Investigation into the tribological characteristics of bidirectional seals based on the mixed lubrication model

Hydraulic actuators are an important executive component of modern aircraft, while reciprocating seals play a crucial role in the hydraulic system. ACGT seal is a new dual-action bidirectional seal introduced by Greene Tweed company, often used in flight control actuator, landing gear systems and other fields. The ACGT seal consists of a plastic slip ring, a rubber ring, and two back-up rings. Compared with the traditional T-section seal, the ACGT seal is more stable and possesses higher wear resistance, which is particularly suitable for long-stroke high-speed application scenarios. To investigate its performance in critical conditions, a two-dimensional finite element model is established in this paper. The whole model is integrated with finite element method and mixed lubrication numerical program. The static contact pressure and sealing length are calculated by finite element software, and then are input into the analysis procedure of lubrication characteristics. The lubrication model includes the lubrication fluid mechanism, microscopic contact model, deformation equation. The tribological characteristics including the friction and leakage of the ACGT seal are revealed in different working conditions.