Pub Date : 2023-09-25DOI: 10.1080/10402004.2023.2261200
Wu Shen, Qufan Si, Pan Shengli, Jianxiu Liu, Aiyun Jiang, Jianglei Fan, Ying Li, Yan Wang
Abstract:The sintered copper based friction materials for high-speed train brake pads have a complex composition, which should possess good physical, mechanical and tribological properties in practical applications. In this paper, four kinds of friction materials were prepared by powder metallurgy technology and the effects of iron powders on the microstructural and tribological properties of copper based friction materials were characterized by scanning electron microscope (SEM) and X-Ray diffraction (XRD). The results showed that the iron powder as the enhanced component could effectively change the friction and wear properties of the experimental materials. The copper based friction materials containing hydroxy iron (1-5μm) have a relatively higher coefficient of friction, the friction coefficient was significantly improved by 16.8% compared with reduced iron under a rotation speed is 4000 r/min. The friction coefficient of friction material containing water atomized iron powder is relatively reliable with 3000-7000 r/min speed range. In the high speed environment, the friction surface of material containing reduced iron or hydroxy iron（1-5μm）mainly are cracks and brittle fractures, and the material containing hydroxy iron（10μm）or water atomized iron has obvious layered structure.Keywords: copper based friction materialsfriction and wearpowder metallurgyDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. Competing Interests:The authors have no relevant financial or non-financial interests to disclose.Additional informationFundingThis work was supported by Key Scientific and Technological Project of Henan Province (Grants No: 232102230055), the National Natural Science Foundation of China (Grants No: U1904175) and Postgraduate Education Reform and Quality Improvement Project of Henan Province (Grants No: YJS2022JD50).
{"title":"Effect of iron powder type on friction and wear properties of copper based friction powder metallurgy material","authors":"Wu Shen, Qufan Si, Pan Shengli, Jianxiu Liu, Aiyun Jiang, Jianglei Fan, Ying Li, Yan Wang","doi":"10.1080/10402004.2023.2261200","DOIUrl":"https://doi.org/10.1080/10402004.2023.2261200","url":null,"abstract":"Abstract:The sintered copper based friction materials for high-speed train brake pads have a complex composition, which should possess good physical, mechanical and tribological properties in practical applications. In this paper, four kinds of friction materials were prepared by powder metallurgy technology and the effects of iron powders on the microstructural and tribological properties of copper based friction materials were characterized by scanning electron microscope (SEM) and X-Ray diffraction (XRD). The results showed that the iron powder as the enhanced component could effectively change the friction and wear properties of the experimental materials. The copper based friction materials containing hydroxy iron (1-5μm) have a relatively higher coefficient of friction, the friction coefficient was significantly improved by 16.8% compared with reduced iron under a rotation speed is 4000 r/min. The friction coefficient of friction material containing water atomized iron powder is relatively reliable with 3000-7000 r/min speed range. In the high speed environment, the friction surface of material containing reduced iron or hydroxy iron（1-5μm）mainly are cracks and brittle fractures, and the material containing hydroxy iron（10μm）or water atomized iron has obvious layered structure.Keywords: copper based friction materialsfriction and wearpowder metallurgyDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. Competing Interests:The authors have no relevant financial or non-financial interests to disclose.Additional informationFundingThis work was supported by Key Scientific and Technological Project of Henan Province (Grants No: 232102230055), the National Natural Science Foundation of China (Grants No: U1904175) and Postgraduate Education Reform and Quality Improvement Project of Henan Province (Grants No: YJS2022JD50).","PeriodicalId":23315,"journal":{"name":"Tribology Transactions","volume":"237 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135816525","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}
Pub Date : 2023-09-22DOI: 10.1080/10402004.2023.2262244
Quan Wang, Qixiang Zhang, Zhiwei Wang, Jiliang Mo, Wenwei Jin, Song Zhu
