Pub Date : 2024-01-31DOI: 10.1177/13506501241229501
Youjie Chen, Manqi Yao, Junying Yang, R. Fu, Linlin Su, Fei Gao
Clarifying the relationship between friction area and brake disc temperature is helpful to optimizing the brake pad structure. Aluminium-based brake disc temperature paired with circular friction blocks of different diameters (45, 60, and 65 mm) is obtained by the TM-I-type reduced-scale inertial braking dynamometer at braking speeds 60–160 km/h and braking force 1.66 kN. On the basis, the thermo-mechanical coupling model of friction pair is established to simulate the evolution of brake disc temperature by ADINA finite-element software, and the thermal energy gradient factor is proposed. Results indicate that the numerical brake disc temperature agrees with the measured, validating the numerical model. The friction area caused the difference of braking pressure, which affects the brake disc temperature. The decrease in the friction area accelerates the disc temperature rise and increases the area ratio of high-temperature zone and maximum temperature difference. The influence degree of friction area on the brake disc temperature varies with friction zone. The thermal energy gradient factor can effectively predict the distribution of temperature gradient on the disc surface.
{"title":"Numerical and experimental study of the relationship between friction area and temperature of aluminium-based brake disc","authors":"Youjie Chen, Manqi Yao, Junying Yang, R. Fu, Linlin Su, Fei Gao","doi":"10.1177/13506501241229501","DOIUrl":"https://doi.org/10.1177/13506501241229501","url":null,"abstract":"Clarifying the relationship between friction area and brake disc temperature is helpful to optimizing the brake pad structure. Aluminium-based brake disc temperature paired with circular friction blocks of different diameters (45, 60, and 65 mm) is obtained by the TM-I-type reduced-scale inertial braking dynamometer at braking speeds 60–160 km/h and braking force 1.66 kN. On the basis, the thermo-mechanical coupling model of friction pair is established to simulate the evolution of brake disc temperature by ADINA finite-element software, and the thermal energy gradient factor is proposed. Results indicate that the numerical brake disc temperature agrees with the measured, validating the numerical model. The friction area caused the difference of braking pressure, which affects the brake disc temperature. The decrease in the friction area accelerates the disc temperature rise and increases the area ratio of high-temperature zone and maximum temperature difference. The influence degree of friction area on the brake disc temperature varies with friction zone. The thermal energy gradient factor can effectively predict the distribution of temperature gradient on the disc surface.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140473894","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 : 2024-01-30DOI: 10.1177/13506501241227487
Congpeng Shao, Haojie Xu, ShuangMin Li, Xu Wang, Qi An
In this paper, a new-type air foil bearing with combined bump foils is proposed. The bump foils are arranged and combined in the axial direction. The local and global stiffness of the bearing can be adjusted by the combination of the bump foils. Mechanical analysis of the bearing is carried out, and the mechanical model of the elastic deformation of the flat foil and the bump foils is constructed. Combined with non-isothermal Reynolds equation and energy equation, a fluid–solid coupling numerical calculation model is constructed. Through the actual bearing test research, the reliability of the established theoretical model is verified. On this basis, combined with the specific example, the influences of the structural parameters of the new-type foil bearing on its mechanical properties and lubrication performance are studied, and the specific influence curves are obtained. It is also found that the new-type bearing proposed in this paper has good adaptability to the shaft deflection. When the shaft is deflected, the bump foil at the axial end increases the minimum film height by generating large elastic deformation, which can help to avoid wear caused by direct contact between the shaft and the foil.
