Pub Date : 2024-04-15DOI: 10.1177/13506501241246029
Penghai Zhang
A theoretical model of the orifice-compensated air bearing with rectangular shape is built to study the stability, the stiffness and the air consumption considering the air film thickness. The study shows that, the pocket volume ratio of less than 0.03 is recommended to avoid the pneumatic hammer. The stability is good and the air consumption is small when the bearing has the high stiffness. Strict control of the structural deformation is crucial as it can significantly affect the stability. Increasing the nozzle number can improve the stability and avoid the choked flow. The findings are of great importance for the design of the orifice-compensated air bearing.
{"title":"Stability of orifice-compensated air bearing with rectangular shape considering air film thickness","authors":"Penghai Zhang","doi":"10.1177/13506501241246029","DOIUrl":"https://doi.org/10.1177/13506501241246029","url":null,"abstract":"A theoretical model of the orifice-compensated air bearing with rectangular shape is built to study the stability, the stiffness and the air consumption considering the air film thickness. The study shows that, the pocket volume ratio of less than 0.03 is recommended to avoid the pneumatic hammer. The stability is good and the air consumption is small when the bearing has the high stiffness. Strict control of the structural deformation is crucial as it can significantly affect the stability. Increasing the nozzle number can improve the stability and avoid the choked flow. The findings are of great importance for the design of the orifice-compensated air bearing.","PeriodicalId":509096,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"33 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140702292","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}
Pub Date : 2024-04-15DOI: 10.1177/13506501241242185
Pedro Amoroso, R. V. van Ostayen, M. D. de Rooij
The rolling-sliding dynamics of large-scale cam-roller contacts are strongly influenced by the inertia of the roller, particularly when slippage occurs. Slippage can potentially impact the reliability of these rolling interfaces. This study introduces an approach to replicate the rolling-sliding dynamics of cam-roller contacts in a large-scale hydraulic drivetrain, on a small scale. For that, we have upgraded our two-roller tribometer to enable cyclic loading, allow the application of resisting torques, and generate inertia torques. These are three essential elements required to mimic the dynamics observed at large scales. A method has been proposed for scaling the roller inertia accordingly. Furthermore, we have implemented a modeling framework from previous work to make predictions under various dynamic conditions. The results show that our small-scale approach can replicate five key characteristics anticipated at a large scale, including those linked to slippage. Small increments in the resisting torque significantly increased the slide-to-roll ratio (SRR) and peak traction force, among others. The simulations also predicted these effects, capturing trends and producing reasonable predictions of the magnitude and relevant features of key parameters. The use of cyclic loading, extra inertia, and adjustable resisting torques, effectively generated repeatable and controllable dynamic rolling-sliding conditions. Our work is significant for the design and development of novel large-scale hydraulic drivetrains. Our findings highlight the importance of reducing slippage at low contact forces to prevent the brusque change in the rolling conditions during the high contact force phase. By doing so, surface damage and detrimental dynamic effects can be prevented.
