Water and solid particulate contamination are the two most common contaminants of lubricated systems and may be highly problematic for these systems. To reduce downtime and prevent failure, lubricant formulations contain detergent and dispersant additives that play an important role in terms of contamination tolerance. In lack of a practical procedure for the determination of the relevant properties, a novel method for the evaluation of the dispersing ability of lubricating oils is introduced. Following and combining established lubricant analysis methods, a procedure with optimum parameters was found. An assessment of the method using fresh and artificially altered lubricating oils allowed a differentiation concerning their dispersing ability.
{"title":"A novel method for the evaluation of the contamination dispersing ability of lubricants (CONTA-DISP)","authors":"Bettina Ronai, Rainer Franz, M. Frauscher","doi":"10.24053/tus-2021-0016","DOIUrl":"https://doi.org/10.24053/tus-2021-0016","url":null,"abstract":"Water and solid particulate contamination are the two most common contaminants of lubricated systems and may be highly problematic for these systems. To reduce downtime and prevent failure, lubricant formulations contain detergent and dispersant additives that play an important role in terms of contamination tolerance. In lack of a practical procedure for the determination of the relevant properties, a novel method for the evaluation of the dispersing ability of lubricating oils is introduced. Following and combining established lubricant analysis methods, a procedure with optimum parameters was found. An assessment of the method using fresh and artificially altered lubricating oils allowed a differentiation concerning their dispersing ability.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47128008","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}
The service life of functional surfaces subjected to rolling loads is limited by fatigue or insuffi cient separation of the rolling partners in the event of inadequate lubrication. These failure mechanisms can be counteracted by hard rolling and thus the introduction of residual compres sive stresses into the border zone, which can, among other things, extend maintenance intervals of production or power generation plants.
{"title":"Hartwalzen zur Festigkeitssteigerung wälzbelasteter Funktionsflächen","authors":"H. Hochbein, Sascha Appelt","doi":"10.24053/tus-2021-0019","DOIUrl":"https://doi.org/10.24053/tus-2021-0019","url":null,"abstract":"The service life of functional surfaces subjected to rolling loads is limited by fatigue or insuffi cient separation of the rolling partners in the event of inadequate lubrication. These failure mechanisms can be counteracted by hard rolling and thus the introduction of residual compres sive stresses into the border zone, which can, among other things, extend maintenance intervals of production or power generation plants.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45935057","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}
Sebastian Sklenak, Jens Brimmers, C. Brecher, Bastian Lenz, A. Mehner
For special applications, the lubrication of gearboxes with liquid lubricants is not feasible. Liquid lubricants lose their positive lubricating properties when exposed to high contact stress and temperature fluctuations, for example. In the food industry and medical technology, liquid lubricants are often not permitted due to hygiene regulations. Solid lubricants offer an approach to implement dry tooth contacts. In this report, three different solid lubricant coating systems are investigated under different operating conditions. The focus of the experi mental investigation is the application behavior in terms of friction force and wear behavior. In a direct comparison, the MoS2:Ti-TiN coating system achieves the highest load level and exhibits a station ary frictional force behavior compared to the a-C:H:Ti-TiN coating system. In the wear investigation, continuous coating wear was found in addition to coating delamination. The layer wear correlates with an increasing friction force in interval operation.
{"title":"Tribologisches Einsatzverhalten von PVD-Festschmierstoffsystemen im fluidfreien Wälzkontakt","authors":"Sebastian Sklenak, Jens Brimmers, C. Brecher, Bastian Lenz, A. Mehner","doi":"10.24053/tus-2021-0023","DOIUrl":"https://doi.org/10.24053/tus-2021-0023","url":null,"abstract":"For special applications, the lubrication of gearboxes with liquid lubricants is not feasible. Liquid lubricants lose their positive lubricating properties when exposed to high contact stress and temperature fluctuations, for example. In the food industry and medical technology, liquid lubricants are often not permitted due to hygiene regulations. Solid lubricants offer an approach to implement dry tooth contacts. In this report, three different solid lubricant coating systems are investigated under different operating conditions. The focus of the experi mental investigation is the application behavior in terms of friction force and wear behavior. In a direct comparison, the MoS2:Ti-TiN coating system achieves the highest load level and exhibits a station ary frictional force behavior compared to the a-C:H:Ti-TiN coating system. In the wear investigation, continuous coating wear was found in addition to coating delamination. The layer wear correlates with an increasing friction force in interval operation.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41722195","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}
Due to advances in power electronics and high-frequency process control, the technology of electrical discharge machining (EDM) has received a decisive technological boost in the last two decades to increase the achievable removal and cutting rates and to minimize the thermally influenced surface zone. At the same time, wire electrical discharge machining in particular has always been characterized by high achievable geometrical accuracy. In addition, a cup-shaped surface structure is formed in EDM as a result of the individual discharge points, which can offer targeted optimization potential with regard to tribological properties in rolling-sliding contacts. For this reason, the objective of this report is the knowledge of the contact fatigue strength of eroded surfaces in comparison to a ground reference with a focus on tribological contact conditions typical for gears.
