TOOTH FOR A SPELLED TORQUE TRANSMISSION ARRANGEMENT AND METHOD FOR MAKING SUCH A TOOTH

Description

[0001] The invention relates to a tooth for a toothed torque transmission arrangement and a method for manufacturing such a tooth, by means of which a tooth engagement in the torque transmission arrangement, in particular a wind turbine gearbox, can be made noise-reduced. The invention further relates to a gear element with such a tooth, a wind turbine gearbox with such a tooth or such a gear element, a computer program for carrying out the method, and a data aggregate for additive manufacturing and / or simulation of the tooth or the gear element.

[0002] From EP 2 774 709 A2 it is known to provide a standardized tooth of a gear pair with a periodic waviness on its tooth flank in order to reduce vibrations caused by irregularities in the tooth mesh of the gear pair under load, thereby increasing uniformity in the tooth mesh and reducing running noise.

[0003] From DE 28 48 206 A1 it is known to provide the tooth flanks of gears with regularly arranged recesses in order to achieve a lubricating film that is as constant as possible between the tooth flanks in mesh, thereby preventing noise generation.

[0004] From US 2010 / 0071495 A1 it is known to provide the tooth flanks of gears with irregularly arranged recesses in order to achieve the highest possible lubricating film between meshing tooth flanks, thereby reducing wear.

[0005] There is a constant need to reduce noise emissions in torque transmission devices, especially gearboxes, that are disturbing to humans.

[0006] The purpose of the invention is to identify measures that enable a reduction of noise emissions in torque transmission devices that are disturbing to humans.

[0007] The problem is solved by a tooth having the features of claim 1, a gear element having the features of claim 8, a wind turbine gearbox having the features of claim 10, a method having the features of claim 11, a computer program product having the features of claim 14, and a data agglomerate having the features of claim 15. Preferred embodiments are specified in the dependent claims and the following description, each of which, individually or in combination, may represent an aspect of the invention. Where a feature is presented in combination with another feature, this serves only to simplify the presentation of the invention and is not intended to imply that this feature cannot also constitute a further development of the invention without the other feature, the scope of protection of the invention being defined by the independent claims.

[0008] One aspect of the invention relates to a tooth for a toothed torque transmission arrangement, with a tooth flank for torque exchange with a mating flank of a gearing partner, wherein the tooth flank has a periodically progressing tooth flank correction with a sinusoidal ripple having a locally progressing period length T, wherein a development of the sinusoidal ripple of the periodically progressing tooth flank correction defines a center line, wherein the periodic tooth flank correction is superimposed with a spatial microstructure, wherein the microstructure has local maxima and / or local minima with respect to the center line as well as a shortest distance t of t < T / 2 between the local maxima and / or the local minima, wherein the shape of the microstructure is dimensioned to generate additional structure-borne sound during the ongoing operation of the torque transmission arrangement.to mask a tonality in the radiated structure-borne sound.

[0009] The periodic tooth flank correction can, in particular, represent a tooth flank correction standardized according to ISO 21771[:2007], which forms a sinusoidal waviness along the surface of the tooth flank. This tooth flank correction, which is generally standardized, is additionally superimposed with the microstructure, which, however, is subordinate to the periodic tooth flank correction. The microstructure does not obscure the periodic tooth flank correction, but rather preserves it as clearly visible. Preferably, within the tolerance zones provided for this tooth flank correction, the microstructure can additionally form peaks and / or valleys in the otherwise essentially three-dimensional, but fundamentally flat in the developed representation, surface of the tooth flank correction. These peaks and / or valleys of the microstructure are particularly pronounced to such an extent that they exceed the intended roughness.At the same time, it is possible to define the peaks and valleys of the microstructure so subtly that the boundary conditions for the design of tooth flank corrections permissible according to ISO 21771[:2007] are not violated. In particular, the requirements for the load-bearing capacity of the tooth according to ISO 6336 are met by superimposing the tooth flank correction with the microstructure. When comparing a cross-sectional image of a tooth with tooth flank correction and with microstructures to a cross-sectional image of an otherwise identical tooth with the same tooth flank correction but without microstructures, the surface profile in the section plane of the tooth with microstructures exhibits a more irregular, especially shaky, pattern, comparable to the interference of superimposed waves.

[0010] In an independent invention not covered by the claims but useful for understanding the present invention, the tooth flank correction is not a periodic tooth flank correction having exactly one locally varying period length T, but rather a tooth flank correction permissible according to ISO 21771[:2007], which in particular need not be exclusively a periodic tooth flank correction having exactly one locally varying period length T. The intended tooth flank correction can also be a non-periodic tooth flank correction and, in particular, can have any of the shape described in ISO 21771[:2007]. The microstructure can therefore superimpose any tooth flank correction defined according to ISO 21771[:2007].This independent invention relates in particular to a tooth for a toothed torque transmission arrangement, with a tooth flank for torque exchange with a mating flank of a gear partner, wherein the tooth flank has a tooth flank correction according to ISO 21771[:2007], wherein the tooth flank correction is superimposed with a spatial microstructure, wherein in particular the microstructure has local maxima and / or local minima as well as a shortest distance t between the local maximum and / or a local minima, wherein the tooth flank has a height H between a root of the tooth and a head of the tooth along a surface normal of the head, wherein 0.00001 ≤ t / H ≤ 0.10, in particular 0.0001 ≤ t / H ≤ 0.05, preferably 0.0005 ≤ t / H ≤ 0.01 and particularly preferably 0.001 ≤ t / H ≤ 0.005 applies. This embodiment can be further developed and expanded as explained above and / or below.