AbstractStick–slip vibration is simultaneously influenced by several factors which share complicated coupling relationships. In this research, an experimental investigation was performed to analyze the evolution law of stick–slip characteristics at different working conditions using a tribometer. The results showed that the disc rotational speed and normal force had noticeable impact on both stick–slip vibration and coefficient of friction (COF). Then, the Stribeck model, which can characterize COF characteristics in the stick–slip process, was employed and the parameters were identified to construct a dynamic relationship between working conditions and COF. Further, the numerical simulations respectively considering and neglecting the dynamic relationship between working conditions and Stribeck model parameters were conducted via an established tribometer analytical model. It was found that the simulation results considering the influence of working conditions on Stribeck model parameters were in better agreement with the experimental results as the stick–slip vibration depends on the combined effect of working conditions and Stribeck model parameters. Therefore, the dynamic relationship between working conditions and Stribeck model parameters is crucial to accurately reveal stick–slip characteristics.Keywords: stick–slip vibrationStribeck modelcoefficient of frictionparameter identificationnumerical simulationDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgementsThe authors are grateful for the financial support of the National Natural Science Foundation of China (No. U22A20181, 52205217), the Natural Science Foundation of Sichuan (No. 2022NSFSC1964) and the Fundamental Research Funds for the Central Universities (2682021CX025).
{"title":"Identification of Stribeck model parameters to accurately reveal stick–slip characteristics of a disc–block friction system","authors":"Quan Wang, Qixiang Zhang, Zhiwei Wang, Jiliang Mo, Wenwei Jin, Song Zhu","doi":"10.1080/10402004.2023.2262244","DOIUrl":"https://doi.org/10.1080/10402004.2023.2262244","url":null,"abstract":"AbstractStick–slip vibration is simultaneously influenced by several factors which share complicated coupling relationships. In this research, an experimental investigation was performed to analyze the evolution law of stick–slip characteristics at different working conditions using a tribometer. The results showed that the disc rotational speed and normal force had noticeable impact on both stick–slip vibration and coefficient of friction (COF). Then, the Stribeck model, which can characterize COF characteristics in the stick–slip process, was employed and the parameters were identified to construct a dynamic relationship between working conditions and COF. Further, the numerical simulations respectively considering and neglecting the dynamic relationship between working conditions and Stribeck model parameters were conducted via an established tribometer analytical model. It was found that the simulation results considering the influence of working conditions on Stribeck model parameters were in better agreement with the experimental results as the stick–slip vibration depends on the combined effect of working conditions and Stribeck model parameters. Therefore, the dynamic relationship between working conditions and Stribeck model parameters is crucial to accurately reveal stick–slip characteristics.Keywords: stick–slip vibrationStribeck modelcoefficient of frictionparameter identificationnumerical simulationDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. AcknowledgementsThe authors are grateful for the financial support of the National Natural Science Foundation of China (No. U22A20181, 52205217), the Natural Science Foundation of Sichuan (No. 2022NSFSC1964) and the Fundamental Research Funds for the Central Universities (2682021CX025).","PeriodicalId":23315,"journal":{"name":"Tribology Transactions","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136059272","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}
Pub Date : 2023-09-11DOI: 10.1080/10402004.2023.2254348
Kang Yan, Hulin Li, Jian Sun, Qi Xin, Ning Ding, Dan Jiang, Xianghui Meng
The design of five-pad tilting-pad journal bearings (TPJB) is complicated because of the uncertainty of design parameters which affects the performance of TPJB greatly. In this study, the numerical lubrication model is established to predict the performance of TPJB. Furthermore, a new optimal method combining the lubrication model and particle swarm method with a comprehensive target is brought out, which can obtain the optimal design parameters correctly and rapidly compared with enumeration method. The performance of TPJB is better after optimization, especially the temperature and frictional coefficient decreasing by about 31.1% and 35.8%, respectively. Moreover, different application scenarios of TPJB need different weight factor combinations in the comprehensive target, which is valuable for different design requirements.
