The Experts below are selected from a list of 1458 Experts worldwide ranked by ideXlab platform

Richard F Salant - One of the best experts on this subject based on the ideXlab platform.

  • the effect of aging in oil on the performance of a radial Lip Seal
    Tribology International, 2014
    Co-Authors: Mindong Lv, Longke Wang, Richard F Salant, Yuming Wang
    Abstract:

    Abstract The effect of aging in oil on the Seal performance of a radial Lip Seal is investigated in the present study by conducting a constant temperature oil bath test to obtain aged rubber samples and Seals, and measuring the changes of material properties and Seal performance with the aging time. The change of Lip surface micro-morphology with the aging time is also measured by using a 3D white light optical interferometer. The leakage and friction torque are computed in a numerical simulation, utilizing a mixed elastohydrodynamic lubrication (EHL) model, to determine how aging in oil affects the Lip Seal performance. Finally, the simulation results of the EHL model are verified by a bench test on aged Lip Seals.

  • The Effect of Wear on the Performance of a Rotary Lip Seal.
    Journal of tribology, 2014
    Co-Authors: Fei Guo, Richard F Salant, Xiaohong Jia, Wang Longke, Yuming Wang
    Abstract:

    Theoretical analysis, combined with experimental verification, is used to study the effect of wear on the performance of a rotary Lip Seal as characterized by the pumping rate and friction torque. The performance of a rotary Lip Seal is determined by the Sealing Lip surface microscopic characteristics and contact characteristics at the Sealing zone. The variation of the contact characteristics with wear has been established based on the variation of the Sealing Lip profiles measured by using a trilinear coordinate measuring instrument. The impression method is used to copy the Lip surface microtopography at different wear times and then an optical interferometer is used to measure the impression surface microtopography to obtain the variation of roughness with wear. The variations of the roughness, contact characteristics, and approximate contact temperature with wear are inserted into a mixed lubrication model to obtain the variations of the pumping rate and friction torque. A comparison of the simulated results with those from experimental measurement verifies the validity of the theoretical analysis.

  • Parameter analysis of the radial Lip Seal by orthogonal array method
    Tribology International, 2013
    Co-Authors: Xiaohong Jia, Fei Guo, Richard F Salant, Yuming Wang
    Abstract:

    Abstract This study investigates the effects of structure, material parameters and assembly conditions on the reverse pumping rate and friction torque of the radial Lip Seal by using a mixed elastohydrodynamic lubrication model. The orthogonal array method is used to make a numerical experiment plan for eight parameters, which are identified as eight control factors. Each factor has five levels. The significance of each parameter on the reverse pumping rate and friction torque of the radial Lip Seal is evaluated by range analysis and F -test. As a result, optimal values of eight parameters are suggested. The Seal with this set of optimal values has a higher reverse pumping rate and lower friction torque than those of a previously-designed Seal.

  • The effect of aging during storage on the performance of a radial Lip Seal
    Polymer Degradation and Stability, 2013
    Co-Authors: Fei Guo, Richard F Salant, Xiaohong Jia, Yuming Wang
    Abstract:

    Abstract Since aging is an inevitable phenomenon during storage of a radial Lip Seal, this study aims to investigate the effect of aging on the Seal performance. An air oven aging test is conducted to produce aged rubber samples and Seal products. An aging life prediction model is constructed to predict the equivalent material properties at any storage temperature. The material property parameters of aged rubber samples are measured in a uniaxial compression experiment. The pumping rate and friction torque of the Seal are calculated through numerical simulation by using a mixed elastohydrodynamic lubrication (EHL) model. A bench test is used to verify the aging life prediction model and the simulation results of the EHL model. Finally, the verified EHL model is used to study how aging during storage affects the Lip Seal performance, as characterized by the leakage and friction torque.

  • a mixed lubrication model of a rotary Lip Seal using flow factors
    Tribology International, 2013
    Co-Authors: Fei Guo, Richard F Salant, Xiaohong Jia, Shuangfu Suo, Yuming Wang
    Abstract:

    Abstract A mixed lubrication model of a rotary Lip Seal using flow factors has been developed. The model consists of coupled fluid mechanics, contact mechanics and deformation mechanics analyses. The fluid mechanics analysis is described by a Reynolds equation that takes into account the surface roughness effect using flow factors. The contact mechanics analysis uses the Greenwood and Williamson model to compute contact pressure. The deformation mechanics analysis utilizes the influence coefficient approach to compute deformation of the Seal. Results for a typical Seal show how the operation parameters and the surface roughness affect Seal behavior.

