibers. Alternatively or additionally, the second material can be given additional functionality by adding fillers. These fillers can, for example, be materials that can dampen the bearing ring, i.e., reduce noise and / or vibration.

[0018] For example, thermosets, thermoplastics, or rubber variants, or polymers in general, can be used. The mechanical properties can be adjusted depending on the type and amount of filler. For example, an intermediate layer optimized for electrical insulation can have a different filler content than an intermediate layer optimized solely for vibration damping. This means that, in one embodiment, the properties of the intermediate layer can be adjusted by changing the amount of filler.

[0019] Such fillers can also prevent chatter and the resulting chatter marks and / or fretting corrosion. Furthermore, such fillers can also provide electrical insulation, in which case the fillers can contain, for example, ceramics such as aluminum oxide, silicon carbide, rutile, zinc oxide, zirconium oxide, silicon nitride, glass, etc. In particular, materials can be used that increase the electrical impedance of the intermediate layer and thus prevent electrical discharge.

[0020] In general, fillers can provide mechanical and / or functional properties. These properties can include, for example, thermoelectric properties and / or thermophysical properties, increased and / or reduced mechanical stress, detection of mechanical strain (via piezoelectric elements, color change, etc.), haptic properties, optical properties, odor properties, reduced and / or increased surface tension, wettability of the interlayer (e.g., addition of lubricants), corrosion properties, or a combination of the listed properties.

[0021] Generally speaking, the interlayer, particularly due to the fillers it contains, can exhibit properties that ensure that the interlayer reacts to temperature, electrical stress, mechanical stress, and / or mechanical strain. As already mentioned above, these properties can be influenced by both the type and quantity of fillers.

[0022] The fibers and / or fillers can be of different sizes and shapes. They can range from a powder in the micrometer range to individual particles in the millimeter range. The fibers and / or fillers can also have different aspect ratios (e.g., from spheres to long fibers).

[0023] The intermediate layer can have grooves in areas that are free of the first and / or the third layer, which grooves are designed to receive elements. The areas of the intermediate layer are areas of the intermediate layer that are accessible from the outside. Elements can engage or snap into the grooves provided in these exposed areas, wherein these elements are, for example, seals that can be used to seal the bearing ring against other surfaces. The elements can also be brushes, in particular grounding brushes, to dissipate electrical charge from the bearing ring. The intermediate layer can also have a plurality of grooves on each exposed side, so that a plurality of elements can be received on each side.

[0024] According to a further embodiment, at least one additional element is embedded in the intermediate layer. The at least one additional element can be an electronic device, a lubricant and / or a lubricant depot. The at least one additional element can be completely embedded in the intermediate layer, e.g. in openings or grooves formed therein, i.e. without contact with the first or third layer. This has the advantage that, for example, in the case of electronic devices, these are insulated in the intermediate layer and are not exposed to any current flow or electrical charge through the first or third layer. Alternatively, the at least one additional element can be embedded in contact with the first and / or the third layer. This can in turn have the advantage that, in the case of electronic devices, e.g.If these are sensors, measurements can be taken directly on the first and / or third layers through contact with these layers. If the additional element is a lubricant or a lubricant reservoir, the intermediate layer can preferably have lubricant outlets, e.g., grooves, leading from the additional elements to the outside. A combination of different additional elements can also be embedded in the intermediate layer.

[0025] Electronic devices as additional elements can be, for example, sensors, chips, antennas and / or cables. For example, the at least one electronic device can be designed to carry out signal processing and can have corresponding elements for this purpose, in particular chips, microprocessors or the like. Similarly, elements can be embedded in the intermediate layer as an electronic device, which implement an antenna for signal transmission. In an exemplary embodiment, the intermediate layer can have a sensor and an antenna, so that the intermediate layer can, on the one hand, detect parameters of the bearing ring or the bearing in which the bearing ring is installed, and can also forward these parameters directly to further devices via the antenna. Optionally, the intermediate layer can additionally have a signal processing unit (e.g.a microprocessor) so that the recorded parameters can at least be pre-processed directly in the intermediate layer.