{"title":"Wälzfestigkeit erodierter Oberflächen im Zwei-Scheiben-Zahnradanalogieversuch","authors":"D. Mevissen, Ugur Küpper, T. Berg","doi":"10.24053/tus-2021-0018","DOIUrl":"https://doi.org/10.24053/tus-2021-0018","url":null,"abstract":"Due to advances in power electronics and high-frequency process control, the technology of electrical discharge machining (EDM) has received a decisive technological boost in the last two decades to increase the achievable removal and cutting rates and to minimize the thermally influenced surface zone. At the same time, wire electrical discharge machining in particular has always been characterized by high achievable geometrical accuracy. In addition, a cup-shaped surface structure is formed in EDM as a result of the individual discharge points, which can offer targeted optimization potential with regard to tribological properties in rolling-sliding contacts. For this reason, the objective of this report is the knowledge of the contact fatigue strength of eroded surfaces in comparison to a ground reference with a focus on tribological contact conditions typical for gears.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45567542","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}
Lukas Lechthaler, F. Pohlkemper, Marie-Isabell Glaubke, Kees Egbers, T. Gries, A. Schneider, Daniel Kaußen, Marina Lehmann, K. Müll, G. Barroso
While carbon fibres can easily absorb forces in the fibre direction, they are extremely sensitive to transverse stress due to their anisotropic material behaviour. During the manufacturing process, unavoidable transverse stresses are induced in the fibre by the drive and deflection godets, which can damage or destroy individual filaments of the roving. The demand for a surface that is gentle on the fibre is offset by the static friction required between the fibre and the godet in order to drive the fibre. The aim of the CarboGerd research project is therefore to develop and validate an optimal godet coating for fibre-protecting and quality-assuring carbon fibre production. For this purpose, both typical coatings (ceramic, Topocrom coatings) and unconventional solutions (elastomer, PACVD coatings) are being tribologically investigated on a laboratory scale and validated on a prototype system.
{"title":"Faserschonende Carbonfaserproduktion durch innovatives Galetten-Oberflächen-Design - CarboGerd","authors":"Lukas Lechthaler, F. Pohlkemper, Marie-Isabell Glaubke, Kees Egbers, T. Gries, A. Schneider, Daniel Kaußen, Marina Lehmann, K. Müll, G. Barroso","doi":"10.24053/tus-2021-0017","DOIUrl":"https://doi.org/10.24053/tus-2021-0017","url":null,"abstract":"While carbon fibres can easily absorb forces in the fibre direction, they are extremely sensitive to transverse stress due to their anisotropic material behaviour. During the manufacturing process, unavoidable transverse stresses are induced in the fibre by the drive and deflection godets, which can damage or destroy individual filaments of the roving. The demand for a surface that is gentle on the fibre is offset by the static friction required between the fibre and the godet in order to drive the fibre. The aim of the CarboGerd research project is therefore to develop and validate an optimal godet coating for fibre-protecting and quality-assuring carbon fibre production. For this purpose, both typical coatings (ceramic, Topocrom coatings) and unconventional solutions (elastomer, PACVD coatings) are being tribologically investigated on a laboratory scale and validated on a prototype system.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48797009","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}
The influence of a friction hysteresis on the self-exciting in a particle-solid-system will be investigated by experiments and a numerical model. For this, a test rig will be presented. This test rig allows to measure the actual acting friction force. Furthermore, a numerical model will be presented which has a differentiation between a time-dependent friction behavior in sliding and sticking. Bigger differences can be observed in the system behavior – even with a quality similar curve of the measured friction hysteresis. For example, in a system with PVC-W particles exists a sharp boundary between an area of stable stick-slip oscillation and an area of subsiding oscillation. In comparison to this, a system with PMMA particles has a smooth transition region between these two areas. The followed simulation studies shown, that the selfexciting mechanism is a complex interaction between the time-dependent behavior during the sliding and sticking and the external average system velocity.
{"title":"Einfluss einer Reibhysterese auf selbsterregte Schwingungen von Partikel-Festkörper-Systemen","authors":"Thomas Fürstner, Matthias Kröger","doi":"10.24053/tus-2021-0020","DOIUrl":"https://doi.org/10.24053/tus-2021-0020","url":null,"abstract":"The influence of a friction hysteresis on the self-exciting in a particle-solid-system will be investigated by experiments and a numerical model. For this, a test rig will be presented. This test rig allows to measure the actual acting friction force. Furthermore, a numerical model will be presented which has a differentiation between a time-dependent friction behavior in sliding and sticking. Bigger differences can be observed in the system behavior – even with a quality similar curve of the measured friction hysteresis. For example, in a system with PVC-W particles exists a sharp boundary between an area of stable stick-slip oscillation and an area of subsiding oscillation. In comparison to this, a system with PMMA particles has a smooth transition region between these two areas. The followed simulation studies shown, that the selfexciting mechanism is a complex interaction between the time-dependent behavior during the sliding and sticking and the external average system velocity.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45665514","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}
At the IMKF, eight different elastomer compounds with different polymer compositions were examined for their demolding characteristics and mold fouling. Ten demolding cycles were carried out for each compound and the fouling of the mold was photo-technical recorded after ten demolding cycles. The used polymer composition does not seem to have any significant influence. However, the components of the compound have a significant influence on the friction characteristics while removing of the vulcanizate from the mold. Crosslinking that begins very early has an initiating influence on mold fouling. The measurable fluctuations in the maximum demolding force that occur could correlate with the internal friction of the polymer with the filler.