{"title":"Replicating the rolling-sliding dynamics of cam-roller contacts in large-scale hydraulic drivetrains: A small-scale approach","authors":"Pedro Amoroso, R. V. van Ostayen, M. D. de Rooij","doi":"10.1177/13506501241242185","DOIUrl":"https://doi.org/10.1177/13506501241242185","url":null,"abstract":"The rolling-sliding dynamics of large-scale cam-roller contacts are strongly influenced by the inertia of the roller, particularly when slippage occurs. Slippage can potentially impact the reliability of these rolling interfaces. This study introduces an approach to replicate the rolling-sliding dynamics of cam-roller contacts in a large-scale hydraulic drivetrain, on a small scale. For that, we have upgraded our two-roller tribometer to enable cyclic loading, allow the application of resisting torques, and generate inertia torques. These are three essential elements required to mimic the dynamics observed at large scales. A method has been proposed for scaling the roller inertia accordingly. Furthermore, we have implemented a modeling framework from previous work to make predictions under various dynamic conditions. The results show that our small-scale approach can replicate five key characteristics anticipated at a large scale, including those linked to slippage. Small increments in the resisting torque significantly increased the slide-to-roll ratio (SRR) and peak traction force, among others. The simulations also predicted these effects, capturing trends and producing reasonable predictions of the magnitude and relevant features of key parameters. The use of cyclic loading, extra inertia, and adjustable resisting torques, effectively generated repeatable and controllable dynamic rolling-sliding conditions. Our work is significant for the design and development of novel large-scale hydraulic drivetrains. Our findings highlight the importance of reducing slippage at low contact forces to prevent the brusque change in the rolling conditions during the high contact force phase. By doing so, surface damage and detrimental dynamic effects can be prevented.","PeriodicalId":509096,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"5 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140699355","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}
Pub Date : 2024-04-13DOI: 10.1177/13506501241245760
Bivash Chakraborty, Biplab Bhattacharjee, P. Chakraborti, N. Biswas
Instruments with high levels of precision commonly use aerostatic bearings. Moreover, the use of porous (Al2O3 membrane) material validates that the pressure is spread uniformly throughout the air film region. The impression of applied load on the thickness of the air film of the aerostatic bearings was evaluated using a certain experimental technique. As the applied load rises, the thickness of the air film expands, and as the compressive stress rises, it contracts. The theoretical model parameters were set using the experimental stipulations. It was discovered that the theoretical model and the experimental data were consistent. The pressure gradient induced in the air film and the air bearings’ capacity for carrying loads were calculated using a theoretical simulation. The results of theoretical modeling and experimental comparison of the different characteristics of porous (Al2O3 membrane) aerostatic bearings based on stiffness and load-carrying capacity are graphically illustrated in this study. Porous aerostatic bearings with Al2O3 membranes have a number of potential applications, including high-speed spindles, precision instruments, microelectromechanical systems, vacuum pumps, cryogenic applications, etc.
{"title":"Evaluation of the performance characteristics of aerostatic bearing with porous alumina (Al2O3) membrane using theoretical and experimental methods","authors":"Bivash Chakraborty, Biplab Bhattacharjee, P. Chakraborti, N. Biswas","doi":"10.1177/13506501241245760","DOIUrl":"https://doi.org/10.1177/13506501241245760","url":null,"abstract":"Instruments with high levels of precision commonly use aerostatic bearings. Moreover, the use of porous (Al2O3 membrane) material validates that the pressure is spread uniformly throughout the air film region. The impression of applied load on the thickness of the air film of the aerostatic bearings was evaluated using a certain experimental technique. As the applied load rises, the thickness of the air film expands, and as the compressive stress rises, it contracts. The theoretical model parameters were set using the experimental stipulations. It was discovered that the theoretical model and the experimental data were consistent. The pressure gradient induced in the air film and the air bearings’ capacity for carrying loads were calculated using a theoretical simulation. The results of theoretical modeling and experimental comparison of the different characteristics of porous (Al2O3 membrane) aerostatic bearings based on stiffness and load-carrying capacity are graphically illustrated in this study. Porous aerostatic bearings with Al2O3 membranes have a number of potential applications, including high-speed spindles, precision instruments, microelectromechanical systems, vacuum pumps, cryogenic applications, etc.","PeriodicalId":509096,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"66 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140706909","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}
Pub Date : 2024-04-13DOI: 10.1177/13506501241246834
Yu Dai, C. Yang, Ru Zhang, Chongyu Liang, Xiang Zhu
With practical physical immersion depth as their joint, the relations between the oil distribution characteristics and the associated no-load power losses for splash-lubricated orthogonal face gears are explored and quantified in this paper. Firstly, a theoretical analytical model is proposed to estimate the churning losses of an isolated face gear considering all the preceding parameters, along with a numerical model of a face gear stirring oil developed based on the sliding mesh strategy. Then the accuracy and correctness of the computational fluid dynamics method are verified with experiments in terms of oil flow behavior and no-load losses. Finally, the physical immersion depth is determined by leveraging the image processing technique and substituted into the theoretical model replacing the static depth with an improvement of prediction accuracy. Last but not least, this practical immersion depth acts as a link to facilitate the communication between the oil distributions and the no-load power losses within the gearboxes.
