Start with the aviation industry

chapter 171

Wang Tianfang and Lin Feng walked over directly.

Liu Xinfa, who was weighing the turbine blades, immediately stopped and greeted, "Mr. Wang, Mr. Lin."

Lin Feng said, "How is it? When will the assembly start?"

This is what Lin Feng cares about the most, and it is also the purpose of Lin Feng's visit to the assembly workshop, just to take a look at the turbine discs being assembled.

Turbine disk is a very important and key part of aero-engine, its performance directly determines the overall performance of the engine.

"The weighing of the blades will be completed immediately, and the static balance of the turbine disk will be carried out immediately."

Lin Feng nodded, and even picked up one of the turbine blades to look at, with a satisfied expression on his face, "Mr. Wang, your precision casting ability is good, and your technical level is very high."

Wang Tianfang said, "You have provided a complete set of detailed precision casting process specifications for the turbine blades. It is no wonder that the quality of the blades is not good."

"This is the first time we have seen such a perfect process specification, and now many process technicians are studying it, taking that set of process procedures as a benchmark."

The quality of parts processing is not only related to the skill level and experience of the workers, but also the process is the decisive factor.

The precision casting process of the turbine blades comes from the system, and of course it is impeccable. Such a high-precision hollow superalloy turbine blade is excellently completed by the precision manufacturing workshop, and the pass rate is very high.

During the conversation between the two, Liu Xinfa weighed a total of more than 100 blades, and then began to statically balance the turbine disk.

The purpose of static balancing is to find out the position and direction of the center of gravity of the turbine disk, and serve as a reference for the assembly of the blades.

"Mr. Wang, it's still a mechanical static balancing equipment, and it's already a numerically controlled one in foreign countries."

The numerical control balance equipment has high precision, simple operation and high degree of automation, which is much more advanced than the mechanical type.

Wang Tianfang said, "We also want to buy a CNC dynamic balancing machine, but they don't sell it, so we have no choice but to use a mechanical one."

Lin Feng said, "Mr. Wang, I have good news for you. The CNC balancing machine does not need to be imported from abroad. Our equipment branch factory is designing and developing it. It is estimated that it will start production soon."

And such a good thing!
Wang Tianfang said pleasantly, "That's great, we want to buy a dynamic balancing machine for disk parts, but they don't sell it, so we don't know what to do."

Leihuo Technology Industrial Group also needs a high-precision CNC dynamic balancing machine. Several well-known foreign manufacturers said they would not sell it. Lin Feng got angry and spent a lot of time to ask the system to help design one.

Lin Feng has already taken the time to draw the general design drawings, CNC system design drawings, and key parts design drawings, and the technicians under the leadership of Cai Wenhao are starting a comprehensive design.

You don't sell it, I design and develop it myself.

If it is a high-precision CNC machine tool, Lin Feng has no other options, but the dynamic balancing machine does not require an industrial mother bed, and can be designed and manufactured.

Liu Xinfa is an old worker. The static balance of the turbine disk was completed in a short time, and he marked the position of the center of gravity on the turbine disk with a red pen. Don't worry.

Then, the assembly of the turbine blades begins.

The mortise at the center of gravity is marked as No. 1 mortise, and he picked a relatively light turbine blade and installed it in the No. 1 mortise.

Take a copper rod and a small hammer, and tap the locking piece lightly, bending the locking piece so that it clings to the turbine disk.

After feeling that there was no problem, I shook the turbine blades by hand, and started the assembly of the second turbine blade when I felt that the swing amount was no problem.

After the locking piece is locked, the turbine blade is not locked firmly, but has a certain range of motion, and must have a certain amount of swing.

The first-stage turbine disc has a total of 33 grooves. After installing a relatively light blade in the No. 1 groove, he installed a relatively heavy blade in the symmetrical No. 16 groove.

The blades are assembled symmetrically, not in sequence starting from No. 1 tongue and groove.

He carefully assembled the turbine blades, his movements were skillful and his speed was relatively fast, and he assembled several blades in a short time.

