Lubricants最新文献

{"title":"Comparative Study on the Lubrication of Ti3C2TX MXene and Graphene Oxide Nanofluids for Titanium Alloys","authors":"Yaru Tian, Ye Yang, Heyi Zhao, Lina Si, Hongjuan Yan, Z. Dou, Fengbin Liu, Yanan Meng","doi":"10.3390/lubricants12080285","DOIUrl":"https://doi.org/10.3390/lubricants12080285","url":null,"abstract":"Titanium alloys are difficult to machine and have poor tribological properties. Nanoparticles have good cooling and lubricating properties, which can be used in metal cutting fluid. The lubrication characteristics of the two-dimensional materials Ti3C2TX MXene and graphene oxide in water-based fluid for titanium alloys were comparatively investigated in this paper. Graphene oxide had smaller friction coefficients and wear volume than Ti3C2TX MXene nanofluid. As to the mechanism, MXene easily formed TiO2 for the tribo-chemical reaction, which accelerated wear. Moreover, GO nanofluid can form a more uniform and stable friction layer between the frictional interface, which reduces the friction coefficient and decreases the adhesive wear. The effects of different surfactants on the lubricating properties of MXene were further investigated. It was found that the cationic surfactant Hexadecyl trimethyl ammonium chloride (1631) had the lowest friction coefficient and anti-wear properties for the strong electrostatic attraction with MXene nanoparticles. The results of this study indicate that 2D nanoparticles, especially graphene oxide, could improve the lubricating properties of titanium alloys. It provides insight into the application of water-based nanofluids for difficult-to-machine materials to enhance surface quality and cutting efficiency. The developed nanofluid, which can lubricate titanium alloys, effectively has very broad applications in prospect.","PeriodicalId":18135,"journal":{"name":"Lubricants","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141925042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theoretical and Experimental Study of Flexible Structure Tilting Pad Bearings Considering Deformation","authors":"Yunyu Wu, Weiwei Zhang, Shuxiang Yi, Xiaojing Wang, Yanyan Qin, Shuxia Peng","doi":"10.3390/lubricants12080284","DOIUrl":"https://doi.org/10.3390/lubricants12080284","url":null,"abstract":"In high-speed and heavy-load conditions, ordinary rigid tilting pad journal bearings experience significant contact stress at the pad pivot points, leading to severe pad deformation and increased wear. A flexible structure tilting pad bearing (FSTPB) is presented in this paper, using spring supports to replace the traditional pivot supports and flexible hinge supports. A theoretical calculation model for tilting pad radial journal bearings considering flexible structure deformation is established, and the impact of elastic deformation on the performance of the flexible structure tilting pad bearings is discussed. Based on theoretical research, vibration experiments on flexible tilting pad bearings under different loading conditions were conducted. The influence of various structural parameters on the vibration characteristics of the flexible tilting pad radial bearings was studied. The results indicate that, compared to ordinary tilting pad bearings, flexible structure tilting pad bearings exhibit excellent vibration reduction characteristics at high speeds. Reducing the bearing clearance, lowering the stiffness of the flexible structure, and increasing the offset angle of the flexible structure contribute to enhancing the operational stability of the bearing–rotor system.","PeriodicalId":18135,"journal":{"name":"Lubricants","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141923026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of Lubrication Performance and Churning Loss under Mixed Lubrication Mode in Gearbox","authors":"Lina Wang, Yi Liu, Kailin Zhang, Yuan Yao, Shuai Shao, Kuangzhou He","doi":"10.3390/lubricants12080283","DOIUrl":"https://doi.org/10.3390/lubricants12080283","url":null,"abstract":"In order to clarify the effect of mixed lubrication methods on the oil flow and power loss of the gearbox, this study adopts a high-precision moving particle semi-implicit (MPS) method to investigate the lubrication of the gearbox under the joint influence of splash lubrication and oil injection lubrication. The accuracy of the numerical method to calculate the churning torque was verified by the constructed test rig. The effects of rotational speed, immersion depth, injection volume rate, and oil injection angle were analyzed and evaluated for lubrication. The results show that better lubrication can be achieved with relatively small churning torques by using a hybrid lubrication method. This provides some references for engineering applications of gearboxes.","PeriodicalId":18135,"journal":{"name":"Lubricants","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141925875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on the Static Performance of Surface-Throttling Frictionless Pneumatic Cylinder through Finite Element Method","authors":"Jingfeng Xu, Siyu Gao, Lizi Qi, Qiang Gao, Min Zhu, Hongbin Yang, Yinze Li, Wenyuan Wei, Lihua Lu","doi":"10.3390/lubricants12070254","DOIUrl":"https://doi.org/10.3390/lubricants12070254","url":null,"abstract":"The equilibrium system is essential for the high-precision movement of the ultra-precision vertical axis. However, the complex assembly process makes orifice-throttling frictionless cylinders difficult to manufacture and prone to air hammering. Surface-throttling frictionless pneumatic cylinders effectively avoid these problems. This paper establishes an improved finite element method (FEM) model of a novel surface-throttling frictionless pneumatic cylinder to investigate its static performance. Furthermore, the static equilibrium