Tribology Online最新文献_第10页

Observation of Grease Fluidity in a Ball Bearing Using Neutron Imaging Technology 用中子成像技术观察滚珠轴承润滑脂流动性

IF 1

Tribology Online Pub Date : 2021-06-15 DOI: 10.2474/TROL.16.146

K. Sakai, Y. Ayame, Y. Iwanami, Nobuharu Kimura, Y. Matsumoto

引用次数: 1

Swelling Behaviour of Static Seals in Redox Flow Batteries 氧化还原液流电池静密封的膨胀行为

IF 1

Tribology Online Pub Date : 2021-06-15 DOI: 10.2474/TROL.16.138

Detlef Jannes, L. Hörl, F. Bauer

{"title":"Swelling Behaviour of Static Seals in Redox Flow Batteries","authors":"Detlef Jannes, L. Hörl, F. Bauer","doi":"10.2474/TROL.16.138","DOIUrl":"https://doi.org/10.2474/TROL.16.138","url":null,"abstract":"This paper analyses the implications of swelling in perspective of sealing technology for redox flow batteries (RFB). Mechanical failure due to swell in static sealing can occur on the elastomeric seal or on sealing flanges. The mechanical failure is in this case a fractured or deformed RFB component because of the swelling pressure. Swelling of such an elastomeric seal is a coupling of different physics phenomena, namely diffusion and solid mechanics. In an assembled RFB, seal swelling increases the contact pressure with the sealing flange, while making the components softer. It shifts the mechanical material properties of the components and also the stress tolerances. Graphite-polymer bipolar plates or PTFE / PP flowframes are common RFB sealing flanges and can become softer due to diffusion of the electrolyte fluid, making the flanges more prone to creep. These are time dependent effects that can create sealing failure or mechanical break of the sealing flanges and must be taken into account in RFB design. The presented experimental and modelling results validate the swelling behaviour for an assembled RFB. The compatibility tables of sealing materials in catalogues do not often differentiate swelling compatibility from chemical compatibility of a fluid. In addition, this paper proposes a basic selection procedure for swelling compatibility based on group experiments on Hansen solubility parameters (HSP).","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"31 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90936909","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}

引用次数: 0

Tribotronic Analysis of Internal Combustion Engine Compression Ring 内燃机压缩环的摩擦学分析

IF 1

Tribology Online Pub Date : 2021-06-15 DOI: 10.2474/TROL.16.125

Konstantinos Tsatsoulis, A. Zavos, P. Nikolakopoulos

{"title":"Tribotronic Analysis of Internal Combustion Engine Compression Ring","authors":"Konstantinos Tsatsoulis, A. Zavos, P. Nikolakopoulos","doi":"10.2474/TROL.16.125","DOIUrl":"https://doi.org/10.2474/TROL.16.125","url":null,"abstract":"The influence of operating conditions of the compression rings on the engine power losses affects confoundedly the design of the Internal Combustion Engines (ICEs). Normalized parameters such as Friction Mean Effective Pressure (FMEP) were used to regulate power losses. The purpose of this work was to create a primary control model of the friction mean effective pressure using an automatic control system. This study incorporates the creation of a mixed-hydrodynamic model for the top compression ring in MATLAB computing environment. The load of ring asperities was predicted using Greenwood-Tripp stochastic model. The pressure distribution along the ring face-width was determined using Reynolds equation through finite difference method with the half-Sommerfeld boundary condition for cavitation outlet zone. This was accomplished by finding the maximum ring pressure for a range of engine speeds and lubricant temperatures. Additionally, the computed results concerning the maximum pressure and the PID controlled characteristics are proposed and compared using a cavitation model. Regarding the automatic system, a PID controller was built using SIMULINK. The numerical results showed that FMEP could be the effective parameter in order to control the engine operation and to proof the tribotronics design in an Internal Combustion Engine.","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"62 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87572956","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}

引用次数: 2

Reynolds Boundary Condition Approximation in Journal Bearings Based on Dynamic Mesh Method 基于动态网格法的滑动轴承雷诺边界条件逼近

