Coin stamping is a great achievement of metal processing in this period and the bud of modern mass production technology. But with the demise of the Roman Empire, this technology was lost for hundreds of years. About BC 1 century, the ancient Greeks made stone wheel mills on the basis of hand mills. This is mechanical and mechanical progress. At about the same time, ancient Rome also developed donkey pulling mill and similar stone wheel mill.
The earliest gear train used in Europe was installed on the odometer of the chariot to record the mileage. The application of lever principle in machinery, such as pulleys and compound pulleys, has become more common at this time, and it is used to lift heavy objects in buildings. Carriages and chariots have also been improved. The development of fluid machinery and power machinery: first, the application scope of orange peel water lifting tools and bucket waterwheels has been expanded; The newly created fluid machinery includes roller and Nordic water mill. The former is mainly used for water supply in Roman cities, and water is lifted from a low place to a high place by turning a screw. The latter is used to grind grain, and the square impeller is driven by water flow, and the power is less than half horsepower. What is more powerful is Vitruwe's water mill. The waterwheel is driven by downward water flow, and the rotation speed of the waterwheel can be adjusted by properly selecting the number of teeth of large and small gears. Its power was about 3 horsepower, and later increased to 50 horsepower, becoming the most powerful prime Mover at that time. Pressure pumps and suction pumps composed of pistons and cylinders have also been developed during this period. Philo pressure pump was first used for fire fighting. Later, there were pumps and pressure pumps that pumped water from wells, as well as double-barrel plunger pumps that the Romans used to put out fires. At this time, the heat engine mainly appeared as a plaything of Greek scholars and philosophers. 1 century Hiro's steam spinning ball (also called Fengshen wheel) is an example of a steamer with water in the lower part of the steam spinning ball. The steam spinning ball is connected with a hollow ball through a branch pipe. There are two tangential nozzles in opposite directions on the ball. When the fire burns under the pot and the water in the ball boils into steam, if the jet reaction force generated is large enough, it will push the ball to rotate continuously. As the first device to convert steam pressure into mechanical power, steam spinning ball is famous all over the world. It may be the first device to apply the principle of jet reaction.
The period from 400 to 1750 in Europe belongs to the Middle Ages, the period before 1000 is the early Middle Ages, and the period from 1000 to 1500 is the late Middle Ages. The next 250 years will be the industrial revolution. The early period lasted about 600 years. Due to the depression of classical culture in ancient Greece and Rome, the development of mechanical technology was in a state of stagnation for a long time. Later, with the development of agriculture and handicrafts, Italy, France, Britain and other countries have set up universities to develop natural sciences and humanities and cultivate talents. At the same time, they absorbed the advanced science and technology of China, Arabia and Islamic Empire at that time, and the mechanical technology began to recover and develop. Western Europe began to smelt pig iron from coal and manufacture large castings. With the development of hydraulic turbines, there has been enough power to drive large bellows made of leather to obtain higher melting temperature, and the number of workshops for casting cannons and clocks has gradually increased, and the weight of castings has also gradually increased. In agriculture, in Roman times, a plow with a curved concave plow plate was used instead of a sharp split plow. There was also a hand drill in this period, and its structure showed that the principle of crank-connecting rod mechanism had been used in machinery. There is a large wheel lathe in processing machinery. In the12nd century and the second half of13rd century, primitive clocks and balance clocks with rope escapement appeared successively. The balance clock is the first practical mechanical clock, which is equipped with an hour hand and a second hand, indicating that the clock gear system has been further developed and widely used in European families in the15th century.
Watches were 1500 years ago. The important improvement is that the coil spring is used to replace the weight to generate electricity, and a ratchet mechanism is added. The success of mechanical clocks is not only the necessity of modern civilization, but also promotes the manufacturing technology of precision parts. Mechanical clocks and watches were later improved in an all-round way, for example, a single pendulum clock replaced the original pendulum clock. 1676, Britain made two kinds of precision clocks with different pendulum lengths for Greenwich Observatory. The pocket watch adopts bimetal, which solves the temperature compensation problem of the balance wheel. In terms of fluid machinery, there are down-flushing or up-flushing water turbines (water mills), windmills and turbines. The horizontal downdraft turbine was improved from the early water mill and has been used as the power for mining, crushing and smelting in the 12 and 13 centuries. This kind of turbine was improved and developed into a large-scale ascending turbine in the14th century, which was used to lift ore. During this period, great progress has been made in hydraulic utilization in western Europe, and the number of turbine workshops has increased rapidly. From 1500 to 1750, mechanical technology has developed very rapidly. The progress in materials is mainly manifested in the use of steel, especially pig iron, instead of wood to manufacture machines, instruments and tools. At the same time, in order to solve the transportation problem in mining, Britain developed horse-drawn rail cars around 1770. Wooden railings were first used, and later they were replaced by railings. During this period, machine tools have also made many achievements: hydraulic rolling machinery and several machine tools, such as gear cutting machine, thread lathe, small pedal grinding wheel grinder and polishing machine for grinding optical instrument lenses.
Water pumps were also developed during this period, mainly used to solve the problems of mine drainage and urban water supply at that time, including mine drainage pumps, forward rotation pumps (1588) and centrifugal pumps (1689). At this time, Italy invented the hydraulic air compressor (commonly known as bellows). It can be used as a blower for steelmaking to replace the old leather tiger. 1759 Large blowers appear again. Wind-driven machinery, such as windmills, has been widely used and its number has increased. There are thousands in Britain alone, which are used for grinding, pumping water and sawing wood. In terms of power machinery, the mine steam pump manufactured by T. savery in England in 1698 was called "Friends of Miners", which pioneered the use of steam to do work. 1705, T. newcomen of England invented the atmospheric steam engine. Although it is not perfect, it is the first relatively reliable steam engine, mainly used to lift water, with a power of 6 horsepower. This kind of steam engine was popularized in Europe before 1750, and later spread to the United States. During this period, engineering science was born in Europe. Many scientists, such as Newton, Galileo, Leibniz, Boyle and Hooke, have laid various theoretical foundations for this new science. In order to encourage inventions, Italy and Britain set up patent offices in 1474 and 156 1 respectively. 65438+In the 1960s, scientific societies were established, such as the Royal Society. Britain began to publish scientific report documents in 1665. France established the French Academy of Sciences almost at the same time. Russia and Germany also established the Russian Academy of Sciences in 1725 and 1770 respectively. These academic institutions broke through the shackles of the church at that time and freely discussed and exchanged academic views and experimental results, thus promoting the development of science and technology and mechanical engineering.