{"title":"Optimization numerically for five-pad tilting-pad journal bearings design based on particle swarm","authors":"Kang Yan, Hulin Li, Jian Sun, Qi Xin, Ning Ding, Dan Jiang, Xianghui Meng","doi":"10.1080/10402004.2023.2254348","DOIUrl":"https://doi.org/10.1080/10402004.2023.2254348","url":null,"abstract":"The design of five-pad tilting-pad journal bearings (TPJB) is complicated because of the uncertainty of design parameters which affects the performance of TPJB greatly. In this study, the numerical lubrication model is established to predict the performance of TPJB. Furthermore, a new optimal method combining the lubrication model and particle swarm method with a comprehensive target is brought out, which can obtain the optimal design parameters correctly and rapidly compared with enumeration method. The performance of TPJB is better after optimization, especially the temperature and frictional coefficient decreasing by about 31.1% and 35.8%, respectively. Moreover, different application scenarios of TPJB need different weight factor combinations in the comprehensive target, which is valuable for different design requirements.","PeriodicalId":23315,"journal":{"name":"Tribology Transactions","volume":"139 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135979309","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}
Pub Date : 2023-09-06DOI: 10.1080/10402004.2023.2256797
S. R. Soria, S. Claramonte, E.A. Nieto Castro, A.M. Alvarez, A. Yawny
Abstract The occurrence of fretting-induced cracks and delamination wear processes in a mixed fretting regime on Alloy 690 steam generator tubes against 304L stainless steel pads was analyzed. Fretting tests in 90° cross-cylinder configuration were performed in air at room temperature. Changes in the contact conditions were evaluated using the energy ratio and the sliding ratio criteria. Damage was characterized using light microscopy, scanning electron microscopy, and optical profilometry. Vickers microindentation was applied to characterize the initial plastic deformation process. It was found that during the initial 1 × 103 cycles, plastic deformation constitutes the main damage mechanism. Thereafter, between 1 × 103 and 1 × 104 cycles, cracks nucleation and propagation accompanied by negligible wear were detected. Beyond 1 × 104 cycles, the dominant main damage mechanism consists of delamination wear assisted by cracks coalescence, and a change from a U-shaped to a W-shaped scar profile was observed in correspondence with the appearance of the delamination wear process.
{"title":"Evolution of fretting induced cracks and delamination wear on alloy 690 steam generator tubes during mixed fretting regime in air at room temperature","authors":"S. R. Soria, S. Claramonte, E.A. Nieto Castro, A.M. Alvarez, A. Yawny","doi":"10.1080/10402004.2023.2256797","DOIUrl":"https://doi.org/10.1080/10402004.2023.2256797","url":null,"abstract":"Abstract The occurrence of fretting-induced cracks and delamination wear processes in a mixed fretting regime on Alloy 690 steam generator tubes against 304L stainless steel pads was analyzed. Fretting tests in 90° cross-cylinder configuration were performed in air at room temperature. Changes in the contact conditions were evaluated using the energy ratio and the sliding ratio criteria. Damage was characterized using light microscopy, scanning electron microscopy, and optical profilometry. Vickers microindentation was applied to characterize the initial plastic deformation process. It was found that during the initial 1 × 103 cycles, plastic deformation constitutes the main damage mechanism. Thereafter, between 1 × 103 and 1 × 104 cycles, cracks nucleation and propagation accompanied by negligible wear were detected. Beyond 1 × 104 cycles, the dominant main damage mechanism consists of delamination wear assisted by cracks coalescence, and a change from a U-shaped to a W-shaped scar profile was observed in correspondence with the appearance of the delamination wear process.","PeriodicalId":23315,"journal":{"name":"Tribology Transactions","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45564480","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}
Pub Date : 2023-09-05DOI: 10.1080/10402004.2023.2254957
L. Maccioni, Lukas Rüth, Oliver Koch, Franco Concli
Abstract To improve roller bearing efficiency, it is essential to identify the sources of power losses and quantify them in the design stage, considering different influencing factors. For oil-lubricated bearings, load-independent power losses ( ) can be the dominant source of dissipation, especially for high-speed and abundant lubrication. In the present work, of a 32208 tapered roller bearing were measured experimentally under various operating conditions; that is, different rotational speeds, temperatures, and geometries of the oil reservoir. A numerical tool, based on computational fluid dynamics, to estimate and provide useful insights to investigate their causes has been developed in the OpenFOAM® environment. Numerical and experimental results show excellent agreement in most of the operating conditions investigated. Oil flows, contributions of different bearing components, and computational effort are discussed in the article.