{"title":"Development and performance research of a new-type air foil bearing with combined bump foils","authors":"Congpeng Shao, Haojie Xu, ShuangMin Li, Xu Wang, Qi An","doi":"10.1177/13506501241227487","DOIUrl":"https://doi.org/10.1177/13506501241227487","url":null,"abstract":"In this paper, a new-type air foil bearing with combined bump foils is proposed. The bump foils are arranged and combined in the axial direction. The local and global stiffness of the bearing can be adjusted by the combination of the bump foils. Mechanical analysis of the bearing is carried out, and the mechanical model of the elastic deformation of the flat foil and the bump foils is constructed. Combined with non-isothermal Reynolds equation and energy equation, a fluid–solid coupling numerical calculation model is constructed. Through the actual bearing test research, the reliability of the established theoretical model is verified. On this basis, combined with the specific example, the influences of the structural parameters of the new-type foil bearing on its mechanical properties and lubrication performance are studied, and the specific influence curves are obtained. It is also found that the new-type bearing proposed in this paper has good adaptability to the shaft deflection. When the shaft is deflected, the bump foil at the axial end increases the minimum film height by generating large elastic deformation, which can help to avoid wear caused by direct contact between the shaft and the foil.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140484552","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 : 2024-01-30DOI: 10.1177/13506501241227093
Kavit R Shah, Atindra Shukla, N. S. Patel, J. Katiyar
This study has investigated the influence of ferrofluid lubrication on metal tribopairs using an indigenous Block-on-Ring tribometer as per the G77 standard. Considering the complexity of the ferrofluid-based tribosystem, the experiments were carried out based on a previously proposed level-based simplified tribosystem. It is observed that the impact of ferrofluid as an interaction parameter and magnetic field as an environmental parameter has significantly affected tribological properties, that is, ∼60% less friction and ∼74% less wear loss compared to an equivalent oil-based tribosystem. Further, it is noticed that ferritic shaft-based tribosystem lubricated with ferrofluid has better tribological characteristics compared to austenitic shaft-based tribosystem. Also, it had been that a specific testing hierarchy is followed between the performance parameters. Any changes in this testing hierarchy might affect the tribological characteristics.
{"title":"Effect of ferrofluid lubrication on tribological performance of metal tribopairs","authors":"Kavit R Shah, Atindra Shukla, N. S. Patel, J. Katiyar","doi":"10.1177/13506501241227093","DOIUrl":"https://doi.org/10.1177/13506501241227093","url":null,"abstract":"This study has investigated the influence of ferrofluid lubrication on metal tribopairs using an indigenous Block-on-Ring tribometer as per the G77 standard. Considering the complexity of the ferrofluid-based tribosystem, the experiments were carried out based on a previously proposed level-based simplified tribosystem. It is observed that the impact of ferrofluid as an interaction parameter and magnetic field as an environmental parameter has significantly affected tribological properties, that is, ∼60% less friction and ∼74% less wear loss compared to an equivalent oil-based tribosystem. Further, it is noticed that ferritic shaft-based tribosystem lubricated with ferrofluid has better tribological characteristics compared to austenitic shaft-based tribosystem. Also, it had been that a specific testing hierarchy is followed between the performance parameters. Any changes in this testing hierarchy might affect the tribological characteristics.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140481409","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 : 2024-01-27DOI: 10.1177/13506501241227478
Arun Kumar, Harsh Rachwani, Manjesh Kumar Singh
We have studied tribological properties of conversion coatings, hard chrome on AISI 430 stainless steel, and zinc phosphate on AISI 1044 carbon steel. These substrates were chosen due to their extensive industrial applications. The goal of the present study is to improve the wear resistance of these substrates through the coatings. We performed nano-indentation and ball-on-disc tribometer experiments to study mechanical and tribological behavior of substrates and coatings. We find that when zinc-phosphate coating is applied to AISI 1044 steel, a new phase Zn2Fe(PO4)2·4H2O (phosphophyllite) is formed on the surface that increases the surface hardness. We further find that coefficient of friction decreases approximately by 8% due to hard-chrome coating on AISI 430 steel and by 48% due to zinc-phosphate coating on AISI 1044 steel under load and speed conditions applied in the present study. We attribute our findings to formation of: (1) an adhering layer of chromium in the case of chrome–steel contact, leading to chrome–chrome contact at the interface of test-specimen and counter-surface, and (2) a glossy layer at interface in the case of phosphate-steel contact, owing to the compaction and crushing of phosphate wear debris. Our wear studies show maximum reductions in specific wear rate to be around 80% and 89% for chrome and zinc-phosphate coatings, respectively. We note that adhesion and abrasion are the primary modes of wear for chrome and zinc-phosphate conversion coatings, respectively at the initial stage. However, adhesive wear switches to delamination wear at a later stage for hard-chrome coating.