[0011] In a further independent invention, which is not covered by the wording of the claims but is useful for understanding the present invention, no tooth flank correction is provided. The microstructure can thus directly superimpose a basic tooth flank shape intended for gearing without this basic shape being modified by a tooth flank correction according to ISO 21771[:2007]. The tooth flank in this embodiment is based in particular on a spur or helical tooth basic shape for involute or cycloidal gearing.This independent invention relates in particular to a tooth for a toothed torque transmission arrangement, comprising a tooth flank for torque exchange with a mating flank of a gearing partner, wherein the tooth flank is based on a basic shape intended for gearing, in particular involute gearing or cycloidal gearing, wherein the basic shape is superimposed by a spatial microstructure, wherein in particular a repeating pattern of the microstructure is formed by local maxima and / or local minima, wherein the local maxima and / or local minima are preferably arranged, in particular alternatingly, in a checkerboard pattern in rows and columns. This embodiment can be further developed and elaborated as described above and / or below.

[0012] It was recognized that while standardized, periodic tooth flank correction can reduce sound pressure or sound pressure level, the remaining frequencies in the radiated structure-borne sound can be very clearly audible to humans during gear meshing under load during torque transmission in the geared torque transmission assembly. The microstructures can blur the main frequencies occurring in the radiated structure-borne sound during a specific tooth flank correction and / or generate additional secondary frequencies, so that the main frequencies are no longer as clear and distinct. The microstructures thus primarily increase the proportion of white noise in the radiated structure-borne sound and, to a lesser extent, if at all, reduce the sound pressure of the radiated structure-borne sound.It has been recognized that increasing white noise can mask and obscure the perception of a specific frequency as noise in human hearing. Although the sound pressure of the radiated structure-borne sound has hardly changed, the blurring of the main frequencies and the increase in white noise can influence noise perception in human hearing. Thus, structure-borne sound radiated from teeth with flank correction but without microstructures can be perceived as disturbing noise, whereas structure-borne sound radiated from teeth with flank correction and microstructures, despite comparable sound pressure, is no longer perceived as disturbing noise.By shaping the microstructure, particularly by selecting the spacing of maxima and / or minima as well as their height and depth, the naturally occurring main frequencies can be modified and / or masked, and / or specific frequencies or frequency ranges with a defined bandwidth can be deliberately generated, thereby increasing the level of white noise in the radiated structure-borne sound. Increasing the white noise in the structure-borne sound radiated from the tooth using these microstructures enables a reduction in noise emissions in torque transmission devices that are disturbing to humans.

[0013] The tooth flank correction according to the invention, which differs from the tooth flank correction according to ISO 21771[:2007], makes it particularly possible to mask a tonality in the structure-borne sound emitted by wind turbines. The tonality in the structure-borne sound is a frequency that stands out from the frequency spectrum of the emitted structure-borne sound with respect to its loudness or loudness level, and which can be determined according to IEC 61400-11. In particular, with the standard basic tooth shape and the tooth flank correction according to ISO 21771[:2007], there is only exactly one tonality, although in principle two, three, four, or even more tones are possible. Typically, the number of tones present is very small, in particular less than five, preferably less than three.Through the tooth flank correction according to the invention, this tonality can be blurred, i.e., masked, over a wider frequency range by the generated additional white noise. As a result, the individual tonality can no longer be resolved by a person as a separate noise. By masking the tonality with the generated white noise around its frequency, this tonality is perceived by humans as less disturbing.When the frequency band determined according to IEC 61400-11 during the operation of an associated torque transmission arrangement, particularly in a wind turbine, is FFT-transformed (FFT: fast Fourier transform), a larger bandwidth is observed in the FFT image area for the tonality in the tooth flank correction according to the invention compared to the standard tooth flank correction. This means that the frequency range around the frequency of the tonality is wider in the tooth flank correction according to the invention compared to the tonality, which is depicted more sharply in the image area in the standard tooth flank correction. If necessary, the white noise in the tonality region can even reduce the amplitude of the frequency of the tonality through destructive interference.The microstructure is not intended to prevent noise generation, but rather to deliberately generate noise in the form of white noise. The aim is not to reduce the noise level of the radiated structure-borne sound by masking the resulting tonal variations, but rather to reduce its perception as disturbing noise by humans. Instead of reducing the generation of structure-borne sound, the perception of the radiated structure-borne sound is adjusted to be less disturbing by supplementing the frequency spectrum of the radiated structure-borne sound with additional audible frequencies in a way that positively influences the perception of a frequency that would otherwise be considered disturbing.This approach utilizes the understanding that not only the volume, but also the specific frequency spectrum in an audible sound has a significant influence on the human perception of a sound as disturbing or not disturbing.

