The Experts below are selected from a list of 14088 Experts worldwide ranked by ideXlab platform
Jorge H O Seabra - One of the best experts on this subject based on the ideXlab platform.
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Friction Torque in rolling bearings lubricated with axle gear oils
Tribology International, 2018Co-Authors: Maroua Hammami, Jorge H O Seabra, Ramiro C. Martins, Carlos M.c.g. Fernandes, Mohamed Slim Abbes, Mohamed HaddarAbstract:Abstract As a part of the main research project within the aim of increasing significantly drive axle efficiency, this work focuses on rolling bearing Friction Torque lubricated with five fully formulated axle gear oils with different viscosity and different formulations. The lubricant tribological behaviour in different rolling bearings was analyzed. A modified Four-Ball Machine was used to test the rolling bearings. The effect of speed, temperature and axial load on rolling bearing Friction Torque was assessed. Experimental results for the internal Friction Torque were validated with an SKF model. Direct comparisons in terms of Friction Torque between axle gear oils when they are lubricating different rolling bearing types are presented and discussed.
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axle gear oils Friction wear and tribofilm generation under boundary lubrication regime
Tribology International, 2017Co-Authors: Jorge H O Seabra, Maroua Hammami, Ramiro C. Martins, Carlos M.c.g. Fernandes, Mohamed Slim Abbes, Nuno Rodrigues, Mohamed HaddarAbstract:Abstract The internal Friction Torque measurements in Cylindrical Roller Thrust Bearings (RTB) lubricated with axle gear oils under boundary film conditions were performed using an axial rolling bearing test rig generating tribofilms. The X-ray photoelectron spectroscopy (XPS) was used to characterize the tribofilms formed on the bearing rollers and raceways. After the tests, wear debris were found on the oil samples which lubricated the surface of the roller bearing raceways for that surface topography measurements and oil analysis (ferrography) were mandatory to measure and to visualize the occurring wear. The results obtained indicate that axle gear oil formulations and their additive packages have got a significant influence in controlling roller bearing Friction and wear under boundary film lubrication.
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Friction Torque in thrust ball bearings lubricated with polymer greases of different thickener content
Tribology International, 2016Co-Authors: David Gon??alves, Armando V. Campos, Samuel Pinho, Beatriz Gra??a, Jorge H O SeabraAbstract:In this work a series of experimental tests were performed in thrust ball bearings lubricated with polymer greases. The tested greases were formulated with the same base oil but different thickener content. A multi-purpose lithium thickened grease was also tested as reference. The Friction Torque was measured at constant temperature and load, while varying the rotational speed. The coefficients of Friction under boundary and full film lubrication were numerically calculated through the optimization of a rolling bearing Friction Torque model to the experimental measurements. The results show that the higher the thickener content, the smaller is the Friction Torque generated by the lubricating greases, phenomenon which was found to be especially important at low speeds and low specific film thickness.
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Torque loss in cylindrical roller thrust bearings lubricated with wind turbine gear oils at constant temperature
Tribology International, 2013Co-Authors: Carlos M.c.g. Fernandes, Ramiro C. Martins, Pedro M P Amaro, Jorge H O SeabraAbstract:Abstract Six fully formulated wind turbine gear oils with the same viscosity grade and different formulations were selected and their physical properties were determined. Cylindrical roller thrust bearing Friction Torque tests were performed on a modified Four-Ball Machine at a constant temperature of 80 °C under the following operating conditions: speed between 75 and 1200 rpm and two loads (700 N and 7000 N). The experimental results showed that wind turbine gear oil formulation has a significant influence on rolling bearing Friction Torque.
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Torque loss in thrust ball bearings lubricated with wind turbine gear oils at constant temperature
Tribology International, 2013Co-Authors: Carlos M.c.g. Fernandes, Ramiro C. Martins, Pedro M P Amaro, Jorge H O SeabraAbstract:Abstract Six fully formulated wind turbine gear oils with the same viscosity grade and different formulations were selected and their physical properties were determined. Thrust ball bearing Friction Torque tests were performed on a modified Four-Ball Machine at a constant temperature of 80 °C under the following operating conditions: speed between 75 and 1200 rpm and two loads (700 N and 7000 N). The experimental results showed that wind turbine gear oil formulation has a significant influence on rolling bearing Friction Torque.