[0026] These electronic devices can therefore be easily integrated directly into the bearing ring. Until now, this required sensors to be attached to the outside of the bearing ring, which could then be damaged from the outside. Another alternative used to date was sensor rolling elements, in which the sensors are arranged in the rolling element, for example in the bore of a sensor roller. However, the solution proposed here of integrating sensors directly into the bearing ring is easier to implement than such sensor rollers and has the further advantage that data and measurements can be recorded and taken directly on the bearing ring. It is therefore not necessary to take measurements using a sensor rolling element and then transfer this information to a bearing ring in order to obtain information about the bearing ring.

[0027] It should be noted that one or more sensors can be embedded in the intermediate layer. A combination of different sensors can also be embedded in the intermediate layer.

[0028] For example, the intermediate layer can contain thin layers of insulating, semiconducting, or electrically conductive material, which form a sensor based on their relative arrangement. For example, a sensor can be formed based on changes in electrical resistance or due to the piezoelectric or semiconducting properties of the intermediate layer or the materials contained in the intermediate layer. Such sensors include, for example, strain gauges, temperature sensors, acceleration sensors, etc. Furthermore, glass fibers can be integrated into the intermediate layer, which then allow conclusions to be drawn, for example, about mechanical stress based on changes in their optical properties. Such glass fibers can also be used as signal transmission elements.

[0029] Alternatively, the intermediate layer itself can serve as a sensor, e.g., as a varistor, PTC, or similar. In this case, the intermediate layer can be made of a suitable material, such as a polycrystalline ceramic, particularly a semiconducting one. For example, an electrical capacitance or electrical resistance of the intermediate layer can be indicative of bearing ring parameters, and the intermediate layer can therefore be used directly as a sensor.

[0030] According to a further embodiment, one or more radially extending openings, i.e., holes, can be provided in the first, second, and / or third layer. These openings are thus formed as radial openings on the circumference. Alternatively, one or more axially extending openings, i.e., holes, can be provided in the first, second, and / or third layer. In this case, axial openings are provided on one or both end faces.

[0031] If one or more openings are present in the first and / or third layer, these can extend completely through the first and / or third layer from the outside of the bearing ring and can be used, in particular, to fill the intermediate layer material during the production of the bearing ring. At the same time, air can be released (in particular to create space for the intermediate layer material).

[0032] One or more openings in the intermediate layer can be used, in particular, to access an embedded electronic device, for example, to insert a cable or fiber optic cable and connect the electronic device. In this case, the openings are preferably provided on one end face of the bearing ring. They can pass completely through the intermediate layer in the axial direction, but can also pass only partially through the intermediate layer, in particular from the outside to an embedded electronic device.

[0033] Furthermore, the one or more openings can serve as anti-rotation devices for the bearing ring. The one or more openings can interact with an element on a housing, shaft, or other component to which the bearing is mounted. This can also ensure that a sensor cable, as mentioned above, is not sheared during operation.

[0034] According to a further aspect, a method for producing a bearing ring as described above is proposed. According to the method, the intermediate layer can be injected or filled between the first and the third layer. For this purpose, two rings, each consisting of the first and the second layer, are arranged relative to one another, and then the intermediate layer is injected or filled between these two rings. This can be done by injection molding, vacuum casting, foaming, or similar technologies. By injecting or filling the intermediate layer, the first and the third layers are connected to one another. Alternatively, the intermediate layer can also be applied to the first or the third layer using a 3D printing process or by coating processes.The respective other layer can then be applied to the 3D-printed or coated intermediate layer and, for example, glued or otherwise connected to it.