{"title":"Load-independent power losses of full-flooded lubricated tapered roller bearings: numerical and experimental investigation of the effect of operating temperature and housing walls distances","authors":"L. Maccioni, Lukas Rüth, Oliver Koch, Franco Concli","doi":"10.1080/10402004.2023.2254957","DOIUrl":"https://doi.org/10.1080/10402004.2023.2254957","url":null,"abstract":"Abstract To improve roller bearing efficiency, it is essential to identify the sources of power losses and quantify them in the design stage, considering different influencing factors. For oil-lubricated bearings, load-independent power losses ( ) can be the dominant source of dissipation, especially for high-speed and abundant lubrication. In the present work, of a 32208 tapered roller bearing were measured experimentally under various operating conditions; that is, different rotational speeds, temperatures, and geometries of the oil reservoir. A numerical tool, based on computational fluid dynamics, to estimate and provide useful insights to investigate their causes has been developed in the OpenFOAM® environment. Numerical and experimental results show excellent agreement in most of the operating conditions investigated. Oil flows, contributions of different bearing components, and computational effort are discussed in the article.","PeriodicalId":23315,"journal":{"name":"Tribology Transactions","volume":" ","pages":""},"PeriodicalIF":2.1,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48074582","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}
Pub Date : 2023-08-30DOI: 10.1080/10402004.2023.2253855
Mian Huang, Bing Yang, Youxin Rong, Lei Zhao, S. Xiao
Abstract The pantograph–catenary system is one of the most commonly used power-receiving modes of metro trains. Its friction and wear performances are related to the safety and stability of train operation. In this study, a copper-impregnated carbon slide plate material, widely used in numerous metro lines in China, is considered as the research object. The problem of abnormal wear of slide plates caused by the decrease in relative humidity in the autumn and winter in tunnels is studied. Current-carrying friction and wear tests under humidity conditions of 20%, 30%, and 40% relative humidity (RH) are performed to reveal the mechanism of seasonal abnormal wear of slide plates and provide a reference for the service of pantograph slide plates under low-humidity conditions. The results reveal that relative humidity significantly influences the wear process of slide plates; further, the wear rate decrease with an increase in relative humidity. As observed by laser scanning confocal microscopy, with an increase in the relative humidity, the mechanical wear of the slide surface is weakened, arc erosion is enhanced, and surface roughness is increased. The Raman spectral scan showed that with the increasing humidity, the graphitization of the surface material decreased significantly, and the molecular structure changed greatly. Scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS) analysis reveal that under high humidity conditions, a relatively complete oxide film forms on the slide plate and plays a role in lubrication and protection.