{"title":"Dry sliding wear behavior of hard-chrome and zinc-phosphate conversion coatings on steel substrates","authors":"Arun Kumar, Harsh Rachwani, Manjesh Kumar Singh","doi":"10.1177/13506501241227478","DOIUrl":"https://doi.org/10.1177/13506501241227478","url":null,"abstract":"We have studied tribological properties of conversion coatings, hard chrome on AISI 430 stainless steel, and zinc phosphate on AISI 1044 carbon steel. These substrates were chosen due to their extensive industrial applications. The goal of the present study is to improve the wear resistance of these substrates through the coatings. We performed nano-indentation and ball-on-disc tribometer experiments to study mechanical and tribological behavior of substrates and coatings. We find that when zinc-phosphate coating is applied to AISI 1044 steel, a new phase Zn2Fe(PO4)2·4H2O (phosphophyllite) is formed on the surface that increases the surface hardness. We further find that coefficient of friction decreases approximately by 8% due to hard-chrome coating on AISI 430 steel and by 48% due to zinc-phosphate coating on AISI 1044 steel under load and speed conditions applied in the present study. We attribute our findings to formation of: (1) an adhering layer of chromium in the case of chrome–steel contact, leading to chrome–chrome contact at the interface of test-specimen and counter-surface, and (2) a glossy layer at interface in the case of phosphate-steel contact, owing to the compaction and crushing of phosphate wear debris. Our wear studies show maximum reductions in specific wear rate to be around 80% and 89% for chrome and zinc-phosphate coatings, respectively. We note that adhesion and abrasion are the primary modes of wear for chrome and zinc-phosphate conversion coatings, respectively at the initial stage. However, adhesive wear switches to delamination wear at a later stage for hard-chrome coating.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140492117","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}
Hybrid porous tilting pad bearings with the advantages of gas porous bearings and tilting pad bearings exhibited excellent rotor-supporting performance with high accuracy and stability. Under hybrid lubrication, the transient adaptive motion of the tilting pads was important for the rotordynamic characteristics. A novel fluid–structure interaction model of hybrid porous tilting pad bearings was developed to investigate the transient hydro forces and the pad's adaptive motion. The rotordynamic coefficients of the hybrid porous tilting pad bearings were identified using the rotor harmonic trajectory. The computational fluid dynamics-fluid–structure interaction model was validated with the experimental data. The effects of eccentricity ratios, rotor speeds, supply pressures, pivot radial stiffnesses, and dampings on the pad adaptive motion and the rotordynamic coefficients were evaluated. The pad self-adaption motions significantly influenced the supporting and vibration-absorbing characteristics of hybrid porous tilting pad bearings.
{"title":"A novel transient computational fluid dynamics-fluid–structure interaction model for the pad adaptive motion and rotordynamic coefficients of hybrid porous tilting pad bearings","authors":"Peng Xia, Xiaofei Jin, Wenlong Song, Yangqiao Liang, Shicheng Xu, Jiabao Liu, Zhansheng Liu, Wensheng Ma","doi":"10.1177/13506501241227708","DOIUrl":"https://doi.org/10.1177/13506501241227708","url":null,"abstract":"Hybrid porous tilting pad bearings with the advantages of gas porous bearings and tilting pad bearings exhibited excellent rotor-supporting performance with high accuracy and stability. Under hybrid lubrication, the transient adaptive motion of the tilting pads was important for the rotordynamic characteristics. A novel fluid–structure interaction model of hybrid porous tilting pad bearings was developed to investigate the transient hydro forces and the pad's adaptive motion. The rotordynamic coefficients of the hybrid porous tilting pad bearings were identified using the rotor harmonic trajectory. The computational fluid dynamics-fluid–structure interaction model was validated with the experimental data. The effects of eccentricity ratios, rotor speeds, supply pressures, pivot radial stiffnesses, and dampings on the pad adaptive motion and the rotordynamic coefficients were evaluated. The pad self-adaption motions significantly influenced the supporting and vibration-absorbing characteristics of hybrid porous tilting pad bearings.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139607024","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 : 2024-01-22DOI: 10.1177/13506501231225135
Yuanying Du, Bojian Chen, Qinxin Cao, Wenshan Wang, Haiyan Pu
Aiming at the crucial issues of serious friction, wear and large leakage in the key friction pair on the aviation plunger pump, the influence factors of pressure and shear flow are introduced to correct the Reynolds governing equation of the clearance flow, the oil film thickness equation considering the deflection of the plunger was established, and the lubrication and leakage characteristics of the plunger/cylinder pair are analyzed using finite element method, and the following conclusions are obtained: the inclination angle of the plunger has a significant influence on the lubrication characteristics of the plunger pair, the maximum oil film pressure of the tilted plunger is significantly greater than that of the non-tilted plunger, a transition from elastohydrodynamic lubrication to mixed lubrication occurs in the plunger/cylinder pair at an inclination angle of 0.00015°. When the inclination angle is 0.00025°, the maximum oil film pressure is about 14 times than that without inclination, and the minimum oil film thickness when the plunger is deflected is significantly smaller than that without inclination. As the pressure difference gradually increases, the leakage ratio of a single plunger/cylinder pair mostly shows an approximate linear increase trend. When the contact length is 17 mm, the leakage amount is the largest and the slope of the varied curve is the steepest, when the unilateral clearance increases above 3 µm, the leakage ratio increases significantly. The research can provide references for the plunger/cylinder pair precise theoretical design and the instability of the core rotating components of aviation plunger pumps.
