Hearing Professor Zhao's words, Tong Xia's eyes on the side also lit up, looking at the black ball in the teacher's hand, it seemed that she had seen some great treasure, but thinking of the teacher's body, her eyes were a little more worried.

As if sensing the entanglement of the students around him, Professor Zhao coughed excitedly a few times, then waved his hand to indicate that he was fine, and then handed the ball in his hand to Tong Xia: "Look, this is the silicon nitride bearing I told you before, I saw it when I visited Europe and the United States in the early eighties, it should be true, take a good look, this thing is very useful......

At this moment, Professor Zhao was like a child who had picked up a novelty, he seemed to be both excited and cheerful, and even his words became extremely light.

Soon the situation of silicon nitride bearings was clarified.

This also starts with the core technology of the helicopter.

Different from fixed aircraft, the core technology of helicopters is divided into several major parts, the most important of which are the power system and transmission system.

The powertrain naturally refers to a high-performance turboshaft engine, while the drivetrain is the part that connects the powertrain to the propeller.

There are many subdivided parts, but no matter which part is inseparable from the support and connection of the bearing, so that the transmission system can run better.

Because of this, bearings are one of the most important mechanical components of a helicopter and are completely indispensable.

Therefore, the quality of bearing performance has a great impact on the helicopter, and even in a sense, it can completely affect the life and death of a helicopter.

So how to judge the performance of a helicopter bearing?

The aviation industry has long defined the standard for this, that is, the bearings of the helicopter can work normally for 30 minutes without damage to the turboshaft engine running at high speed without lubricating oil injection.

Don't underestimate this condition, not to mention that the general bearing will not be damaged for 30 minutes, it is estimated that the inner roller will be broken due to the high temperature caused by strong friction in 5 minutes.

It is important to know that the running speed of the turboshaft engine is very high, even if there is a reduction gear control, the transmission rate is amazing, which leads to the helicopter transmission system has been running at high speed, and the supporting bearings naturally have to withstand the friction and high temperature brought by it.

Because of this, the stable operation of the helicopter lubrication system is very important, because it can not only reduce the friction coefficient of the transmission system, increase the number of revolutions, but also use the lubricating oil to cool the bearing balls and ensure the safety of the bearing.

But as the saying goes, the moon is cloudy and sunny, and people have good and bad luck, and the lubrication system on the helicopter is already complicated.

Do you want to watch the bearing balls in the helicopter shatter, and the helicopter transmission gets stuck and falls straight down?

Designers naturally don't want this to happen, so how to make the bearing can run smoothly for half an hour under the extreme conditions of weak lubricating oil or even no oil, so that the helicopter can land safely has become the goal of designers and engineers.

Therefore, since the sixties, superalloy steel has replaced the original ordinary low-carbon steel to become the main material of high-performance bearing balls, and the effect is naturally good, but the problem is that high-temperature alloy steel has added nickel, chromium, cobalt and other metal materials, coupled with special requirements for metallurgy and heat treatment, resulting in the high cost of such bearings.

In addition, in addition to high temperature resistance, this kind of superalloy steel has not made significant progress compared with mild steel in terms of friction coefficient, thermal expansion rate, and creep resistance, and its heavier mass makes helicopter designers not satisfied.

In this context, industrial ceramic materials, which started in the 50s and gradually matured in the 60s and 70s, began to enter the field of vision of helicopter designers and engineers.

After some experimentation and demonstration, they found that a ceramic material called silicon oxide has diamond-like hardness, steel-like strength, and is as light as aluminum, and most importantly, these properties do not change significantly at temperatures of more than 1,200 degrees Celsius.

Such a good thing is obviously the coveted ball material for helicopter bearings.

"In this regard, the Americans are still very strong, and they have been widely used in the late seventies, and by the mid-eighties, all the newly produced American helicopters have used this kind of silicon nitride ball bearing; the Europeans are much behind, and when I visited Europe, they had just begun to demonstrate and test, as for our own ......."

Professor Zhao sighed as he spoke, and then picked up the silicon nitride balls in his hand, his expression was a little dazed, but he turned his head to look at Zhuang Jianye and the others with some excitement: "I thought that we would have to make silicon nitride ball bearings in the mid-to-late nineties, but I didn't expect that your Tengfei Group has already done it, why haven't you published such an important technical achievement? ”

At first, Professor Zhao was still very calm, but as he spoke, a decisive momentum of killing emanated undisguisedly, and his face was even more terrifying, obviously moving the real fire.

It is no wonder that Professor Zhao is so, when he was in the capital, the reputation of Tengfei Group was very polarized, and now he has never even heard of such a core achievement that is enough to make domestic helicopter technology take a big step forward, which makes the old man inevitably think of whether it is deliberately aimed at Tengfei Group.

Seeing Professor Zhao like this, Zhuang Jianye just wanted to explain, but before he could think of how to phrase it, he saw Liu Chun sitting next to Professor Zhao with a smile, and a sentence almost made Zhuang Jianye's heart rise to his throat: " Seeing that you are older than me, I will call you Brother Zhao, tell me the truth, Brother Zhao, the Tengfei Aviation Technology R&D Center that engaged in these silicon nitride balls never thought of publishing this thing as a technical achievement, for them this is a gadget that can be used to transform achievements and earn some pocket money after the failure of the experiment, and they don't pay attention to it at all, so it is normal for you to not see it, Brother Zhao. ”

Zhuang Jianye couldn't wait to rush over and press Liu Chun, the old thing, and then sew up the blind mouth, dare to say this, aren't you afraid of making Professor Zhao roll his eyes again?

If he didn't say anything else, seeing Professor Zhao's wooden appearance like being struck by lightning at this moment, he knew that the old man's trembling little heart was shocked again.

In fact, Professor Zhao thinks that this silicon nitride bearing is already very remarkable, but it is just a failed product in Rentenfei Group, and it is used for pocket money gadgets.

Professor Zhao is almost eighty years old, and for the first time, he feels that his three views have collapsed, and he deeply doubts whether his life has been in vain, such cutting-edge things are all products of failure, gadgets, so what is the helicopter he has been working on all his life? Les Miserables?