{"title":"Study on Friction and Wear Properties of Copper-Impregnated Carbon Slide Plate Under Different Humidity Conditions","authors":"Mian Huang, Bing Yang, Youxin Rong, Lei Zhao, S. Xiao","doi":"10.1080/10402004.2023.2253855","DOIUrl":"https://doi.org/10.1080/10402004.2023.2253855","url":null,"abstract":"Abstract The pantograph–catenary system is one of the most commonly used power-receiving modes of metro trains. Its friction and wear performances are related to the safety and stability of train operation. In this study, a copper-impregnated carbon slide plate material, widely used in numerous metro lines in China, is considered as the research object. The problem of abnormal wear of slide plates caused by the decrease in relative humidity in the autumn and winter in tunnels is studied. Current-carrying friction and wear tests under humidity conditions of 20%, 30%, and 40% relative humidity (RH) are performed to reveal the mechanism of seasonal abnormal wear of slide plates and provide a reference for the service of pantograph slide plates under low-humidity conditions. The results reveal that relative humidity significantly influences the wear process of slide plates; further, the wear rate decrease with an increase in relative humidity. As observed by laser scanning confocal microscopy, with an increase in the relative humidity, the mechanical wear of the slide surface is weakened, arc erosion is enhanced, and surface roughness is increased. The Raman spectral scan showed that with the increasing humidity, the graphitization of the surface material decreased significantly, and the molecular structure changed greatly. Scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS) analysis reveal that under high humidity conditions, a relatively complete oxide film forms on the slide plate and plays a role in lubrication and protection.","PeriodicalId":23315,"journal":{"name":"Tribology Transactions","volume":"66 1","pages":"953 - 964"},"PeriodicalIF":2.1,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46473562","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}
Pub Date : 2023-08-30DOI: 10.1080/10402004.2023.2253867
Ujjawal Arya, F. Sadeghi, Saeed Aamer, A. Meinel, H. Grillenberger
Abstract This article presents an investigation into oil starvation in different cage pocket shapes of a horizontally mounted ball bearing. A counter-rotating angular contact ball bearing test rig (CRACTR) was used to visualize the oil distribution inside specially manufactured transparent bearing cages using detailed images from a high-speed camera. Three different cage types were investigated using various oils dyed with ultraviolet dye. The identification of oil and air regions elucidated the oil distribution in the cage pocket and the formation of oil–air striations on the ball surface under various operating conditions. The experimental results demonstrated that raceway motion, ball submersion level, oil properties, and cage pocket shape influenced oil starvation inside the bearing cage. ANSYS Fluent software was also used to develop an equivalent two-phase computational fluid dynamics (CFD) model for the test bearing. Results from the CFD model corroborate well with the experimentally observed oil distribution for all test cages and establish the strong influence of cage geometry on oil starvation and bearing lubrication. GRAPHICAL ABSTRACT
{"title":"In Situ Visualization and Analysis of Oil Starvation in Ball Bearing Cages","authors":"Ujjawal Arya, F. Sadeghi, Saeed Aamer, A. Meinel, H. Grillenberger","doi":"10.1080/10402004.2023.2253867","DOIUrl":"https://doi.org/10.1080/10402004.2023.2253867","url":null,"abstract":"Abstract This article presents an investigation into oil starvation in different cage pocket shapes of a horizontally mounted ball bearing. A counter-rotating angular contact ball bearing test rig (CRACTR) was used to visualize the oil distribution inside specially manufactured transparent bearing cages using detailed images from a high-speed camera. Three different cage types were investigated using various oils dyed with ultraviolet dye. The identification of oil and air regions elucidated the oil distribution in the cage pocket and the formation of oil–air striations on the ball surface under various operating conditions. The experimental results demonstrated that raceway motion, ball submersion level, oil properties, and cage pocket shape influenced oil starvation inside the bearing cage. ANSYS Fluent software was also used to develop an equivalent two-phase computational fluid dynamics (CFD) model for the test bearing. Results from the CFD model corroborate well with the experimentally observed oil distribution for all test cages and establish the strong influence of cage geometry on oil starvation and bearing lubrication. GRAPHICAL ABSTRACT","PeriodicalId":23315,"journal":{"name":"Tribology Transactions","volume":"66 1","pages":"965 - 978"},"PeriodicalIF":2.1,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47004875","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}
Pub Date : 2023-08-24DOI: 10.1080/10402004.2023.2251536
Yi Zhang, Wen Wang, G. Wang, Peng Huang, Jimin Xu, Kun Liu