{"title":"Splash lubrication for an orthogonal face gear using numerical investigation integrating image processing","authors":"Yu Dai, C. Yang, Ru Zhang, Chongyu Liang, Xiang Zhu","doi":"10.1177/13506501241246834","DOIUrl":"https://doi.org/10.1177/13506501241246834","url":null,"abstract":"With practical physical immersion depth as their joint, the relations between the oil distribution characteristics and the associated no-load power losses for splash-lubricated orthogonal face gears are explored and quantified in this paper. Firstly, a theoretical analytical model is proposed to estimate the churning losses of an isolated face gear considering all the preceding parameters, along with a numerical model of a face gear stirring oil developed based on the sliding mesh strategy. Then the accuracy and correctness of the computational fluid dynamics method are verified with experiments in terms of oil flow behavior and no-load losses. Finally, the physical immersion depth is determined by leveraging the image processing technique and substituted into the theoretical model replacing the static depth with an improvement of prediction accuracy. Last but not least, this practical immersion depth acts as a link to facilitate the communication between the oil distributions and the no-load power losses within the gearboxes.","PeriodicalId":509096,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"49 214","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140708500","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}
Pub Date : 2024-04-02DOI: 10.1177/13506501241242151
Yan Feng, Xiujiang Shi, Xi Qun Lu, Wen Sun, Kun Peng Liu, Yun Fei Fei
Ship gas turbine bearings are subjected to heavy loads and intricate interface micromorphologies, predominantly operate in a mixed lubrication regime. Excessive asperity relative sliding can cause transient high-temperature spikes at contact points, leading to scuffing failures. Dynamic parameters such as bearing friction and clearance, along with vibrations causing fluctuating velocities and loads, further influence the lubrication condition that, in its turn, can increase the risk of scuffing. This study focuses on oil-lubricated gas turbine bearings, accounting for their typical transient working conditions and real surface roughness. The coupling characteristics of ball bearing dynamics, lubrication, and flash temperature are explored. Findings indicate that the most severe contact conditions occur at azimuth angles of 0° and 360°. The risk of ball Scuffing failure exceeds that of the inner raceway. As axial load increases under the azimuth angle of 360°, the area with zero film thickness is increasing, elevating the chances of asperity contact, friction coefficient, and interface temperature, which is detrimental to lubrication. To mitigate pitting and scuffing failures, it's recommended to maintain the bearing's maximum hertz pressure below 1.21 GPa.
{"title":"Study on scuffing failure of gas turbine ball bearing based on 3D mixed lubrication and dynamics","authors":"Yan Feng, Xiujiang Shi, Xi Qun Lu, Wen Sun, Kun Peng Liu, Yun Fei Fei","doi":"10.1177/13506501241242151","DOIUrl":"https://doi.org/10.1177/13506501241242151","url":null,"abstract":"Ship gas turbine bearings are subjected to heavy loads and intricate interface micromorphologies, predominantly operate in a mixed lubrication regime. Excessive asperity relative sliding can cause transient high-temperature spikes at contact points, leading to scuffing failures. Dynamic parameters such as bearing friction and clearance, along with vibrations causing fluctuating velocities and loads, further influence the lubrication condition that, in its turn, can increase the risk of scuffing. This study focuses on oil-lubricated gas turbine bearings, accounting for their typical transient working conditions and real surface roughness. The coupling characteristics of ball bearing dynamics, lubrication, and flash temperature are explored. Findings indicate that the most severe contact conditions occur at azimuth angles of 0° and 360°. The risk of ball Scuffing failure exceeds that of the inner raceway. As axial load increases under the azimuth angle of 360°, the area with zero film thickness is increasing, elevating the chances of asperity contact, friction coefficient, and interface temperature, which is detrimental to lubrication. To mitigate pitting and scuffing failures, it's recommended to maintain the bearing's maximum hertz pressure below 1.21 GPa.","PeriodicalId":509096,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"326 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140754341","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}
Pub Date : 2024-03-22DOI: 10.1177/13506501241240023
Wenguang Zhou, Rupeng Zhu, Wenzheng Liu, Jingjing Wang
Installation error is one of the most prominent factors affecting the lubrication of face gear. To analyze the lubrication performance of the face gear with installation errors, the installation error model of the orthogonal face gear transmission system is established. Then, the contact path, equivalent curvature radius, load distribution and entrainment velocity are studied using the face gear loaded tooth contact analysis (LTCA). On this basis, the lubrication governing equations of the face gear are established according to the elastohydrodynamic lubrication (EHL) theory. In addition, the oil film thickness, oil film pressure and coefficient of friction in the process of face gear drives are calculated using the method of progressive mesh densification (PMD). Finally, the effects of axis intersection angle error, axis intersection error and axial displacement error on lubrication characteristics are analyzed. The results reveal that when the axial intersection angle error and axial displacement error are negative and the axial intersection error is positive, the minimum oil film thickness of the face gear tooth surface is less than that without error. When the error values are the same, the minimum oil film thickness and coefficient of friction have larger changes with the axial displacement error than with the axis intersection error, and the contact path has a bigger movement range.