Yuming Wang - One of the best experts on this subject based on the ideXlab platform.

  • Effect of friction coefficient on the mixed lubrication model of rotary Lip Seals
    Proceedings of the Institution of Mechanical Engineers Part J: Journal of Engineering Tribology, 2019
    Co-Authors: Jiang Bingqi, Fei Guo, Huang Xing, Xiaohong Jia, Yuming Wang
    Abstract:

    This study is devoted to the effect of different coefficients on the calculation results of the rotary Lip Seal mixed lubrication model. It was proved by experiments that the dry friction coefficie...

  • the effect of aging in oil on the performance of a radial Lip Seal
    Tribology International, 2014
    Co-Authors: Mindong Lv, Longke Wang, Richard F Salant, Yuming Wang
    Abstract:

    Abstract The effect of aging in oil on the Seal performance of a radial Lip Seal is investigated in the present study by conducting a constant temperature oil bath test to obtain aged rubber samples and Seals, and measuring the changes of material properties and Seal performance with the aging time. The change of Lip surface micro-morphology with the aging time is also measured by using a 3D white light optical interferometer. The leakage and friction torque are computed in a numerical simulation, utilizing a mixed elastohydrodynamic lubrication (EHL) model, to determine how aging in oil affects the Lip Seal performance. Finally, the simulation results of the EHL model are verified by a bench test on aged Lip Seals.

  • The Effect of Wear on the Performance of a Rotary Lip Seal.
    Journal of tribology, 2014
    Co-Authors: Fei Guo, Richard F Salant, Xiaohong Jia, Wang Longke, Yuming Wang
    Abstract:

    Theoretical analysis, combined with experimental verification, is used to study the effect of wear on the performance of a rotary Lip Seal as characterized by the pumping rate and friction torque. The performance of a rotary Lip Seal is determined by the Sealing Lip surface microscopic characteristics and contact characteristics at the Sealing zone. The variation of the contact characteristics with wear has been established based on the variation of the Sealing Lip profiles measured by using a trilinear coordinate measuring instrument. The impression method is used to copy the Lip surface microtopography at different wear times and then an optical interferometer is used to measure the impression surface microtopography to obtain the variation of roughness with wear. The variations of the roughness, contact characteristics, and approximate contact temperature with wear are inserted into a mixed lubrication model to obtain the variations of the pumping rate and friction torque. A comparison of the simulated results with those from experimental measurement verifies the validity of the theoretical analysis.

  • effects of the radial force on the static contact properties and Sealing performance of a radial Lip Seal
    Science China-technological Sciences, 2014
    Co-Authors: Le Huang, Longke Wang, Yuming Wang
    Abstract:

    The radial force is a critical factor to determine the Sealing performance of radial Lip Seals. The effects of radial force produced by garter spring and interference on the static contact properties and Sealing performance of a radial Lip Seal are investigated by numerical simulations and experiments. Finite-element analysis and mixed elastohydrodynamic lubrication simulation are used. Radial force, contact width, temperature in the Sealing zone, the reverse pumping rate and friction torque are measured. A critical value of interference for a cost-effectively designed radial Lip Seal is found. Spring force is required to compensate the decrease of the radial force because of the interference and used as a possible way to obtain intelligent control of Sealing performance. The quantitative results gotten in this study could provide guide for the Seal design and improvement.

  • The effect of texture on the shaft surface on the Sealing performance of radial Lip Seals
    Science China Physics Mechanics & Astronomy, 2014
    Co-Authors: Fei Guo, Xiaohong Jia, Zhi Gao, Yuming Wang
    Abstract:

    On the basis of elastohydrodynamic model, the present study numerically analyzes the effect of various microdimple texture shapes, namely, circular, square, oriented isosceles triangular, on the pumping rate and the friction torque of radial Lip Seals, and determines the microdimple texture shape that can produce positive pumping rate. The area ratio, depth and shape dimension of a single texture are the most important geometric parameters which influence the tribological performance. According to the selected texture shape, parameter analysis is conducted to determine the optimal combination for the above three parameters. Simultaneously, the simulated performances of radial Lip Seal with texture on the shaft surface are compared with those of the conventional Lip Seal without any texture on the shaft surface.

Juliusz B Gajewski - One of the best experts on this subject based on the ideXlab platform.