Carlos M.c.g. Fernandes - One of the best experts on this subject based on the ideXlab platform.
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Friction Torque in rolling bearings lubricated with axle gear oils
Tribology International, 2018Co-Authors: Maroua Hammami, Jorge H O Seabra, Ramiro C. Martins, Carlos M.c.g. Fernandes, Mohamed Slim Abbes, Mohamed HaddarAbstract:Abstract As a part of the main research project within the aim of increasing significantly drive axle efficiency, this work focuses on rolling bearing Friction Torque lubricated with five fully formulated axle gear oils with different viscosity and different formulations. The lubricant tribological behaviour in different rolling bearings was analyzed. A modified Four-Ball Machine was used to test the rolling bearings. The effect of speed, temperature and axial load on rolling bearing Friction Torque was assessed. Experimental results for the internal Friction Torque were validated with an SKF model. Direct comparisons in terms of Friction Torque between axle gear oils when they are lubricating different rolling bearing types are presented and discussed.
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axle gear oils Friction wear and tribofilm generation under boundary lubrication regime
Tribology International, 2017Co-Authors: Jorge H O Seabra, Maroua Hammami, Ramiro C. Martins, Carlos M.c.g. Fernandes, Mohamed Slim Abbes, Nuno Rodrigues, Mohamed HaddarAbstract:Abstract The internal Friction Torque measurements in Cylindrical Roller Thrust Bearings (RTB) lubricated with axle gear oils under boundary film conditions were performed using an axial rolling bearing test rig generating tribofilms. The X-ray photoelectron spectroscopy (XPS) was used to characterize the tribofilms formed on the bearing rollers and raceways. After the tests, wear debris were found on the oil samples which lubricated the surface of the roller bearing raceways for that surface topography measurements and oil analysis (ferrography) were mandatory to measure and to visualize the occurring wear. The results obtained indicate that axle gear oil formulations and their additive packages have got a significant influence in controlling roller bearing Friction and wear under boundary film lubrication.
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Torque loss in cylindrical roller thrust bearings lubricated with wind turbine gear oils at constant temperature
Tribology International, 2013Co-Authors: Carlos M.c.g. Fernandes, Ramiro C. Martins, Pedro M P Amaro, Jorge H O SeabraAbstract:Abstract Six fully formulated wind turbine gear oils with the same viscosity grade and different formulations were selected and their physical properties were determined. Cylindrical roller thrust bearing Friction Torque tests were performed on a modified Four-Ball Machine at a constant temperature of 80 °C under the following operating conditions: speed between 75 and 1200 rpm and two loads (700 N and 7000 N). The experimental results showed that wind turbine gear oil formulation has a significant influence on rolling bearing Friction Torque.
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Torque loss in thrust ball bearings lubricated with wind turbine gear oils at constant temperature
Tribology International, 2013Co-Authors: Carlos M.c.g. Fernandes, Ramiro C. Martins, Pedro M P Amaro, Jorge H O SeabraAbstract:Abstract Six fully formulated wind turbine gear oils with the same viscosity grade and different formulations were selected and their physical properties were determined. Thrust ball bearing Friction Torque tests were performed on a modified Four-Ball Machine at a constant temperature of 80 °C under the following operating conditions: speed between 75 and 1200 rpm and two loads (700 N and 7000 N). The experimental results showed that wind turbine gear oil formulation has a significant influence on rolling bearing Friction Torque.
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Friction Torque of cylindrical roller thrust bearings lubricated with wind turbine gear oils
Tribology International, 2013Co-Authors: Carlos M.c.g. Fernandes, Ramiro C. Martins, Jorge H O SeabraAbstract:Abstract Planetary gearboxes used in wind turbines very often have premature bearing and gear failures, some of them related to the lubricants used. Five fully formulated windmill gear oils with the same viscosity grade and different formulations were selected and characterized. The lubricant tribological behavior in a cylindrical roller thrust bearing was analyzed. A modified four-ball machine was used to assemble the bearings. They were submitted to an axial load and the tests were performed at velocities ranging between 150 and 1500 rpm. Experimental results for the operating temperatures and for the internal Friction Torque are presented.