IF 1

Tribology Online Pub Date : 2021-04-15 DOI: 10.2474/TROL.16.81

Wanjun Xu, Y. Tian, Yingwei Song, Mingjie Zhang, Jiangang Yang

{"title":"Reynolds Boundary Condition Approximation in Journal Bearings Based on Dynamic Mesh Method","authors":"Wanjun Xu, Y. Tian, Yingwei Song, Mingjie Zhang, Jiangang Yang","doi":"10.2474/TROL.16.81","DOIUrl":"https://doi.org/10.2474/TROL.16.81","url":null,"abstract":"This paper proposed a new approach to Reynolds boundary condition approximation in journal bearing CFD analysis. Dynamic mesh method was applied to approach the location where the rupture of oil film or cavitation started. A numerical model of half bearing geometry was constructed to obtain the Half-Sommerfeld solution. Using the solution, a pseudo-transient analysis was subsequently conducted. The boundary at the minimum film thickness was treated as the moving boundary. The Reynolds boundary condition was satisfied at a certain point when the pressure derivative of boundary nodes approached zero over the course of mesh growth. The analytical results were compared against the results of published works. It was discovered that the resulting cavitation angle and oil film pressure were consistent with those obtained by taking the Reynolds equation approach, with only slight differences observed from those obtained via the cavitation experiments and models. The proposed method is an extension of Reynolds boundary condition according to the CFD approach. It is considered an alternative to other cavitation models intended for journal bearings.","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"22 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91004431","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}

引用次数: 4

Proposition of Thermal-Diffusion-Induced Spiral Model for the Rapid Oil-Film Breakdown Process during Scuffing 磨损过程中油膜快速破裂的热扩散诱导螺旋模型的提出

IF 1

Tribology Online Pub Date : 2021-04-15 DOI: 10.2474/TROL.16.89

Mamoru Tohyama, Takashi Izumi, S. Sanda

{"title":"Proposition of Thermal-Diffusion-Induced Spiral Model for the Rapid Oil-Film Breakdown Process during Scuffing","authors":"Mamoru Tohyama, Takashi Izumi, S. Sanda","doi":"10.2474/TROL.16.89","DOIUrl":"https://doi.org/10.2474/TROL.16.89","url":null,"abstract":"The dominant factors and processes for the rapid progression of scuffing from a partial area to an entire surface under lubricated, plane contact, and pure sliding conditions were studied by performing an in situ observation of the surface, and in situ measurements of the oil-film thickness and temperature distributions during scuffing. Transitions of the oil-film thickness were measured using three-wavelength optical interferometry, and the temperature distributions of the sliding surface were measured using thermography. It was observed that oil-film breakdown progressed from a partial area to an entire surface within several tens of milliseconds under high sliding speed and high-load conditions. The proposed process of the rapid progression of oil-film breakdown on the surface was described using the \"thermal-diffusion-induced spiral model.\" The processes in the model are as follows: (I) the frictional heat generated in a solid contact area diffused into the adjacent region of the surface; (II) the oil-film temperature in the adjacent region increased within a short time, as the films were very thin (several tens of nanometers); (III) the viscosities of the oil-films decreased; (IV) the solid contact area grew larger, and these phenomena repeated continuously until the oil-film breakdown reached the entire surface.","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"14 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83490225","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}

引用次数: 0

Influence of Surface Texture on the Performance of Hydrodynamic Journal Bearing Operating under Turbulent Regime 紊流工况下表面织构对流体动压滑动轴承性能的影响

IF 1

Tribology Online Pub Date : 2021-04-15 DOI: 10.2474/TROL.16.99

R. K. Awasthi, Jagjit Singh Maan

引用次数: 4

Evaluation of Friction Durability of Extremely Thin Diamond-Like Carbon Films by Statistical Cluster and Regression Analyses of Friction Coefficient 基于统计聚类和摩擦系数回归分析的极薄类金刚石膜摩擦耐久性评价

IF 1

Tribology Online Pub Date : 2021-04-15 DOI: 10.2474/TROL.16.113

S. Miyake, M. Miyake

{"title":"Evaluation of Friction Durability of Extremely Thin Diamond-Like Carbon Films by Statistical Cluster and Regression Analyses of Friction Coefficient","authors":"S. Miyake, M. Miyake","doi":"10.2474/TROL.16.113","DOIUrl":"https://doi.org/10.2474/TROL.16.113","url":null,"abstract":"We studied the tribological properties of extremely thin DLC films at high temperature. The films were deposited on nickel phosphorus (NiP) or Si substrates using filtered cathodic vacuum arc (FCVA) or plasma chemical vapor deposition (P-CVD). The nanoindentation hardness values and elastic moduli of the films were lower on NiP than on Si. The nanofriction force of the FCVA-DLC film on NiP was low at room temperature, but very high at high temperature. In this hard film, the lubricous adsorbate was removed by sliding at high temperature, making it easily damaged through the large deformation of NiP. In contrast, the friction force of the P-CVD-DLC films on both substrates was low at high temperatures. In this case, the lubricous tribochemical products from the P-CVD-DLC film reduced friction and wear. The friction map dependences on load and number of reciprocating cycles were evaluated using a friction test and statistical cluster analysis. The friction durability of both films depended more strongly on load on NiP than on Si, with the friction coefficients on Si being almost independent of load. At high temperatures and load, the durability of the FCVA-DLC film on NiP decreased and this film was easily damaged. P-CVD on NiP and Si substrates using statistical methods. From our results, we draw the following conclusions:","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"2007 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82579902","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}

