Aircraft engine USES what kind of bearing, how to achieve high temperature resistant and lubrication?
- bearing knowledge
Materials and lubricant is the key.
Under the first said the main aircraft engine -
Turbine engine, the combustion chamber temperature can reach more than 1500 degrees, usually the speed of the turbine blade is close to a round of up to more than 30000, 20000.
For mechanical parts in aircraft engine running environment is a very harsh environment.
But should pay attention to the point, this kind of the high temperature of 1500 degrees is actually occur in the combustion chamber and the nozzle.
Not in the position of the bearing.
First take a look at a typical structure of the jet engine, here we can see the whole engine temperature of the highest part is actually the red part, and truly under the red part involved in the action only a set of gas turbine.
That is only a circle on the drawing of the turbine will be on the edge of the annular combustion chamber exports part under the effect of high temperature gas.
This can lead to bearing has a great deal of 'living space'.
Continue to break down this shaft, we can find the location of the bearing distance turbine has a long distance.
, of course, this is a relatively simple turbojet engines, but more complex turbojet engine bearing is also far away from the turbine.
This leads to a truly is passed on to the bearing temperature is not high, only 300 degrees.
If not higher than many people think?
Therefore, in this part of the bearing is used in a wide range of the high hardness, high temperature resistant M50Nil as the main material of bearing steel.
At the same time a lot of people say air bearing are made from nitriding process improve the hardness, actually not completely -
That is more than 20 years ago, now in China is to use the titanium nitride coating.
This is a kind of artificial ceramic material.
Hardness is close to the diamond melting point at 2930 degrees.
This material is currently the best engine bearing materials (
So in the picture above these gold bearing components is also a kind of navigation after observation basic stability.
The second is the lubricating oil.
In in the design of aviation engine oil, lubricating oil on the bearing not only lubrication, and 'water', use plenty of lube oil flushing away bearing heat.
We see the distribution of aviation engine oil is mainly in the above three bearing, after the three bearing in the lubricating oil is heated, would be the lube oil cooler (
Lubricating oil cooler)
In heat dissipation, such, role in most of the heat engine bearing will by the lubricating oil and to carry out.