calculation of the dual-cylinder system is concerned. The radial bearing capacity and support force requirements for the surface-throttling aerostatic bearings are obtained. The outcomes provide theoretical guidance for optimizing cylinder parameters. It ensures that the ultimately optimized cylinder meets the requirements for radial bearing capacity and support force of the ultra-precision vertical axis while minimizing air consumption. Finally, the accuracy of the proposed method is verified through computational fluid dynamics (CFD) calculation and experiments.","PeriodicalId":18135,"journal":{"name":"Lubricants","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141649505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Simulations and Experimental Validation of Squeeze Film Dampers for Aircraft Jet Engines","authors":"Markus Golek, Jakob Gleichner, Ioannis Chatzisavvas, Lukas Kohlmann, Marcus Schmidt, Peter Reinke, Adrian Rienäcker","doi":"10.3390/lubricants12070253","DOIUrl":"https://doi.org/10.3390/lubricants12070253","url":null,"abstract":"Squeeze film dampers are used to reduce vibration in aircraft jet engines supported by rolling element bearings. The underlying physics of the squeeze film dampers has been studied extensively over the past 50 years. However, the research on the SFDs is still ongoing due to the complexity of modeling of several effects such as fluid inertia and the modeling of the piston rings, which are often used to seal SFDs. In this work, a special experimental setup has been designed to validate the numerical models of SFDs. This experimental setup can be used with various SFD geometries (including piston ring seals) and simulate almost all conditions that may occur in an aircraft jet engine. This work also focuses on the inertia forces of the fluid. The hydrodynamic pressure distribution of a detailed 3D-CFD model is compared with the solution of the Reynolds equation including inertia effects. Finally, the simulation results are compared with experimental data and good agreement is observed.","PeriodicalId":18135,"journal":{"name":"Lubricants","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141651628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Rigid-Flexible Coupled Collision Force in a Variable Load Offshore Wind Turbine Main Three-Row Cylindrical Roller Bearing","authors":"Xiaoxu Pang, Di Zhu, Xu Zuo, Dongfeng Wang, Wenlu Hao, Ming Qiu, Duo Liu","doi":"10.3390/lubricants12070252","DOIUrl":"https://doi.org/10.3390/lubricants12070252","url":null,"abstract":"In response to the limitations and one-sidedness of the simulation results of a rigid three-row cylindrical roller bearing for an offshore wind turbine main shaft under constant-load conditions, this paper proposes a simulation analysis method under variable loads. A contact mechanics model and a flexible body model are established, and the rigid-flexible coupled treatment is applied to the bearing’s inner and outer ring and cages. Based on variable load conditions, the theoretical speeds, simulated speeds, and acceleration responses of the pure rigid model and the rigid-flexible coupled model are compared, and the model is validated. Finally, the dynamic and transient responses reveal the time-varying characteristics of bearing loads and stress distribution patterns under different driving speeds and contact friction coefficients in the rigid-flexible coupled model. The conclusions are as follows: the rotational error of the rigid model is 1.67 to 3.76 times greater than that of the rigid-flexible coupled model, and the acceleration trend of the rigid-flexible coupled model is more stable with smaller speed fluctuations. The average forces on the thrust roller and cages increase with the driving speed, while those on the radial roller, cages, and inner ring decrease with the driving speed. The average force on the near-blade end cage is approximately 1.19 to 1.59 times that of the far end. The average force on the roller and cages significantly decreases with decreasing friction coefficient, with a reduction ranging from 50.08% to 76.41%. The maximum stress of the bearing increases with increasing driving speed. The novel simulation method for a rigid-flexible, coupled, three-row cylindrical roller bearing model under variable load conditions proposed in this paper can more accurately simulate the dynamic response of offshore wind turbine main shaft bearings during service. The results obtained in this paper provide highly valuable guidance for the research and design of offshore wind turbine main shaft bearings.","PeriodicalId":18135,"journal":{"name":"Lubricants","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141656979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing Lubrication Performance of Plastic Oil Lubricant with Oleic Acid-Functionalized Graphene Nanoplatelets and Hexagonal Boron Nitride Solid Lubricant Additives","authors":"Soumya Sikdar, P. L. Menezes","doi":"10.3390/lubricants12070251","DOIUrl":"https://doi.org/10.3390/lubricants12070251","url":null,"abstract":"The study explored the viability of using waste plastic oil (PO) as an alternative lubricant to petroleum-based lubricants in industrial settings. To enhance the lubrication performance of the PO, this study incorporated cost-efficient, oleic acid-modified, graphene nano platelets [GNP (f)] and hexagonal boron nitride [hBN (f)] nano solid lubricant additives into the PO in various concentrations, forming functionalized nano lubricants. The PO and its functionalized nano lubricant’s rheological, dispersion stability, thermal degradation, friction, and wear performance were investigated. Results manifest that incorporating GNP (f) and hBN (f) into the PO significantly enhanced the viscosity and dispersion stability. In addition, it was seen