{"title":"Einfluss der Polymerfunktionalisierung auf Adhäsion, Reibung und Formverschmutzung","authors":"Matthias Kröger, Stefan Haupt, J. Krüger","doi":"10.24053/tus-2021-0021","DOIUrl":"https://doi.org/10.24053/tus-2021-0021","url":null,"abstract":"At the IMKF, eight different elastomer compounds with different polymer compositions were examined for their demolding characteristics and mold fouling. Ten demolding cycles were carried out for each compound and the fouling of the mold was photo-technical recorded after ten demolding cycles. The used polymer composition does not seem to have any significant influence. However, the components of the compound have a significant influence on the friction characteristics while removing of the vulcanizate from the mold. Crosslinking that begins very early has an initiating influence on mold fouling. The measurable fluctuations in the maximum demolding force that occur could correlate with the internal friction of the polymer with the filler.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68958221","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}
The radial load of a radial lip seal indicates how strongly the sealing lip is pressed on the shaft. The radial load significantly affects the function of the seal. The German standard DIN 3761-9 describes the measurement of the radial load according to the split-shaft method but leaves room for interpretation. During the revision of the standard, a parameter study was conducted at the University of Stuttgart. This study analyses the influence of the measurement device, the mandrels and the measuring procedure on the results. Based on the study results, recommendations are derived and summarized in a best-practice guideline, which should enable an appropriate and reproducible measurement of the radial load.
{"title":"How to measure the radial load of radial lip seals","authors":"Simon Feldmeth, M. Stoll, F. Bauer","doi":"10.24053/tus-2021-0014","DOIUrl":"https://doi.org/10.24053/tus-2021-0014","url":null,"abstract":"The radial load of a radial lip seal indicates how strongly the sealing lip is pressed on the shaft. The radial load significantly affects the function of the seal. The German standard DIN 3761-9 describes the measurement of the radial load according to the split-shaft method but leaves room for interpretation. During the revision of the standard, a parameter study was conducted at the University of Stuttgart. This study analyses the influence of the measurement device, the mandrels and the measuring procedure on the results. Based on the study results, recommendations are derived and summarized in a best-practice guideline, which should enable an appropriate and reproducible measurement of the radial load.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44692486","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}
Regine Schmitz, F. Haupert, Justus Rüthing, Michael Sigrüner, Nicole Strübbe
Based on the conventional pin-on-disc test method, a tribology test rig was adapted and optimized regarding its ability to characterize polymer fibers. The method is explained and first applications in the field of tribological characterization of single fibers are presented. The test sequence to investigate the polymer fibers (diameters of only a few 100 µm) is generated in such a way that data can be recorded continuously as a function of time in the wear range from a few 10 µm to several 100 µm even during the first few minutes. The test mode starts by applying line load and dynamically progresses to area load by changing the contact area during the measurement. It is shown that single fibers can be characterized with respect to their friction and wear properties in different tribological systems. The dependence of the wear rates of fiber material, surface roughness of the counter bodies and lubrication rates is presented.
{"title":"Tribologische Charakterisierung von Polymerfasern unter Trockenreibung, Mischreibung und Hydrodynamik mittels einer optimierten Pin-on-Disc-Prüfmethode","authors":"Regine Schmitz, F. Haupert, Justus Rüthing, Michael Sigrüner, Nicole Strübbe","doi":"10.24053/tus-2021-0015","DOIUrl":"https://doi.org/10.24053/tus-2021-0015","url":null,"abstract":"Based on the conventional pin-on-disc test method, a tribology test rig was adapted and optimized regarding its ability to characterize polymer fibers. The method is explained and first applications in the field of tribological characterization of single fibers are presented. The test sequence to investigate the polymer fibers (diameters of only a few 100 µm) is generated in such a way that data can be recorded continuously as a function of time in the wear range from a few 10 µm to several 100 µm even during the first few minutes. The test mode starts by applying line load and dynamically progresses to area load by changing the contact area during the measurement. It is shown that single fibers can be characterized with respect to their friction and wear properties in different tribological systems. The dependence of the wear rates of fiber material, surface roughness of the counter bodies and lubrication rates is presented.","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44320728","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}
{"title":"Editorial des Gastherausgebers Professor Dr. Adrian Rienäcker","authors":"A. Rienäcker","doi":"10.24053/tus-2021-0007","DOIUrl":"https://doi.org/10.24053/tus-2021-0007","url":null,"abstract":"","PeriodicalId":53690,"journal":{"name":"Tribologie und Schmierungstechnik","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47419746","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}