What prevents oil from leaking from the bearing chamber into the compressor or turbine gas path?

• A. Bearing Seals
• B. Gaskets
• C. O-rings
• D. Shields

Answer: (A)

Oil must be kept inside the bearing chamber and not allowed to migrate into the compressor or turbine gas path. Bearing seals provide a tight barrier around the rotating shaft where it passes through the bearing housing, forming a controlled seal that accommodates rotation and high temperatures. They’re designed to minimize leakage with designs like labyrinth or brush seals and work with the engine’s oil scavenging system to remove any inevitable leakage. Gaskets and O-rings seal static joints, not dynamic, high-speed shaft interfaces, so they aren’t suited to this role. Shields don’t create a true fluid seal; they mainly deflect oil rather than prevent leakage. That’s why bearing seals are the appropriate choice.