I. Velkavrh, Katharina Dimovski, F. Kafexhiu, Thomas Wright
In this work, an approach towards automated extraction and evaluation of static and kinematic coefficients of friction is presented. By replacing manual evaluation with an automated process, this approach yields promising results, simplifies data handling, and saves significant time. The methodology shows potential for application to a wide range of experimental data and provides advanced processing capabilities using the extracted and mathematically evaluated data points. However, for data with high signal- to-noise ratios, automatic detection still requires further optimization to improve accuracy.
{"title":"Enhanced Efficiency in Coefficient of Friction Evaluation through Automated Data Processing","authors":"I. Velkavrh, Katharina Dimovski, F. Kafexhiu, Thomas Wright","doi":"10.24053/tus-2023-0014","DOIUrl":"https://doi.org/10.24053/tus-2023-0014","url":null,"abstract":"In this work, an approach towards automated extraction and evaluation of static and kinematic coefficients of friction is presented. By replacing manual evaluation with an automated process, this approach yields promising results, simplifies data handling, and saves significant time. The methodology shows potential for application to a wide range of experimental data and provides advanced processing capabilities using the extracted and mathematically evaluated data points. However, for data with high signal- to-noise ratios, automatic detection still requires further optimization to improve accuracy.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46216647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface topography has a strong influence on friction in lubricated sealing contacts. In this context, FE contact simulations of measured representative surface sections are presented and compared with the wellknown Greenwood-Williamson contact model. Based on the FE simulation, the flow factors for the deformed gap topography are determined. This enables the consideration of real surface topography in EHD simulations of engineering parts.
{"title":"Untersuchung des Einflusses der Oberflächentopografie auf EHD-Kontakte mittels FE-Simulation","authors":"Martin Wittmaack, Markus André, Katharina Schmitz","doi":"10.24053/tus-2023-0012","DOIUrl":"https://doi.org/10.24053/tus-2023-0012","url":null,"abstract":"Surface topography has a strong influence on friction in lubricated sealing contacts. In this context, FE contact simulations of measured representative surface sections are presented and compared with the wellknown Greenwood-Williamson contact model. Based on the FE simulation, the flow factors for the deformed gap topography are determined. This enables the consideration of real surface topography in EHD simulations of engineering parts.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42541917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a procedure model for the experimental determination of wear coefficients by means of a two-disk tribometer. The approach presented allows any slide-to-roll ratios (SRR) to be set in order to be able to reproduce rolling-sliding contacts in addition to pure sliding contacts. The wear coefficients were calculated by means of tactile surface measurement on the one hand and gravimetric measurement on the other. Both methods show very good agreement. The tribometer tests presented are based on an application example from the field of roller bearing technology. Finally, the experimentally measured wear depths of the test discs are compared with a numerical wear simulation.
{"title":"Experimentelle Ermittlung von Verschleißkoeffizienten ölgeschmierter Kontakte an einem Zwei-Scheiben-Tribometer","authors":"A. Winkler, M. Bartz, S. Wartzack","doi":"10.24053/tus-2023-0013","DOIUrl":"https://doi.org/10.24053/tus-2023-0013","url":null,"abstract":"This paper presents a procedure model for the experimental determination of wear coefficients by means of a two-disk tribometer. The approach presented allows any slide-to-roll ratios (SRR) to be set in order to be able to reproduce rolling-sliding contacts in addition to pure sliding contacts. The wear coefficients were calculated by means of tactile surface measurement on the one hand and gravimetric measurement on the other. Both methods show very good agreement. The tribometer tests presented are based on an application example from the field of roller bearing technology. Finally, the experimentally measured wear depths of the test discs are compared with a numerical wear simulation.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47323801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wood is widely used in impact limiters of transport casks for radioactive material. Encapsulated by an outer and inner steel structure, spruce wood is often applied in layers of alternating direction. The friction at the interfaces between these layers is of crucial importance for the impact and energy absorption e.g., at an accidental impact of a cask against a hard component. In order to get detailed information for corresponding numerical calculations, in this study the friction coefficient for the combinations wood-wood and wood-steel was measured in the temperature range between -40 °C and 90 °C according to the relevant stress conditions for such casks. Results show decreasing friction with increasing temperature, ranging from 0.43 at -40 °C to 0.22 for 90 °C for wood-steel combinations and from 0.3 at -40 °C to 0.24 at 90 °C to for a wood-wood combination.