{"title":"Modeling and analysis of elastohydrodynamic lubrication of orthogonal face gear with installation errors","authors":"Wenguang Zhou, Rupeng Zhu, Wenzheng Liu, Jingjing Wang","doi":"10.1177/13506501241240023","DOIUrl":"https://doi.org/10.1177/13506501241240023","url":null,"abstract":"Installation error is one of the most prominent factors affecting the lubrication of face gear. To analyze the lubrication performance of the face gear with installation errors, the installation error model of the orthogonal face gear transmission system is established. Then, the contact path, equivalent curvature radius, load distribution and entrainment velocity are studied using the face gear loaded tooth contact analysis (LTCA). On this basis, the lubrication governing equations of the face gear are established according to the elastohydrodynamic lubrication (EHL) theory. In addition, the oil film thickness, oil film pressure and coefficient of friction in the process of face gear drives are calculated using the method of progressive mesh densification (PMD). Finally, the effects of axis intersection angle error, axis intersection error and axial displacement error on lubrication characteristics are analyzed. The results reveal that when the axial intersection angle error and axial displacement error are negative and the axial intersection error is positive, the minimum oil film thickness of the face gear tooth surface is less than that without error. When the error values are the same, the minimum oil film thickness and coefficient of friction have larger changes with the axial displacement error than with the axis intersection error, and the contact path has a bigger movement range.","PeriodicalId":509096,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":" 29","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140220461","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}
Pub Date : 2024-03-18DOI: 10.1177/13506501241239490
Pedro Amoroso, R. V. van Ostayen, M. D. de Rooij
This work introduces two innovative rolling pair concepts to minimize slippage and reduce mass in cam-roller systems of large-scale hydraulic drivetrains: The variable contact length and the Shifting Contact Geometry concepts. Both aim to improve traction in the low contact force phase in cyclically loaded rolling contacts. The shifting contact geometry concept was validated using three custom rolling contacts: a line contact, a double elliptical contact, and a combination of both (i.e., shifting contact geometry). The tests were conducted under synchronized cyclic loading to mimic the conditions in a hydraulic drivetrain. Furthermore, a model from previous work was implemented to make predictions and compare them against the experimental results. During preliminary tests, the double elliptical contact displayed superior tractive behavior than the line contact under the same load thanks to higher contact pressures. Under synchronized cyclic loading, the line contact displayed high sensitivity to applied resisting torques at low contact forces, leading to high slide-to-roll ratios and traction force peaks. In contrast, the rolling pair with shifting contact geometry exhibited minimum slippage even under high resisting torques, resulting in substantially lower (and in most cases negligible) slide-to-roll ratio and traction force peaks. The simulations also captured this behavior, proving the validity of the model for predicting and comparing the rolling-sliding dynamics of these two different rolling pairs. This study demonstrates that rolling pairs with shifting contact geometry can not only improve the tribological performance of cam-roller contacts in large-scale hydraulic drivetrains but also yield a more favorable dynamic behavior.