Lin Feng felt relieved.

At the same time, I feel a little envious in my heart. There are so many skilled workers in Phoenix Factory, and all of them are PayPal.

While thinking about this, suddenly the voice of arguing not far away caught his attention, and Wang Tianfang also saw it.

Where is the assembly area of ​​the turboshaft eight engine, a few technicians and a few workers are surrounded there, and it seems that something happened.

"Boss Lin, let's go and have a look." Wang Tianfang suggested.

After the two came over, they saw that there was a quality problem. To be precise, there was a problem with the gear of the turboshaft eight-speed reduction unit.

The eighth turboshaft is also designed as a unit body, which is also a total of five units. The reduction unit body is mainly composed of a reduction casing and a reduction gear. The function is to reduce the high speed of tens of thousands of revolutions to thousands of revolutions.

"I think there's something wrong with the reduction gear."

The person who spoke was an old craftsman, who looked to be in his fifties, with a little gray hair on his temples, and wearing a pair of presbyopic glasses.

"Old Hou, why do you think there is something wrong with the gear?"

The inquirer was a supervisor technician, in his thirties, of medium height.

Lao Hou said, "The feel tells me that something is wrong. When I turn the driving gear, I find that the feeling is different."

You can tell me there is something wrong with the gear just by feeling it!
The technician in charge didn't believe it, turned the driving gear of the reduction unit with his hand, and said, "I think there is no problem, it's normal."

Another technician also turned around a few times, nodded and said, "There should be no problem, and the sound is normal."

Lao Hou insisted, "I think there is a problem, the feel is a bit wrong."

Wang Tianfang and Lin Feng had been listening by the side and understood what was going on.

"Quality is no small matter. Since someone thinks there is a problem, they should check it carefully and find out if there is any problem."

Wang Tianfang spoke, and of course everyone complied. The technicians immediately checked the qualification certificate of each gear of the reducer unit, and the inspector also measured the tooth spacing of each gear.

"Lao Hou, there should be no problem. Every gear is qualified, and there is no problem with the assembly."

At this time, Lao Hou finally stopped saying anything. In fact, he really wanted to say that there was something wrong with the hand feeling, but he knew that this reason could not convince everyone.

Lin Feng suggested, "To determine whether there is a problem with the gears of the reducer unit, these inspections alone are not enough."

Everyone looked at Lin Feng together.

Some people also recognized him as the boss of Leihuo Technology Industrial Group, and a technician even greeted Lin Feng on his own initiative.

"Mr. Lin, you are a technical expert, what kind of inspections do you need to do in this situation?"

Lin Feng was not stingy with giving advice, and said with a smile, "Since a series of inspections have not found any problems, it is safer to do another gear meshing inspection."

Gear mesh check?
They really can't!
They are just technicians in the aero-engine assembly workshop. They specialize in the assembly of aero-engines, but they only have a half-knowledge about gears.

The gears are not processed and manufactured by the Phoenix Factory, but there is a special gear factory. Gear processing and inspection involve a series of very professional knowledge.

"Mr. Lin, how to check gear meshing?"

Lin Feng smiled, "It's a little troublesome to talk about."

Wuyou opened his mouth, "Mr. Lin, you will teach everyone a lesson about gear meshing inspection."

Lin Feng said, "Firstly, we need to design and manufacture a checker, then install two pairs of gears on the checker, and then apply coloring agent to one of the gears, and turn the gear slightly to see the coloring of the tooth surfaces of the other gear. "

Everyone listened carefully.

Some technicians immediately took out pens and notebooks, and quickly recorded what Lin Feng said in the notebooks.

This is knowledge.

There are only benefits to documenting these things.

"When Boss Lin said that, I'm taking a stand."

"Mr. Lin, why are you so powerful? You also understand these things."

Lin Feng smiled, "I read about this method of inspection in books."

Wang Tianfang said, "You have to ask Mr. Lin's students about this. Our Mr. Lin insists on reading books every day. Over time, the professional knowledge in our minds will gradually become richer."

"No wonder Mr. Lin is so powerful!"