[0014] The tooth can be a, preferably one-piece, part of a gear, rack, or other component that, in a meshed state, can exchange torque with the mating component to which it meshes. The tooth typically has a root connected to a base body and a head extending away from the base body, the root and head being connected via the tooth flank designed for torque transmission in a specific direction. In particular, two tooth flanks acting in opposite directions are provided, each capable of exchanging torque with the mating component in its respective direction. Preferably, the mating component also has at least one tooth designed according to the invention. The root and head can be connected to each other via end faces not designed for torque transmission.The periodic tooth flank correction and the spatial microstructure are particularly preferred only on those tooth flanks where a torque exchange also takes place in the designated application, so that unnecessary machining effort can be saved.

[0015] Tooth flank correction is a deliberate deviation from the tooth shape of a tooth that, without tooth flank correction, is based on a basic shape intended for a specific type of gear, such as involute or cycloidal gearing. Tooth flank correction is understood to be, in particular, a gear modification as presented and standardized in ISO 21771[:2007]. Tooth flank correction is characterized by a shape that can be described by a relatively simple mathematical formula, such as a sine function or polynomial function. For example, the gear modification, based on a developed representation of the basic tooth shape ("tooth flank development"), is designed as a waveform with a constant period or frequency and a constant amplitude, which can then be described by a simple sine function.The wave-shaped gear modification extends particularly along a straight direction of propagation, which is neither curved nor discontinuous in the developed representation of the basic tooth shape. Perpendicular to this direction of propagation, the wave shape is generally identical in all sectional views of the developed representation of the basic tooth shape.

[0016] The microstructure can form as a valley or depression and / or as a peak or elevation, relative to the unfolding of the sinusoidal undulation of the periodically occurring tooth flank correction. Since the unfolding of the sinusoidal undulation of the periodically occurring tooth flank correction defines the centerline, it is possible that microstructures created by a material-removing machining process, such as laser machining, will exclusively form depressions with minima. Furthermore, it is possible that an additive manufacturing process, such as sputtering, will exclusively produce elevations with maxima relative to the centerline defined by the unfolding.

[0017] Preferably, the microstructures have both depressions forming minima and elevations forming maxima, which are particularly preferably produced by a chipless forming process, for example, embossing. In particular, the microstructure has a plurality of distinct and spaced-apart sub-regions, each forming a depression or an elevation, resulting in a structured surface that is discontinuous and / or irregular along imaginary lines. These sub-regions have, for example, an area of ​​160 µm² to 740 µm², preferably in the range of 800 µm² to 1200 µm², and particularly preferably 1000 µm² to 3000 µm² or even larger, in order to mask audible tonal variations in the radiated structure-borne sound.Since the microstructure does not need to be optimized for improved lubrication, the depressions and elevations of the microstructure have significantly different dimensions compared to surface structures designed for improved lubrication.

[0018] The microstructure, based on a flattened representation of the tooth shape resulting from the tooth flank correction ("tooth flank correction flattening"), can exhibit a plurality of locally distributed maxima and / or minima, which are arranged regularly, but preferably irregularly, relative to one another. With respect to the tooth flank correction flattening, the maxima and minima can have different spacings or deflections and / or different spacings. Preferably, in contrast to a tooth flank correction designed as a waveform, the maxima and minima of the microstructure are arranged not only in one direction of propagation, but in both surface directions of the tooth flank. The microstructure can, in particular, form a two-dimensional topology with respect to the tooth flank correction flattening.The maxima and / or minima of the microstructure are particularly larger and / or their deviation from the tooth flank correction pattern is greater than a typical roughness resulting after the tooth flank correction is generated. The microstructure does not represent a roughness that automatically arises from the tooth flank correction after its generation, but is deliberately created through an additional machining process. However, the machining process used to generate the microstructure may well result in an arbitrary or stochastically distributed arrangement of maxima and / or minima and / or achieve a lower roughness than the machining process used to generate the tooth flank correction.In particular, the microstructure is provided that a local maximum is located at a distance t from the nearest local minimum and / or from the nearest local maximum, and the tooth flank between a foot of the tooth and a head of the tooth has a height H along a surface normal of the head, wherein 0.00001 ≤ t / H ≤ 0.10, in particular 0.0001 ≤ t / H ≤ 0.05, preferably 0.0005 ≤ t / H ≤ 0.01 and particularly preferably 0.001 ≤ t / H ≤ 0.005.