{"title":"Rolling pairs with shifting contact geometry: Design, development, and validation","authors":"Pedro Amoroso, R. V. van Ostayen, M. D. de Rooij","doi":"10.1177/13506501241239490","DOIUrl":"https://doi.org/10.1177/13506501241239490","url":null,"abstract":"This work introduces two innovative rolling pair concepts to minimize slippage and reduce mass in cam-roller systems of large-scale hydraulic drivetrains: The variable contact length and the Shifting Contact Geometry concepts. Both aim to improve traction in the low contact force phase in cyclically loaded rolling contacts. The shifting contact geometry concept was validated using three custom rolling contacts: a line contact, a double elliptical contact, and a combination of both (i.e., shifting contact geometry). The tests were conducted under synchronized cyclic loading to mimic the conditions in a hydraulic drivetrain. Furthermore, a model from previous work was implemented to make predictions and compare them against the experimental results. During preliminary tests, the double elliptical contact displayed superior tractive behavior than the line contact under the same load thanks to higher contact pressures. Under synchronized cyclic loading, the line contact displayed high sensitivity to applied resisting torques at low contact forces, leading to high slide-to-roll ratios and traction force peaks. In contrast, the rolling pair with shifting contact geometry exhibited minimum slippage even under high resisting torques, resulting in substantially lower (and in most cases negligible) slide-to-roll ratio and traction force peaks. The simulations also captured this behavior, proving the validity of the model for predicting and comparing the rolling-sliding dynamics of these two different rolling pairs. This study demonstrates that rolling pairs with shifting contact geometry can not only improve the tribological performance of cam-roller contacts in large-scale hydraulic drivetrains but also yield a more favorable dynamic behavior.","PeriodicalId":509096,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"43 19","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140231501","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}
Pub Date : 2024-03-18DOI: 10.1177/13506501241235726
Alexandre Medeiros, Raphael Cardoso, José Oliveira Júnior, Salete Alves
One of the main reasons for failure in the wind turbine is the wear between the gear teeth during the power conversion and changes in the rotation speed, which is also generally associated with changes in the lubrication regimes. In this sense, vibration and signal analysis are frequently used in predictive maintenance as they usually permit the identification of deviations in the proper functioning of the equipment. Thus, this work aims to apply the continuous wavelet transform (CWT) to correlate gear wear and vibration signals, using visual and straightforward analysis. An experimental setup of a gear system was used to analyze vibration signals from different tooth gear damages. Gears with different levels and modes of damage were used in order to evaluate the sensitivity of vibration signals to them. The features from vibration signals were extracted by Morlet wavelet analysis. Results demonstrate that the proposed method accurately detected the early failure by visualization in frequency–time maps.
{"title":"Failure analysis of gear using continuous wavelet transform applied in the context of wind turbines","authors":"Alexandre Medeiros, Raphael Cardoso, José Oliveira Júnior, Salete Alves","doi":"10.1177/13506501241235726","DOIUrl":"https://doi.org/10.1177/13506501241235726","url":null,"abstract":"One of the main reasons for failure in the wind turbine is the wear between the gear teeth during the power conversion and changes in the rotation speed, which is also generally associated with changes in the lubrication regimes. In this sense, vibration and signal analysis are frequently used in predictive maintenance as they usually permit the identification of deviations in the proper functioning of the equipment. Thus, this work aims to apply the continuous wavelet transform (CWT) to correlate gear wear and vibration signals, using visual and straightforward analysis. An experimental setup of a gear system was used to analyze vibration signals from different tooth gear damages. Gears with different levels and modes of damage were used in order to evaluate the sensitivity of vibration signals to them. The features from vibration signals were extracted by Morlet wavelet analysis. Results demonstrate that the proposed method accurately detected the early failure by visualization in frequency–time maps.","PeriodicalId":509096,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140232353","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}
Pub Date : 2024-03-15DOI: 10.1177/13506501241238280
Lei Liu, Rong Kong, Zhiwei Chen
The prediction of load-dependent losses of gear pairs is a topic of constant concern, which depends largely on the modelling of friction coefficient in tooth meshing. Although the current load-sharing based models can handle the friction coefficient in mixed elastohydrodynamic lubrication regimes, dynamics behaviour of each tooth pair or the time variation of direction of normal contact load is not taken into consideration. This study proposes a new method for modelling efficiency of spur gear pairs in transient operating conditions by coupling the multi-tooth meshing model with the friction coefficient model. The friction coefficient is modelled through load-sharing function, and the gear dynamics model is established with regard to alternate meshing of single-double tooth pair and time variation of direction of normal load and mesh stiffness. The model is validated by comparing the calculated results of friction coefficients and load-dependent losses with experimental data in published literatures, showing good agreement. At the end, the efficiency model is applied to two types of gear pairs to investigate the influence of tooth shapes and operating parameters on the load-dependent losses of gear pairs.
