Tooth for a low-wear toothing arrangement for load transmission

Abstract

The invention relates to a tooth (22) for a toothing arrangement for load transmission, having a support surface (24) for supporting on a second tooth, wherein a solid lubricating layer system (26) is provided at least in the support surface (24), wherein the solid lubricating layer system (26) has an inner reservoir layer (30) having at least one metal element and a cover layer (32) forming an outer side (34) of the solid lubricating layer system (26), wherein the cover layer (32) has, as a solid lubricant, a metal oxide formed from the metal element of the reservoir layer (30), and abrasively separated metal oxide elements of the cover layer (32) can be regenerated by oxidation of the metal elements of the reservoir layer (30). Under typical operating conditions in the toothing arrangement, the solid lubricant in the cover layer (32) of the tooth (22) can be easily regenerated by tribo-oxidation of the metal elements from the reservoir layer (30) of the tooth (22), such that a lubricated toothing arrangement with low wear is made possible.

Description

[0001] FLENDER GMBH Düsseldorf, January 5, 2026 Our reference: FD 45745 / GR 2024P04759WO

[0002] Flender GmbH

[0003] Alfred-Flender-Str. 77, 46395 Bocholt, Germany

[0004] Tooth for a low-wear gear arrangement for load transmission

[0005] Description

[0006] The invention relates to a tooth for a gear assembly by means of which static and / or dynamic load transmission can be effected, as well as to such a gear assembly, such a transmission, such a gear coupling, and such uses. The invention further relates to a data agglomerate for the virtual representation of such a gear assembly for the purpose of additive manufacturing and / or simulation.

[0007] WO 2015 / 135832 Al shows a tooth coupling with load-transmitting teeth, in which the respective toothing has an internal toothing and an external toothing meshed with the internal toothing to transmit the load.

[0008] From EP 4425 013 Al a tooth of a gear is known in which a tooth flank correction is superimposed with periodically running microstructures in order to mask structure-borne noise generated during rolling.

[0009] It is known to lubricate gear couplings with lubricating oil or grease.

[0010] From CN 112879527 B, a splined connection is known in which the teeth of a gear have micropores on a power-transmitting tooth flank for receiving lubricating oil. It is known to add particulate solid lubricants, such as graphite or M0S2, to liquid lubricants, for example lubricating oil, in order to improve the lubricating properties and reduce the friction between the lubricated friction partners.

[0011] From US 2022 / 0364636 Al, a tooth of a gear is known, the rolling tooth flank of which has a first coating of titanium, chromium or diamond-like carbon (DLC) and a second coating applied to the first coating with a disulfide, in particular WS2 or M0S2.

[0012] From Konopka, D.; Pape, F.; Heimes, N.; Behrens, B.-A.; Möhwald, K.; Poll, G.

[0013] “Functionality Investigations of Dry-Lubricated Molybdenum Trioxide Cylindrical Roller Thrust Bearings” Coatings 2022, 12, 591. https: / / doi.org / 10.3390 / coatingsl2050591 An axial cylindrical roller bearing with rolling bearing rings is known, which incorporates a dry lubrication system based on molybdenum, for which a molybdenum (Mo) reservoir and molybdenum trioxide (MoOs) as a cover layer were applied by physical vapor deposition (PVD).

[0014] From CN 10825311 A a tooth of a gear is known, on the support surface of a tooth flank partial areas with microstructures are provided, wherein the microstructure has grooves filled with M0S2 which are covered by a cover layer, so that a self-lubrication of the tooth results under high temperature.

[0015] There is a constant need to reduce wear in a gear assembly.

[0016] The object of the invention is to demonstrate measures that enable a low-wear gear arrangement. This object is achieved by a tooth with the features of claim 1, a gear arrangement with the features of claim 8, a transmission with the features of claim 9, a gear coupling with the features of claim 12, a use with the features of claim 13, a use with the features of claim 14, and a data agglomerate with the features of claim 15.

[0017] Preferred embodiments are specified in the dependent claims and the following description, each of which, individually or in combination, can represent an aspect of the invention, the scope of protection being determined by the claims. If a feature is presented in combination with another feature, this serves only to simplify the presentation of the invention and is in no way intended to imply that this feature cannot also constitute a further development of the invention without the other feature.