[0019] The distance t is defined by a minimum distance between extreme values ​​of the microstructure, where the extreme values ​​in question can be maxima and / or minima. In the case of an alternating arrangement of maxima and minima, the distance t is defined by the distance between the lowest point of the minimum and the highest point of the adjacent maximum. However, it is also possible that, with respect to a development of the basic shape of the tooth or the tooth flank correction, two maxima and / or two minima are arranged one after the other. In this case, the distance t is defined by the distance between the highest points of the two adjacent maxima or by the distance between the lowest points of the two adjacent minima.In microstructure designs where the maximum and / or minimum is not formed by a single point, but by a plateau, a line or similar, the distance t is the shortest distance along a straight line that connects at least two points of the maximum or minimum across a height difference.

[0020] The distance t is particularly smaller than the expected deformation of the tooth under load. Preferably, the distance t is at least an order of magnitude smaller than the expected deformation of the tooth under load. In particular, 0.5 µm ≤ t ≤ 25 µm, preferably 1 µm ≤ t ≤ 20 µm, more preferably 5 µm ≤ t ≤ 15 µm, and most preferably 8 µm ≤ t ≤ 12 µm, for example, t = 10 µm ± 1 µm.

[0021] In particular, 0.00005 ≤ t / T ≤ 0.49, more specifically 0.0001 ≤ t / T ≤ 0.05, preferably 0.0005 ≤ t / T ≤ 0.01, and most preferably 0.001 ≤ t / T ≤ 0.005. This allows for local maxima and / or minima of the microstructure to occur within a single period T of the tooth flank correction by a factor of five, ten, or even more. This avoids audible beat frequencies in the radiated structure-borne sound and increases the level of white noise.

[0022] Preferably, the tooth flank correction has an amplitude A in the direction of a surface normal of the tooth flank, particularly the non-corrected one, and the microstructure has a deflection a in the direction of a surface normal of the tooth flank relative to the midline of the tooth flank correction, wherein 0.00005 ≤ a / A ≤ 0.50, particularly 0.0001 ≤ a / A ≤ 0.10, preferably 0.0005 ≤ a / A ≤ 0.05, and most preferably 0.001 ≤ a / A ≤ 0.01. The amplitude A of the tooth flank correction is determined relative to the base body of the tooth without tooth flank correction and in the direction of the respective surface normal of this tooth along the considered course of the tooth flank correction. Preferably, the amplitude of the tooth flank correction is the same in the direction of the surface normal and against the surface normal and oscillates around a center line of the tooth flank correction that coincides with the surface of the tooth without tooth surface correction.The deflection of the microstructure, i.e., the height of the local maximum and / or the depth of the local minimum, is small compared to the tooth flank correction development, so that the technical effect of the tooth flank correction is not impaired. Furthermore, the minima of the microstructure can be so small that a lubricant, especially lubricating oil, can easily adhere to the tooth flank through adhesion and / or capillary action. Under load, the maxima of the microstructure can be elastically deformed, resulting in a damping effect and improved running smoothness.

[0023] The microstructure can have a deflection a in the direction of a surface normal of the tooth flank, in relation to a tooth flank correction pattern and / or a tooth flank pattern, wherein the deflection a is, in particular, smaller than the expected deformation of the tooth under load. Preferably, the deflection a is smaller by at least an order of magnitude than the expected deformation of the tooth under load. In particular, 0.5 µm ≤ a ≤ 25 µm, preferably 1 µm ≤ a ≤ 20 µm, more preferably 5 µm ≤ a ≤ 15 µm, and most preferably 8 µm ≤ a ≤ 12 µm, for example, a = 10 µm ± 1 µm. The distance a to the respective developed surface determines the maximum height of a maximum and / or the maximum depth of a minimum relative to the developed surface as the reference height.

[0024] It is particularly preferred that the tooth flank correction and the microstructure extend uniformly across the entire tooth flank, both laterally and longitudinally. The lateral direction runs parallel to a designated axis of rotation of an associated gear, while the longitudinal direction runs from the tooth root to the tooth tip. The lateral and longitudinal directions are essentially perpendicular to each other. This avoids the formation of distinct sub-areas of the tooth flank that could be differentiated, for example, by differing light reflection properties. This prevents the occurrence of unpredictable effects on noise behavior caused by abrupt changes in surface texture between two sections of the tooth flank.

[0025] In particular, the microstructure along the tooth flank correction is aperiodic, specifically randomly and / or stochastically distributed. This non-periodic distribution of maxima and minima in the microstructure prevents vibrations caused by the microstructure itself, which could lead to audible structure-borne sound. Instead, it can increase the level of white noise.

