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.
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.
