Research On The Performance Of Dynamic Seal Based On The Isotropic Hypothess Of PTFE

Hydraulic seal is a very important part in the hydraulic system, whose performance directly influences how well the system works. Compared with static sealing, dynamic sealing’s mechanism is significantly complex, due to the relative motion at the contact surface. As hydraulic system tends to operate in heavy pressure and high speed conditions, early failure of dynamic sealing often happens. Therefore, if this article can establish accurate model, analyse how working conditions and the property of sealing material affect the performance of dynamic seal, and provide theoretical support for optimizing the seal material. Then this work will be valuable.This article takes the dynamic sealing between the cylinder and the vane in a hydraulic swing motor for an example, which is composed of PTFE ring and O rubber ring. Taking PTFE as an isotropic material, this article mainly studied the influence of the seal medium conditions and the properties of the seal material on the performance of dynamic seal with the elastohydraulic lubrication method, the analyses and verifies the mathematical model with the fluid-solid interaction method.Firstly, this article discusses the mechanism of the dynamic seal, analyses and calculates the structural deformations of dynamic seal. Taking the roughness of contact surfaces into consideration, the article establishes a model to calculate the lubricant film thickness in the sealing gap. Then, a leakage and viscous friction model are formed to observe how the working condition and material properties affect the film thickness, leakage and viscous friction. Thus evaluates the performance of dynamic seal.Then, a structural model and a fluid model are built by ADINA respectively, from which the fluid-solid interaction model for simulation analysis is built. Thus, a calculation and analysis is performed to indicate the relationship between seal performance and working conditions together with the sealing material, which is prepared to verify the accuracy of the results from elastohydraulic lubrication method.Finally, this article analyses the charactieristics of elastohydraulic lubrication and fluid-solid interaction method, then analyze the consistency and inconsistency of the results from the two methods. To some extent, the fluid-solid interaction method verifies the accuracy of the results from elastohydraulic lubrication method.