[0026] Preferably, the microstructure is designed such that, when comparing a tooth with these microstructures to an otherwise identical tooth without microstructures, a Fast Fourier Transform (FFT) of the structure-borne sound emitted by the tooth with microstructures, with otherwise identical torque transmission in the same toothed torque transmission arrangement, shows a wider bandwidth of at least one frequency maximum of the tonality in the image area of ​​the Fast Fourier Transform. The tooth according to the invention thus exhibits a different acoustic property compared to a standard tooth without a microstructure, which includes a masking of the audible tonality by an increased bandwidth of the tonality in the image area of ​​the FFT, achieved with the aid of the microstructure.The emitted structure-borne sound can be represented by a frequency spectrum determined according to IEC 61400-11, which is considered within the image area of ​​the FFT. Due to the larger bandwidth, the lower and higher adjacent surrounding frequency lines of the tooth with microstructure are boosted, for example, within a frequency range of + / - 100 Hz, around the considered frequency maximum of the main frequency, thus increasing masking on the left and right sides of the frequency maximum. Additionally or alternatively, the microstructure generates additional secondary frequencies beyond those that would also occur without the microstructure. In particular, the amplitude of the secondary frequency is significantly smaller, for example, by an order of magnitude, than the amplitude of the nearest main frequency in the image area. Furthermore, the secondary frequency also exhibits a larger bandwidth than the main frequency without the microstructure.Without microstructure, the structure-borne sound radiated from the tooth under load results in discrete, superimposed frequencies. In the FFT image, each of these frequencies appears as a very narrow amplitude peak at a specific frequency, with a very small bandwidth at best. However, microstructures can blur this frequency, broadening the bandwidth and introducing slight deviations. The original main frequency, which still represents the maximum of the respective bandwidth, becomes less distinct and noisier. Consequently, the respective frequency is perceived as less disturbing by the human ear.

[0027] The tooth flank is preferably based on a straight or oblique tooth shape for involute or cycloidal toothing. The superimposition of the tooth flank correction with the microstructure can be applied to a wide variety of different tooth shapes. Restriction to a specific tooth shape is not necessary.

[0028] A further aspect of the invention relates to a gear element, in particular a gear or rack, for a toothed torque transmission arrangement with a plurality of teeth, which can be designed and further developed as described above, wherein the tooth flank correction has an amplitude A in the direction of a surface normal of the non-tooth flank-corrected tooth flank and the microstructure has a deflection a in the direction of a surface normal of the tooth flank relative to the center line of the tooth flank correction, wherein microstructures are formed differently for at least one tooth flank of different teeth with respect to their distance t and / or their deflection a and / or the periodic tooth flank correction of these teeth is shaped substantially differently, in particular with respect to the period length T and / or a phase offset between these teeth.By increasing the white noise in the structure-borne sound emitted by the tooth of the gear element using microstructures, a reduction of noise emissions in torque transmission devices that are disturbing to humans is made possible.

[0029] In another embodiment, the tooth pitch of the gear element is variable in the circumferential direction. This means that the distance between two teeth in the circumferential direction can differ. The difference in the circumferential direction is, in particular, less than 1° for the circumferential angle. This can reduce periodic noise behavior, thereby increasing the frequency spectrum of the radiated structure-borne sound and thus also the level of white noise.

[0030] In particular, the tooth flanks with differently shaped microstructures exhibit essentially the same mean roughness Ra and / or essentially the same square roughness Rq. This can result in successive teeth of the gear element exhibiting at least slightly different noise characteristics. Especially at high speeds, when the subsequent gear meshing events alternate rapidly, this can further increase the level of white noise.

[0031] Another aspect of the invention relates to a wind turbine gearbox for a wind turbine, particularly one installed in a populated area, comprising at least one gear element that can be designed and further developed as described above. By increasing the white noise in the structure-borne sound radiated by the tooth using microstructures, a reduction in noise emissions from the wind turbine gearbox that are disturbing to humans is made possible. This allows a wind turbine to be positioned closer to a populated area without disturbing the residents with noise perceived as such. This, in turn, makes it possible to increase the number of onshore wind turbines, even in populated areas, and to increase the share of renewable energy in a region's energy mix without disturbing residents and consumers.In particular, this can increase the share of locally generated energy for neighboring consumers, thereby avoiding power losses resulting from energy transmission over long distances.

[0032] A further aspect of the invention relates to a method for manufacturing a tooth, which can be designed and further developed as described above, or a gear element, which can be designed and further developed as described above, in which a tooth whose tooth shape is based on involute or cycloidal gearing is provided on at least one tooth flank with a periodically progressing tooth flank correction and a spatial microstructure superimposed on the tooth flank correction, wherein the tooth flank correction is produced by a mechanical machining process, in particular grinding, polishing and / or honing. The tooth flank correction can be carried out in a conventional manner without the production of the microstructures having a negative influence on it.By increasing the white noise in the structure-borne sound emitted by the tooth using microstructures, a reduction in noise emissions in torque transmission devices that are disturbing to humans is made possible.

[0033] Preferably, the microstructures are generated after the tooth flank correction. Additionally or alternatively, the generation of the basic tooth shape and the tooth flank correction can be performed at least partially simultaneously. This allows for the mass production of teeth with tooth flank correction, with the microstructure only being generated in an additional finishing step for those applications where there is a risk of noise pollution from structure-borne sound. In applications where noise pollution is not a concern, such as wind turbine gearboxes intended for offshore wind farms, the finishing step of generating microstructures can be omitted. This enables cost-effective manufacturing.

