Types of bearings used in jet engines.

 Types of bearings used in jet engines.

Type of Bearing	Advantages	Disadvantages	TBO	Scrap Life
Ball Bearings	- Handle both radial and axial loads efficiently. - Low friction & high-speed capability.	- Limited load-carrying capacity. - Prone to skidding under light loads.	5,000 - 15,000 hours	Based on wear limits, typically 20,000+ hours.
Roller Bearings	- Higher radial load capacity than ball bearings. - Reduced skidding.	- Cannot handle high axial loads. - Increased friction compared to ball bearings.	5,000 - 15,000 hours	Typically 20,000+ hours or until excessive wear.
Tapered Roller Bearings	- Can handle both axial and radial loads. - High load-carrying capability.	- Higher friction losses. - Requires precise lubrication.	10,000 - 20,000 hours	Scrap life based on wear and damage, ~25,000+ hours.
Needle Bearings	- Compact and lightweight. - Suitable for limited radial space applications.	- Lower load capacity compared to roller bearings. - High sensitivity to contamination.	7,000 - 15,000 hours	Based on wear condition, ~20,000+ hours.
Hydrodynamic Bearings	- No direct metal-to-metal contact, reducing wear. - Long service life with proper lubrication.	- Requires continuous oil supply. - Performance is affected by oil viscosity changes.	15,000 - 30,000 hours	Can exceed 30,000 hours if well-maintained.
Magnetic Bearings	- Virtually no wear due to no physical contact. - Low maintenance and high-speed operation.	- Complex and expensive. - Requires electronic control.	20,000+ hours	Typically 40,000+ hours; depends on system reliability.

 

Type	Load Capacity	Speed Capability	Maintenance Needs	Typical Applications	TBO (hours)	Scrap Life (hours)
Ball Bearings	Medium	High	Moderate	Main shaft, gearbox	5,000 - 15,000	~20,000+
Roller Bearings	High (Radial)	Medium	Moderate	Main shaft, compressors	5,000 - 15,000	~20,000+
Tapered Roller Bearings	High (Axial & Radial)	Medium	High	Turbofan main shafts	10,000 - 20,000	~25,000+
Needle Bearings	Low	High	High	Gearboxes	7,000 - 15,000	~20,000+
Hydrodynamic Bearings	Very High	Very High	High	Large engines, high-speed rotors	15,000 - 30,000	30,000+
Magnetic Bearings	Unlimited (No Contact)	Extremely High	Low	Advanced & high-speed engines	20,000+	40,000+