that GNP (f) and hBN (f) nano lubricants lowered the coefficient of friction (COF) by 53% and 63.63% respectively, compared to the PO. However, the GNP (f) and hBN (f) nano lubricants demonstrated a 3.16% decrease and a 50.08% increase in wear volume relative to the PO. Overall, the GNP (f) and hBN (f) nano lubricants displayed a synergistic friction behavior, while they exhibited an antagonistic behavior pertaining to the wear volume. The study elucidated the mechanisms underlying friction and wear performance of the nano lubricants.","PeriodicalId":18135,"journal":{"name":"Lubricants","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141663025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling of Static and Dynamic Elastomer Friction in Dry Conditions","authors":"Fabian Kaiser, Daniele Savio, Ravindrakumar Bactavatchalou","doi":"10.3390/lubricants12070250","DOIUrl":"https://doi.org/10.3390/lubricants12070250","url":null,"abstract":"Understanding the tribological behavior of elastomers in dry conditions is essential for sealing applications, as dry contact may occur even in lubricated conditions due to local dewetting. In recent decades, Persson and co-authors have developed a comprehensive theory for rubber contact mechanics and dry friction. In this work, their model is implemented and extended, particularly by including static friction based on the bond population model by Juvekar and coworkers. Validation experiments are performed using a tribometer over a wide range of materials, temperatures and speeds. It is shown that the friction model presented in this work can predict the static and dynamic dry friction of various commercial rubber materials with different base polymers (FKM, EPDM and NBR) with an average accuracy of 10%. The model is then used to study the relevance of different elastomer friction contributions under various operating conditions and for different roughness of the counter surface. The present model will help in the development of novel optimized sealing solutions and provide a foundation for future modeling of lubricated elastomer friction.","PeriodicalId":18135,"journal":{"name":"Lubricants","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141666192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Tribological and Adsorption Performance of Chlorophenyl Silicone Oil Using Different Ceramic Materials under High Temperature","authors":"Jie Cheng, Yan Meng, Fangxu Sun, Luo Yue, Xue Zhou, Peng Wei, Hui Zhao, Xiangli Wen, P. Bai, Qian Zhao, Yonggang Meng, Yu Tian","doi":"10.3390/lubricants12070249","DOIUrl":"https://doi.org/10.3390/lubricants12070249","url":null,"abstract":"With the development of technical requirements, the current challenges faced by bearing materials mainly revolve around high-temperature conditions and the trend towards material lightweighting. Full ceramic bearings are the new candidate due to their excellent properties. This article details the tribological and adsorption performance of chlorophenyl silicone oil (CPSO) as a high-temperature lubricant in ceramic tribological systems (ZrO2, Al2O3, and Si3N4). Among the three ceramic tribological systems, the lubrication performance can be ordered as Si3N4 > Al2O3 > ZrO2, as the wear rates of the ZrO2 and Al2O3 tribo-systems are almost 1135.67 and 283.33 times larger than that of the Si3N4 tribo-system, respectively. The observed results can be explained by the superior adsorption performance of CPSO on a Si3N4 ceramic surface, which was calculated by molecular dynamic simulation. The molecular dynamic simulation results show the adsorption energy of CPSO/Si3N4 is almost 54.09 and 61.18 times higher compared to that on ZrO2 and Al2O3 ceramics. These findings provide experimental and theoretical insights for understanding the lubrication performance of CPSO in a full ceramic tribo-system.","PeriodicalId":18135,"journal":{"name":"Lubricants","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141672107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-Response Optimization and Experimental Investigation of the Influences of Various Coolant Conditions on the Milling of Alloy 20","authors":"Youlei Zhao, Na Cui, Zhenxian Hou, Jing Li, Junqiang Liu, Yapeng Xu","doi":"10.3390/lubricants12070248","DOIUrl":"https://doi.org/10.3390/lubricants12070248","url":null,"abstract":"This study investigates the machining processes of Alloy 20 under different cooling conditions: Minimum Quantity Lubrication (MQL), Carbon Dioxide (CO2), and the hybrid MQL + CO2 approach. The research focuses on optimizing the cutting parameters, understanding the surface characteristics, analysing the tool wear patterns, and evaluating the chip formation. Face-centred CCD-based response surface methodology (RSM) is applied in order to identify the optimized cutting conditions. Surface roughness, tool wear, and chip morphology are examined through SEM imaging. Surface roughness characteristics reveal distinctive characteristics for each coolant condition: MQL cooling results in a relatively rough surface with tool nose degradation, CO2 cooling shows scratches on the surface and tool chipping, and MQL + CO2 cooling yields a smoother finish with close and continuous chip formation under the optimized conditions. This study contributes valuable insights into the complex interactions between cutting parameters and coolants, aiding in the optimization of machining processes for improved outcomes of the machining of Alloy 20. Based on the RSM outcomes, the optimal parametric settings obtained are Vc = 44 m/min, f = 0.04 mm/rev, and ap = 0.43 mm.","PeriodicalId":18135,"journal":{"name":"Lubricants","volume":null,"pages":null},"PeriodicalIF":3.1,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141674997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}