"We have to learn from Mr. Lin, read more books, and learn more."

After some compliments, a technician also asked, "Mr. Lin, but we don't have the inspection tool you mentioned, so what should we do?"

Yes, no gages!
Doesn't that mean there's no way to check.

Lin Feng smiled, "It doesn't matter if there is no gage, I have a temporary method."

After finishing speaking, he picked up a reducer casing on the table in the eyes of everyone, looked at it, and said loudly, "Give me some colorant and a clean rag."

There was no shortage of these items in the assembly workshop, and someone quickly brought over what Lin Feng needed.

In the eyes of everyone, Lin Feng first wiped the gear to be inspected with a clean rag, and then carefully brushed the colorant on the driving gear with a soft brush, explaining while brushing.

"The toner must be applied evenly, and every tooth surface must be brushed. Do not brush other places except the tooth surface."

After brushing the colorant, Lin Feng put both the driving gear and the driven gear into the reducer casing, and then gently rotated the driving gear.

After turning it around, he removed the two gears, picked up the driven gear that hadn't been painted with colorant, and waved, "Everyone, come and take a look."

The two gears are in contact with each other during the rotation just now, and the tooth surface of the driven gear has colorant.

Everyone gathered together one after another.

Lin Feng said, "Look carefully at the coloring of the driven gear and the coloring agent on the tooth surface."

"Hey, why is it in such a shape?"

"Some are like irregular triangles, some are oval, and some are olive-shaped."

"Why are the shapes inconsistent?"

Everyone became commotion, you said something, I said something, Wang Tianfang's face gradually became serious, as the chief engineer, even if he didn't specialize in the design and processing of gears, he knew a little bit.

"Boss Lin, there must be a problem with the gear."

Lin Feng nodded, "Yes, there is a problem. Fortunately, Master Hou found something wrong with his hand. Otherwise, if such a gear is installed on the engine, I'm sure there will be a problem within one or two hundred hours at most."

Hearing this, Wang Tianfang's expression changed.

Many people even secretly thought in their hearts, it's so dangerous, thanks to Mr. Lin who found out that there is really a problem with the gear.

If there is a problem with the meshing of the gears, the factory test may not be able to find it. It must wait for the engine to be installed on the helicopter and fly for one or two hundred hours in the field before the problem is discovered.

This problem is serious.

No wonder many people secretly thought it was dangerous.

Wang Tianfang's face showed a bit of anger, "What's wrong with the gear factory, every gear has a certificate of conformity, and there is almost a big problem."

Lin Feng said, "The dimensions of the gears should be qualified, but there is a problem with the meshing. Maybe they didn't check the gear meshing."

The previous gears were French originals. Starting from this batch of gears, the French side provided the blanks, and a domestic gear factory was responsible for processing and manufacturing. It is impossible for the French to provide a complete set of process regulations for the gears. It is good to provide design drawings.

It is estimated that the gear factory compiled the gear manufacturing and processing process regulations based on their many years of processing experience. During the final quality inspection, they only checked the dimensions according to the design drawings, and did not check the gear meshing.

Lin Feng also read the method of gear meshing inspection in a foreign language technical document. Because he has a god-level learning talent, he not only has a photographic memory, but also basically understands and digests this inspection method.

"Give me another pair of gears."

There are more than just this pair of reducer gears placed here. Lin Feng saw at least several pairs, and was going to check another pair to see the situation.

Or the method just now, first wipe the gears with a clean rag, then evenly coat each tooth surface of the driving gear with this colorant, then put the pair of gears into the reducer casing, and then turn them gently Drive gear.
The pair of gears were removed from the reducer casing, and Lin Feng waved his hand, "Everyone, come over and have a look at the condition of this gear."

Everyone gathered around again, and under the illumination of the light, the coloring of each tooth surface of the gear was clearly visible.

"It's different this time."

"Basically they are long ovals, and the ratio of the major axis to the minor axis is basically above 2."

"It's completely different from the pair of gears just now."

