What are the special requirements for aircraft engine bearings, and how to achieve high temperature resistance and lubrication?
First of all, let's understand the operating conditions of aircraft engines:
1. High speed, the speed of the general aircraft engine is more than 18000 rpm, and the requirements for materials are very high at such a high speed.
2. High temperature, the engine operating temperature is very high, the operating temperature of the bearing may also reach 300 °C, the bearing material needs to be able to withstand high temperature.
3. High reliability, whether it is a civil aircraft or a fighter jet, the requirements for reliability are very high, and a slight difference in the pool is a matter of human life.
Due to the high operating temperature of the bearing, the outer ring is made of AISI M50 material with high temperature resistance and high temperature stability, which can still reach 58HRC hardness at 300°C.
When running at high speed, because the inner ring of the bearing is rotating, the centrifugal force is very large, and the cross-section of the inner ring of the bearing bears the hoop tensile stress, so there can be no microscopic cracks on the surface of the inner ring to avoid crack propagation under tensile stress, so AISI M50NiL material is often used as the inner ring.
Due to the very high speed, in order to reduce the additional load brought by the centrifugal force of the steel ball, the ceramic material with relatively light weight and high hardness, such as silicon nitride (Si3N4) or titanium carbide (TiC), is generally used as the steel ball material, and sometimes in order to increase the wear resistance of the inner and outer rings of the bearing and reduce the friction, the inner and outer ring raceways are also sprayed with ceramics.
The engine temperature can be more than 300 °C, the highest is more than 1500 °C, how to bear the temperature is only 300 °C, this is the credit of the lubrication system, in fact, the bearing lubrication system also has a main function is cooling
Part of it is lubrication, engine bearing lubrication is actually similar to the lubrication of general bearings, because the bearing speed is too high, can not use contact sealing, so the engine bearing is a labyrinth sealing method, but the lubricating oil he uses is much better, because the operating temperature is too high, the general lubricating oil is easy to oxidize and deteriorate, so it is generally used synthetic oil MIL-PRF23699HTS.
If you want to know more bearing information,please contact us :
sales@cwlbearing.com
service@cwlbearing.com
Post time: Aug-14-2025