Ramiro C. Martins - One of the best experts on this subject based on the ideXlab platform.
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Friction Torque in rolling bearings lubricated with axle gear oils
Tribology International, 2018Co-Authors: Maroua Hammami, Jorge H O Seabra, Ramiro C. Martins, Carlos M.c.g. Fernandes, Mohamed Slim Abbes, Mohamed HaddarAbstract:Abstract As a part of the main research project within the aim of increasing significantly drive axle efficiency, this work focuses on rolling bearing Friction Torque lubricated with five fully formulated axle gear oils with different viscosity and different formulations. The lubricant tribological behaviour in different rolling bearings was analyzed. A modified Four-Ball Machine was used to test the rolling bearings. The effect of speed, temperature and axial load on rolling bearing Friction Torque was assessed. Experimental results for the internal Friction Torque were validated with an SKF model. Direct comparisons in terms of Friction Torque between axle gear oils when they are lubricating different rolling bearing types are presented and discussed.
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axle gear oils Friction wear and tribofilm generation under boundary lubrication regime
Tribology International, 2017Co-Authors: Jorge H O Seabra, Maroua Hammami, Ramiro C. Martins, Carlos M.c.g. Fernandes, Mohamed Slim Abbes, Nuno Rodrigues, Mohamed HaddarAbstract:Abstract The internal Friction Torque measurements in Cylindrical Roller Thrust Bearings (RTB) lubricated with axle gear oils under boundary film conditions were performed using an axial rolling bearing test rig generating tribofilms. The X-ray photoelectron spectroscopy (XPS) was used to characterize the tribofilms formed on the bearing rollers and raceways. After the tests, wear debris were found on the oil samples which lubricated the surface of the roller bearing raceways for that surface topography measurements and oil analysis (ferrography) were mandatory to measure and to visualize the occurring wear. The results obtained indicate that axle gear oil formulations and their additive packages have got a significant influence in controlling roller bearing Friction and wear under boundary film lubrication.
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Torque loss in cylindrical roller thrust bearings lubricated with wind turbine gear oils at constant temperature
Tribology International, 2013Co-Authors: Carlos M.c.g. Fernandes, Ramiro C. Martins, Pedro M P Amaro, Jorge H O SeabraAbstract:Abstract Six fully formulated wind turbine gear oils with the same viscosity grade and different formulations were selected and their physical properties were determined. Cylindrical roller thrust bearing Friction Torque tests were performed on a modified Four-Ball Machine at a constant temperature of 80 °C under the following operating conditions: speed between 75 and 1200 rpm and two loads (700 N and 7000 N). The experimental results showed that wind turbine gear oil formulation has a significant influence on rolling bearing Friction Torque.
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Torque loss in thrust ball bearings lubricated with wind turbine gear oils at constant temperature
Tribology International, 2013Co-Authors: Carlos M.c.g. Fernandes, Ramiro C. Martins, Pedro M P Amaro, Jorge H O SeabraAbstract:Abstract Six fully formulated wind turbine gear oils with the same viscosity grade and different formulations were selected and their physical properties were determined. Thrust ball bearing Friction Torque tests were performed on a modified Four-Ball Machine at a constant temperature of 80 °C under the following operating conditions: speed between 75 and 1200 rpm and two loads (700 N and 7000 N). The experimental results showed that wind turbine gear oil formulation has a significant influence on rolling bearing Friction Torque.
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Friction Torque of cylindrical roller thrust bearings lubricated with wind turbine gear oils
Tribology International, 2013Co-Authors: Carlos M.c.g. Fernandes, Ramiro C. Martins, Jorge H O SeabraAbstract:Abstract Planetary gearboxes used in wind turbines very often have premature bearing and gear failures, some of them related to the lubricants used. Five fully formulated windmill gear oils with the same viscosity grade and different formulations were selected and characterized. The lubricant tribological behavior in a cylindrical roller thrust bearing was analyzed. A modified four-ball machine was used to assemble the bearings. They were submitted to an axial load and the tests were performed at velocities ranging between 150 and 1500 rpm. Experimental results for the operating temperatures and for the internal Friction Torque are presented.