Lin Feng said, "Everyone can see that the coloring marks are basically in the shape of an ellipse, which is an ideal situation for gear meshing."

"Mr. Lin, are you saying that the meshing condition of this pair of gears is much better than that of the previous pair of gears?"

"Yes, the meshing situation is much better. More than 90.00% of the colored marks are elliptical, which means that the gear meshing is ideal. If the ratio of the major axis to the minor axis of the ellipse is more than 2, it will be better."

After explaining the science to everyone, Lin Feng said to Wang Tianfang, "Mr. Wang, I suggest that each pair of gears should be checked for meshing as just now. Only if they pass the test can they be installed, and if they fail, they can be returned to the gear factory."

A look of gratitude appeared on Wang Tianfang's face, "Well, we must do a mesh check."

Lin Feng said again, "Who gave me a blank sheet of paper."

Immediately, a technician brought over a blank piece of paper, Lin Feng didn't ask for a pencil, and drew a sketch on the white paper with his own pen.

"Replacing the inspection fixture with the reducer casing is only a temporary solution, not a long-term solution. A special inspection fixture needs to be made, and the inspection fixture should be designed in this way."

Drawing a sketch is a test of one's mechanical drawing skills. Undoubtedly, Lin Feng's skills are very solid, and this sketch is very standardized.

"Boss Lin drew a good picture."

"This is not a sketch. I didn't see it with my own eyes. I must have thought it was drawn with a ruler."

"."

Hearing such words, Lin Feng scolded with a smile, "Stop flattering, immediately draw the specific design drawings of the inspection fixture according to this picture, and hurry up to make the inspection fixture."

In the end, this sketch was carefully taken over by a technician in charge of the assembly workshop, folded solemnly, and put in his pocket.

Not long after, Lin Feng and Wuyou let go, but heated discussions rang out in the assembly workshop.

"Thanks to Mr. Lin."

"Lao Hou felt that there was something wrong with the gears, and Mr. Lin found out that the gears were not meshed as soon as he checked."

"Fortunately, it was discovered before assembly. If it goes to the outfield, it will probably cause a big accident."

"Boss Lin is really amazing, I saw him again today."

"."

Many people in the assembly workshop were discussing what happened just now with admiration on their faces. Wang Tianfang and Lin Feng had already walked out of the assembly workshop.

"Boss Lin, thank you very much."

"Mr. Wang, why are we so polite between the two of us? What happened just now was just a matter of little effort."

"Come on, let's have a drink or two, my treat."

Lin Feng looked at the time and said with a smile, "Time flies so fast, it's almost time to get off work."

in the office.

"Harry Potter and the Chamber of Secrets" has been written, and Lin Feng does not plan to write a third book for the time being, at least in two or three months.

Instead of writing a book, Lin Feng was seriously looking at the design drawings. There were several design drawings on the big table in the reading room next to his office.

These are all the more important design drawings of the LH1500 turboshaft engine. After the designers completed the design, they were proofread and reviewed, and finally sent to Lin Feng.

General design drawings may not be checked by Lin Feng himself, and it is enough to guide the designers to carry out the design. Of course, the more important design drawings are different.

Lin Feng looked at it very seriously, and if there were any problems, he would mark them out with a pencil. If he didn't see the problem, he would compare it with the design drawings in his mind, and try to maintain a high degree of consistency.

If it is the same as the design drawing in his mind, Lin Feng will sign his name in the approval column, so that the design drawing of this part is truly completed.

"There is a problem with this place, the tolerance should be smaller."

"The design structure of this place needs to be changed."

In one or two hours, Lin Feng read all the design drawings. Most of them had no problems.

After reading these design drawings, he just sat down on his office chair and drank two sips of tea when there was a knock on the office door.

He Hua opened the door and came in, with a happy expression on his face, "Boss, good news."

Seeing that He Hua was so happy, Lin Feng suddenly became interested and asked, "Mr. He, what good news makes you so happy."

He Hua didn't play tricks, and put the things in his hands on Lin Feng's desk, "Boss, take a look at what this is."

(End of this chapter)