  • additives contents in pag and synthetic motor base oils and their effect on electrostatic phenomena in a rotating shaft oil Lip Seal system
    IEEE Transactions on Dielectrics and Electrical Insulation, 2013
    Co-Authors: Juliusz B Gajewski, Marek J Glogowski
    Abstract:

    The paper presents the results of experiments on the electrostatic aspects of anti-wear (AW) and friction modifier (FM) additives (agents) when these are added to PAG (polyalkylene glycol) and PAO 6 (synthetic) motor base oils to obtain their blends. Experiments are carried out in a rotating shaft-oil-Lip Seal system (a friction junction) which is a specially built experimental facility to be the simplified model of an engine crankcase in the interior of which an earthed metal shaft rotates at given angular velocities from 500 up to 1000 rpm. The AW and FM additives contents in blends are 0.1 and 0.5 wt%. Oil temperature is controlled electronically and changed from 60 up to 110°C. An 88-mm diameter Lip Seal is used in the experiments. Electric potential of a stiffening ring of the Lip Seal tested is measured directly with an electrometer. The experimental results are the relationships of the potential induced in a stiffening ring to shaft's angular velocity and to the temperature of pure base oils and their blends with AW and FM agents.

  • anti wear additive content in fully synthetic pao and pag base oils and its effect on electrostatic and tribological phenomena in a rotating shaft oil Lip Seal system
    Journal of Physics: Conference Series, 2013
    Co-Authors: Juliusz B Gajewski, Marek J Glogowski
    Abstract:

    The paper presents the results of experiments on electrostatic and tribological aspects of different anti-wear additive's contents when an additive is blended with different fully synthetic (poly-α-olefin) and PAG (polyalkylene glycol) base oils in a rotating shaft–oil and oil–Lip Seal interfacial system. The experimental results are the relationships of electric potential induced in a Lip Seal's stiffening ring to angular velocity of a rotating metal shaft and to temperature of the oils tested. The braking torque of a shaft is measured with a torquemeter sensor connected directly with a microprocessor-based system for controlling the rotational speed and for measuring the shaft's braking torque and oil temperature. The beneficial and promising results are obtained for PAG when an external DC electric field is applied to the system and the braking torque is then reduced for a certain combination of the base oil and additive's contents. On the basis of the former and present research results an analysis is made to permit one to show how the type of the oils and additives tested can affect both interfaces: rotating shaft–oil and oil–Lip of the Lip Seal and especially the braking torque.

  • Base Oil and Its Blends with ZDDP and Their Effect on Tribocharging, Braking Torque and Electrical Double Layers in a Friction Junction
    Tribology Letters, 2010
    Co-Authors: Juliusz B Gajewski, Marek J. Głogowski
    Abstract:

    The paper presents the results of experiments on tribocharging of a blend of mineral-base oil and different zinc dialkyldithiophosphate (ZDDP) contents in a friction junction. A friction junction is constituted by a rotating shaft, a film of pure base oil, or its blend with the ZDDP, and a rotary Lip Seal, which is the interfacial system as a whole. Experiments were carried out on the specially built experimental facility to be a simplified model of an engine’s crankcase (or sump) in whose interior an earthed metal shaft rotated at given angular velocities. Electric potential of a stiffening ring of a Lip Seal, which is a measure of tribocharging, was measured directly with an electrometer. The stiffening ring’s potential is induced by charge in the film of pure base oil or the ZDDP-oil blend and is a function of the oil temperature for different angular shaft velocities and the ZDDP contents. The potential is presented in the form of some characteristics. Also the effects of an external DC electric field on the braking torque of the rotating steel shaft were examined for a range of oil temperatures, angular velocities, and ZDDP contents, and here the torque is presented for one temperature and different DC voltages of both polarities. An analysis of the research results obtained permitted us to show how the ZDDP content in a blend with the base oil tested, angular velocity, and oil temperature could affect tribocharging in the interfacial systems: the rotating shaft-oil and oil-Lip Seal, as well as the whole oil film in between and both electrical double layers (EDLs) at the surfaces of a shaft and of a Lip of a rotary Lip Seal in the friction junction.

  • tribocharging in a rotating shaft oil Lip Seal system for different engine base oils additive and their blends
    Journal of Electrostatics, 2009
    Co-Authors: Juliusz B Gajewski, Marek J Glogowski
    Abstract:

    Abstract The paper presents the results of experiments on tribocharging of different mineral, semisynthetic, and synthetic base oils and their blends with additives. An antiwear additive ZDDP (zinc dialkyldithiophosphate) is tested when added to base oils in different percentages by weight. Experiments are carried out on the specially built experimental facility to be a simplified model of an engine crankcase in whose interior an earthed metal shaft rotates at given angular velocities. The potential of a stiffening ring of a Lip Seal is measured directly with an electrometer. The potential is a measure of tribocharging in a rotating shaft–oil–Lip Seal system, friction junction, and especially between both interfaces: shaft surface–oil and oil–Lip of a Lip Seal. The experimental results are presented in the form of some characteristics that are relationships of the potential induced in the stiffening ring with oil's temperature for different angular shaft's velocities and additives, contents. The oil's temperature ranges from 60 to 110 °C and is controlled automatically. The angular velocities of a shaft used are 500 and 1500 rpm. The additive contents in the blends with different base oils are 0.1 and 0.2%. The pure base oils of all the types and some Lip Seals are also examined. Moreover, the influence of an external DC electric field applied between the earthed shaft and the stiffening ring on the braking torque of the shaft is examined for a range of temperatures of the pure oils and their blends with the additive used, angular velocities, and additive contents. The electric field is produced while applying the high DC voltage of both polarities between the shaft and the ring. The absolute value of the voltage is in a range from 500 to 1500 V.

  • Interpretation of the results of research on tribocharging in a rotating shaft–oil–Lip Seal system
    Journal of Electrostatics, 2009
    Co-Authors: Juliusz B Gajewski, Kazimierz Gatner
    Abstract:

    Abstract A rotating shaft, rotary Lip Seal, and oil creating a film between the surfaces of a shaft and of a Lip of the Seal sets up a system, which is relatively simple geometrically, but complex physically and electrochemically. Such a system is characteristic of all machinery, engines, etc. where rotating parts and Seals occur. In the experiments and tests performed to date different real commercial motor oils, original base oils, additives to base oils (antiwear and extreme pressure additives), Lip Seals, and shafts with different roughness have been used for a range of oil temperatures and shaft angular velocities. Tribocharging in the interfacial system: rotating shaft–oil–Lip Seal (the friction junction) is observed and analysed. Other experiments were performed to compensate for the electric field generated in the system applying an external DC electric field and to find its effect on friction and the braking torque of the shaft. The results show that tribocharging can exert influence on the braking torque of a rotating shaft. The reduction of the braking torque under the action of an external DC electric field is also observed. The similar experiments are repeated with the use of pure base oils and additives including zinc dialkyldithiophosphate (ZDDP). Tribocharging is evident in the case of pure base oils and when these are blended with ZDDP. The external DC electric field also reduces the braking torque while applying the DC voltage to the system. Here the authors try to interpret the former and last research results in their physical aspect and to answer some questions.

Marek Gawlinski - One of the best experts on this subject based on the ideXlab platform.

Marek J Glogowski - One of the best experts on this subject based on the ideXlab platform.

  • additives contents in pag and synthetic motor base oils and their effect on electrostatic phenomena in a rotating shaft oil Lip Seal system
    IEEE Transactions on Dielectrics and Electrical Insulation, 2013
    Co-Authors: Juliusz B Gajewski, Marek J Glogowski
    Abstract:

    The paper presents the results of experiments on the electrostatic aspects of anti-wear (AW) and friction modifier (FM) additives (agents) when these are added to PAG (polyalkylene glycol) and PAO 6 (synthetic) motor base oils to obtain their blends. Experiments are carried out in a rotating shaft-oil-Lip Seal system (a friction junction) which is a specially built experimental facility to be the simplified model of an engine crankcase in the interior of which an earthed metal shaft rotates at given angular velocities from 500 up to 1000 rpm. The AW and FM additives contents in blends are 0.1 and 0.5 wt%. Oil temperature is controlled electronically and changed from 60 up to 110°C. An 88-mm diameter Lip Seal is used in the experiments. Electric potential of a stiffening ring of the Lip Seal tested is measured directly with an electrometer. The experimental results are the relationships of the potential induced in a stiffening ring to shaft's angular velocity and to the temperature of pure base oils and their blends with AW and FM agents.

  • anti wear additive content in fully synthetic pao and pag base oils and its effect on electrostatic and tribological phenomena in a rotating shaft oil Lip Seal system
    Journal of Physics: Conference Series, 2013
    Co-Authors: Juliusz B Gajewski, Marek J Glogowski
    Abstract:

    The paper presents the results of experiments on electrostatic and tribological aspects of different anti-wear additive's contents when an additive is blended with different fully synthetic (poly-α-olefin) and PAG (polyalkylene glycol) base oils in a rotating shaft–oil and oil–Lip Seal interfacial system. The experimental results are the relationships of electric potential induced in a Lip Seal's stiffening ring to angular velocity of a rotating metal shaft and to temperature of the oils tested. The braking torque of a shaft is measured with a torquemeter sensor connected directly with a microprocessor-based system for controlling the rotational speed and for measuring the shaft's braking torque and oil temperature. The beneficial and promising results are obtained for PAG when an external DC electric field is applied to the system and the braking torque is then reduced for a certain combination of the base oil and additive's contents. On the basis of the former and present research results an analysis is made to permit one to show how the type of the oils and additives tested can affect both interfaces: rotating shaft–oil and oil–Lip of the Lip Seal and especially the braking torque.

