Wang Zhilin, who finally found the problem, muttered his gratitude to the tutorial author, and quickly picked up a stack of calculation drawings spread out on the table, and trotted all the way to Guo Jingshan, the chief engineer of the 602 Institute upstairs.

He is also the general person in charge of the introduction of imitation work in the straight 9.

You must know that this project was the same as J-7F at the earliest, and it was started by the 602 Institute and the 122 Factory with a huge amount of money (80-year token value) raised by themselves, and several units involved in the project were all in debt for this, which is enough to see his courage and courage.

However, to engage in research and development in the aviation industry, it is not enough to have courage and courage.

Today's Bingcheng Aircraft Industry Group is struggling with the localization rate and reliability of the navy and army armament type.

"Mr. Guo, Mr. Guo, I found a problem!"

Wang Zhilin was holding both hands at the moment, and it was inconvenient to knock on the door, so he had to stand at the door and whisper to Guo Jingshan's office.

The latter, who was buried in front of the table, looked up and saw only a figure standing in the doorway, but because the upper half of his body was almost completely spread out and covered by the half-rolled drawings, he couldn't see who it was.

But the one who came here in this way must be the technician in the office.

"You come in first, put your things down."

Guo Jingshan straightened the hair that was only on the side of his ears, and motioned for someone to put things on his desk.

Then he saw the identity of the other party:

"Are you...... Xiao Wang, who graduated last year, Wang Zhilin? ”

It stands to reason that he is the chief engineer of the research institute, and it is unlikely that he will remember every newcomer in the institute, but Wang Zhilin is very good in his group of newcomers, especially in the field of numerical computing, which has been very popular recently, so it is inevitable to leave some impressions.

"Yes, Mr. Guo, I am Wang Zhilin."

Wang Zhilin nodded as he sorted out the original messy drawings.

"What did you just say you found?"

Guo Jingshan, who put on his glasses again, recognized that the transmission system on the drawing was on the Z-9 - of course, this is actually not difficult, after all, the helicopter models that the entire 602 has really landed are only Z-5 and Z-9, and even a novice who has never studied aviation can see the difference between the two.

"I found that there was a problem with the original design of the French, there was a big problem."

"Oh?"

Guo Jingshan's eyes, who were smiling just now, instantly became sharp:

"Where exactly?"

"The tail output bevel gear pair of the final reducer has insufficient strength margin."

Wang Zhilin flipped out a drawing from below and pointed to a few locations circled by red pencils on it:

"I checked the original design materials provided by the French side, because the Dolphin was actually developed from the Skylark helicopter, so I borrowed a lot from the original design, and designed the current final drive on the first model SN365, and I calculated that the maximum transmission power of the tail output bevel gear is 220kW."

"In the following models, as the engine power continued to increase, the maximum load in flight also increased, and the French aerospace company only added the tail output bevel gear vibration polishing process to improve its surface contact strength, but did not modify the structure itself, so ......"

"So the model we copied has actually been in the situation of high-load operation of the tail rotor transmission mechanism all the time?"

Guo Jingshan was also a little stunned when he heard this.

Very outrageous cause of the failure, but if it were French......

It doesn't seem to be so outrageous.

"That's right, and that's what the original French designed."

Wang Zhilin nodded and continued to explain:

"Our original standard in the helicopter is to copy the French military standard, the French can't check it, let's follow it again and definitely can't check it out, today I had a whim, with the new national military standard just issued, I immediately found that it was not ......."

Industrial standards are the same as the law, and they must not be retroactive, otherwise they must be messed up.

Therefore, in principle, the projects that have been completed before the new national military standard comes into effect should continue to use the old standard to ensure the consistency of use and maintenance.

However, due to the special situation in Huaxia, there are still a large number of projects that have been nominally completed, but in fact only partially completed.

Straight 9 is one of them.

And whether these equipment should continue to use the old standard or replace it with the new standard, even Chang Haonan cannot give a one-size-fits-all method to decide.

It can only be decided by the respective project teams.

Fortunately, the specific helicopter standards are mostly additions and not many changes have been made, so there is no risk of overturning the entire model and starting over.

After a pause, Wang Zhilin continued:

"However, I have a preliminary improvement idea, you can increase the modulus of the bevel gear pair and increase the tooth width appropriately, so that the installation position of the large bevel gear remains unchanged and the small bevel gear moves backwards, so that the strength margin can be improved without changing the shaft intersection angle, transmission ratio and steering, and the only price is that the fairing volume of the engine must become larger, but the helicopter, the aerodynamic shape needs to be considered is not much......"

"In addition, since it has been decided to modify the final reducer, simply do nothing, the problem of planetary gear bearing life and lack of emergency lubrication system can also be solved in the process of this shipborne modification......"

"Although I have not yet made detailed calculations, it is preliminarily estimated that if these measures are implemented, at least the maximum take-off weight of the aircraft can be increased from 4 tons to 4.5 tons, and the external load will also be increased accordingly, at least to ensure that it can carry submarine search equipment and two anti-submarine torpedoes at the same time, and the increased range can meet the requirements of the army aviation unit to cross the target strait and the medium- and long-range anti-submarine flight requirements of carrier-based helicopters even in the case of large loads......"

Wang Zhilin put forward a lot of suggestions for improvement.

The computer's slow computing speed wasn't all a downside, at least it gave him plenty of time to think.

A lot of this stuff was what he thought of while waiting for the results.

"Xiao Wang, what you said is actually the next key area of our group, the localization and improvement of the rotor, tail rotor and final reducer, and we also applied for a project of the Seiko plan in the middle of the year."

Guo Jingshan was relieved at first, but then looked embarrassed:

"But the Z-9 is still in the state of serial delivery, and there is really no condition to ...... at the moment."

"Could you consider having French Aerospace improve the parts delivered? After all, they have the same problem with their own models......"

"It's hard."

Wang Zhilin's thoughts were only halfway through when he was interrupted by Guo Jingshan raising his hand:

"90 years later, although the French manufacturing plant is still delivering the ordered engine parts to us, but the technical team of their design unit has all withdrawn, and said that they will not respond to any of our technical requests, and then we tried to contact several times, but all of them were closed, otherwise in the case of a full set of technical information, the delivery of the Z-9A will not be delayed until this year."

"In this case, is it difficult to use a hot face to stick to someone's cold buttocks?"

"This ......"

Obviously, the latter has a point.

But Wang Zhilin is still a little unwilling:

"Then let's improve the ...... of straight 9"

"Let's take it step by step, now at least the direction of solving the problem is clear, and all that remains is to gnaw hard bones piece by piece......"

Guo Jingshan sighed softly.

Everyone wants to solve the problem in one step, but for the Huaxia aviation industry, there are indeed few such opportunities.

He has been in the industry for more than 30 years, and he has only heard that he met such a god man when he was engaged in turbojet 14 in 606 last year.

It's a pity that people are not engaged in helicopters.

Although both fixed-wing aircraft and helicopters can fly, the basic principles are very different, and under normal circumstances, few people cross borders in this way.

"Okay, then I'm ......"

Just as Wang Zhilin was about to pack up his things and go back to the office, a sharp knock on the door came from behind him.

"Mr. Guo, there is a call from Factory 122 to find you, saying that our main reducer has fallen!"

The two men who had been buried between the drawings looked up at the door almost at the same time:

"Huh?"

"Really?"

(End of chapter)