[0018] One aspect of the invention relates to a tooth for a gear arrangement for load transmission, with a support surface for support against a second tooth, wherein at least in the support surface a solid lubricant layer system is provided, wherein the solid lubricant layer system has an inner reservoir layer comprising at least one metallic element and a cover layer forming an outer surface of the solid lubricant layer system, wherein the cover layer comprises a metal oxide formed from the metallic element of the reservoir layer as a solid lubricant and abrasively separated metal oxide elements of the cover layer can be regenerated by oxidation of the metallic elements of the reservoir layer.

[0019] It has been recognized that in a gear assembly, it is possible to use solid lubrication instead of oil or grease lubrication by employing a metal oxide as the solid lubricant. This oxide can be generated and / or regenerated through tribo-oxidation of metallic elements beneath the bearing surface. However, if steel and / or an iron-containing material is used for the surface of each tooth in a gear assembly—that is, the first tooth of the first gearing partner and the second tooth of the second gearing partner—there is a risk that the iron (Fe) in the material will oxidize to rust (FeO, Fe₂O₃) during tribo-oxidation, leading to additional abrasion in the bearing surface.The invention is based on the finding that there are also metal oxides, for example MoOs, which not only do not lead to abrasive wear, but even qualify as solid lubricants and whose presence can have a friction-reducing effect. If part of the surface layer is subject to abrasive wear, the abrasically separated solid lubricant particles from the surface layer do not lead to an increase in wear, but rather to a reduction in friction and / or a reduction in further wear.

[0020] Simultaneously, it is even possible that the abrasically separated solid lubricant particles are regenerated by tribo-oxidation, which is normally considered a damage mechanism. This occurs through the oxidation of the metallic elements, particularly those present in elemental and / or metallic form, from the reservoir layer, thereby regeneratively replacing the abrasically separated solid lubricant particles. The top layer can migrate into the reservoir layer through tribo-oxidation and restore a sufficiently large layer thickness at the expense of the reservoir layer. Deeper areas of the reservoir layer can be protected from oxidation processes by the oxidation of the metallic elements at the edge of the reservoir layer facing the top layer. Thus, the structural integrity and chemical composition of the reservoir layer, which may have shrunk slightly in thickness, are not significantly affected.

[0021] If a metal oxide forming the solid lubricant is abraded away, it is initially possible that the detached metal oxide element will be pressed back into the bearing surface. If the detached metal oxide element is completely removed from the gear area, this solid lubricant particle can no longer cover the outer surface of the coating layer, allowing atmospheric oxygen to penetrate the coating layer more easily. When this atmospheric oxygen, having penetrated the coating layer, encounters a metallic element in the reservoir layer, tribo-oxidation can oxidize the metallic element, specifically to the metal oxide that constitutes the solid lubricant. This process replaces and regenerates the removed solid lubricant particle without requiring any repair or maintenance.

[0022] It was also recognized that in a gear arrangement, applications can occur where significantly lower surface pressures and significantly lower temperatures and heat generation can occur compared to an axial cylindrical roller bearing. This results in less abrasive wear, while the operating conditions still allow for the regeneration of abrasively separated solid lubricant particles through tribo-oxidation. Furthermore, in a gear arrangement, significantly less contacting sliding and / or relative movement under load is to be expected compared to an axial cylindrical roller bearing, leading to considerably lower wear effects. Likewise, cold welding in the area of ​​the bearing surfaces of the pressed teeth is not expected under the anticipated operating conditions of the gear arrangement.Under the loads and operating conditions expected in the gear assembly, timely regeneration of the relatively small amount of solid lubricant particles that have been detached can occur even with a comparatively slow tribo-oxidation kinetics of the metallic elements from the reservoir layer. Therefore, compared to an axial cylindrical roller bearing, the lower surface pressure in the gear assembly allows for less wear due to abrasion. However, the temperature and the remaining lower surface pressure are still sufficient for the slower tribo-oxidation kinetics to enable timely regeneration of the correspondingly smaller amount of solid lubricant particles, thus achieving a particularly long maintenance-free service life for the gear assembly.Under typical operating conditions in the gear arrangement, the solid lubricant in the tooth's surface layer can be easily regenerated by tribo-oxidation of the metallic elements from the reservoir layer of the tooth, thus enabling a low-wear lubricated gear arrangement.