[0035] To ensure a secure bond between the various layers, i.e. the first layer and the intermediate layer as well as the second layer and the intermediate layer, the surfaces of the respective layers, in particular the first and third layers, can be subjected to pretreatment. Such pretreatment can serve as surface preparation or primer preparation for better bonding of the individual layers. Such pretreatment can include, for example, cleaning, sandblasting, turning, knurling, etching, plasma activation, or applying a chemical primer (e.g. phosphating). The pretreatment roughens the respective surface, for example, so that the layer applied or arranged on it adheres better.

[0036] Further advantages and advantageous embodiments are set forth in the description, the drawings, and the claims. In particular, the combinations of features set forth in the description and the drawings are purely exemplary, so the features may also be present individually or in other combinations.

[0037] Short character description

[0038] The invention will be described in more detail below with reference to exemplary embodiments illustrated in the drawings. The exemplary embodiments and the combinations shown in the exemplary embodiments are purely exemplary and are not intended to define the scope of the invention. This scope is defined solely by the appended claims.

[0039] They show:

[0040] Fig. 1 : a schematic sectional view of a bearing ring according to a first embodiment;

[0041] Fig. 2: a schematic sectional view of a bearing ring according to a second embodiment;

[0042] Fig. 3: a schematic sectional view of a bearing ring according to a third embodiment;

[0043] Fig. 4: a schematic perspective sectional view of a bearing ring according to a fourth embodiment;

[0044] Fig. 5: a schematic sectional view of a bearing ring according to the fourth embodiment;

[0045] Fig. 6: a perspective sectional view of a bearing ring according to a fifth embodiment; Fig. 7: a schematic sectional view of a bearing ring according to a sixth embodiment;

[0046] Fig. 8: a schematic perspective partial sectional view of a bearing ring according to the sixth embodiment;

[0047] Fig. 9: a perspective sectional view of a bearing ring according to a seventh embodiment; and

[0048] Fig. 10: a perspective sectional view of a bearing ring according to an eighth embodiment.

[0049] Detailed description of the invention

[0050] In the following, identical or functionally equivalent elements are identified by the same reference symbols.

[0051] Fig. 1 shows a bearing ring 1. Although a ball bearing outer ring is shown in Fig. 1, the bearing ring 1 can generally be used in a rolling bearing, e.g. a ball or roller bearing, or in a plain bearing.

[0052] The race 1 is constructed in a sandwich structure with three layers 2, 6, 4. The first layer 2 at least partially forms a running surface 8. The second layer 6 represents an intermediate layer arranged on the first layer 2. The third layer 4 is at least partially arranged on the intermediate layer 6 and forms the surface 10 opposite the running surface.

[0053] In the embodiment shown in Fig. 1, the bearing ring 1 is depicted as an outer ring, with the running surface being formed by the inner circumferential surface 8 and the surface opposite the running surface being formed by the outer circumferential surface 10. However, it should be noted that the outer circumferential surface 10 can also be the running surface and the inner circumferential surface 8 the surface opposite the running surface.

[0054] In the following, the bearing ring 1 is described in the design of an outer ring, although all designs are transferable to all of the alternative designs mentioned above. In order to provide a high load-bearing capacity of the running surface and the surface opposite the running surface, the first and third layers 2, 4 consist of materials, e.g. hardened steel, which are capable of providing both a stable and load-bearing running surface that can withstand contact with rolling elements or a counter-running surface, as well as a load-bearing surface opposite the running surface that can withstand contact with a housing, e.g. The intermediate layer 6, on the other hand, can be made of materials such as polymer, duromer or other plastics, which provide a functionality that differs from the functionality of the first and third layers 2, 4.For example, the material of the intermediate layer 6 can be used to dampen vibrations, to electrically insulate the first and third layers 2, 4, or to reduce the weight of the entire bearing ring 1. Other functionalities can also be provided by this intermediate layer 6.