引用次数: 0

Study on Relations of High-Pressure Viscosity Properties and the Polymer Behavior of Various Viscosity Index Improver-Blended Oil (Part 2) 不同粘度指数改进剂调合油高压粘度特性与聚合物行为关系的研究(二)

IF 1

Tribology Online Pub Date : 2021-03-31 DOI: 10.2474/TROL.16.38

H. Hata, Y. Tamoto

{"title":"Study on Relations of High-Pressure Viscosity Properties and the Polymer Behavior of Various Viscosity Index Improver-Blended Oil (Part 2)","authors":"H. Hata, Y. Tamoto","doi":"10.2474/TROL.16.38","DOIUrl":"https://doi.org/10.2474/TROL.16.38","url":null,"abstract":"Using high-pressure viscosity measurements of 23 kinds of VII-blended oil reported in Part 1, a high-pressure viscosity prediction formula for VII-blended oil was derived. This equation is expressed in a so-called Barus formula, and the pressure-viscosity coefficient is the secant pressure-viscosity coefficient α B ( p ) -Bl (= ln( η pt / η ot ) / P ) in each ln( η pt ) ‒ P relation curve. The calculation formula of α B ( p ) -Bl is composed of the corresponding base oil value α B ( p ) -Bf , the polymer coil itself pressure-viscosity coefficient α Pm and the polymer concentration w Pm (wt%). In relation to mentioned above, the volume fraction of one polymer molecule in hydrodynamically equivalent sphere, and the volume fraction of the hydrodynamic volume occupied in 100 cm 3 of VII-blended oil at critical concentration c * of polymer coil were investigated. It was also found that the viscosity index VI o -Bl in the atmospheric pressure of the VII-blended oil drops with pressure. For this reason, the effect of temperature on the ln( η pt ) ‒ P relation curve, the influence of polymer type and base oil in η i ‒ P ‒ t relationship, and the influence of polymer type on atmospheric pressure viscosity η ot ‒ t relationship were discussed.","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"38 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81358144","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}

引用次数: 0

Friction and Wear Properties of Hard Coatings on Steel Surfaces under Lubrication with a Fully Formulated Oil with a Mo Additive 含Mo添加剂的全配方油润滑下钢表面硬涂层的摩擦磨损性能

IF 1

Tribology Online Pub Date : 2021-03-31 DOI: 10.2474/TROL.16.59

K. Nakagome, Kaisei Sato, H. Okubo, Seiya Watanabe, S. Sasaki

{"title":"Friction and Wear Properties of Hard Coatings on Steel Surfaces under Lubrication with a Fully Formulated Oil with a Mo Additive","authors":"K. Nakagome, Kaisei Sato, H. Okubo, Seiya Watanabe, S. Sasaki","doi":"10.2474/TROL.16.59","DOIUrl":"https://doi.org/10.2474/TROL.16.59","url":null,"abstract":"When various sliding components of combustion engines protected with hard coatings are slid with automotive lubricants, unexpected interfacial phenomena may occur because typical automotive lubricants have been formulated with additives suitable for steel/steel sliding components. Therefore, understanding the effects of hard coatings on the performance of lubricant additives is crucial for further improving the lubrication properties of fully formulated oils through the optimization of additive formulations for hard coatings. In this study, friction tests were performed with a steel surface against steel surfaces coated with two ceramic materials and two diamond-like carbon materials under lubrication with a fully formulated oil. Atomic force microscopy and X-ray photoelectron spectroscopic (XPS) investigation of the steel surfaces after the friction tests revealed that the tribofilms comprised a bottom layer composed of calcium compounds and a top layer composed of phosphorous, zinc, and sulfur compounds. The thickness of each layer, which is closely related to the wear property, depends on the hard coating material. Moreover, XPS analysis focusing on the molybdenum element suggested that rate of chemical kinetics to form MoS 2 differs among the hard coating materials, and dominantly affects the frictional property.","PeriodicalId":23314,"journal":{"name":"Tribology Online","volume":"57 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80491369","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}

引用次数: 1

The Clarification of Friction Mechanism in Oil Lubrication for CNx Coating by In-Situ Observation of Friction Area with Reflectance Spectroscopy 用反射光谱法原位观察CNx涂层摩擦区，阐明CNx涂层油润滑摩擦机理

IF 1

Tribology Online Pub Date : 2021-03-31 DOI: 10.2474/TROL.16.49

T. Okamoto, N. Umehara, M. Murashima, Koji Saito, K. Manabe, Keiji Hayashi

引用次数: 5