[0023] The tooth can be a power transmission element of a gearing partner, for example, a radially outwardly projecting portion of a gear or rack, a radially inwardly projecting portion of a ring gear, or an axially projecting portion of an axial gear (“Hirth gear”). The tooth can interact with a second tooth of another gearing partner to transmit power; this tooth is hereinafter also referred to as the “first tooth” to better distinguish it from the other “second tooth.” Preferably, the second tooth is designed analogously to the tooth interacting with it (the first tooth). The first and second teeth can, in particular, be based on involute gearing, optionally with a flank correction to modify the involute gearing. However, other gearing configurations are also possible.

[0024] The gear arrangement establishes a meshing connection between two separately designed gear teeth by having at least one first tooth of the first gear tooth press against the tooth flank of at least one second tooth of the second gear tooth to transmit or support a load. In this gear arrangement, for example, two gears can form a spur gear, an internal gear can mesh with an external gear, or a pinion can interact with a rack. The first and second gear teeth can perform a relative motion with each other, in which the first tooth rolls on the second tooth, and a subsequent first tooth rolls on the subsequent second tooth, and so on.However, it is also possible that in the gear arrangement the gear partners are stationary relative to each other and primarily only support static loads, whereby the static loads can change in magnitude, which can result in slight relative movements of the pressed-on support surface of the teeth due to elastic deformations of the teeth under the applied load.

[0025] The bearing surface is a surface area of ​​the first tooth and / or the second tooth where the teeth are pressed against each other during load transmission. Typically, the bearing surface is located exclusively on the tooth flanks. If the gear arrangement is designed for only one load direction, it is even possible for only one tooth flank of a tooth to be used as the bearing surface, so that it may be sufficient to apply the solid lubricating layer system to only one tooth flank of the respective tooth. In particular, both tooth flanks of the respective tooth, and preferably the entire outer surface of the tooth, can be provided with the solid lubricating layer system to simplify manufacturing.Preferably, the solid lubrication system is provided either only on the at least one tooth or only on the at least one second tooth, so that it is possible to provide the solid lubrication system only on one of the gear partners of the gear arrangement, thereby keeping the manufacturing effort for the gear arrangement low.

[0026] The solid lubricant system is specifically free of oil, grease, or other separate lubricants. A friction-reducing effect, similar to lubrication between the pressed teeth in the bearing surface area, can be achieved solely by the solid lubricant present in the solid phase. Since the solid lubricant is a metal oxide, the metallic element intended for the solid lubricant can be stored in the reservoir layer and generated from the reservoir layer by oxidation, particularly tribo-oxidation, and embedded in the top layer.

[0027] The solid lubricant results in a lower coefficient of friction between the first and second teeth in the bearing surface area compared to the coefficient of friction at the same location without the solid lubricant. Metal oxides that lead to a higher coefficient of friction and / or increased wear, such as rust (FeO, Fe2Os), do not qualify as solid lubricants. Typically, the solid lubricant and the associated metal oxide exhibit a layered structure similar to graphite and / or a plate-like structure similar to PTFE.The surface pressure occurring in the support surface allows the solid lubricant to be pressed against the surface of the solid lubricant layer system and / or against an opposing support surface, whereby the surface pressures expected in a gear arrangement should be high enough that the solid lubricant can grip and / or clamp onto the unevenness of the existing surface roughness and prevent, for example, a relative movement of the pressed-together surfaces caused by elastic deformation.

[0028] It can slide more easily and with less wear from support surfaces on the flat surface of the solid lubricant, which has a lower coefficient of friction.

[0029] The reservoir layer of the solid lubricating system can be applied to the core of the respective tooth. The core of the tooth can be made of steel, onto which the reservoir layer can be applied, particularly by additive manufacturing and / or coating. Due to the metallic elements in the reservoir layer, good bonding of the reservoir layer to the steel material of the respective tooth can be expected. In particular, it can be provided that metallic elements have penetrated the steel material of the tooth by diffusion, thereby achieving a better bonding effect of the reservoir layer. The reservoir layer can, in particular, be composed of several superimposed layers to provide a layer thickness sufficient for the planned service life of the gear assembly.The reservoir layer is particularly preferably applied in a non-oxidizing atmosphere, for example with the aid of an inert protective gas, in order to avoid oxidation of the metallic elements in the reservoir layer.

