In the entire waterwheel power system, if the shape of the waterwheel blades can be borrowed from bionics, or a shortcut can be taken directly from nature, then there is no shortcut for the gears.

Of all the creatures in nature, none seems to have evolved a gear structure. Gears are completely purely man-made.

Li Mengxi had to immerse himself in the exploration of gears.

Use the controlled variable method to analyze how many variables there are in gears? Material, shape, thickness, number of teeth, tooth shape, tooth length, tooth distribution, and various relationships between gears, etc.

In terms of material, the thirty-seven hydraulic stone mills installed in various places in Julu all used wooden gears. As a result, the wooden gears were damaged a lot during this period.

Although, the production efficiency of hydraulic stone mill is very advantageous, and the cost of making wooden gears is not high. Make more spare gears and replace them if they are broken, which will not affect the continuous operation of the water mill.

But changing it back and forth is always troublesome.

Gears generally do not require high strength. It seems that bronze gears from the Spring and Autumn Period and the Warring States Period have been unearthed. It is also said that bronze has a relatively high hardness and is more suitable for making gears.

As for the material, wooden gears are not very durable. There are two improvements in material: iron and bronze. It just depends on which one is more suitable.

Li Mengxi was very confused about the shape of gears. In his impression, gears are almost all round. What can square gears do? What can triangular gears do?

When it comes to shape, there are as many types of gears as there are shapes.

Li Mengxi knew nothing about special-shaped gears, so he could only use the exhaustive method to try all the gears of all shapes.

Apart from the factors of gear shape and gear thickness, it seems that the thicker the gear, the better. After all, the thicker the gear, the stronger it is. Considering that if the gear is made of metal, the thickness will be too thick and the weight will be too large, which will affect the overall efficiency. Therefore, the best solution is to use hollow gears, thickening the edges of the gears to increase strength, and hollowing out the center of the gears to reduce weight.

Li Mengxi held two palm-sized gears in his hand, one with twelve teeth and the other with thirty-six teeth. He was wondering whether more teeth would turn faster or fewer teeth would turn faster.

The gear is installed on the small waterwheel and linked with the small millstone. The waterwheel rotates slowly under the impact of the water flow from the wooden trough.

The efficiency of the entire hydraulic system is determined by the rotation speed of the grinding disc. The higher the rotation speed of the grinding disc, the higher the efficiency.

Li Mengxi checked the two hundred numbers and silently counted the number of revolutions of the millstone during the two hundred numbers.

Then, I changed the gear with thirty-six teeth, and also counted two hundred times to check the number of revolutions of the grinding disc.

After one round of testing, Li Mengxi found that the grinding wheel rotated more times when it had thirty-six teeth, three more times.

After thinking for a moment, Li Mengxi was keenly aware of the anomaly. If it is true that the more teeth, the faster the rotation, then thirty-six teeth are three times as much as twelve teeth, and the rotation speed should be three times higher, not just three or two turns higher. .

Li Mengxi realized that this was an error.

Later, Li Mengxi did several more rounds of experiments, and the results proved what he expected. The data of twelve teeth and thirty-six teeth were slightly up and down, but it was obvious that these two gears acted on the stone mill, and the speed of the stone mill increased. exactly the same.

One conclusion is drawn - the speed has nothing to do with the number of teeth on a single gear.

Since the number of teeth itself has nothing to do with efficiency, there is not much need for improvement. Regarding the number of teeth, the only thing that needs to be considered is the difficulty of production.

If the gear is produced by the casting method, there is not much difference in the difficulty of producing a few more teeth. However, each tooth of the gear with fewer teeth can be made larger and stronger, and it is less likely to be damaged. Therefore, the number of gear teeth,

Take the middle value, twenty-four teeth is more appropriate.

Li Mengxi carefully wrote down the test results. He stopped writing, raised his head and thought about the next test plan.

In the next step, gear linkage, the same big gear, the big gear and the pinion, the pinion and the big gear, what will be the result?

In the first step, Li Mengxi installed the twelve-tooth small gear on the waterwheel and the thirty-six-tooth large gear on the millstone. Then, he counted two hundred times silently and recorded the number of revolutions of the millstone.

This process is repeated ten times and the average value is taken.

In the second step, in reverse order, the thirty-six-tooth large gear is installed on the water truck, and the twelve-tooth small gear is installed on the millstone.

Just after counting two hundred, Li Mengxi was shocked to find that the rotation speed of the millstone had increased several times, which was extremely abnormal.

Li Mengxi quickly tried a few more times, with the same result: the grinding wheel rotated several times faster.

Li Mengxi was surprised and puzzled, so he changed the size of the gears, and the speed could be increased several times.

Li Mengxi recalled the knowledge he had learned, and he suddenly remembered that it seemed... it was angular velocity, rotational speed, something like that.

It seems that where the two gears are in contact, the linear speed is the same, but the angular speed may be different, and thus the rotational speed is also different.

(For a pair of gears, the number of teeth should be inversely proportional to the speed...) Li Mengxi probably thought of that bit of knowledge.

Inspiration strikes.

In the past, in order to find something to replace the stone grinding machine, I built a pulverizer, but I found that neither animal power nor human power could reach the speed required by the pulverizer. Even if water power was used, the water power speed was much higher, but it was still far from enough.

Now I suddenly discovered a way to increase the speed. If you install an oversized gear with 200 teeth on the waterwheel, make a smaller grinding wheel, and install a small gear with 20 teeth on the grinding plate, then, assuming that the waterwheel speed is once every two seconds.

Rotation, that is, if it is thirty revolutions per minute, through the linkage of the gears, the speed of the waterwheel, thirty revolutions per minute, is magnified onto the millstone, which is ten times faster! It will become three hundred revolutions per minute!

