The Development History of Hydraulics
A long time ago, there were records of using the force of wind and water flow to make certain "institutions" work on behalf of people. About 5000 years ago, there were ships that relied on wind power, and 2000 years ago, there were water tankers that operated using water flow.
However, whether it is the sailboat mentioned above or the method of using fluid force on a water wheel, they are different from current hydraulic mechanisms.
The same method as using fluid force on sailboats and waterwheels. The most commonly used torque converter currently is in cars.
Place two electric fans facing each other side by side, let one fan rotate, and under the driving force of its wind, make the other fan, which is not connected to the electric fan, rotate. The hydraulic torque converter operates using this principle.
The hydraulic mechanisms used in presses and excavators utilize fluid flow power in a different way from the above. They operate based on the fluid pressure (static pressure) in the Pascal hydraulic press principle.
The Pascal principle was discovered in the mid-17th century, but it took nearly 200 years for the price of convenient hydraulic mechanisms to reach an acceptable level.
In 1882, there was a record of the use of hydraulic pressure in the reciprocating motion of Longmen Chuangbing. It is very interesting to associate this with the widespread adoption of the Henry acid converter steelmaking method in the 1860s. At that time, the originally expensive steel could be mass-produced using the acid converter method at a very low cost.
The manufacturing of annular pressure fluid containers requires the use of point strength steel, so it can be said that the production of low-cost steel is closely related to hydraulic machinery.
By 1920, hydraulic pumps had developed to a certain level and reliable pressure sources could be easily obtained.
Afterwards, hydraulic mechanisms can not only perform simple reciprocating movements. It can also freely adjust speed, reversing time, etc., and its usage range gradually expands towards grinding machines, drawing machines, and drilling machines.
In the Second World War. Hydraulic technology is developing at an astonishing speed. Hydraulic and servo mechanisms have been developed and adopted with astonishing momentum in aircraft, ships, and weapons.
After the war, these precision hydraulic and servo mechanisms also extended to the general industry and achieved significant development.
In Japan, it corresponds to the industrial revival of the 1950s. It is popular to introduce hydraulic technology from overseas, with the most being imported from the United States.
Therefore, when it comes to hydraulic machines and hydraulic mechanisms. Its English name is quite confusing.
The Pascal principle was proposed in 1654 when Blaise Pasca (1623-1662, France) wrote "Fluid Equilibrium Theory" at the age of 31, introducing the principles of hydraulic presses.
At that time, there were many theories about what vacuum was. Fill a bottom glass tube with mercury, which is about Im long. Standing with the bottom facing upwards in the mercury tank, the mercury drops to a height of 8 marks. At this time, the remaining cavity on the upper part of the glass tube is called the Torricelli vacuum.
The most controversial issue at that time was whether this vacuum was truly a space with nothing or something that the eyes could not see.
Scholars of scholastic philosophy who intersect with the Aristotelian school argue that "nature abhors vacuum," so it is generally believed that when Descartes saw the tools of his empty experiments from Pascal, he still did not change his mind. He believed that the so-called vacuum was actually filled with very small material "ether.".
Pascal believed that "relevant natural phenomena must be proven through experiments.". So with the help of his brother-in-law Berry, he repeatedly conducted experiments on Torrico's empty space to see what substance it was.
Sometimes, the height of the empty mercury column in Cuotori is measured at the top and foothills of Mount Dom.
The height of the mountaintop and foothills is about 1000m, and the circularity of the mercury column measured at the mountaintop is about 76mm lower than that measured at the mountain view.
Now, records of the experimental equipment and various instruments used by Pascal himself are still preserved.
Pascal verified the special cases related to the equilibrium problem of pressure and mercury column, as well as the fluid symmetry problem. He completed two papers, "On the Weight of the Atmosphere" and "Theory of Fluid Equilibrium", approximately seven years after starting several experiments.
When he introduced the principle of a hydraulic press in "Fluid Balance Theory", he wrote: "Fill a closed container with water and open two ports. The area of one port is 100 times that of the other. Seal the two ports with pistons." This way, a small piston can withstand a large piston by 100 people. "This is now known as the" Pascal principle. ".
When applying this principle to a hydraulic press, any force of any magnitude can be obtained by utilizing a relationship proportional to the piston area. Therefore, a new type of lever machinery was developed at that time.
However, like ordinary levers and bolts, when the small piston is pressed down 100mm, the large piston only rises 1mm. In other words, the total workload remains unchanged.
Pascal also combined the problem of constant workload with the problem of center of gravity to prove it.
Compared to "hydraulic" or "hydraulic engineering," the English word for "hydraulic" is "hydraulic", and the English Chinese dictionary states "hydraulic", "water science", "hydraulics". The adjective "hydraulic" refers to "hydraulic", "water use", "hydraulics", etc. It is also used as an example of a compound word for "hydraulic pressure".
There is a deep relationship between "hydraulic pressure" and "water pressure". Water is a liquid that exists in nature in its most easily usable form. When performing certain operations with a liquid, one will first think of water, and there is no liquid that is easier to obtain or cheaper than it.
The prototype of the hydraulic mechanism is the water press and its principle used in the Pascal experiment. Replacing water with hydraulic pressure was only 100 years ago.
After the publication of "Principles of Hydraulic Press" in 1654, for a long period of approximately 230 or 240 years, hydraulic pressure was used instead of hydraulic pressure.
It goes without saying that even now, "water pressure" is still used, but compared to hydraulic pressure, it is only used in certain fields and in small quantities. It is generally difficult to attract attention. For example, for the forging machinery used for forming red hot iron blocks, there is a risk of fire when using oil, so water pressure is used.
The initial steam engine was manufactured based on Westin's patent. This patent appeared in 1663.
100 years later, Watt invented the improved steam engine. Make various improvements to the steam engine. Widely used as an industrial power component.
Before that, only waterwheels and windmills were used as power components. It goes without saying that precision machine tools have not yet emerged. Even pumps or cranes are all handmade, initially using wood as raw material.
When using wood as raw material, there is no problem of rusting.
From the early 19th century to the second half, various machine tools were developed and quite perfect hydraulic machinery was also manufactured.
However, there are limitations to water use, such as rust and corrosion issues, and poor lubrication. And the usage temperature must be limited to 0-100 ℃, etc. These restrictions are very troublesome.
Construction machinery commonly used outdoors, such as water compressors, may freeze and fail to operate in severe winter, and must be frequently replenished with water in hot summer due to evaporation.
From the early 19th century to the end of the 19th century, with the simplification of the production process of high-strength steel, commonly used equipment was further popularized for precision machining machine tools. Its power components include gasoline engine (internal combustion engine), diesel engine (internal combustion engine), and electric motor.
Afterwards, a method of refining lubricating oil with petroleum emerged, which suddenly transitioned from hydraulic pressure to hydraulic pressure.