Mohamed Haddar - One of the best experts on this subject based on the ideXlab platform.
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Friction Torque in rolling bearings lubricated with axle gear oils
Tribology International, 2018Co-Authors: Maroua Hammami, Jorge H O Seabra, Ramiro C. Martins, Carlos M.c.g. Fernandes, Mohamed Slim Abbes, Mohamed HaddarAbstract:Abstract As a part of the main research project within the aim of increasing significantly drive axle efficiency, this work focuses on rolling bearing Friction Torque lubricated with five fully formulated axle gear oils with different viscosity and different formulations. The lubricant tribological behaviour in different rolling bearings was analyzed. A modified Four-Ball Machine was used to test the rolling bearings. The effect of speed, temperature and axial load on rolling bearing Friction Torque was assessed. Experimental results for the internal Friction Torque were validated with an SKF model. Direct comparisons in terms of Friction Torque between axle gear oils when they are lubricating different rolling bearing types are presented and discussed.
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axle gear oils Friction wear and tribofilm generation under boundary lubrication regime
Tribology International, 2017Co-Authors: Jorge H O Seabra, Maroua Hammami, Ramiro C. Martins, Carlos M.c.g. Fernandes, Mohamed Slim Abbes, Nuno Rodrigues, Mohamed HaddarAbstract:Abstract The internal Friction Torque measurements in Cylindrical Roller Thrust Bearings (RTB) lubricated with axle gear oils under boundary film conditions were performed using an axial rolling bearing test rig generating tribofilms. The X-ray photoelectron spectroscopy (XPS) was used to characterize the tribofilms formed on the bearing rollers and raceways. After the tests, wear debris were found on the oil samples which lubricated the surface of the roller bearing raceways for that surface topography measurements and oil analysis (ferrography) were mandatory to measure and to visualize the occurring wear. The results obtained indicate that axle gear oil formulations and their additive packages have got a significant influence in controlling roller bearing Friction and wear under boundary film lubrication.
Maroua Hammami - One of the best experts on this subject based on the ideXlab platform.
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Friction Torque in rolling bearings lubricated with axle gear oils
Tribology International, 2018Co-Authors: Maroua Hammami, Jorge H O Seabra, Ramiro C. Martins, Carlos M.c.g. Fernandes, Mohamed Slim Abbes, Mohamed HaddarAbstract:Abstract As a part of the main research project within the aim of increasing significantly drive axle efficiency, this work focuses on rolling bearing Friction Torque lubricated with five fully formulated axle gear oils with different viscosity and different formulations. The lubricant tribological behaviour in different rolling bearings was analyzed. A modified Four-Ball Machine was used to test the rolling bearings. The effect of speed, temperature and axial load on rolling bearing Friction Torque was assessed. Experimental results for the internal Friction Torque were validated with an SKF model. Direct comparisons in terms of Friction Torque between axle gear oils when they are lubricating different rolling bearing types are presented and discussed.
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axle gear oils Friction wear and tribofilm generation under boundary lubrication regime
Tribology International, 2017Co-Authors: Jorge H O Seabra, Maroua Hammami, Ramiro C. Martins, Carlos M.c.g. Fernandes, Mohamed Slim Abbes, Nuno Rodrigues, Mohamed HaddarAbstract:Abstract The internal Friction Torque measurements in Cylindrical Roller Thrust Bearings (RTB) lubricated with axle gear oils under boundary film conditions were performed using an axial rolling bearing test rig generating tribofilms. The X-ray photoelectron spectroscopy (XPS) was used to characterize the tribofilms formed on the bearing rollers and raceways. After the tests, wear debris were found on the oil samples which lubricated the surface of the roller bearing raceways for that surface topography measurements and oil analysis (ferrography) were mandatory to measure and to visualize the occurring wear. The results obtained indicate that axle gear oil formulations and their additive packages have got a significant influence in controlling roller bearing Friction and wear under boundary film lubrication.
