The dynamic seals used for aircraft gearbox are of precision design and undergo stringent quality checks for obtaining clearance for aircraft fitment. These dynamic seals are capable of operating under severe environmental conditions with high reliability and very low leakage rate. In the present paper different types of rotary dynamic seals and their comparative performance for aircraft gearbox applications are discussed. Pressure diagram for a circumferential seal has also been presented along with factors to be considered during assembly of these seals. Finally a case study for a circumferential seal is presented and test results analyzed.

Key words: Dynamic Seals, Face Seals, High SpeedAircrafts