I don't know if you've ever noticed when you fly an airplane, especially during takeoff and landing, that the engine of an airplane always jingles, like when the blades come loose and collide. Yes, the blades in the engine are actually loose. You may be surprised, airplane engines are such an important thing, the components inside should not be stable? How can the blade be loose?
If the blades of the engine are loose, how can they not fall off while generating so much power? In fact, the design of engine blade is built on mortise and mortise structure, which is a kind of very unique architectural structure invented by the ancient people of our country 39bet-xsmb-xổ số tây ninh-xổ số binh phước-xổ số binh dương-xổ số đồng nai. Mortise and tenon, is a kind of you to me. I have you, a tightly connected special structure.
The "Never Loose Nut" from Japan, which is now widely used in high-speed trains, also uses mortise and tenon principles. So since mortise and tenon structures are designed to keep things tightly connected, isn't the blade of an aircraft engine loose?
Why does it use this mortise and tenon structure? Actually, the mortise and tenon structure in the engine was slightly altered. Each blade is stuck one by one in the tenon of the turntable through a specially shaped tenon. Although it looks very tight, there is a small gap between the tenon and the tenon. This is why the blade starts to ring when the engine is working. So why is the blade designed to be loose? Wouldn't it be safer to be stuck?
Not really. As you can imagine, the fans of the engines that generate the power to lift this gigantic plane must be turning extremely fast. After the engine starts to work, its rotational speed will increase continuously. As the rotational speed gets faster and faster, the centrifugal force of the blade will increase, and the blade will show a tendency to continuously throw out. Therefore, the mortise and tenon structure of the blade can avoid the blade from being thrown out by the strong centrifugal force.
And when the blade rotates at high speed, it is hard to avoid having contact with the surrounding parts. this time, if a blade is scratched or inhaled particles or any obstacles in open state, causing the minor scratches, thus losing a part of the quality, the high speed rotating blade under the centrifugal force will be smaller than the other leaves. If this happens to a fan, don't worry, because its speed is slow, even if the blade is missing also doesn't matter.
But with aircraft engines, it's a different story. If the centrifugal force on one blade is affected, the center of the fan will deviate, creating a vibration that will affect the mechanical structure. Prolonged vibration can exacerbate cracks and lumps in the blade, destroying the otherwise intact blade.
To avoid this situation happened, now such loose mortise and tenon joint structure used in aircraft engine blade is produced, the scientific name is called "fir mortise and tenon joint structure" type engine is to make all of the blade is at work in a dynamic equilibrium, it is every gap left by the blade is gave their self-regulation ability, centrifugal force is small, It slides a little less, and the centrifugal force slides a little more. This keeps the center of gravity of the fan at its geometric center and minimizes the threat of vibration. In addition, each blade is an independent individual. When a blade has a problem, it only needs to repair or replace the broken one, which greatly reduces the maintenance cost. It is a very scientific design!