Abstract This work aims to investigate the friction and vibration behaviors of a liquid–solid two-phase flow supported bearing-rotor system for the early monitoring and assessing of oil contamination resulting from externally ingested particles. Based on a Jeffcott rotor test rig, the lubricating oil in journal bearing was mixed with micron-scale silica particles of different sizes and concentrations. The vibration monitoring techniques utilizing eddy current, photoelectric, and piezoelectric sensors were conducted to detect the rotor displacement amplitude and bearing acceleration online. According to the quantitative evaluation, the vibration frequency spectrum, shaft trajectory, and the bearing surface characteristics were analyzed and classified at different conditions of particle parameters. Furthermore, the lubricating mechanism at bearing interface which possesses a strong interactive coupling effect with rotor vibration was deduced and illustrated. The results showed that although the sizes of ingested micron particles were less than the minimum oil-film thickness, they usually exhibited detrimental effects on the flow stability and fluid support. As the particle size or concentration increased, the interaction between particles and bearing surfaces led to the burrs in time-domain waveform, reverse displacements in rotor orbit, higher frequency harmonics in vibration spectrum, and the scratches on the bearing surface. The occurrence of continuous three-body friction could induce misalignment, blockage, oil starvation, and rub-impact fault. Furthermore, the detectability of particle contamination and damage microstructure of bearing surface was described for reference.
{"title":"Experimental Detection of Lubrication Characteristics in a Solid–Liquid Two-Phase Flow Supported Bearing-Rotor System Using Vibration Monitoring Techniques","authors":"Yi Zhang, Wen Wang, G. Wang, Peng Huang, Jimin Xu, Kun Liu","doi":"10.1080/10402004.2023.2251536","DOIUrl":"https://doi.org/10.1080/10402004.2023.2251536","url":null,"abstract":"Abstract This work aims to investigate the friction and vibration behaviors of a liquid–solid two-phase flow supported bearing-rotor system for the early monitoring and assessing of oil contamination resulting from externally ingested particles. Based on a Jeffcott rotor test rig, the lubricating oil in journal bearing was mixed with micron-scale silica particles of different sizes and concentrations. The vibration monitoring techniques utilizing eddy current, photoelectric, and piezoelectric sensors were conducted to detect the rotor displacement amplitude and bearing acceleration online. According to the quantitative evaluation, the vibration frequency spectrum, shaft trajectory, and the bearing surface characteristics were analyzed and classified at different conditions of particle parameters. Furthermore, the lubricating mechanism at bearing interface which possesses a strong interactive coupling effect with rotor vibration was deduced and illustrated. The results showed that although the sizes of ingested micron particles were less than the minimum oil-film thickness, they usually exhibited detrimental effects on the flow stability and fluid support. As the particle size or concentration increased, the interaction between particles and bearing surfaces led to the burrs in time-domain waveform, reverse displacements in rotor orbit, higher frequency harmonics in vibration spectrum, and the scratches on the bearing surface. The occurrence of continuous three-body friction could induce misalignment, blockage, oil starvation, and rub-impact fault. Furthermore, the detectability of particle contamination and damage microstructure of bearing surface was described for reference.","PeriodicalId":23315,"journal":{"name":"Tribology Transactions","volume":"39 1","pages":"929 - 942"},"PeriodicalIF":2.1,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59898797","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}
Pub Date : 2023-08-23DOI: 10.1080/10402004.2023.2250397
W. Dai, P. Lan
Abstract This study compared the tribological performance of four commercial oil-impregnated porous polymer materials and proposed a new benchmark test to measure their dynamic oil bleeding rate. Results were further evaluated using a half-life model. To reveal the structure-performance relationship, the effects of material properties, surface roughness and porosity on the water contact angle (WCA) were discussed using a combined model based on the Wenzel and Cassie-Baxter equations. Results showed that higher WCAs indicated higher oil content at the interface, which favors better tribological performance. The material with a highly fibrous pore structure demonstrated the best performance, with low friction and temperature as well as the longest half-life. It is suggested that optimizing the fibrous content and pore size can improve the performance and extend the life of oil-impregnated porous polymer. This research provides valuable insights into the evaluation and design of oil-impregnated porous polymer materials for improved tribological performance in various applications.