{"title":"Lubrication and leakage characteristic research of aviation plunger pump considering plunger deflection","authors":"Yuanying Du, Bojian Chen, Qinxin Cao, Wenshan Wang, Haiyan Pu","doi":"10.1177/13506501231225135","DOIUrl":"https://doi.org/10.1177/13506501231225135","url":null,"abstract":"Aiming at the crucial issues of serious friction, wear and large leakage in the key friction pair on the aviation plunger pump, the influence factors of pressure and shear flow are introduced to correct the Reynolds governing equation of the clearance flow, the oil film thickness equation considering the deflection of the plunger was established, and the lubrication and leakage characteristics of the plunger/cylinder pair are analyzed using finite element method, and the following conclusions are obtained: the inclination angle of the plunger has a significant influence on the lubrication characteristics of the plunger pair, the maximum oil film pressure of the tilted plunger is significantly greater than that of the non-tilted plunger, a transition from elastohydrodynamic lubrication to mixed lubrication occurs in the plunger/cylinder pair at an inclination angle of 0.00015°. When the inclination angle is 0.00025°, the maximum oil film pressure is about 14 times than that without inclination, and the minimum oil film thickness when the plunger is deflected is significantly smaller than that without inclination. As the pressure difference gradually increases, the leakage ratio of a single plunger/cylinder pair mostly shows an approximate linear increase trend. When the contact length is 17 mm, the leakage amount is the largest and the slope of the varied curve is the steepest, when the unilateral clearance increases above 3 µm, the leakage ratio increases significantly. The research can provide references for the plunger/cylinder pair precise theoretical design and the instability of the core rotating components of aviation plunger pumps.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139606245","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 : 2024-01-08DOI: 10.1177/13506501231224005
Scott Bair, W. Habchi
Many engineering estimates of the film thickness in the concentrated contacts of real machines have come from extrapolations of measurements of elastohydrodynamic lubrication film thickness performed in glass on steel elastohydrodynamic rigs. Such estimates are likely to have large errors due to shear dependence of viscosity. The classical film thickness formulas employed have not been validated except for some Newtonian reference liquids at room temperature because the real pressure-viscosity response measured in viscometers has been ignored. A blend of polyalpha olefin base oils with mild shear-thinning has been employed in a line contact calculation to assess the effects of shear-dependent viscosity on the power-law exponents of the classical film thickness formula. The exponents on the pressure-viscosity coefficient and on the elastic modulus of the solids are not sensitive to the non-Newtonian effect. The exponents on ambient pressure viscosity and velocity are slightly reduced by shear-thinning. The exponents on pressure and scale are substantially increased by the shear dependence. The usual practice of measuring film thickness in an elastohydrodynamic rig to obtain an effective “[Formula: see text]-value” to use in a classical Newtonian film thickness formula will overstated the film thickness of a liquid which is shear dependent in the elastohydrodynamic lubrication inlet.