[0030] The top layer of the solid lubricant system can form an outer surface of the system and the associated tooth that is exposed to the environment or mechanical contact in the support surface. The top layer is located outside the reservoir layer, while the reservoir layer is located inside the top layer. The top layer may be directly connected to the reservoir layer via a diffusion zone or bonded to the reservoir layer via an intermediate layer, preferably exactly one, which acts as an adhesion promoter. Due to the solid lubricant in the top layer, the outer surface of the top layer and the solid lubricant system can exhibit a particularly low coefficient of friction, thus achieving low wear due to abrasion with this type of solid lubrication.

[0031] The metallic element that is to react to form a metal oxide through oxidation is basically any chemical element that is located in the periodic table of elements to the left and below a dividing line from boron to astatine and in particular also includes the group of metalloids and can exist as a metallic bond in the solid phase.

[0032] Suitable metallic elements are characterized by the fact that their oxidized form can form a solid lubricant with a friction-reducing effect and can be oxidized by tribo-oxidation in a tribochemical reaction under the operating conditions expected in the gear arrangement.

[0033] Tribo-oxidation is the oxidation of a reactant under mechanical stress. Due to the operating conditions of the gear assembly, a temperature and pressure can exist in the area of ​​the pressed-together bearing surfaces of the adjacent teeth that permits the oxidation of a metallic element in the reservoir layer, accessible to atmospheric oxygen, to the metal oxide that forms the solid lubricant. In particular, it can be designed so that the metallic elements of the reservoir layer do not oxidize at normal pressure (1 bar) and room temperature (20°C), even when exposed to atmospheric oxygen, since insufficient activation energy for oxidation is present under such conditions. This ensures that no unintentional oxidation of the metallic elements of the reservoir layer occurs, but only tribo-oxidation during the operation of the gear assembly.

[0034] The operating conditions in the gear arrangement lead in particular to a maximum surface pressure p, which occurs, for example, during torque surges. ma x in the support area of ​​500 N / mm 2 < p ma x < 900 N / mm 2 , in particular

[0035] 600 N / mm 2 < p max < 700 N / mm 2 , while preferably in regular normal operation a surface pressure p of 150 N / mm² 2 < p < 500 N / mm 2 , in particular

[0036] p = 300 N / mm 2 ± 50 N / mm 2 prevails. Due to heat generation in the area of ​​the gear arrangement, under the operating conditions, a temperature T in the area of ​​the support surface of 20°C < T < 80°C, preferably 23°C < T < 50°C and particularly preferably 25°C < T < 30°C is assumed.

[0037] In particular, an intermediate layer is provided between the reservoir layer and the top layer to bond the top layer to the reservoir layer. This intermediate layer comprises a metal oxide formed from the metallic element of the reservoir layer, having a lower oxidation state than the metal oxide of the top layer. The intermediate layer preferably acts as an adhesion promoter between the top layer and the reservoir layer to ensure good bonding of the top layer. Furthermore, if the solid lubricant in the top layer is to be a metal oxide with a higher oxidation state, for example MoO₄, the oxidation of the metallic elements in the reservoir layer may initially produce a metal oxide with a lower oxidation state as an intermediate product, for example MoO₄, which remains in the intermediate layer until it is further oxidized to the solid lubricant with the higher oxidation state.Due to the similarity of the elements, good bonding of the layers and good mass transport of the fully or partially oxidized metallic element to the outer surface can be achieved, particularly through diffusion. The top layer preferably contains MoO₂ and / or MoO₃ as a solid lubricant, and / or the reservoir layer contains Mo as a metallic element. Investigations have shown that molybdenum as a metallic element in the reservoir layer can be oxidized to the solid lubricant MoO₂ and / or MoO₃ by tribo-oxidation, thus enabling automatic regeneration of the solid lubricant in the top layer. However, other metallic elements are also conceivable that, in their oxidized form, have a friction-reducing effect and can be generated by tribo-oxidation under the operating conditions occurring in the gear arrangement.

