Research On Dynamic Seal Performance Of Anisotropic PTFE

This article aims at building a evaluation model, which uses leakage rate as its indicator, to evaluate the dynamic seal performance of a combined seal consisted of an O-ring and a modified PTFE bar. This model is built to provide theoretical basis for the design of electric hydraulic swing motor used seal. Based on the elastohydrodynamic lubrication(EHL) theory, parameters related to PTFE’s anisotropy, temperature field and surface roughness are introduced into the model, as well as other parameters used in previous one. Later, the influence of PTFE anisotropy, important operating condition parameters, material mechanics property parameters and modified methods is discussed in detail. Then, a numerical solution is reached in MATLAB and a thermal-fluidstructure coupled interaction simulation is performed in ADINA. Comparing the data obtained from MATLAB and ADINA, the mathematical model and the simulation model can be tested reciprocally.First, on the base of EHL theory, a mathematical model used to calculate the leakage rate is built, which takes many factors into consideration, especially these concerned with the PTFE’s anisotropy, temperature field and surface roughness. A thermal-fluid-structure coupling can be achieved using it, since the temperature field is considered; the effect of the PTFE’s anisotropy can be studied explicitly at the same time, as it is reflected directly in the formula of film thickness.Then, calculate the leakage rate when PTFE is regarded as anisotropic material and isotropous respectively and make comparison between them, so that the influence of PTFE’s anisotropy can be looked into further. What’s more, the effects of important operating condition parameters, material mechanics property parameters and modified methods are discussed as well.Finally, a thermal-fluid-structure coupled model is established in ADINA and impacts of former mentioned parameters on the film thickness, pressure field and temperature field are analyzed. To verify the mathematical model and the simulation model, the results from MATLAB and ADINA are compared in many aspects.