{"title":"Effects of a typical shear dependent viscosity on analytical elastohydrodynamic lubrication film thickness predictions: A critical issue for the classical approach","authors":"Scott Bair, W. Habchi","doi":"10.1177/13506501231224005","DOIUrl":"https://doi.org/10.1177/13506501231224005","url":null,"abstract":"Many engineering estimates of the film thickness in the concentrated contacts of real machines have come from extrapolations of measurements of elastohydrodynamic lubrication film thickness performed in glass on steel elastohydrodynamic rigs. Such estimates are likely to have large errors due to shear dependence of viscosity. The classical film thickness formulas employed have not been validated except for some Newtonian reference liquids at room temperature because the real pressure-viscosity response measured in viscometers has been ignored. A blend of polyalpha olefin base oils with mild shear-thinning has been employed in a line contact calculation to assess the effects of shear-dependent viscosity on the power-law exponents of the classical film thickness formula. The exponents on the pressure-viscosity coefficient and on the elastic modulus of the solids are not sensitive to the non-Newtonian effect. The exponents on ambient pressure viscosity and velocity are slightly reduced by shear-thinning. The exponents on pressure and scale are substantially increased by the shear dependence. The usual practice of measuring film thickness in an elastohydrodynamic rig to obtain an effective “[Formula: see text]-value” to use in a classical Newtonian film thickness formula will overstated the film thickness of a liquid which is shear dependent in the elastohydrodynamic lubrication inlet.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139447058","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 : 2024-01-08DOI: 10.1177/13506501231224256
Abdurrahim Dal
The nanolubricant's effectiveness on the bearings’ performance depends on the types of nanoparticles, volume ratio, and their size and/or diameter. Although the nanolubricant influences on the characteristics of the journal bearings are well known, cost-effective solutions for using nanolubricants, have continued to need in industrial applications. Because the nanoparticle's diameter plays a key role in the fluid with nanoparticle additives, research on its effect is important for hydrodynamic journal bearing. In this work, the nanoparticle diameter impacts on the characteristics of the hydrodynamic journal bearings are investigated with under thermal effects. At first, four hydrodynamic journal bearings have different parameters such as radial clearance and bearing length–diameter ratio are considered and designed. Then, the lubricant flow through the radial clearance is modeled with Dowson's equation. Besides, the temperature field in the journal and the lubricant are governed by the heat conduction and energy equations, respectively. The physical and thermal properties of the nanolubricant are expressed by considering nanoparticle diameter and the volume ratio. Then, an algorithm is developed to solve the mathematical models based on the finite difference method. Finally, a serial simulation is conducted under different nanoparticle diameters and operational conditions. When the nanoparticle diameter becomes small, the temperature and pressure values of the nanolubricant, load capacity, and stiffness increase.
{"title":"Investigation of nanoparticle diameter influences on performance of hydrodynamic journal bearings operating with nanolubricant","authors":"Abdurrahim Dal","doi":"10.1177/13506501231224256","DOIUrl":"https://doi.org/10.1177/13506501231224256","url":null,"abstract":"The nanolubricant's effectiveness on the bearings’ performance depends on the types of nanoparticles, volume ratio, and their size and/or diameter. Although the nanolubricant influences on the characteristics of the journal bearings are well known, cost-effective solutions for using nanolubricants, have continued to need in industrial applications. Because the nanoparticle's diameter plays a key role in the fluid with nanoparticle additives, research on its effect is important for hydrodynamic journal bearing. In this work, the nanoparticle diameter impacts on the characteristics of the hydrodynamic journal bearings are investigated with under thermal effects. At first, four hydrodynamic journal bearings have different parameters such as radial clearance and bearing length–diameter ratio are considered and designed. Then, the lubricant flow through the radial clearance is modeled with Dowson's equation. Besides, the temperature field in the journal and the lubricant are governed by the heat conduction and energy equations, respectively. The physical and thermal properties of the nanolubricant are expressed by considering nanoparticle diameter and the volume ratio. Then, an algorithm is developed to solve the mathematical models based on the finite difference method. Finally, a serial simulation is conducted under different nanoparticle diameters and operational conditions. When the nanoparticle diameter becomes small, the temperature and pressure values of the nanolubricant, load capacity, and stiffness increase.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2024-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139445584","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}
In the process of machine and mechanical operation, it is inevitable to face problems such as friction and wear. At present, there are many solutions to solve the problems. As a very effective method, surface texturing has been applied in many projects. In recent years, surface texturing has made great achievements in the study of friction pair surface, which is of great significance to improve the tribological properties of friction pair surface. In this paper, the author reviews the main research results of surface texturing in controlling friction in recent years and points out the research purpose and development status of surface texture. The preparation of texturing is summarized and analyzed from two aspects: shape and size control accuracy and surface quality. The research on the anti-friction mechanism of texture is reviewed, and the three states of dry friction, fluid lubrication, and boundary lubrication are analyzed, respectively. The optimization of morphology and parameters was discussed, and the optimal parameter range was obtained. Finally, the above aspects of the full text are summarized, and the problems faced by all aspects are put forward. Combined with the actual situation of the current research, the future development prospect of surface texture technology is prospected.