[0038] In particular, the top layer comprises PTFE and / or carbon, for example, graphite. In addition to the solid lubricant formed from the metal oxide, the top layer may also contain further friction-reducing components, which preferably also form a solid lubricant. This can, in particular, improve the bonding of the solid lubricant formed from the metal oxide, which is subsequently formed from the metallic elements of the reservoir layer. For example, PTFE and / or graphite layers pressed onto the support surface can make it more difficult for a metal oxide regenerated by tribo-oxidation to fall out of the layer matrix of the top layer, thus reducing the risk of loss of the solid lubricant formed from the metal oxide due to abrasive wear.

[0039] Preferably, the top layer and / or the reservoir layer comprises nanotubes, wherein the nanotubes in particular comprise carbon and / or molybdenum. The nanotube can, for example, be composed of carbon and / or molybdenum and be compressed layer by layer under pressure in the support surface, thereby providing a flat and abrasion-resistant surface design with a low coefficient of friction. Particularly preferably, the nanotube is at least partially filled with other components, for example, graphite and / or PTFE particles, which can be squeezed out of the nanotube under pressure and can also provide a friction-reducing effect in the vicinity of the nanotube. Particularly preferably, the top layer and / or the reservoir layer are applied by a coating process, in particular PVD.This makes it possible to create certain predefined layer thicknesses, if necessary by applying several layers on top of each other, for the top layer and / or the reservoir layer.

[0040] In particular, it is provided that the top layer has a layer thickness d of

[0041] 20 nm < d < 120 nm, in particular 40 nm < d < 100 nm and preferably 60 nm < d < 80 nm and / or the reservoir layer has a layer thickness D of 0.5 pm < D < 4.0 pm, in particular 0.8 pm < D < 2.0 pm and preferably 1.0 pm < D < 1.5 pm. With such dimensioning of the layer thicknesses, a long, in particular maintenance-free, service life for the gear assembly and the solid lubricant layer system can be expected.

[0042] Another aspect concerns a gear arrangement for load transmission, with a first tooth for introducing a load and a second tooth, which can be supported on a bearing surface against the first tooth, for discharging the load, wherein the first tooth and / or the second tooth is designed as a single tooth that can be configured and further developed as described above. Under typical operating conditions in the gear arrangement, the solid lubricant in the surface layer can be easily regenerated by tribo-oxidation of the metallic elements from the reservoir layer, thus enabling a low-wear lubricated gear arrangement of the transmission.

[0043] Another aspect concerns a transmission, particularly for a rail vehicle, with a gear arrangement that can be designed and further developed as described above for transmitting transmission power. Preferably, the gear arrangement is part of a spur gear. Particularly preferably, the gear arrangement is part of a planetary gear, wherein the planetary gear is a planet gear of a planetary gear set and a ring gear meshed with the planet gear. Under typical operating conditions in the gear arrangement of the transmission, the solid lubricant in the surface layer can be easily regenerated by tribo-oxidation of the metallic elements from the reservoir layer, thus enabling a low-wear lubricated gear arrangement of the transmission.

[0044] Another aspect concerns a gear coupling for connecting an input shaft to an output shaft, comprising an internal gear and an external gear supported on the internal gear, wherein a gear arrangement, which can be designed and further developed as described above, is located between the internal and external gears. The gear coupling can be incorporated into an industrial wind turbine. The wind turbine can be designed for industrial power generation and is generally dimensioned for a rated output of at least 2 MW, preferably at least 5 MW, and particularly preferably at least 15 MW, and is specifically designed for offshore operation. This implies a corresponding power density in the gearbox and corresponding dimensions for the components of the wind turbine, especially the gear arrangement as part of the gearbox.Preferably, the gear coupling is provided in the drive train of a rail vehicle, for example, in the power flow direction between a drive motor and / or gearbox on the one hand and a drive wheel on the other, in particular to create a rotatable and preferably also tiltable torque-transmitting connection of the drive wheel resting on a rail to a height-adjustable wagon. Compared to a relatively movable gear in a gearbox, the gear coupling exhibits particularly low relative movements in the area of ​​the Ab support surfaces. Under typical operating conditions in the gear arrangement of the gear coupling, the solid lubricant in the surface layer can be easily regenerated by tribo-oxidation of the metallic elements from the reservoir layer, thus enabling a low-wear lubricated gear arrangement of the gear coupling.

