Week 2: Bearings and Seals

What determines the number of bearings in a gas turbine engine?

Length and weight of the engine, and number of rotors

What is the purpose of Main Engine Bearings?

Support the Compressor and Turbine Rotors and allow them to rotate freely

Do Split-spool compressors require more bearings than Solid-spool compressors?

Yes

What is the purpose of Accessory Bearings?

Absorb loads created by drive shafts and gears

What are the two types of Bearings?

- Ball Bearings
- Roller Bearings

Which Bearings are used on compressor and turbine rotor shafts and absorb BOTH Radial and Axial loads?

Ball Bearings

Which Bearings are used in areas of high Centrifugal force and absorb Radial loads ONLY?

Roller Bearings

What is the purpose of a Seal?

Prevent the oil from escaping its normal path of flow

What are the 3 types of seals?

- Labyrinth
- Thread
- Carbon

Which oil seal uses reverse threading and Centrifugal force to retain oil in the bearing cavity?

Thread

Which type oil seal controls leakage by engine bleed air (air pressure) on one side?

Labyrinth

Which type oil seal is a spring-loaded carbon seal mated with machined surface (rotating seal), which creates the seal?

Carbon