[0034] Microstructures are preferably created by embossing, laser processing, and / or electrical discharge machining (EDM). Embossing allows structures to be mechanically created on the tooth flank surface after flank correction, for example, by piercing, scribing, knurling, and / or pressing or rolling a negative mold of the microstructure. Laser processing, in particular, allows a portion of the tooth flank surface to be removed by applying energy at a specific point, for example, by vaporization. The size and / or depth, as well as the local energy input, can be easily adjusted by appropriately focusing a laser beam. Laser processing enables the creation of virtually any shape and distribution of maxima and minima for the microstructure.In erosion, for example, spark erosion uses a localized energy input to remove a portion of the tooth's material from the surface of the tooth flank. In chemical erosion, this can be achieved through a chemical reaction, such as etching.

[0035] Another aspect of the invention relates to a computer program product comprising commands which, when the program is executed by a data processing unit of a machine tool, cause the machine tool to execute the method, which can be developed and further refined as described above. By increasing the white noise in the structure-borne sound radiated from the tooth using the microstructures, a reduction in noise emissions in torque transmission devices that are disturbing to humans is made possible.

[0036] One aspect further concerns a data agglomerate with data packages summarized 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, or in the gear element, which can be designed and further developed as described above, wherein the data packages are prepared for additive manufacturing of the components of the tooth or gear element, in particular by 3D printing, when processed by a data processing device for operating a machine tool for the additive manufacturing of devices.to perform and / or, in the case of processing by a data processing device for the purpose of carrying out a technical simulation, to perform a simulation of the functioning of the tooth or the gear element and to output the simulation results generated thereby 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 with measurement data obtained on a real produced 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 according to the invention described above.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 be stored in a spatially distributed manner, but adapted to one another in such a way that, if all data packages are combined in a common data processing unit, the resulting data agglomerate provides all the necessary data for additive manufacturing and / or technical simulation using the data processing unit for the device according to the invention. For example, the data packages are each separate parts of a data library ("Library").which are combined to form the data agglomerate and 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 shown, for example, in US 2017 / 286572 A1, the disclosure of which is hereby incorporated by reference as part of the invention.

[0037] 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.

[0038] 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 can be moved 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 then only be meaningfully assembled.

[0039] Additionally or alternatively, it is possible to use the data packages 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 with the help of the data agglomerate and / or, in particular in the case of particularly 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.

[0040] The data agglomerate enables cost-effective prototyping and / or cost-effective computer-based simulation to study the functionality of the tooth and / or gear element, identify problems in specific applications, and find improvements. The solution to the problem underlying the invention can be easily and cost-effectively verified using the data agglomerate.

[0041] The invention is explained below by way of example with reference to the accompanying drawings and preferred embodiments. If a feature is shown in combination with another feature in a specific embodiment, this serves only to simplify the presentation of the invention using that embodiment and is not intended to imply that this feature cannot also be a further development of the invention without the other feature, the scope of protection of the invention being defined by the independent claims. The drawings show: Fig. 1 : a schematic perspective view of a tooth, Fig. 2 : a schematic detail view of Detail II from Fig. 1 , Fig. 3 : a schematic sectional view of the tooth made of Fig. 2 in a tooth flank development, Fig. 4 : a schematic sectional view of the tooth made of Fig. 2 in a tooth flank correction procedure, Fig. 5 : a schematic sectional view of a first alternative to the tooth made of Fig. 2 in a tooth flank correction procedure, Fig. 6 : a schematic sectional view of a second alternative to the tooth made of Fig. 2 in a tooth flank correction procedure, Fig. 7 a) - l) : schematic perspective views of a tooth with different shapes of microstructures, Fig. 8 : a schematic qualitative representation of an image area of ​​an FFT of a frequency spectrum of a wind turbine gearbox with standard teeth and Fig. 9 : a schematic qualitative representation of the frequency spectrum from Fig. 8 , which could result in a wind turbine gearbox with teeth according to the invention.

[0042] The in Fig. 1 The tooth 10 shown can, in particular, be part of a gear for a wind turbine gearbox of an (inland) wind turbine, where noise pollution affecting people is to be avoided. The tooth 10 has a root 12, which can be integrally connected to a disc-shaped body of a gear, and a radially outward-facing head 14. The root 12 and the head 14 can be connected via axially oriented end faces 16. Furthermore, the root 12 and the head 14 can be connected via tangentially oriented tooth flanks 18. In the illustrated embodiment, the tooth 10 has a basic shape 20, as used for involute gearing. At least one tooth flank 18, preferably both tooth flanks 18, are provided with a standardized tooth flank correction 22, which in the illustrated embodiment is a periodically oscillating waveform.In the illustrated embodiment, a wavefront of the tooth flank correction 22, which is designed as a waveform, is slightly chamfered to a width b of the tooth 10, so that straight lines 24 passing through points in phase with the waveform are also chamfered. Alternatively, the tooth flank correction 22 can be designed as any tooth flank correction 22 according to ISO 21771[:2007].