[0045] A further aspect of the invention relates to the use of a gear arrangement, which can be designed and further developed as described above, at a temperature and surface pressure sufficient for the oxidation of the metallic elements of the reservoir layer to the solid lubricant of the cover layer. Under typical operating conditions in the gear arrangement, the solid lubricant in the cover layer can be easily regenerated by tribo-oxidation of the metallic elements from the reservoir layer, thus enabling a low-wear lubricated gear arrangement.

[0046] A further aspect of the invention relates to the use of a gear arrangement, which can be designed and further developed as described above, at a temperature and surface pressure sufficient to transfer the solid lubricant of the coating layer from the first tooth to the second and / or from the second tooth to the first tooth. If a solid lubricant particle should detach from the coating layer, it is possible to press this solid lubricant particle into the bearing surface of the other tooth, thereby gradually coating the tooth not provided with the solid lubricant system. This allows the tooth that was not originally coated with a solid lubricant to acquire a friction-reducing surface, at least in certain areas. Abrasion of the coating layer can even lead to an additional friction-reducing lubricating effect due to the pressed-on solid lubricant.Under typical operating conditions in the gear arrangement, the solid lubricant in the cover layer can be easily regenerated by tribo-oxidation of the metallic elements from the reservoir layer, thus enabling a low-wear lubricated gear arrangement.

[0047] One further aspect concerns a data agglomerate with data packages combined in a common file or distributed across different files for representing the three-dimensional shape design and / or the interactions of all components provided in the tooth, which can be designed and further developed as described above, and / or in the gear arrangement, which can be designed and further developed as described above, wherein the data packages are prepared, when processed by a data processing device for operating a machine tool for the additive manufacturing of devices, for the additive manufacturing of the components of the tooth and / or the gear arrangement, in particular by 3D printing, and / or, when processed by a data processing device for carrying out a technical simulation, for a simulation of the functioning of the tooth and / or the gear arrangement.to perform simulations and output the simulation results generated for further use, in particular for the purpose of providing proof of fatigue strength as a function of variable loads and / or variable temperature stresses and, if necessary, to compare them with measurement data obtained on a real, manufactured device according to the invention and / or on a prototype of the device according to the invention. The data packages of the data agglomerate are specifically adapted to the inventive design of the respective device described above in order to adequately represent the interaction of the components of the device according to the invention during processing in the data processing unit. The data packages can, in particular, be stored in a spatially distributed manner, but are adapted to each other in such a way that, in the event that all data packages are combined in a common data processing unit,The data agglomerate thus assembled provides all the necessary data for additive manufacturing and / or technical simulation with the aid of the data processing device for the device according to the invention.

[0048] For example, the data packages are each separate parts of a data library ("Library"), which are combined to form the data agglomerate and are adapted to each other with respect to their relative dimensions and / or absolute dimensions and / or material properties corresponding to the respective device according to the invention. The data agglomerate can represent a virtual embodiment of the respective device according to the invention in the form of a so-called "digital twin," enabling a virtual investigation in the form of a simulation or a physical realization using an additive manufacturing process. Such a digital twin is, for example, presented in US 2017 / 286572 A1, the disclosure of which is hereby incorporated by reference as part of the invention.When the data processing unit of the machine tool processes the data agglomerate, the device according to the invention is produced, so that after the processing of the data agglomerate in the data processing unit the device according to the invention is obtained, at least in the form of a prototype.

[0049] In particular, each data package can represent a separately executed component of the respective associated device according to the invention, so that the individual components can be easily assembled in their relative position and / or relative mobility, both physically and / or virtually, in order to realize the interactions essential to the invention. In particular, it is possible, with the aid of the respective data packages, to produce the various components of the respective device separately and, if necessary, from different materials by additive manufacturing and subsequently assemble them into a prototype of the respective device.The division of the data of the data agglomerate into different data packages thus enables in a simple way a sequential additive manufacturing of components of the respective device that are movable relative to each other in the form of a kit of parts, which is prepared for the interaction of the components of the prototype according to the invention to solve the problem underlying the invention and can only be meaningfully assembled.