{"title":"Dynamic Bleeding Behavior of Commercial Oil-Impregnated Porous Polymers","authors":"W. Dai, P. Lan","doi":"10.1080/10402004.2023.2250397","DOIUrl":"https://doi.org/10.1080/10402004.2023.2250397","url":null,"abstract":"Abstract This study compared the tribological performance of four commercial oil-impregnated porous polymer materials and proposed a new benchmark test to measure their dynamic oil bleeding rate. Results were further evaluated using a half-life model. To reveal the structure-performance relationship, the effects of material properties, surface roughness and porosity on the water contact angle (WCA) were discussed using a combined model based on the Wenzel and Cassie-Baxter equations. Results showed that higher WCAs indicated higher oil content at the interface, which favors better tribological performance. The material with a highly fibrous pore structure demonstrated the best performance, with low friction and temperature as well as the longest half-life. It is suggested that optimizing the fibrous content and pore size can improve the performance and extend the life of oil-impregnated porous polymer. This research provides valuable insights into the evaluation and design of oil-impregnated porous polymer materials for improved tribological performance in various applications.","PeriodicalId":23315,"journal":{"name":"Tribology Transactions","volume":"66 1","pages":"920 - 928"},"PeriodicalIF":2.1,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42045085","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}
Pub Date : 2023-08-17DOI: 10.1080/10402004.2023.2247041
Joseph F. Shore, Anant S. Kolekar, N. Ren, A. Kadiric
Abstract We present an experimental investigation into the influence of oil viscosity on gear churning losses in splash-lubricated transmission systems. The inertia rundown method was used to perform tests on a single gear within a cylindrical housing with several oils of different viscosities at several immersion depths. A complex and nonmonotonic relationship between churning torque and viscosity was observed that was highly influenced by the rotational speed, with higher viscosity oils resulting in lower churning torque at higher speeds in some cases. This was attributed to a reduction in effective immersion depth due to oil being centrifugally distributed around the casing by the rotating gear, an effect that was observed to be more pronounced with higher viscosity oils. An effective immersion depth parameter, dependent on the rotational speed of the gear and the lubricant viscosity, was defined to account for this phenomenon. Gear churning losses could be better predicted using an existing empirical model when this parameter was used instead of the nominal immersion depth as is usually done.
{"title":"An Investigation Into the Influence of Viscosity on Gear Churning Losses by Considering the Effective Immersion Depth","authors":"Joseph F. Shore, Anant S. Kolekar, N. Ren, A. Kadiric","doi":"10.1080/10402004.2023.2247041","DOIUrl":"https://doi.org/10.1080/10402004.2023.2247041","url":null,"abstract":"Abstract We present an experimental investigation into the influence of oil viscosity on gear churning losses in splash-lubricated transmission systems. The inertia rundown method was used to perform tests on a single gear within a cylindrical housing with several oils of different viscosities at several immersion depths. A complex and nonmonotonic relationship between churning torque and viscosity was observed that was highly influenced by the rotational speed, with higher viscosity oils resulting in lower churning torque at higher speeds in some cases. This was attributed to a reduction in effective immersion depth due to oil being centrifugally distributed around the casing by the rotating gear, an effect that was observed to be more pronounced with higher viscosity oils. An effective immersion depth parameter, dependent on the rotational speed of the gear and the lubricant viscosity, was defined to account for this phenomenon. Gear churning losses could be better predicted using an existing empirical model when this parameter was used instead of the nominal immersion depth as is usually done.","PeriodicalId":23315,"journal":{"name":"Tribology Transactions","volume":"66 1","pages":"906 - 919"},"PeriodicalIF":2.1,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43588522","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：