[0055] As can be seen in Figures 1 and 2, the intermediate layer 6 can be designed with different radial and circumferential dimensions and shapes. This can depend on the desired functionality. If the intermediate layer 6 is intended to achieve a weight reduction, the intermediate layer 6 should take up more volume of the entire bearing ring 1, as shown in Fig. 1. If the intermediate layer 6 is only intended to prevent electrical current from flowing through the bearing ring 1, a thin intermediate layer 6 is sufficient, as shown in Fig. 2. This applies in particular to DC voltages, for which a relatively thin insulator layer which has a desired dielectric strength is sufficient. For high-frequency currents, an electrical capacitance is necessary which is as small as possible in order to achieve the desired high impedances. In this case, the intermediate layer 6 should therefore be thicker, as shown in Fig. 1, for example.Furthermore, the geometry of the sandwich structure should be coordinated with the connection dimensions of the bearing seat to avoid short circuits.

[0056] If the bearing ring 1 is a bearing ring for an angular contact ball bearing or tapered roller bearing, as shown in Fig. 3, the intermediate layer 6 can extend corresponding to the bevel of the running surface 8. In this case, the intermediate layer 6 can extend as far as the outer circumferential surface 10, since in this case the load from the bearing ring 1 to a housing (not shown) is not transferred in the region of the circumferential surface 10 in which the intermediate layer 6 is located, but only in the region of the circumferential surface 10 in which the third layer 4 is provided. The intermediate layer 6 therefore does not have to withstand high loads in the region of the circumferential surface 10, but can instead serve there, for example, for damping or the like.

[0057] The intermediate layer 6 can be formed from filled (e.g., ceramics such as aluminum oxide, silicon carbide, rutile, zinc oxide, zirconium oxide, glass, and silicon nitride, etc.) or (fiber- or particle-) reinforced polymers, as shown in Figures 4 and 5. Such an intermediate layer 6 is particularly well suited to preventing electrical discharge by significantly increasing the electrical impedance. Due to this intermediate layer structure 6, very low capacitances with very high impedance values ​​can be achieved.

[0058] In one embodiment, the intermediate layer 6 can have grooves 16, as shown in Fig. 6. Additional elements can engage in these grooves 16, which either represent the functionality of the intermediate layer 6 or enable additional functionality. For example, these additional elements can be grounding brushes that can come into contact with another element of a bearing. Alternatively, these additional elements can be seals or the like. These can contact elements surrounding the bearing to seal the bearing.

[0059] In a further embodiment, it is possible to embed sensors in the intermediate layer 6. For this purpose, sensors, monitoring systems, or the like can be embedded in the intermediate layer 6. The sensors 18 can be, for example, thermocouples, vibration sensors, or load sensors. By embedding them in the intermediate layer 6, the sensors 18 can be mounted close to the running surfaces to improve data accuracy when recording information, for example, from rolling elements rolling on the running surface 8. Such sensors 18 can be used to detect vibrations in the bearing, for example.

[0060] The sensors 18 can either be embedded directly into the intermediate layer, without contact with the first or third layer 2, 4, or they can be in contact with one of the layers 2, 4. As shown, for example, in Fig. 8, the sensors 18 can be placed on the layer 2 and then overmolded with the intermediate layer 6. The sensors 18 can be designed as NFC or other wireless sensors. Alternatively, it is also possible to connect the sensors 18, for example, to a readout electronics system via cables 20 that are embedded in the intermediate layer 6 and lead out of it.

[0061] The position and orientation of the sensors 18, whereby only one sensor 18 can be embedded in the intermediate layer 6, can depend on the type of sensor. If information from the running surface 8 is to be detected, the sensor 18 can be arranged in contact with the first layer 2 (for the embodiment of Fig. 8). If, however, information from a housing is to be detected, the sensor 18 can be arranged in contact with the third layer 4.