[0050] Additionally or alternatively, it is possible to use the data packets of the data agglomerate in a virtual environment during a technical simulation to calculate and / or predict the individual components of the respective device, their interactions, the physical state, and / or the changes in physical parameters depending on various boundary conditions and / or over time of the associated device according to the invention. This also allows for further use in verifying whether the device according to the invention, based on the assumed configuration and taking into account the assumed simulated influences, is sufficiently suitable for its intended purpose. If the data agglomerate is processed by a data processing device that models the simulation environment, it is possible to investigate the behavior of the device according to the invention, taking into account boundary conditions, particularly changing ones.This makes it possible, for example, to investigate centrifugal force effects on individual components of the device according to the invention as a function of various static and / or dynamic loads and / or different operating temperatures, whereby such simulation results can be incorporated into the creation of a fatigue strength analysis. Preferably, the simulation results obtained after processing the data agglomerate in the data processing unit for the simulation environment are stored in order to compare them with measurement data obtained from a real, manufactured device according to the invention and / or from a prototype of the device according to the invention. This makes it possible to assess the quality of the simulation results obtained using the data agglomerate and / or, particularly in the case of large deviations, to identify measurement errors and / or faulty measurements.This simplifies and improves non-destructive quality control of the device according to the invention.

[0051] The data agglomerate enables the cost-effective production of prototypes and / or computer-based simulations to study the functionality of the device under consideration, identify problems in the specific application, and find improvements. The solution to the problem underlying the invention can be easily and cost-effectively verified using the data agglomerate.

[0052] The invention is explained below by way of example with reference to the accompanying drawings and preferred embodiments, wherein the features shown below can represent an aspect of the invention, either individually or in combination, the scope of protection being defined by the claims. If a feature is shown in combination with another feature in the exemplary drawings and the accompanying description, this serves only to simplify the presentation of the invention and is not intended to imply that this feature cannot also be a further development of the invention without the other feature. The drawings show:

[0053] Fig. 1: a schematic sectional view of a double-jointed coupling for a rail vehicle, Fig. 2: a schematic perspective view of a tooth of a toothed coupling of the double-jointed coupling from Fig. 1 and

[0054] Fig. 3: a schematic sectional view of a detail of the tooth from Fig. 2.

[0055] The double-jointed coupling 10 for a rail vehicle shown in Fig. 1 can couple a wheel hub 12 rolling on a rail to a height-adjustable wagon. A gearbox and / or a drive motor can be provided in the height-adjustable wagon, with drive power being introduced via a spur gear into an external gear 14 of a housing 16 of the double-jointed coupling 10. The drive power can be transmitted via a first gear coupling 18, designed as a curved gear, to a tiltable shaft 19, in particular designed as a continuous hollow shaft, which transmits the drive power to the wheel hub 12 via a second gear coupling 20, in particular also designed as a curved gear and / or splined coupling. The spur gear with the external gear 14, the first gear coupling 18, and / or the second gear coupling 20 can be designed with a solid lubricant.

[0056] A first tooth 22, shown by way of example in Fig. 2, can be part of a first gearing partner of the solid-lubricated spur gear with the external gear 14, the first gear coupling 18, and / or the second gear coupling 20, and interact with a second tooth (not shown) of a second gearing partner. The first tooth 22 has a solid lubrication system 26 at least in a support surface 24 where the teeth are pressed together. The second tooth can also have a further solid lubrication system, wherein preferably only one of the interacting gearing partners has the solid lubrication system 26. Preferably, the solid lubrication system 26 is formed over the entire cylindrical surface 28 of the corresponding gearing partner enclosing the corresponding tooth, wherein preferably the axial sides of the gearing partner are also provided with the solid lubrication system 26.

[0057] As shown in Fig. 3, the solid lubricant system 26 can be applied to the material 29 of the first tooth 22, in particular steel. The solid lubricant system 26 has an inner reservoir layer 30, which is particularly adjacent to the material 29 of the first tooth 22 and which, for example, has a layer thickness D of approximately 2 pm. The solid lubricant system 26 also has a cover layer 32, which forms an outer surface 34 exposed to the environment and is connected directly or via an intermediate layer to the reservoir layer 30. The cover layer 32 has, for example, a layer thickness d of approximately 100 nm. The reservoir layer 30 and / or the cover layer 32 can, in particular, be connected to the respective adjacent material via diffusion zones. Preferably, the reservoir layer 30 and / or the cover layer 32 are applied as a PVD coating.

[0058] The reservoir layer 30 can contain metallic elements, in particular molybdenum (Mo), while the top layer 32, as a solid lubricant, comprises the corresponding metal oxide, in particular MoO₂ and / or MoO₃. If a metal oxide particle forming the solid lubricant should be lost, the metallic element from the reservoir layer 30 can be oxidized by tribo-oxidation and regeneratively replace the lost solid lubricant particle.