{"title":"Friction coefficients for wood-wood and wood-steel high pressure contact under temperatures between -40 °C and 90 °C","authors":"M. Neumann, T. Gleim, T. Gradt","doi":"10.24053/tus-2023-0007","DOIUrl":"https://doi.org/10.24053/tus-2023-0007","url":null,"abstract":"Wood is widely used in impact limiters of transport casks for radioactive material. Encapsulated by an outer and inner steel structure, spruce wood is often applied in layers of alternating direction. The friction at the interfaces between these layers is of crucial importance for the impact and energy absorption e.g., at an accidental impact of a cask against a hard component. In order to get detailed information for corresponding numerical calculations, in this study the friction coefficient for the combinations wood-wood and wood-steel was measured in the temperature range between -40 °C and 90 °C according to the relevant stress conditions for such casks. Results show decreasing friction with increasing temperature, ranging from 0.43 at -40 °C to 0.22 for 90 °C for wood-steel combinations and from 0.3 at -40 °C to 0.24 at 90 °C to for a wood-wood combination.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46254321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tristan Brückner, Hanno Paschke, Peter Kaestner, Isabella Hahn, Sabine Siebert, S. Weber
Sealless rolling bearings for use under media lubricated conditions are exposed to high tribocorrosive loads. To achieve the necessary wear resistance while keeping up the corrosion properties of the corrosion resistant steels low-temperature-plasma-diffusion-treatments were conducted. When scaling-up the developed low-temperature-plasma-nitriding-processes to industrial dimensions, it is necessary to reach the required surface conditions independently of the parts placement within the batch. Upscaling to industrial batch processes was analyzed by using the example of rolling bearings. To achieve a homogeneous treatment result, relevant factors like temperature distribution and component placement were taken into account. This allows to draw conclusions about the surface layer properties in dependence of temperature, batch arrangement and position within the batch to verify the treatment results homogeneity.
{"title":"Aus Wissenschaft und Forschung 13Tribologie + Schmierungstechnik · 70. Jahrgang · 2/2023DOI 10.24053/TuS-2023-0008 Untersuchungen zur wirtschaftlichen Nutzung von Niedertemperatur-Nitrier- prozessen durch Übertragung auf Behandlungen im industriellen Maßstab [POSEIDON (II)]","authors":"Tristan Brückner, Hanno Paschke, Peter Kaestner, Isabella Hahn, Sabine Siebert, S. Weber","doi":"10.24053/tus-2023-0008","DOIUrl":"https://doi.org/10.24053/tus-2023-0008","url":null,"abstract":"Sealless rolling bearings for use under media lubricated conditions are exposed to high tribocorrosive loads. To achieve the necessary wear resistance while keeping up the corrosion properties of the corrosion resistant steels low-temperature-plasma-diffusion-treatments were conducted. When scaling-up the developed low-temperature-plasma-nitriding-processes to industrial dimensions, it is necessary to reach the required surface conditions independently of the parts placement within the batch. Upscaling to industrial batch processes was analyzed by using the example of rolling bearings. To achieve a homogeneous treatment result, relevant factors like temperature distribution and component placement were taken into account. This allows to draw conclusions about the surface layer properties in dependence of temperature, batch arrangement and position within the batch to verify the treatment results homogeneity.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46168508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ivan Grozev, Sagar Dalal, Nazlim Bagcivan, Serhan Bastuerk, Christian Lueffe, Thomas Stahl
With the purpose of improving our predesign approach and increasing the end-product sustainability by going from resource wasting field testing to slender tribological model testing, we looked closer to commonly relevant calculation approaches as • Plint’s and Alliston-Greiner’s Energy Pulse (EP) • Matveesky’s friction power intensity (FPI) • Transmitted Energy (TE) to achieve fast and feasible tribo-system ranking for wind turbine bearing cases. With the concept of transmitted friction energy (Ef), satisfactory results were reached. We learned that 2-Disc tribometer may be used to simulate 100 % sliding, making comparison of different slippage rate easier by only using one tribometer, thus reducing measurement inaccuracies caused by different type of machines (e.g., pin on disc) or operator’s influence.