{"title":"Prediction of mechanical efficiency of spur gear pairs based on tribo-dynamics model of multi-tooth meshing","authors":"Lei Liu, Rong Kong, Zhiwei Chen","doi":"10.1177/13506501241238280","DOIUrl":"https://doi.org/10.1177/13506501241238280","url":null,"abstract":"The prediction of load-dependent losses of gear pairs is a topic of constant concern, which depends largely on the modelling of friction coefficient in tooth meshing. Although the current load-sharing based models can handle the friction coefficient in mixed elastohydrodynamic lubrication regimes, dynamics behaviour of each tooth pair or the time variation of direction of normal contact load is not taken into consideration. This study proposes a new method for modelling efficiency of spur gear pairs in transient operating conditions by coupling the multi-tooth meshing model with the friction coefficient model. The friction coefficient is modelled through load-sharing function, and the gear dynamics model is established with regard to alternate meshing of single-double tooth pair and time variation of direction of normal load and mesh stiffness. The model is validated by comparing the calculated results of friction coefficients and load-dependent losses with experimental data in published literatures, showing good agreement. At the end, the efficiency model is applied to two types of gear pairs to investigate the influence of tooth shapes and operating parameters on the load-dependent losses of gear pairs.","PeriodicalId":509096,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"95 S4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140237938","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}
Pub Date : 2024-03-15DOI: 10.1177/13506501241238812
Rakesh Kumar Singh, Chiranjit Sarkar
Brakes, which are the safety component of any automobile used to control the motion of the vehicle as per the driver's choice. In conventional brakes, friction lining materials are used, which affect the health of human beings and pollute the environment. Hence, there is a need to look for new types of brake systems. In the present work, a new type of electromechanical (EM) drum brake is designed that does not use friction lining materials for brake application. It can use magnetorheological (MR) fluid as well as magnetic powder (MP) for brake application. The presented brake has been designed to operate in hybrid mode that is, shear plus compression mode. When MR fluid is used, these brakes face the problem of the leakage of MR fluid which motivates to use of MP. In addition to the design of the new brake, the performance of the new brake has been tested with MR fluid and MP separately on a full-scale brake inertia dynamometer. The performance test results have been compared for both MR fluid and MP and compared with conventional friction brakes. 14.56% and 11.38% more braking torque have been observed for MP compared to that of MR fluid in shear and hybrid mode respectively. In addition to the performance study, the effect of MR fluid and MP on brake shoe surface properties has been studied.
{"title":"Comparison of performance and tribological properties of electromechanical brake with magnetorheological fluid and magnetic powder","authors":"Rakesh Kumar Singh, Chiranjit Sarkar","doi":"10.1177/13506501241238812","DOIUrl":"https://doi.org/10.1177/13506501241238812","url":null,"abstract":"Brakes, which are the safety component of any automobile used to control the motion of the vehicle as per the driver's choice. In conventional brakes, friction lining materials are used, which affect the health of human beings and pollute the environment. Hence, there is a need to look for new types of brake systems. In the present work, a new type of electromechanical (EM) drum brake is designed that does not use friction lining materials for brake application. It can use magnetorheological (MR) fluid as well as magnetic powder (MP) for brake application. The presented brake has been designed to operate in hybrid mode that is, shear plus compression mode. When MR fluid is used, these brakes face the problem of the leakage of MR fluid which motivates to use of MP. In addition to the design of the new brake, the performance of the new brake has been tested with MR fluid and MP separately on a full-scale brake inertia dynamometer. The performance test results have been compared for both MR fluid and MP and compared with conventional friction brakes. 14.56% and 11.38% more braking torque have been observed for MP compared to that of MR fluid in shear and hybrid mode respectively. In addition to the performance study, the effect of MR fluid and MP on brake shoe surface properties has been studied.","PeriodicalId":509096,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140241262","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}
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