[0043] Just as the basic form 20 of tooth 10 is superimposed by the tooth flank correction 22, the tooth flank correction 22 is in turn superimposed by a microstructure 26 which is in Fig. 2 is shown in detail. In the tooth flank correction development, the tooth flank correction 22 defines a center line that is used as a reference for the shape design of the microstructure 26. The in Fig. 2 The detail shown depicts a portion of the tooth flank 18, extending over approximately 90% of a quarter period (T / 4) of the wave-shaped tooth flank correction 22. For simplified explanation, see in Fig. 2 In the illustrated embodiment of the microstructure 26, maxima 28 and minima 30 are arranged alternately side by side and one behind the other in a rectangular row-and-column structure, in particular in a checkerboard pattern and / or similar to tiles. Alternatively, the microstructure 26 can, for example, have only maxima 28, only minima 30, or both maxima 28 and minima 30. The maxima 28 and minima 30 can follow a sinusoidal structure, wherein the maxima 28 and minima 30 have exactly the same distances t and exactly the same deflections a relative to each other, and occupy exactly the same area within the tooth flank 18. Preferably, the course of the rows and columns of the microstructure 26 is inclined relative to the wavefront of the tooth flank correction 22 and the straight line 24.Such a microstructure 26 can be produced, for example, by imprinting a rolling negative form on the surface of the tooth flank 18 after the creation of the tooth flank correction 22.

[0044] As in Fig. 3 As shown, the tooth flank correction 22 exhibits a jittery pattern due to the superimposed microstructure 26. This jittery pattern results from the interference of the microstructure 26, which has a significantly shorter period and amplitude compared to the period and amplitude of the waveform-shaped tooth flank correction 22. As shown in Fig. 4 As shown, the microstructure 26 can have a sinusoidal shape.

[0045] As in Fig. 5 As shown, the microstructure 26 can also have a non-sinusoidal shape, for example, by generating the minima 30 of the microstructure 26 by laser processing or electrical discharge machining (EDM). The distances between the minima 30 can be equal, resulting in a periodic, but not sinusoidal, shape for the microstructure. Preferably, the distances between the minima 30 are of different sizes and are arbitrarily determined within defined limits. In particular, the depth of the respective minima 30 is different.

[0046] As in Fig. 6 As depicted, the microstructure 26 can be highly arbitrary and stochastically distributed with respect to the position of the minima 30 as well as their size and depth or height. Such a microstructure 26 can be produced, for example, by chemical erosion, such as etching.

[0047] As in Fig. 7 a) - l As shown in the figure, the microstructure 26 can have many different shapes and / or patterns. The respective tooth 10 can, in particular, be designed with or without tooth flank correction 22 according to ISO 21771[:2007]. The respective microstructure 26 can, for example, have only maxima 28, only minima 30, or both maxima 28 and minima 30, whereby the maxima 28 and minima 30 can, in particular, be arranged alternately with each other. However, it is also possible that the shortest distance t is defined by two consecutive maxima 28 and / or minima 30.

[0048] As in Fig. 8 As shown, a frequency spectrum 32 of a wind turbine gearbox with standard teeth, determined according to IEC 61400-11, can exhibit an amplitude profile 34 over a frequency 36. Here, a specific frequency stands out significantly with respect to its amplitude compared to the other frequencies and represents a tonality 38 in the measured radiated structure-borne sound. Within a frequency range 40 around the tonality 38, only frequencies with very low amplitudes are present.

[0049] As in Fig. 9 As shown, compared to the one in Fig. 8 In the frequency spectrum 32 shown, within the frequency range 40 around the tonality 38 as the main frequency, several secondary frequencies 42 are generated by the teeth 10 according to the invention in the manner of white noise. These secondary frequencies 42 have a lower amplitude than the tonality in the region of the main frequency, but a higher amplitude than most other frequencies in the frequency spectrum 32. If the tonality 38 as the main frequency is loud enough to be audible, the secondary frequencies 42 are also sufficiently audible to mask the tonality. The secondary frequencies 42 can form sidebands for the tonality 38, so that the bandwidth of the tonality 38 is broadened in the image area of ​​the FFT, which is shown for the sake of simplifying the representation of the secondary frequencies 42 in the Fig. 9 However, this only hints at the representation that actually results in the image area of ​​the FFT.

Claims

1. Tooth (10) for a toothed torque transmission assembly, having a tooth flank (18) for torque exchange with a counter flank of a meshing partner, wherein the tooth flank (18) has a periodically extending tooth flank correction (22) having a sinusoidal corrugation having a locally extending period length T, wherein a development of the sinusoidal corrugation of the periodically extending tooth flank correction (22) defines a centre line, characterized in that the periodic tooth flank correction (22) is overlaid with a spatial microstructure (26), wherein, with respect to the centre line, the microstructure (26) has local maxima (28) and / or local minima (30) and a shortest distance t of t < T / 2 between the local maxima (28) and / or the local minima (30), wherein the formation of the microstructure (26) is dimensioned for generating additional structure-borne sound during operation of the torque transmission assembly, in order to mask a tonality in the structure-borne sound emitted.