Claims

Patent claims 1. Tooth (22) for a gear arrangement for load transmission, with a support surface (24) for support against a second tooth, wherein at least in the support surface (24) a solid lubricant layer system (26) is provided, wherein the solid lubricant layer system (26) an inner reservoir layer (30) comprising at least one metallic element and a cover layer (32) forming an outer surface (34) of the solid lubricant layer system (26), characterized by the fact that the top layer (32) as a solid lubricant comprises a metal oxide formed from the metallic element of the reservoir layer (30) and Abrasively separated metal oxide elements of the cover layer (32) can be regenerated by oxidation of the metallic elements of the reservoir layer (30).

2. Tooth (22) according to claim 1, wherein an intermediate layer is provided between the reservoir layer (30) and the cover layer (32) for connecting the cover layer (32) with the reservoir layer (30), wherein the intermediate layer comprises a metal oxide formed from the metallic element of the reservoir layer (30) with a lower oxidation number than the metal oxide of the cover layer (32).

3. Tooth (22) according to claim 1 or 2, wherein the cover layer (32) comprises MoO2 and / or MoOs as a solid lubricant and / or the reservoir layer (30) comprises Mo as a metallic element.

4. Tooth (22) according to any one of claims 1 to 3, wherein the cover layer (32) comprises PTFE and / or carbon.

5. Tooth (22) according to any one of claims 1 to 4, wherein the cover layer (32) and / or the reservoir layer (30) comprises nanotubes.

6. Tooth (22) according to one of claims 1 to 5, wherein the cover layer (32) and / or the reservoir layer (30) are applied by a coating process.

7. Tooth (22) according to one of claims 1 to 6, wherein the cover layer (32) has a layer thickness d of 20 nm < d < 120 nm, in particular 40 nm < d < 100 nm and preferably 60 nm < d < 80 nm and / or the reservoir layer (30) has a layer thickness D of 0.5 pm < D < 4.0 pm, in particular 0.8 pm < D < 2.0 pm and preferably 1.0 pm < D < 1.5 pm.

8. Gear arrangement for load transmission, comprising a first tooth (22) for introducing a load and a second tooth which can be supported on the first tooth (22) on a support surface (24) for discharging the load, wherein the first tooth (22) and / or the second tooth is configured as a tooth according to one of claims 1 to 7.

9. Gearbox, in particular for a rail vehicle, with a gear arrangement according to one of claims 1 to 8 for transmitting a gearbox power.

10. Gearbox according to claim 9, wherein the gear arrangement is part of a spur gear.

11. Gearbox according to claim 9 or 10, wherein the gear arrangement is part of a planetary gear set, the planetary gear set being a planetary gear of a planetary gear set and a ring gear meshed with the planetary gear.

12. Gear coupling (18, 20) for coupling an input shaft to an output shaft, comprising an internal gear set and an external gear set supported on the internal gear set, wherein a gear arrangement according to claim 8 is formed between the internal gear set and the external gear set.

13. Use of a gear arrangement according to claim 8 at a temperature and surface pressure sufficient for the oxidation of the metallic elements of the reservoir layer (30) to the solid lubricant of the cover layer (32).

14. Use of a gear arrangement according to claim 8 at a temperature and surface pressure sufficient to transfer the solid lubricant of the cover layer (32) from the first tooth (22) to the second and / or from the second tooth to the first tooth (22).

15. Data agglomerate comprising data packages combined in a common file or distributed across different files for representing the three-dimensional shape design and / or the interactions of all components provided in the tooth (22) according to one of claims 1 to 7 and / or in the gear arrangement according to claim 8, wherein the data packages are prepared for this purpose. in processing by a data processing device for operating a machine tool for the additive manufacturing of devices, to carry out additive manufacturing of the components of the tooth (22) and / or the gear arrangement, in particular by 3D printing and / or in processing by a data processing device to carry out a technical simulation, to perform a simulation of the functioning of the tooth (22) and / or the gear arrangement and to output the simulation results generated in the process for further use, in particular for the purpose of providing proof of fatigue strength as a function of variable loads and / or variable temperature loads.

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