With several attractive properties, rotary lip seals are widely used in aircraft utility system, and their reliability estimation has drawn more and more attention. This work proposes a reliability estimation approach...With several attractive properties, rotary lip seals are widely used in aircraft utility system, and their reliability estimation has drawn more and more attention. This work proposes a reliability estimation approach based on time-varying dependence analysis. The dependence between the two performance indicators of rotary lip seals, namely leakage rate and friction torque, is modeled by time-varying copula function with polynomial to denote the time-varying parameters, and an efficient copula selection approach is utilized to select the optimal copula function. Parameter estimation is carried out based on a Bayesian method and the reliability during the whole lifetime is calculated based on a Monte Carlo method. Degradation test for rotary lip seal is conducted and the proposed model is validated by test data. The optimal copula function and optimal order of polynomial are determined based on test data. Results show that this model is effective in estimating the reliability of rotary lip seals and can achieve a better goodness of fit.展开更多
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 perfor...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.展开更多
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 frictio...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.展开更多
基金co-supported by the National Natural Science Foundation of China (51875015,51620105010,51675019)Natural Science Foundation of Beijing Municipality(L171003)。
文摘With several attractive properties, rotary lip seals are widely used in aircraft utility system, and their reliability estimation has drawn more and more attention. This work proposes a reliability estimation approach based on time-varying dependence analysis. The dependence between the two performance indicators of rotary lip seals, namely leakage rate and friction torque, is modeled by time-varying copula function with polynomial to denote the time-varying parameters, and an efficient copula selection approach is utilized to select the optimal copula function. Parameter estimation is carried out based on a Bayesian method and the reliability during the whole lifetime is calculated based on a Monte Carlo method. Degradation test for rotary lip seal is conducted and the proposed model is validated by test data. The optimal copula function and optimal order of polynomial are determined based on test data. Results show that this model is effective in estimating the reliability of rotary lip seals and can achieve a better goodness of fit.
基金supported by the National Natural Science Foundation of China(Grant No.51175283)the National Science and Technology Major Project of China(Grant No.2013ZX04010021)the Ph.D Programs Foundation of Ministry of Education of China(Grant No.20130002110006)
文摘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.
基金supported by the National Natural Science Foundation of China(Grant No.51175283)the National Science and Technology Major Project of China(Grant No.2013ZX04010021)the Specialized Research Fund for the Doctoral Program(Grant No.20130002110006)
文摘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.