2. Tooth (10) according to Claim 1, wherein 0.00005 ≤ t / T ≤ 0.49, in particular 0.0001 ≤ t / T ≤ 0.05, preferably 0.0005 ≤ t / T ≤ 0.01, and particularly preferably 0.001 ≤ t / T ≤ 0.005.

3. Tooth (10) according to Claim 1 or 2, wherein the tooth flank correction (22) has an amplitude A in the direction of a surface normal of the non-tooth-flank corrected tooth flank (18) and the microstructure (26) has a deflection a in relation to the centre line of the tooth flank correction (22) in the direction of a surface normal of the tooth flank (18), wherein 0.00005 ≤ a / A ≤ 0.50, in particular 0.0001 ≤ a / A ≤ 0.10, preferably 0.0005 ≤ a / A ≤ 0.05, and particularly preferably 0.001 ≤ a / A ≤ 0.01.

4. Tooth (10) according to any one of Claims 1 to 3, wherein the tooth flank correction (22) and the microstructure (26) extend identically in area both in the width direction (b) and in the longitudinal direction of the tooth flank (18), in particular the entire tooth flank (18), wherein the width direction (b) extends parallel to a designated axis of rotation of an associated gear wheel and the longitudinal direction extends from the tooth base to the tooth head, wherein the width direction (b) and the longitudinal direction are aligned substantially at right angles to one another.

5. Tooth (10) according to any one of Claims 1 to 4, wherein a course of the microstructure (26) over the tooth flank correction (22) is formed aperiodically, in particular arbitrarily and / or randomly distributed.

6. Tooth (10) according to any one of Claims 1 to 5, wherein the microstructure (26) is designed such that, in a comparison of a tooth (10) with these microstructures (26) with an otherwise identical tooth (10) without microstructures (26), a Fast Fourier Transform of a structure-borne sound emitted from the tooth (10) with microstructures (26), with an otherwise identical torque transmission in the same toothed torque transmission assembly, has a greater bandwidth of the at least one frequency maximum of the tonality (38) in the image range of the Fast Fourier Transform.

7. Tooth (10) according to any one of Claims 1 to 6, wherein the tooth flank (18) is based on a straight-toothed or helical-toothed base shape (20) for evolvent teeth or cycloid teeth.

8. Toothed element, in particular a gear wheel or toothed rack, for a toothed torque transmission assembly having a plurality of teeth (10) according to any one of Claims 1 to 7, wherein the tooth flank correction (22) has an amplitude A in the direction of a surface normal of the non-tooth-flank corrected tooth flank (18) and the microstructure (26) has a deflection a in the direction of a surface normal of the tooth flank (18) in relation to the centre line of the tooth flank correction (22), wherein differently formed microstructures (26) are formed for at least one tooth flank (18) of various teeth (10) with respect to their distance t and / or their deflection a, and / or the periodically extending tooth flank correction (22) of these teeth (10) is formed substantially differently, in particular with respect to the period length T and / or a phase offset between these teeth (10).

9. Toothed element according to Claim 8, wherein the tooth flanks (18) having differently formed microstructures (26) have a substantially equal mean roughness Ra and / or a substantially equal square roughness Rq.

10. Wind power gear for a wind power plant, in particular erected in inhabited space, having at least one toothed element according to Claim 8 or 9.

11. Method for manufacturing a tooth (10) according to any one of Claims 1 to 7 or a toothed element according to Claim 8 or 9, in which a tooth (10), the tooth shape (20) of which is based on evolvent teeth or cycloid teeth, is provided on at least one tooth flank (18) with a periodically extending tooth flank correction (22) and a spatial microstructure (26) superimposed on the tooth flank correction (22), wherein the tooth flank correction (22) is created by a mechanical chip-removing method, in particular grinding, polishing, and / or honing.

12. Method according to Claim 11, in which the microstructures (26) are created chronologically after the creation of the tooth flank correction (22).

13. Method according to Claim 11 or 12, in which the microstructures (26) are created by embossing, laser machining, and / or eroding.

14. Computer program product comprising commands which, when the program is executed by a data processing device of a machine tool, cause it to carry out the method according to any one of Claims 11 to 13.

15. Data agglomerate comprising data packets which are combined in a common file or distributed across different files and intended for depicting the three-dimensional formation and / or the interactions of all constituent parts provided in the tooth (10) according to any one of Claims 1 to 7 or in the toothed element according to Claim 8 or 9, wherein the data packets are prepared so as, when they are processed by a data processing device for operating a machine tool for additive manufacturing of devices, to additively manufacture the constituent parts of the tooth (10) or toothed element, in particular by 3D printing, and / or when they are processed by a data processing device for carrying out a technical simulation, to carry out a simulation of the functioning of the tooth (10) or the toothed element and output thus generated simulation results for further use, in particular in order to provide a verification of the fatigue strength as a function of variable loads and / or variable thermal loading.