{"title":"Introduction With its higher efficiency than solar panels, wind power is a fast-growing worldwide industry, with over 650GW of capacity installed all over the world now. 1.9 GW of freshly installed offshore wind capacity brought the total German fleet to 56.1 GW in 2021. This makes up over 28.000 turbines for now with number rising. Aus Wissenschaft und Forschung 31Tribologie + Schmierungstechnik · 70. Jahrgang · 2/2023DOI 10.24053/TuS-2023-0010 Simplified tribological approach for predesign of…","authors":"Ivan Grozev, Sagar Dalal, Nazlim Bagcivan, Serhan Bastuerk, Christian Lueffe, Thomas Stahl","doi":"10.24053/tus-2023-0010","DOIUrl":"https://doi.org/10.24053/tus-2023-0010","url":null,"abstract":"With the purpose of improving our predesign approach and increasing the end-product sustainability by going from resource wasting field testing to slender tribological model testing, we looked closer to commonly relevant calculation approaches as • Plint’s and Alliston-Greiner’s Energy Pulse (EP) • Matveesky’s friction power intensity (FPI) • Transmitted Energy (TE) to achieve fast and feasible tribo-system ranking for wind turbine bearing cases. With the concept of transmitted friction energy (Ef), satisfactory results were reached. We learned that 2-Disc tribometer may be used to simulate 100 % sliding, making comparison of different slippage rate easier by only using one tribometer, thus reducing measurement inaccuracies caused by different type of machines (e.g., pin on disc) or operator’s influence.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135478570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Vorgerd, P. Tenberge, Alexander Thomas, Nadja Aufderstroth
Gear damage, e.g. scuffing, reacts sensitively to the local dissipation of frictional heat during a full gear mesh. Several empirical friction models have been established in relevant literature. These can be used to calculate the gear friction locally or averaged over a mesh. For calibration purpose, experimental data from twin disc machines with stationary contact conditions are mostly used. However, the assignment of the model as well as the consideration of topographical, rheological and geometrical effects is often subject to uncertainties. In this paper, a method is presented to measure the power losses of high-speed spur gears up to vt = 100 m/s. The measurement principle uses the calorimetric properties of the circulating lubricant. The implementation of the measurement setup in a highspeed gear test rig reduces thermal interferences from sealings and bearings. Analysis regarding the measurement quality show that the measurement method delivers reproducible results with a high measurement resolution over a wide range of operating conditions.
{"title":"Kalorimetrische Messung der Ver- zahnungsverlustleistung im Bereich hoher Umfangsgeschwindigkeiten","authors":"J. Vorgerd, P. Tenberge, Alexander Thomas, Nadja Aufderstroth","doi":"10.24053/tus-2023-0009","DOIUrl":"https://doi.org/10.24053/tus-2023-0009","url":null,"abstract":"Gear damage, e.g. scuffing, reacts sensitively to the local dissipation of frictional heat during a full gear mesh. Several empirical friction models have been established in relevant literature. These can be used to calculate the gear friction locally or averaged over a mesh. For calibration purpose, experimental data from twin disc machines with stationary contact conditions are mostly used. However, the assignment of the model as well as the consideration of topographical, rheological and geometrical effects is often subject to uncertainties. In this paper, a method is presented to measure the power losses of high-speed spur gears up to vt = 100 m/s. The measurement principle uses the calorimetric properties of the circulating lubricant. The implementation of the measurement setup in a highspeed gear test rig reduces thermal interferences from sealings and bearings. Analysis regarding the measurement quality show that the measurement method delivers reproducible results with a high measurement resolution over a wide range of operating conditions.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42532029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Siewerin, Johannes Schmelz, Karl J. Raddatz, T. Tobie, K. Stahl
In large gear drives, through-hardened ring gears or internal gears are often in contact with case-hardened pinions. This offers economic advantages, but involves an increased risk of wear during its operation. Various test methods exist to evaluate the expected wear of the used gear-lubricant-system, but typically with case-hardened gears only. A direct transfer of the test results to the application in field is not known so far. In this study, influences from different surface hardness and surface roughness values as well as lubricating conditions were systematically investigated on a FZG back-to-back test rig. The results prove a higher risk for strong wear for hard-soft gear pairings. Based on these results, a calculation method for the wear lifetime of gears was extended to allow an estimation of the wear lifetime of gear pairings with different surface hardness based on standard wear tests.
{"title":"Wear Calculation for Hard-Soft Gear Pairings Depending on Surface Hardness and Roughness","authors":"B. Siewerin, Johannes Schmelz, Karl J. Raddatz, T. Tobie, K. Stahl","doi":"10.24053/tus-2023-0004","DOIUrl":"https://doi.org/10.24053/tus-2023-0004","url":null,"abstract":"In large gear drives, through-hardened ring gears or internal gears are often in contact with case-hardened pinions. This offers economic advantages, but involves an increased risk of wear during its operation. Various test methods exist to evaluate the expected wear of the used gear-lubricant-system, but typically with case-hardened gears only. A direct transfer of the test results to the application in field is not known so far. In this study, influences from different surface hardness and surface roughness values as well as lubricating conditions were systematically investigated on a FZG back-to-back test rig. The results prove a higher risk for strong wear for hard-soft gear pairings. Based on these results, a calculation method for the wear lifetime of gears was extended to allow an estimation of the wear lifetime of gear pairings with different surface hardness based on standard wear tests.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47082459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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