{"title":"Research progress of surface texturing to improve the tribological properties: A review","authors":"Yansheng Liu, Xuefeng Yang, Junbei Ma, Kunjie Li, Maolong Chen, Yanguang Gu","doi":"10.1177/13506501231222522","DOIUrl":"https://doi.org/10.1177/13506501231222522","url":null,"abstract":"In the process of machine and mechanical operation, it is inevitable to face problems such as friction and wear. At present, there are many solutions to solve the problems. As a very effective method, surface texturing has been applied in many projects. In recent years, surface texturing has made great achievements in the study of friction pair surface, which is of great significance to improve the tribological properties of friction pair surface. In this paper, the author reviews the main research results of surface texturing in controlling friction in recent years and points out the research purpose and development status of surface texture. The preparation of texturing is summarized and analyzed from two aspects: shape and size control accuracy and surface quality. The research on the anti-friction mechanism of texture is reviewed, and the three states of dry friction, fluid lubrication, and boundary lubrication are analyzed, respectively. The optimization of morphology and parameters was discussed, and the optimal parameter range was obtained. Finally, the above aspects of the full text are summarized, and the problems faced by all aspects are put forward. Combined with the actual situation of the current research, the future development prospect of surface texture technology is prospected.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139153884","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 : 2023-12-27DOI: 10.1177/13506501231222673
Meiling Wang, Zhiqiang Huang, Weiji Qian, Gang Li
To solve the problem of premature failure of the rubber stator of the screw pump due to wear, reduce the frictional resistance torque of the screw pump to solve the problem of difficulty in starting after the shutdown of the screw pump production system in Daqing Oilfield. The effects of micron dot texture and lubricating medium on the tribological properties of 42CrMo metal and acrylonitrile–butadiene rubber mating surfaces were studied by theoretical analysis and tribological tests. The friction coefficient, wear amount, and rubber wear morphology were used as the measurement indexes of drag reduction, wear resistance, and wear degree, respectively. The results showed that the best combination of texture area ratio and the lubricating medium was 10% silicone grease, the friction coefficient and wear amount were reduced by 11% and 10.7%, respectively, compared with untextured, and the main order of chip storage and oil supply effect was 10% > 5% > 15%.
{"title":"Study of the effect of laser textured rotors on the starting performance of metal–rubber mating pairs under different lubricating media environments","authors":"Meiling Wang, Zhiqiang Huang, Weiji Qian, Gang Li","doi":"10.1177/13506501231222673","DOIUrl":"https://doi.org/10.1177/13506501231222673","url":null,"abstract":"To solve the problem of premature failure of the rubber stator of the screw pump due to wear, reduce the frictional resistance torque of the screw pump to solve the problem of difficulty in starting after the shutdown of the screw pump production system in Daqing Oilfield. The effects of micron dot texture and lubricating medium on the tribological properties of 42CrMo metal and acrylonitrile–butadiene rubber mating surfaces were studied by theoretical analysis and tribological tests. The friction coefficient, wear amount, and rubber wear morphology were used as the measurement indexes of drag reduction, wear resistance, and wear degree, respectively. The results showed that the best combination of texture area ratio and the lubricating medium was 10% silicone grease, the friction coefficient and wear amount were reduced by 11% and 10.7%, respectively, compared with untextured, and the main order of chip storage and oil supply effect was 10% > 5% > 15%.","PeriodicalId":20570,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":null,"pages":null},"PeriodicalIF":2.0,"publicationDate":"2023-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139153983","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}
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