If so, add another level of gear, increase it ten times, and the stone grinding speed will increase to 3,000 rpm, and increase it ten times again, to 30,000 rpm.

The pulverizer needs a high enough speed, and now there is a way to solve the problem.

Li Mengxi's requirements for the shape and size of the waterwheel have changed. In the past, the waterwheel had to make a trade-off in terms of manufacturing difficulty and power. It could not be too large or too small. Now, because of the need to increase the speed, the bigger the gear, the better.

, the greater the size difference, the more obvious the gears will be.

This chapter is not over yet, please click on the next page to continue reading! In order to verify whether the speed-increasing gear is feasible, Li Mengxi immediately summoned craftsmen to build a giant waterwheel and gears.

It is not difficult to make a waterwheel. The difficulty is in the gears. It is not difficult to make a giant gear. The difficulty is in making a bunch of gears from large to small that can cooperate with each other.

Since the circumference of a circle is 360 degrees, it is easiest to make the number of gear teeth that is divisible by 360.

In order to make the oversized gears, Li Mengxi had no choice but to improvise an oversized compass and an oversized protractor. Then he drew the drawings on a large piece of ground in the house. No one else could help him, so he could only sketch them tooth by tooth.

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Many days later, the giant waterwheel was built, but Li Mengxi still had not finished drawing the gear drawing. He had started over again many times. Because the drawing accuracy was not enough, each tooth only had to be slightly off, and more and more of the gears were off at the end.

, the number of teeth can be reduced by one length.

Li Mengxi truly felt that although gears looked ordinary, they were really difficult to process.

Li Mengxi's painting collapsed for the seventh time. He squatted on the drawing, lost his pen, and rubbed his eyes tiredly.

The craftsmen on the side couldn't bear it. They came over and asked cautiously, "Commander, what do you want to do? Tell us and see if we can help."

Li Mengxi raised his head and looked at the craftsmen. He looked at the sincere faces of the craftsmen full of concern and smiled, "Okay. I want to make a big gear. Every tooth must be the same. There is no mistake."

After listening, the craftsman nodded seriously, as if he understood. Li Mengxi even doubted whether the craftsmen were capable of calculating the complex diameter, circumference and gear ratio between the gear sets.

Facts have proved that the creativity of the working people is endless.

All the gears used in the water mill were all drawn by Li Mengxi.

The craftsmen don't know how to draw such complicated drawings. Now if they are asked to make the gears themselves, they can only make the whole circle, and there is nothing they can do about the individual teeth on the circle.

The craftsmen couldn't handle the complexity, so they came up with another method. They simply made the teeth movable and then installed them one by one.

The specific operation method is that the craftsmen only spent half a day making the mold, and then cast a bunch of teeth. Then, they placed the teeth one by one around the rim, and finally tied them with ropes simply and crudely.

, just like that, the gear is created.

The craftsmen carried several large gears. Li Mengxi walked over with a rope ruler and measured the diameters of several large gears. Then he used a pen to calculate the gear ratio and the rotational speed ratio installed in the system. However, after calculation, Li Mengxi found that it was impossible.

Proportion.

A certain gear has seventy-nine teeth, and another gear has eighty teeth. Li Mengxi can't figure out how seventy-nine and eighty gears can bisect 360 degrees. How big is the error?

, can the gears turn and are they not stuck?

"Then, let's set it up and try it." In order to respect the fruits of the craftsmen's work, Li Mengxi decided to give it a try.

The craftsmen lifted and held the two huge gears together and installed them together. Then, they turned the gears manually.

Li Mengxi originally thought that the gear with a strange number of teeth would inevitably get stuck, but unexpectedly, it turned smoothly. Li Mengxi waited for a long time and did not find it stuck.

This involved something that Li Mengxi couldn't understand. He looked at the whirring gears and felt a little confused.

The gear rotated for a long time without being damaged. When it stopped, Li Mengxi asked with confusion, "When you install the iron teeth, do they happen to be just enough? Just a few? Just enough? What a coincidence?"

The craftsmen smiled and said, "How could it be such a coincidence? In the end, it was all too short."

"Then...how did you do it?"

"Easy! If it's short, cut off a section of wood and tighten the wood tightly."

Li Mengxi was stunned on the spot.

"Oh! That's it!"

Li Mengxi suddenly felt that he seemed a bit stupid. Who said that the number of gear teeth must be divisible by 360 degrees? Who said that the number of teeth between gears must be an integer multiple? Who said that to make gears, you must first make the disc and then the teeth.

Instead, we can't just arrange the teeth first and then make the disc.

This is like the allusion of Zheng people buying shoes. You can buy shoes of the right size by using a ruler, and you can also buy the right size by measuring your feet.

The craftsmen's method is undoubtedly to directly measure the feet. They don't draw pictures, and they don't consider any proportions. They only consider the simplest problem, just placing the iron teeth in a full circle. The result is not precise enough, but it is obviously sufficient.

The gears used were made so easily.

The craftsmen's methods gave Li Mengxi great inspiration. He no longer drew pictures. He also used the craftsmen's methods. He first made four kinds of wooden circles: super huge, huge, large, and medium. Then, he put the iron teeth one by one.

I put it on the wooden circle until it couldn't fit anymore, and there was still a little distance left in the wooden circle. I just saw a section of the wood, and then pulled the two ends together to form another circle.

The four gears are carved using the same method.

Assemble them together and turn the largest gear. The gear rotates slowly and slowly. You can see that although the big gear rotates extremely slowly, the second one moves, and the third one below moves.

When it moved, the last small gear with the size of a basin whined and turned very fast, at an unknown speed, and there were countless afterimages.
Chapter completed!