  • tribocharging in a rotating shaft oil Lip Seal system for different engine base oils additive and their blends
    Journal of Electrostatics, 2009
    Co-Authors: Juliusz B Gajewski, Marek J Glogowski
    Abstract:

    Abstract The paper presents the results of experiments on tribocharging of different mineral, semisynthetic, and synthetic base oils and their blends with additives. An antiwear additive ZDDP (zinc dialkyldithiophosphate) is tested when added to base oils in different percentages by weight. Experiments are carried out on the specially built experimental facility to be a simplified model of an engine crankcase in whose interior an earthed metal shaft rotates at given angular velocities. The potential of a stiffening ring of a Lip Seal is measured directly with an electrometer. The potential is a measure of tribocharging in a rotating shaft–oil–Lip Seal system, friction junction, and especially between both interfaces: shaft surface–oil and oil–Lip of a Lip Seal. The experimental results are presented in the form of some characteristics that are relationships of the potential induced in the stiffening ring with oil's temperature for different angular shaft's velocities and additives, contents. The oil's temperature ranges from 60 to 110 °C and is controlled automatically. The angular velocities of a shaft used are 500 and 1500 rpm. The additive contents in the blends with different base oils are 0.1 and 0.2%. The pure base oils of all the types and some Lip Seals are also examined. Moreover, the influence of an external DC electric field applied between the earthed shaft and the stiffening ring on the braking torque of the shaft is examined for a range of temperatures of the pure oils and their blends with the additive used, angular velocities, and additive contents. The electric field is produced while applying the high DC voltage of both polarities between the shaft and the ring. The absolute value of the voltage is in a range from 500 to 1500 V.

  • electrostatic and tribological phenomena and their effect on the braking torque in the shaft oil Lip Seal system
    Journal of Physics: Conference Series, 2008
    Co-Authors: Juliusz Gajewski, Marek J Glogowski
    Abstract:

    The former research [1] was carried out on the influence of tribocharging in a system: metal rotating shaft-oil-Lip Seal on its work, especially on changes in the shaft braking torque with the increasing angular shaft velocity and oil temperature. The results obtained suggested that there be a possibility of reducing the braking torque by an external electric field. The compensation for the electric field generated in the system by natural tribocharging was proposed. The reduction in the braking torque seemed possible while applying an external DC electric field to the system. In general, the torque tended to increase with the increasing DC electric field for a variety of the oils and Lip Seals used and for different shaft angular velocities (rotational speeds) and oil temperatures. The braking torque reduction was achieved only for one Lip Seal and some different oils, which was and is a promising, expected result. The research results were yet presented elsewhere [1–3] and here some novel attempt has been made to interpret the results obtained in their physical—tribological and especially electrostatic—aspects since there has been a lack of such an interpretation in the literature of the subject.

  • Effects of engine base oil type and ZDDP on the electrical double layer in the rotating shaft-oil-Lip Seal system with and without an external DC electric field
    2008 IEEE International Conference on Dielectric Liquids ICDL 2008, 2008
    Co-Authors: Juliusz B Gajewski, Marek J Glogowski
    Abstract:

    The paper presents the results of experiments on tribo-charging of\na blend of mineral base oil and different zinc dialkylditophosphate\n(ZDDP) contents. Experiments were carried out on the specially built\nexperimental facility to be a simplified model of an engine crankcase\nin whose interior an earthed metal shaft rotated at given angular\nvelocities. The potential of a stiffening ring of a Lip Seal was\nmeasured directly with an electrometer. The experimental results\nare presented in the form of some characteristics that are relationships\nof the potential induced on the stiffening ring to the oil temperature\nfor different angular shaft velocities and the ZDDP contents. Also\nthe effects of an external DC electric field on the braking torque\nof the steel shaft were examined for a range of oil temperatures,\nangular velocities, and ZDDP contents. An analysis of the research\nresults obtained permitted one to show how the ZDDP content in a\nblend with the base oil tested, angular velocity, and oil temperature\ncould affect charging in the interface system: rotating shaft-oil\nand oil-Lip Seal, as well as the whole oil film in between and both\nelectrical double layers (EDL) at the surfaces of the shaft and of\nthe Lip of a Lip Seal.