[0062] Similar to the embedding of the sensors 18, it is also possible to embed lubrication into the intermediate layer 6. For example, one or more lubricant reservoirs or depots, such as the sensors 18, can be embedded in the intermediate layer 6. During operation, lubricant can be dispensed from these lubricant depots. Alternatively, one or more grooves or recesses can be provided in the intermediate layer 6 to allow oil flow. This eliminates the need to provide additional lubrication grooves or the like.

[0063] As can be seen in Fig. 9, the bearing ring 1 can have a radial opening 22 in the third layer 4. Alternatively, the opening 22 can also be provided in the first layer 2 or extend from the first layer 2 or the third layer 4 through the intermediate layer 6. Although only one opening 22 is shown, several radial openings 22 can also be provided. These can extend from the outside of the bearing ring 1 completely through the first and / or the third layer 2, 4 and serve in particular to fill the material of the intermediate layer 6 during the production of the bearing ring 1.

[0064] Furthermore, one or more axial openings 24 can be provided in the end faces 12 of one or more of the layers 2, 4, 6. Such an axial opening is shown as an example in Fig. 10. In the embodiment shown, the opening 24 is arranged in the intermediate layer 6, although an axial opening can also be provided in one of the other layers 2, 4. Such an axial opening 24 can be used, for example, to access the embedded electronic device 18, for example, to insert or remove a cable 20 (see Fig. 2).

[0065] It should be noted that the openings shown in Figures 9 and 10 can be combined as desired with each other and with the other designs of the bearing ring 1 as shown in Figures 1 to 8.

[0066] In summary, the bearing ring described here can provide the usual functionality of a bearing ring, including the load-bearing capacity of the inner and outer surfaces, as well as additional functionality. At the same time, however, the bearing ring does not change its external dimensions, so it can replace conventional bearing rings with the same dimensions.

[0067] List of reference symbols

[0068] bearing ring

[0069] inner surface

[0070] exterior surface

[0071] Intermediate layer

[0072] Running surface / inner surface outer surface

[0073] End faces

[0074] Fillers

[0075] Nut

[0076] Additional element / sensor

[0077] Cable radial opening axial opening

Claims

Patent claims 1. Bearing ring (1) with a sandwich structure made up of at least three layers (2, 4, 6), wherein the first layer (2) at least partially forms a running surface (8), wherein the second layer (6) is arranged as an intermediate layer on the first layer (2), and wherein the third layer (4) is arranged at least partially on the intermediate layer (6), wherein the first layer (2) is formed from a first material, the intermediate layer (6) is formed from a second material, and the third layer (4) is formed from a third material, wherein the second material differs from the first and the third material, and wherein the second material of the intermediate layer (6) comprises a material that fulfills an insulating, damping, and / or weight-reducing function.

2. Bearing ring according to claim 1, wherein the first material and the third material are identical or wherein the first and the third material are different.

3. Bearing ring according to claim 1 or 2, wherein the second material is a plastic, in particular a polymer, duromer, thermoplastic, a plastic composite, and / or a ceramic plastic, and / or a metal.

4. Bearing ring according to one of the preceding claims, wherein the second material is fiber-reinforced and / or contains fillers.

5. Bearing ring according to one of the preceding claims, wherein the first material and / or the third material comprises one of the group consisting of metal, ceramic, composite materials, in particular non-polymer-based composite materials.

6. Bearing ring according to one of the preceding claims, wherein the intermediate layer (6) has grooves (16) in areas which are free from the first and / or the third layer (2, 4) which are designed to receive elements.

7. Bearing ring according to claim 6, wherein the elements are grounding brushes.

8. Bearing ring according to one of the preceding claims, wherein at least one additional element (18, 20) is embedded in the intermediate layer (6).

9. Bearing ring according to one of the preceding claims, wherein one or more radially extending openings (22) are provided in the first and / or the third layer (2, 4) and / or the intermediate layer (6).

10. Bearing ring according to one of the preceding claims, wherein one or more axially extending openings (22, 24) are provided in the first and / or the third layer (2, 4) and / or the intermediate layer (6).

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